# Dual SDX10 Tapped Horn



## Oklahoma Wolf

Greetings, fellow bass nuts. Some of you may remember me from this thread, which chronicles the progress of my very first tapped horn project. Even before I was finished with that one, I always intended to go back and do it all over again; improving on the design as I better learned from my experience with that first project what made for a good tapped horn.

After several months of work, with a lot of help from many other people, this thread is the result. I was going to wait on this until I actually got started the building phase, but I think I'll post this early now that the drivers have been ordered.

My original goals were to replicate the Tang Band horn mentioned above in a smaller package with greater output and greater bandwidth. This here design isn't the best I can do for these woofers, but folding a more complex design into a package I can build is something that I'm still working on. So, I tried to keep this as simple as possible.

Here's what I wanted from this design:


16-100Hz at 115dB in half space, 120dB+ in room at LP
less than 550L before materials
shallow, to enable better use as a riser
Other than that, I didn't really have too many other limits on it. The result of all my work is that I have a 533L design here before materials that will do 113dB in half space at 16Hz with 300W before reaching Xmax. Based on experience with my last TH project, it will have no trouble at all sustaining 120 at LP, because that horn already hits 120 at LP. It will also likely handle 600W+ before the woofers get into any kind of excursion trouble, so I'm going to push it at 2 ohms off one channel of my RMX-1850HD. It may or may not be highpassed... we'll see. It has the kind of headroom my old horn can only dream about, so I may not need to. 

A drawing of the final Sketchup file is below, and my Hornresp file is attached. As drawn, it's 79x42x13.2." Big, but very shallow. I could fit four of these, two in front of two, behind my screen if I needed to. Building won't start until the snow goes away... I can't do any woodworking outside until it does, and there's no room inside.

Materials needed will include three sheets of 3/4" plywood. The four sheets needed for the last one was really too much. The throat will be braced, but other than that I won't be doing much extra bracing due to the shallow depth. I'll be picking up several 1" dowels, however... if I feel like the horn's gonna need the extra bracing, I'll use them. PL Premium will again be used - two large tubes will do. The open space in front of the throat and above the mouth will house a Speakon, and two of the horn's folds will get a thin lining of polyfill much in the same vein as the last horn I built.

I'll post a diagram with the actual plans for construction and/or the Sketchup file once I start building. I'm reluctant to let anyone try my unproven design before I know what it's like in the flesh.

Hornresp screenshots with 350W in, half space, excursion peaking at a safe 20mm above the corner:


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## gperkins_1973

Hi there,

I just flipped through your other thread and am very interested in the possibility off doing a horn myself. I have pretty much zero knowledge on horns as I have only built sealed and ported subs. I would be interested in finding out what I would need to build in order to beat my current 2 15 cu ft ported Q18 subs. My winisd plot for my 17.5hz tune (which is the one out off the 3 I have on my subs) shows 117db at 20hz and 120db at 30hz for one sub. Now I haven't really properly tested them fully but I have space in each corner for about 36" wide by 22" deep by however high. I am guessing I wouldn't be able to use my Q18's as the box would either be massive or the driver specs just wouldn't allow for a good horn.

I see that you were comparing to the mach audio driver and you favoured the horn over it. There seems to be alot more and more with regards to horns that is making me think there must be a good reason why so many people are building them.

I would appreciate your advice if you wouldn't mind. 

cheers and looking forward to your build.

cheers

Graham


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## Oklahoma Wolf

Start here, with Soho's most excellent spreadsheet and a copy of Hornresp: http://www.hometheatershack.com/for...sheet-dum-everyone.html?highlight=spreadsheet

These days, I start all my designs with that spreadsheet. It saves me a _lot_ of time. My hunt for good TH drivers usually starts with finding ones that have an Fs about 1.6 times higher than the corner frequency I want, as well as a nice low Vas to keep the box size down. From there I plug them into the spreadsheet and then Hornresp and see which ones come out best. I then usually do a fair bit of tweaking from the output of the spreadsheet to get all the little things just right.

If you're looking for a 17Hz corner, I can tell you right now the SDX10 is almost perfect. It actually likes being at 17Hz better than 16Hz. I haven't looked at the Q18 to see how it does in a horn.

I like tapped horns because they're more efficient and they sound better than direct radiators when done right. 350W into my Tang Band TH gives me about 10dB more output across the board than my Mach 5 IXL 18.2.2 LLT with 600W. It doesn't play as low, and is much larger, but that's ok. Horns aren't for everyone, but I'm definitely hooked.


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## gperkins_1973

Thanks for that I will have a look at that. I did download hornsrep and tried reading the help section and pretty much got confused from the off. There are some off the driver parameters that I don't seem to have that are required in hornsrep.

Sounds like its time to read.

cheers

Graham


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## Oklahoma Wolf

Hornresp will calculate many needed parameters... double click each field to see. 

The program does have a steep learning curve, that's for sure.


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## Oklahoma Wolf

Drivers have arrived. First impressions... I picked the right tools for the job. These things are seriously beefy... much more so than the Tang Band woofers I used last time. Diaphragms are nice and strong - the compression ratio of the horn should be no problem at all for them. At any rate, they're in one piece and the DMM says the coils are just fine. I'm good to go when the warm weather gets here. I'll break them in sometime between now and then when I get a chance.

Here's a picture of them on top of the Tang Band horn:










And one posed inside the TB horn to give some idea how the SDX compares to the W8Q-1071F:


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## hgoed

I'm very interested in your build progress, if you're still working on it. Man, 'though, will that be a big cabinet. I've been measuring around my room to see where I could put one, but I don't have anywhere to hide it away. Maybe instead of a couch...


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## Oklahoma Wolf

Haven't started yet, but will be soon. Winter was real late leaving town, and because of the unusually heavy snowfall we got there was a high flood risk. Didn't want to start anything and end up having to clear out in a hurry. But it looks like the flood risk is dwindling to almost nothing now.

All I need at the moment is a couple people to pay up what they owe me, and I can go on a wood buying trip.

Big is a relative term. This thing should do mid 120's with ease in room at one meter down to 16Hz or so. My current tapped horn already hits 120 at listening position, and this one will blow it out of the water. Hard to come up with anything direct radiating that would compete with it in any less space for the same $500 or so it takes to build one of these


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## hgoed

I agree it's likely worth it. That's why I've been trying to see if I could emulate your design. I think I read somewhere that you can put your sub on the front wall out of sight. I'm thinking I'd have to do some sort of floor platform, but the 42" dimension would have to come down a bit, maybe by straightening out the box to make it longer. 

I'll probably have to dust out my cranium and learn enough to design two single SDX10 tapped horns. I've got four of those drivers laying around, slated for sealed, but in looking at your response I was thinking I could do a hybrid tapped horn--longer and thinner-- and integrate a sealed compartment into where one of your folds would be. Sealed seems like it would integrate well where the tapped horn starts to break up. 

I just started reading about this last night, so excuse me if I'm speaking nonsense.

I hear you about the weather. I'm waiting to work with my garage open but it was still snowing off and on around here as of last week and now it's just pouring.


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## Oklahoma Wolf

They're a steep learning curve, but I enjoy difficult challenges like this. There are a number of tutorials on Hornresp and Akabak floating around both here and at AVS that can get you started there. Pay special attention to lilmike and Soho54 - these guys really know their stuff.

With regards to mine, you don't necessarily have to have the mouth firing out the end panel. As long as it's at the end of the horn, and the exact same area, you can put it on the bottom panel or either side as well. I'm just end firing it because I'm too lazy to bother with driver access panels.

Single driver tapped horns with these is an option. Two would take more wood than one of mine, but would give you many more placement options. I haven't done a lot of experimenting there. I already have a tapped horn that's bigger than this will be... only have the room for one more 

Sealed? Not following there, I'm afraid. Isolating one side of the driver in a sealed box isn't a tapped horn anymore, it's a more traditional front loaded horn.

Edit - can't believe I forgot to post the break-in video:


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## hgoed

By the sealed, I meant just integrating a seperate sealed sub into the same overall structure (I wish I could draw it)--it would require a different folding pattern, leaving dead space which would be used for the second driver/sealed compartment. It would probably be more of a pain than just doing a separate box and folding neatly like you have done.


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## Oklahoma Wolf

I would forget about that idea, honestly, if you want to fire the sealed unit right into the room alongside the TH. Integrating two different types of subwoofers isn't that easy to begin with, and it's even trickier with horns. You'd have issues with time alignment and phase, not to mention the fact that a single sealed SDX 10 will not keep up at all with the same thing in a decently designed tapped horn.

With the sealed box firing into the tapped horn somewhere down the line... that would change things drastically. Not sure how it could be made to work and still sound good. I doubt you can even simulate that situation with Hornresp. Definitely not something I'd suggest experimenting with for a beginner.


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## hgoed

I'd come to the same conclusion.

What do you use for between 60-100 Hz? Or, am I missing something?


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## mdrake

Great job on the design!! If you dont mind I might just copy your build.


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## Oklahoma Wolf

hgoed said:


> What do you use for between 60-100 Hz? Or, am I missing something?


Truth be told, even though the simulations say my current tapped horn shouldn't sound good up to 100Hz, it does. I think it has around a 6dB dip at 80Hz, which I barely notice. It covers the whole LFE channel... no other subwoofers needed. I now get the punch in the chest during Star Trek 2009's warp scenes I always missed with my 11Hz IXL 18.2.2 build. I love horns.

I should be pushing almost three octaves of usable bandwidth on the SDX design... that's not easy to do in a tapped horn. EQ is recommended for best performance... I suggest the MiniDSP and a copy of REW for that. Cheapest and probably the best way to do it.



mdrake said:


> Great job on the design!! If you dont mind I might just copy your build.


Go right ahead... I was hoping this one would prove interesting enough for at least a couple other people to try it out


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## hgoed

Very interested now. I've got a miniDSP on the way anyway. Now, if I figure out how to copy yours, I'll have to also figure out what to do with my other pair of SDX10. Shouldn't be too hard as I seem to have an unlimited supply of speaker envy.


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## Oklahoma Wolf

Build two, wire them at 2 ohms, run each off a channel of an EP4000, and see how long it takes the cops to show up :R 

Or just keep the extras on hand in case you clank the coils off the backplates by accident. Really though, that won't be too easy. Hornresp does not factor in a few important things into the excursion plots, like suspension compliance getting stiffer as the cone moves in, or the effects of the compression ratio increasing as it does so. It also doesn't figure on the effects of the changes in BL after Xmax. I fully expect to see 130dB at one meter out of this thing in my room, corner loaded, without the drivers even moving much past Xmax. But I'll want to quit before it gets to that level. Hard enough to get up close to the one I have now, when it's pegging my SPL meter at one meter.

I tried to make it as easy as possible to build. I managed my first one ok with no help, though it was a bit tough at times due to 3/4" plywood not exactly being light for the two biggest panels. The biggest challenge really was making sure I gooped enough PL Premium on to insure there were no leaks.

Soon as I get my wood I'll post the Sketchup file and a drawing with dimensions. That should make copying easier


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## Zeitgeist

Hope it turns out well! I have a new found interest in horns, so I generally try to follow new horn builds...

I wish that I was more adept at folding and optimizing horn designs. It's much more work than it seems at first glance!


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## gperkins_1973

When do you think you will be running some REW sweeps. It would be very interesting to see how it looks.

cheers

Graham


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## Oklahoma Wolf

When I get the measurement gear for that. Not sure when that'll be. I can do some in room stuff with my SPL meter, but it won't be anywhere near accurate.


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## gperkins_1973

Cool, what do you think the lowest decent frequency you would pick up with that horn. As you know I enquired about horns a while ago. Really struggled folding the things. I can use sketchup but found it confusing when trying to fold it. Could you make this horn wider and less deeper?

120db is more than my Q's model in their 15 cu ft boxes in my 17hz tune and I am modelled with 1000 watts input power.

Also I presume horns are just as critical with positioning like ported/sealed subs. Is this correct?


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## Oklahoma Wolf

Well... that's not quite as easy to answer as you might expect. The room depends a lot on how low it will reach with any kind of useful output. A sealed airtight room might get good SPL down to 11-12Hz on this thing. But if it's open to the rest of the house like mine, anything below the low corner is gravy.

I'm a highpass nazi with the one I have now. It will do reference to 14Hz and has significant output down as low as 13, but I try not to let it play that stuff. I have it set to drop like a rock below 15Hz. The trouble is, the lower you go below the corner, the more the horn will amplify second order distortion. At a certain point, all you'll hear is distortion and nothing of the fundamental. For example, the Tang Band horn will play 10Hz. Just not at audible levels. And when you start turning it up, suddenly it attacks you with high levels of 20Hz.

And that's actually how I know Hornresp overpredicts excursion. For a long time, my Reckhorn B-2 was boosting at 14Hz due to some weird interaction between the EQ and highpass filters. Effectively, I had no highpass at 10Hz at all... it was more like 6Hz. I actually had it running at reference levels during Tron Legacy when it was set that way. Massive distortion, but no clattering voice coils.

Once I got the Reckhorn set straight thanks to REW, all I get now is intimidating levels of clean LFE on that same movie. Can't wait to try that flick with the new one.

That said, I will soon have two 16Hz tapped horns in here. 13Hz at reference shouldn't be a problem with them both working. I just can't go any lower than that because the TB horn is going to be out of its depth trying to keep up with the new guy.

Yep - placement is still important.


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## gperkins_1973

I think 13-14hz in the real world is low enough for pretty much most movies and music especially if its clean down to that frequency. Any pics off this thing standing proud to get an idea on size.


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## Oklahoma Wolf

I'll do better than that - here's a video I did of the TB horn for showing off purposes. Screen size is 102" diagonally.

Shows the horn pegging the SPL meter by the mouth. It was hitting 122dB peaks at listening position. This is back when the B-2 was boosting 14Hz, as well... haven't done a video of it since.






Makes me want to rub my hands and cackle with evil glee when I think that the SDX horn should get louder than this while being thinner at the same time 

13-14 is at the point where you need to start moving away from horns if you're really serious about those frequencies at high levels. This design will only do that for some few people fortunate enough to have rooms good enough to allow it. Like I said - anything you get below the low corner should be considered gravy.


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## gperkins_1973

Impressive indeed and that's not even the dual 10 either. The trouble with trying to achieve sub 13hz at loud levels is sealed and lots off them. That as you know cost big bucks and considering the amount off money you need to spend to get clean distortion free sub 10hz bass its not worth it in my opinion as its far cheaper to get 15hz and up which is where most stuff is in the low frequency range if that.

Really looking forward to the SDX TH results.


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## Oklahoma Wolf

Yep. Not that you can't do 10Hz with a horn, it just becomes impractical enough to not be worth it. Driver choices get scarce, and box sizes go way up. My IXL 18.2.2 for example models great in a 1300L 10Hz TH design. Will I ever build it? Not a chance. In fact, I might be selling that driver soon. I just don't use it anymore.

The thing about the Tang Band horn is, I stumbled into doing a better design in reality than I realized. The challenge with the new guy is to do those same things on purpose this time. Thankfully, Hornresp has improved by leaps and bounds since then, and I've learned a lot.

Only thing I can't get around on the new one is that it's a longer design due to the kludge block in the throat to make the tap position come out right. But there's really no way around that without coming up with some exotic fold I wouldn't be able to put together (I'm honestly about as much of a woodworking master as Tim "The Toolman" Taylor). I figure keeping it easy for me to build is more important than really optimizing the space in the cabinet. As long as it still fits into three sheets of ply, I'm happy.


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## hgoed

Played around with Hornresp the other night and I couldn't get a single driver version to work below about 22Hz. I also couldn't find any way to improve your design, so I can confidently say "nice work" for whatever my opinion is worth.

One question--how did you chose that 13.2" width. I'm guessing it was just a convenient number, or is there something more to it? If not, do you see any reason I couldn't up that number to about 15" which would allow me to cut that 42" dimension down to about 37.5" and keep the same area?

Thanks again for the inspiration, and the starting point from which I've found a lot to read.


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## Oklahoma Wolf

A single driver version requires roughly half the horn but keeping the same horn length. I can think of ways to improve it, but they either require upping the folding difficulty or more wood. As long as the current version proves as good in reality as it simulates, I'll be happy with it.

Width is chosen to be the narrowest it can get and still easily mount the drivers using 3/4 plywood. I think I left about a half inch wiggle room. This also allows much less bracing, because I'm using thicker wood with narrower spans.


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## Oklahoma Wolf

Say, is it just me or are there three big sheets of wood and two big tubes of PL next to my old tapped horn?










Once again, I went with C2 grade shop birch from Windsor. 11 ply, as good as it ever was. You couldn't beat the price with a bat even _before_ they put it on sale for the month of May. $30 a sheet means all my wood cost me $95.

So far, I'm in this project about $320 for drivers, $95 for wood, $12 for screws, and $20 for two gigantic tubes of PL Premium. I get $447 when I do the math. 

Of course, I did have to drop $60 into the gas tank to go get the wood from Medicine Hat...


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## hgoed

I was hoping you'd go first...now I'm drooling, waiting for your progress. As little comfort as it offers, I can tell you that I paid about twice as much for a 5x5 sheet of baltic birch. These things are a money drain no matter how you look at it, but so far, it's been quite worth it. Even if the filthy rich could buy something 2% better, they'd never really own it.
Please post your progress.:clap:


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## Oklahoma Wolf

This stuff ain't baltic birch quality, but it's pretty much the best quality imported cheap stuff I can find around here. The veneer will still peel if you let it, which is why I leave all the screws in after building, even after PL. 

Home Depot's shop birch can't touch this stuff. 5 ply < 11 ply.


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## hgoed

OK...maybe a stupid question (I'm quite the building novice)...why would one want remove the screws? Finished look?


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## Oklahoma Wolf

Yeah. I've never really cared about making screws vanish though. Screws are cheap.


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## Oklahoma Wolf

And now the fun part - giving away the plans 










Sketchup zip file attached. It's 2D, but all internal panels are 300mm deep. Not hard to remember. I was too lazy to make this one 3D.


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## Oklahoma Wolf

3K has some errors in the corners, it turns out. No horn gain on the two 180 degree bends. Spent the morning working on it, and I now have a version 3L. Box length gets slightly shorter, horn gets slightly taller. 

Not bothering with the Hornresp sim on this one. It's almost identical to 3K with a slightly higher corner. In comparisons with the Tang Band horn, however, the slightly higher corner and corresponding 3" shorter horn length is probably an issue with my quick and dirty Sketchup measuring. I won't lengthen this one any more out of concerns I'll run out of wood.

As is, 3L still fits on 3 sheets of stock. Still need the extension piece on that one internal panel. But there's horn gain in the corners again. Probably not the most mathematically accurate, but this is literally all I am willing to do on this. Y'all can pick 3K or 3L as you wish. I'm building 3L. Hoping to start cutting wood later this week as I find time.


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## hgoed

Would you be willing to add top/bottom measurements for those two turns, corresponding to the 233mm and the 137mm ones in the 3k plan? I think it would simplify tracing out board placement onto the side walls.


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## Oklahoma Wolf

Better? Zip file in post 35 has been updated.


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## hgoed

Thanks!


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## hgoed

It looks like you're using a 1.8mH series inductor. The graphs on hornresp look subtly better with the inductor in place-slightly flatter spl curve and about 1mm less peak excursion-but I'm not sure if there is another reason. Is this why? Also, how do you actually hook up the inductor?


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## Oklahoma Wolf

I'm not using an inductor.


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## hgoed

Ok, then I'm confused. Why's the Le set to 3.2?


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## Oklahoma Wolf

Probably forgot to set it back to the normal value after I modeled it as such. The difference in the intended passband is mostly negligible. The inductor helps with the peaks a bit above 100Hz, but that's about it.


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## hgoed

Skipping it. I was actually surprised that you would have had included one, given the graphs (although admittedly a little better) were almost the same.


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## Oklahoma Wolf

More goodies: my cutlist diagram and the Hornresp sim for version 3L.


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## Zeitgeist

How important is the tolerances on the width of the boards?

Not sure how to accurately cut 51/64ths? 

Or was that metric converted to standard?


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## Oklahoma Wolf

Metric conversion. I use the Cutlist output just to determine where all the cuts go... I do the actual cutting in metric down to the last millimeter.

That way, PL has less open spaces to fill. Also, because those internal panels are 11.8" wide and the plywood is 48," you want the cuts on supply piece 3 to be as accurate as possible. There's no real room for error. Part of the fun I had making the internal width as wide as possible and yet still fitting on three sheets of plywood.


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## hgoed

I suspect variation in the individual drivers would make more of a sonic difference than a small rounding error in cutting boards. The few boxes I've made, I rounded to the nearest kerf width, and that seemed to serve me fine. 

I'd complain about the mm, but I wish my country would switch to metric so I don't have to keep track of things like 51/64ths in my head while I'm working.


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## Oklahoma Wolf

Speaking of drivers, I made a point over at my AVS forum thread I should make here as well. As per Hornresp simulations, this design will stay roughly within Xmax up to 300 watts. It'll take 600W or so for the drivers to approach Xmech. 

Just wanted to caution people - try not to feed this design more than 500-600W. Add more jiggawatts at your own peril, Doc Brown. Exceeding Xmax a little bit is ok, exceeding Xmech will require new drivers. Hornresp doesn't account for a few things in the excursion graphs, so reality will probably see a fair bit less excursion than the sims show, but better safe than sorry.

Can't get enough SPL with 500W into one of these? Time to build a second one. You're still going to be coming in under a grand, if you go by what I've paid so far. Nothing wrong with headroom


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## hgoed

Any progress?

I'm gathering materials to try out your design regardless. I really like the efficiency, as low-power is a real concern with my home design. I had to modify things to sell the idea to the boss. For better or worse, I'm going to build the box as a base for a couch. Actually, the dimensions you give are perfect for a daybed, but I was planning to make the box a bit wider and narrower with the same port length, so as to make the overall piece not as obtrusive in my living room and more consistent with a normal couch. As a side benefit, where I place it, the back will be at the point of the first reflection of my front speakers (the width allows capture of all three), so I can kill a few birds with the one design. 

I hope you don't see this as a perversion of your work, but if I can make a tapped horn look nice in a modern living room, maybe I could convince some people that quality and crazy don't have to coincide.

Also--I'm still going to use my other two drivers in a sealed box (but separate). If I can't make them integrate properly, I've got lot's of other uses for them. I'm thinking I need a bunch more...


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## Oklahoma Wolf

I've made lots of progress watching the rain refuse to stop for two solid weeks. It's gotta be dry out there for me to cut wood. Can't do that in the house, so I'm at the mercy of the elements 

Otherwise, once the wood is cut, I'll probably have the whole thing done in a week. 

If you want to try a refold, that's up to you. I just made it so it would be easiest for me to build it. The way I have it folded now, it can't get any wider and still come in at less than three plywood sheets, but making it wider would help the response and sensitivity a bit.


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## Oklahoma Wolf

Well, I _would_ have gotten the woodcutting done today, but somebody's circular saw needs that somebody to go out and buy it a new plywood blade. How did I find this out? The hard way, of course.

I got one cut done, and only one - the new saw guide. Used the old two part guide with a perpendicular board for strengthening to make it.

Gee, do you think the blade's warped at all?










Thankfully, this is only the saw guide. I intentionally left scrap in there for when I do the real cut on one of the side panels from this sheet. So, all is not lost on the wood supply side of it yet.

Here's my cutting platform, built from scrap pieces of pressure treated 2x4:










The drill is so powerful it buried the screws halfway to China in there, so I'm not worried about the saw blade hitting them. Will still avoid cutting near where the screws are.










The bad blade. Lasted me through five sheets of this stuff, and five only. Not sure if that's normal, but around here the pickings are slim for saw blades. Will grab a new one tomorrow if I can and get back at this on the weekend. If the weather holds.


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## gperkins_1973

As I said on the avsforum, WOW! I finally see wood. I really can't wait to see the results on this.


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## Oklahoma Wolf

You and me both. I thought the house was going to float away with the amount of rain we had in the last two weeks.


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## gperkins_1973

What thickness ply are you using just out off interest. Also when do you think you will have it finished?


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## Oklahoma Wolf

18mm - 3/4." C2 grade shop birch, 11 ply void free. I love this stuff... cheap, not too badly warped, looks halfway decent, sturdy, cheap...

Finished? Heaven only knows right now. Hoping for Sunday. That might be a bit optimistic.


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## Oklahoma Wolf

New blade in the house. Also grabbed a few last minute things. Another box of screws just in case 200 isn't enough, the straight brackets that will hold the kludge block to the one panel I can't cut to size (they will be removed before the last panel goes on), and a couple plastic scrapers.

Also grabbed a 1" wood boring bit for the Speakon.










Now, I just need the rain to go away... again...


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## gperkins_1973

Wicked stuff. There always seems to be things getting in the way of progress. 

Don't let it damper your spirits. LOL.


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## Oklahoma Wolf

Gasp... Wolfie's getting stuff done. Uh-oh!

Not a cloud in the sky today, so I was out there making sawdust. Unfortunately, I only managed to get two of the three sheets chopped up today. I don't know about you guys, but when I've been out in the sun and I stop sweating, I also stop working in the sun.

Cutting the two biggest panels for this project is hard enough. Doing it when I haven't been able to exercise properly since last June due to knee issues only makes things harder. I need to work on my cardio.

That said, I am pleased to report that 4 of 12 panels are done and they are accurate to +/- 1mm. You know the saying "measure twice, cut once?" I'm a little more OCD than that. I measured 4-5 times for each cut. Took 3 hours that way, but at least I now have panels way more accurate than the last tapped horn had.

Something else I learned - the new "saw guide" is actually less accurate than the two piece metal straightedge. It's bowed 4mm out in the middle. I had to mount a scrap board to it and clamp it down for tension to make it accurate. As a result, I'm going to have to use the two piece on the final sheet. Those cuts have to be as accurate as I can make them, and I don't see any other way to do it. The two piece has one section that's bowed inward by 1mm. That's acceptable, I think. I'll clamp a stiffening board to it, like in the below picture of my new saw guide - should keep it from bowing inward.

One last thing before pictures. The 40 tooth carbide tipped saw blade is the best thing I ever did. Thanks go to lilmike for the suggestion. Way faster than the plywood blade was, and just as clean cutting.










First cut of the day. Much, much better.










One of the big side panels done.










Working on the mouth side. That masking tape was a suggestion by someone to keep the birch layer from chipping. It didn't work. The saw ripped the tape right off the wood. Ah well... I'm not building a work of art, here. I picked this wood because it was cheap, but good quality.










Four pieces done, in their place of final assembly in front of the projector screen. Tomorrow, I hope to be recovered enough to finish off that last panel.


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## gperkins_1973

Keep the pictures coming!


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## Oklahoma Wolf

I'll do my best. I think I'll put the Fuji J10 aside for the old Nikon 3700 tomorrow though. The Fuji takes terrible pics on auto mode. Glad I didn't pay a lot for it.


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## gperkins_1973

Cool, just keep those clouds away.


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## Oklahoma Wolf

A picture is worth a thousand words:










But I'll toss some words in anyway. All panels are now done and ready for the assembly phase. I had to wait almost all day for the clouds to quit spitting on me, so I wasn't sure how much time I had to get this done. As a result, I only have the one picture.

The two piece saw guide worked perfectly today with the stiffening board clamped in place. Not one cut was off by more than 2mm, and several were dead on. And I mean perfect - 300mm exactly. I had perhaps 10mm of scrap left over on this last sheet after cutting four 8' strips 300mm wide.

The assembly is going to go way better on this project than the last one. Speaking of, that part may start Wednesday. I need a day to rest. I hope to have this beast up and rumbling by Friday.


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## Oklahoma Wolf

Day one of assembly phase is over. I got as much done as I could. Some roadblocks included a badly warped driver baffle that is still not straight after 3 hours in the sun, and a compact florescent bulb that failed in a way that looked, smelled, and sounded just like an electrical fire starting.

Seriously, that bulb had me racing all over the basement flipping breakers like crazy until I found the problem. I hate those things.

Anyway, I'm almost at the point I can start with the PL. Thanks to the sawhorses, this part of things went much easier. Once again, the jigsaw chose to annoy me while cutting the driver holes, but I think I got them to the point the surrounds won't rub on the cuts now.

I don't know why I bought a new countersink bit. Five minutes into this, and I suddenly remembered why I stopped using the old one on the last build.

And now, pictures.










Check out my innovative clamping method for the top and bottom panels. These were warped, so I piled weight in there to keep them straight while I drilled and screwed up from underneath.



















Working on the driver mounting holes and screws. Wanted to be dead sure of no surround rubbing on the sides of the cutout, so I had one of the SDX's help me with that.










Getting closer. To compensate for the panel warp, I used the weight again to hold it straight so I can drill the mounting holes tomorrow. Maybe the panel will be straight on its own by then... the weight stays there overnight.










Last two panels going in.










Another angle.










Does... does it look like a tapped horn yet? Please say yes. My body is aching something fierce 

Looks positively skinny compared to the Tang Band horn, but make no mistake... this one is still plenty huge.

Hope to make more progress tomorrow. Will get things done as I can.


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## Oklahoma Wolf

Important note - due to reality differing slightly from the last Hornresp model, I have updated the model to reflect measurements I took of the project a few minutes ago. See attached file for what I should be getting from the final product.

That said, I expect the low corner to drop some, even more than this model shows. My Tang Band horn ended up at 15.5Hz, down from 16Hz. The length of this horn is similar.


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## gperkins_1973

That looks like one easy build there. Good stuff. When will it be up and running.


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## Oklahoma Wolf

Might be Saturday now. I want the PL to cure on the bottom before the top goes on so I can check for leaks, so I'll do most of the gluing today, finish it off tomorrow, and then the drivers go in on Saturday. Since I left so little room for drivers, I need to make sure I chisel off any PL beads that might keep them from mounting properly.

It's going to be fun to reach the back screws on that innermost driver even with my long arms. This isn't like the Tang Band build, where I had two oval drivers going in right at the mouth.


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## gperkins_1973

I thought you would be putting the drivers in before you put the last side on. 

What spl are you expecting at 15-16hz?

I bet its heavy.


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## Oklahoma Wolf

In room, against at least one wall? Should do at least 118dB at 1M at 15Hz with 300W in. I'll be running it corner loaded, eighth space, with 350W, so I should see a good bit more than that.

Heavy seems hardly the word... I'm glad those plastic sawhorses are holding :rofl2:


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## gperkins_1973

> Should do at least 118dB at 1M at 15Hz with 300W in



That's pretty impressive. So 3m away from the LP, would that about about 109db at 15hz.


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## Oklahoma Wolf

Depends on the room.

Truth be told, the SDX drivers are only a little behind those used in the Danley DTS-10 in terms of total displacement. If I did good, this box will compete well in terms of SPL with that one. I won't make any promises though, and there's no question it will sound different. I just don't know how different.


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## gperkins_1973

They offer massive performance so if yours in similar then it will be awesome.

Good stuff!


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## Oklahoma Wolf

That's the idea 

I didn't set out to match that box on purpose, but as time went on and I started seeing measurements of the DTS-10 and its drivers, I realized I was closer than I thought. Even the TB W8Q-1071F horn I built is not that far off in terms of driver displacement. Too bad that one turned out to be so unrealistically gigantic.

Realistically though, I expect this project is still a fair bit bigger than the Danley and I don't have the advantage of knowing everything Tom Danley knows. I'll be ecstatic if this thing ends up being even close to Tom's work. All I wanted was an improvement on the TB horn, really, and I think I've easily done that.

And it never hurts to learn new stuff. Learned a lot from the last horn, learning more from this one. Next time, I'll try multiple flare rates. I could have had a better horn than this with these drivers... need to get the folding of the multiples nailed down. My horn modeling abilities are way ahead of my construction abilities.

Anyway, back to the project with me now. Drilling the final holes this morning... PL goes down this afternoon.


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## Oklahoma Wolf

PL phase 1 is complete - all panels are permanently married to the bottom panel now.

This went a whole lot smoother than the last time. Mostly because I knew this time I had enough time to lay down a nice, slow bead... no need to rush things. The partial tube of PL from the storage room did indeed yield useful adhesive, but I had to squeeze the gun grip like Hercules to get it out of there. However, as a result, it looks like I will get this whole project done without even touching my second new tube of the stuff.

Did I get some on my hands? Yes. But the second I did, I went over and washed my hands with the mineral spirits. As a result, I don't seem to have stained hands this time. Of course, I didn't kick the bucket of mineral spirits over this time either. This was helpful in cleaning my slipjoint pliers too, which were in charge of removing and replacing the nail in the PL.

I also used several pieces of scrap wood this time for resting the PL tube on, so I have a lot less of the stuff smeared all over the horn panels inside.

And now, pictures. I decided not to use polyfill at all in this one, though it will get stuffed inside the dead space in front of the horn throat just in case.










Getting ready to PL the first panel... the throat block.










The old tube, ready to go.










Throat segment in place, including the driver baffle. The driver baffle was tough, because it was still warped to kingdom come. 










How I pushed out the warp so I could screw the panel down. The dowel has now been removed. That panel ain't going anywhere now.










PL goes down for the last panel. I did inner panels first so that the two side panels would hold the big bottom panel true while I worked on the inner fold panels, and then did the outer panels last with the inner panels holding things true. Worked out great.










All done. Tomorrow I check for leaks, measure and drill screw holes for the top, and PL the top on. Drivers go in Saturday.


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## Oklahoma Wolf

I'm thinking of a word. Starts with "D" - four letters. Rhymes with "fun."










That's all she wrote for the assembly phase. I will have some PL stains on my hands after this one. After pre-drilling a total of seven locator screws, I heaved the top panel in place, got on top of it, and went to town with the drill.

At the end of all this, I still have an untouched tube of PL. Those interested in trying this project should be warned though... I would have needed it had I not had the old stuff in the storage room. Buy two big tubes. Or four little ones. Too much is better than too little. I also have an untouched box of screws left over... 200 was enough for this one with some left over.

Panel fitment is miles better than the last tapped horn, but the top doesn't quite square up as I'd like. Ah well... close enough for horseshoes and hand grenades.

Some pics of today's progress:










Ready to start. Horn off the sawhorses.










Before anything else, I scraped off some of the excess PL and removed the brackets holding the kludge block in place. I forgot to plug the screw holes with PL, but no big deal - they don't go all the way through anyway.










My oops from the other day.










Changed my brain on the polyfill. Thin layer at the throat. Yes, I did remove that errant staple.










Using the two piece saw guide to mark for the guide lines.










Laying down the guide lines using both saw guides to insure straightness.










Final PL beads laid down.


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## gperkins_1973

That's sure gonna be fun getting them drivers in there. Will you be firing her up tomorrow then?


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## Oklahoma Wolf

Yes, and yes.


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## Mike P.

Awesome horn! Can't wait to hear what you think about the in room response.


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## Oklahoma Wolf

Thanks 

Me too. It should come fairly close to the older one, which is currently +/- 2dB at listening position corner loaded between 25-80Hz with no EQ to speak of. I need a better EQ than the Reckhorn B-2 to make it totally flat. Plans are in the works to buy a MiniDSP for that purpose.

The Reckhorn does have EQ applied, but that's only to flatten out its own response and give me a proper highpass.


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## killa12222

WOW, now that is crazy! How heavy is it? Should be interesting seeing it in action!


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## Oklahoma Wolf

It's probably close to the 170lb mark without the drivers. That should keep it from walking around


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## Oklahoma Wolf

I got the drivers in and ran some sine waves. Guys, I am so disappointed right now...







...that you can't be here to experience this     

Fed it with 15V for testing. Low corner is approximately 16.3Hz. No leaks found. Usable extension to 13.5Hz with 15V in. At 13, it gives you more harmonics than fundamental.

It was kind of hard to listen for leaks with everything in the room rattling and all, but all I really heard was the sound of the diaphragms moving. Nothing I can do about that with the woofers so close to the mouth. Drivers look to do just fine with the 3:1 compression ratio. I had them moving pretty good. Nothing near Xmax, but just enough to see what she could do.

This thing has a real chance of beating the stuffing out of the Tang Band horn. Can't wait for the real fun later today. I'd best go upload some pictures.


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## Oklahoma Wolf

Picture time again.










Everything lined up and ready for driver installation and wiring.










Gardner-Bender duct seal ($2 at your local electrical supply or hardware store) is a handy thing to use for sealing drivers and other things. Using the last of my 12 gauge hookup wire on this project. I only have white left, so I'll wrap the negative lead with electrical tape on the end. Drivers will be wired in series (8 ohm to the amp - it's a currently bridged RMX-1850HD).










Getting ready to duct seal the Speakon. Heh... Speakon. Speakon, speakoff. Speakon, speakoff. Speakon, spea... hey, who threw the popcorn? Aim at my mouth next time, willya?










Duct seal in place, ready to install.










Wires were soldered to the Speakon. I have no fast-on connectors for 12 gauge handy and didn't want to buy them.










Rear driver duct sealed and mounted.










Both drivers in place and wired. Now, let's get us a Speakon on that big 10 gauge wire from the amp.










Ready for testing!


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## Oklahoma Wolf

I got the Percy Jackson minotaur fight on video 

Good news and bad news. Good news is, the new guy hits like a meteor. Bad news... reference level on this scene makes bad noises happen. The drivers were ever so slightly kissing the backplates. Measured 122dB sustained at 1M, corner loaded.

I suspect this is a highpass issue more than anything else. This is how the Reckhorn B-2 is calibrated:










Even so, it's a bit disappointing that the old Tang Band horn can take this scene without bad noises. Even so, that design is still way too big to be practical, and has an advantage in that the compression ratio is higher.

Currently, the old horn is stacked on the new one. I expect to be joining the two to the amp before too long.

All in all, I'm calling this mission accomplished. The SDX horn mostly does what the TB horn does in less space. That's all I wanted. Wait until I highpass it properly... I should get a bit more SPL out of it 

Tried to get MCACC to calibrate the system with just the one horn... it screwed everything up. I must have had the mic placement wrong.


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## Oklahoma Wolf

Ok, last major update for the day until I can get the video uploaded.

Clanking drivers was indeed down to the highpass being too low. I'm just not used to dealing with drivers that have XBLL motors. The Tang Band woofers, when they get to Xmax, stop pushing as hard and start absorbing power instead. The SDX's keep pushing.

Therefore, a properly set highpass is somewhat more critical with the SDX horn. I strongly suggest to anyone interested to grab a MiniDSP. While you could still use something like my Reckhorn B-2, it's not easy at all to get it set up right for this horn. 

Now that that's out of the way, I just ran my first full movie through the SDX horn. And the TB horn, too. Incredible Hulk. The sonic cannon scene was out of this world with both horns running at the same time. That said, I need to try and do some EQ'ing. I have too much above 50Hz this way. Another excuse to buy a MiniDSP.

A couple more pictures:










The standing wave correction MCACC applied to the SDX horn for Percy Jackson.










The two horns side by side. One's 850L after materials, one's about 730L.










Yes, I did end up having to stack a 180lb horn on top of another horn by myself. That was not easy. Old one on top, new one on the bottom. Center speaker removed due to low clearance otherwise. While moving the TB horn around, I heard rattling inside. Did a few horn acrobatics, and some loose dried PL fell out of the mouth. Explains the odd noises I heard from it now and then.

Each horn is getting a channel of the 1850HD at 8 ohms, clip limiters off. The two get incredibly loud together, even with the improper highpass.

Giving the two a rest for the evening. I think I've had enough five star bass for one day, and the power is going crazy here. Tomorrow, I'll see if I can get the response smoothed out some and fix the highpass.


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## robbo266317

Quote: Yes, I did end up having to stack a 180lb horn on top of another horn by myself. :no:

I don't think OH&S would approve.


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## killa12222

180lb!! Imagine if your horn was build using MDF :yikes:

On the other hand, any issues with your neighbours complaining? :hsd:


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## Oklahoma Wolf

robbo266317 said:


> Quote: Yes, I did end up having to stack a 180lb horn on top of another horn by myself. :no:
> 
> I don't think OH&S would approve.


Meh... I may have my health problems, but I'm still 6' 6" and plenty strong for my size. Once lifted one of my 1988 New Yorkers off the jackstands one rear wheel at a time because the jack failed 



killa12222 said:


> On the other hand, any issues with your neighbours complaining? :hsd:


Nope - we're on the edge of town, and the only neighbor is in her 90's. I don't normally listen to stuff over reference anyway. I couldn't until this second horn... the room is open to the rest of the basement, which in turn is open to the whole house. Takes a lot of SPL to fill all that up. That's why I was so unhappy with one 18" in a vented box.

Anyway, the video's online now:






I wanted to get more of that scene on there, but I also wanted to stop the drivers from clanking. I might do a better video some other time.


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## killa12222

Lucky! Whenever I try to crank my bass, the neighbour comes knockin on my fence :crying:

Anyway, how does the horn sound on music?


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## Oklahoma Wolf

Haven't tried it with music yet.

This morning I got the Reckhorn re-calibrated. I got MCACC to run properly. I then tested using Flight of the Phoenix.

Big, big improvement for the SDX horn from yesterday, even though I was calibrating and running both horns. Measured 120dB one meter from the mouth of the SDX horn, and I don't think I saw the front driver move past maybe 15mm both ways. But then again, that's with both horns working. As I have the time, I want to recalibrate to use only the SDX horn and see if it's out of trouble now. But I'm waiting on decent measurement gear too, so my general observations will have to do for now. Would rather do it all when I can get those measurements so I don't have to be constantly tweaking the Reckhorn.

I did try to get some measurements with the old SPL meter and cal file, but high level sine wave testing this morning tells me it's nowhere near accurate below 20Hz. 

Anyway, here are the before and after tweaks to the Reckhorn's low pass filter:










Green is before, purple is after. 3dB decrease at 15Hz vs. before.


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## Oklahoma Wolf

Did a little more testing this afternoon using test tones and sine waves. In room response looks to be a lot like the graph of the Reckhorn's output with some nulls here and there.

As to excursion, I tested high level sine waves from 10-15Hz. 13Hz looks to be the problem area for the SDX design. I ran both horns up to +5dB, and 13 was where I saw the most excursion on the SDX horn. The TB horn didn't have a problem with it, but that's because the W8Q-1071F's motor runs out of gas faster past Xmax, as mentioned.

That said, with the new lowpass settings, running at +5dB, I couldn't get the SDX drivers to bottom out this time. So, I'm safe now to well above reference level. Of course, having two horns doesn't hurt, there, either.

So, I think for prospective builders I'm going to suggest a 12Hz 48db/octave highpass. Higher if you want to really get the SPL out of it. Lower if you have a small room. I want to do 96dB/octave, which will require that MiniDSP I mentioned. It's becoming a priority to get one now.

In terms of audible harmonics, I didn't hear any until 0dB with the current highpass settings on the super low stuff. I'm talking 12-14Hz. 10Hz produced harmonics at -5dB. 14Hz fundamental was very strong. 15 even more so... measured 106dB on the SPL meter. And of course, 16 is where the horn starts to really get going.


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## hgoed

Looks great! I'm glad I watched and waited as I have a better idea of what's involved. I did get a MiniDSP, so maybe I'll try a low and steep crossover as you suggested.


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## Oklahoma Wolf

Good plan. I should mention that the B-2 I'm using only has a 24dB/octave highpass. 48dB should do wonders for this design.

15Hz is no problem for the design. 14Hz and below is when it starts to go crazy. Around 13 is where I was clanking coils @ reference.


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## hgoed

Even to me this seems like something I should just work out myself, but I thought I'd ask anyway...

I'm visualizing the build process with your pics and I'm wondering when you decided to bring the project inside? I'm guessing you cut everything outside and assembled on-site...or do I have to buy more Advil?


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## Oklahoma Wolf

Cut everything outside, built it inside. Easier to get it down the stairs myself if I do it in pieces 

Had to build it inside... took me a few days to get it all done with my schedule. 4 hours for the dry fit, about 3 hours for PL on the lower section, another 3-4 hours to finish things off.

I probably could have done all the gluing in one day, but I didn't have the time for that.


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## Oklahoma Wolf

One week on, and both tapped horns are nicely dialed in. On Wednesday, I hit them hard (so I thought) with Unstoppable. Saw levels of 118dB sustained at listening position, no driver got even close to Xmax. Not only were my pants legs moving, so was my hair.

Repeated the experiment this evening with the first Lord of the Rings movie, extended edition. Got pounded on by the horns the whole time. Again, 118dB sustained on a frequent basis. No clip lights on the amp, no drivers in trouble.

Will be watching the Two Towers tomorrow, and Return of the King on Monday. That last one will probably see me bump up the LFE some more. I've never experienced these movies on a decent system, and I aim to have fun with it 

At any rate, I have no regrets about building a second tapped horn. The amount of headroom I have now is insane :hsd:


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## Oklahoma Wolf

New video. Two horns are better than one


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## hgoed

I could actually feel your system through mine over YouTube!!
I can't do two horns so I may never experience the same, but the energy was exciting none the less. 

Someone else posted that their bass system actually caused ripples in their screen. Did you notice that? Their claim seemed like it would require quite a bit of air movement (beyond reasonable sound) to me, but if your system didn't cause a problem, I'm pretty sure I'll be OK.


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## Oklahoma Wolf

No screen ripples - the mouths of the horns are firing into the corner, and nowhere near the screen. It takes a serious amount of SPL to cause problems in this house.


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## Larry McConville

Good Afternoon,

I never caused my screen to ripple during standard program material; however, I have done so while playing around with ~10Hz sign waves.

6 sealed Mael-X w 2400w/each...



hgoed said:


> I could actually feel your system through mine over YouTube!!
> I can't do two horns so I may never experience the same, but the energy was exciting none the less.
> 
> Someone else posted that their bass system actually caused ripples in their screen. Did you notice that? Their claim seemed like it would require quite a bit of air movement (beyond reasonable sound) to me, but if your system didn't cause a problem, I'm pretty sure I'll be OK.


----------



## Oklahoma Wolf

New video... Flight of the Phoenix plane crash this time. Had the LFE running just a wee bit hot - measured 124dB at LP just before the camera started recording. Too bad I didn't catch it doing that on video.

Had to bolt the Tang Band horn (top) to the SDX horn (bottom) after this. It tried to walk right off of there. I also added some chain at the very top so the pair of them won't fall over as a unit.

They will still go louder than this.


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## ironglen

Oklahoma Wolf said:


> I don't normally listen to stuff over reference anyway. I couldn't until this second horn... the room is open to the rest of the basement, which in turn is open to the whole house. Takes a lot of SPL to fill all that up. That's why I was so unhappy with one 18" in a vented box.


Great documentation, design, and build :T 

My house seems quite similar, and all the subs I listed below (18" & two 12"s) do a good job, but nothing like others have with a lone 15" in a small room. I've vowed to use an infinite baffle for any future house to achieve desired spl without taking up space, but thanks to you, a tapped horn built as a second row riser will now be a definite possibility.


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## Oklahoma Wolf

Got some measurements today. Still waiting on better measuring gear, but these should do for now.

Before I show y'all these, just remember - they were done with a cheap eBay SPL meter, no cal file, with the C weighting option checked. The most accurate part of this setup is the Behringer UCA222 used to capture these.

Current placement is corner firing, like so... SDX horn is on the bottom, Tang Band dual 8x12" horn on top:










First, Wolfhorn SDX by itself, listening position. 90dB sweep. This is the loudest I can run it without wall panels vibrating, and the loudest I _will_ run it without a highpass. SDX drivers don't grow on trees, and I can't afford to replace them.










Now, before I show the other two graphs of both horns through the Reckhorn, I want to remind you how the B-2's highpass and EQ is currently set (purple line):










Ok, now both horns through the B-2, 90dB sweep:










Now, take this one with a BIG grain of salt. This one had the walls rattling, which almost certainly got picked up by the meter. 95dB sweep (or so it should have been):










All of this is with the meter at LP.


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## ironglen

Correct me if I'm wrong, but aren't those going pretty deep for TH's? What kind of spl do you reckon you'd get from only the Wolfhorn SDX at LP? That build really has me excited about a possible riser somewhere down the road!


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## Oklahoma Wolf

Not for 16Hz TH's 

I have usable extension to 14Hz in room, but the two horns will not quite do 14Hz at reference in here without second order distortion (the further you go below the corner, the more distortion of this type there will be). YMMV - if you have a less challenging room than I do, you'll probably get more below the corner than I do due to room gain.

I've already had the SDX horn do just over reference at LP by itself without too much trouble, but I didn't have a good enough highpass on it to get the most from it. As a result, the coils were clattering on the backplates ever so slightly from trying to play too low. A proper highpass, and it should match or even beat what the dual Tang Band horn can do, which is 120dB at LP. Together, I have insane headroom. Right now the two horns combined will do 120dB at LP with the drivers maybe at about half of Xmech.

Both designs are able to rival the SPL of a Danley DTS-10, but I can't promise they will match it in any other ways. The SDX isn't quite ideal for tapped horn use (the drivers in the DTS are), but it's close enough to do the job. The idea is really to present a cheap alternative to the DTS, and I think I managed to do that successfully. This way, people with really big spaces to fill can get a couple of these built without breaking the bank.

Just be sure to highpass properly. 48db/octave is strongly recommended. Start rolling it off by 16Hz already if you have a room open to the rest of the house, like I do. A MiniDSP is your friend.


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## ironglen

I know this is a tough question but I'm curious :whistling:, but you anticipated greater output from the SDX TH and it seems to have fallen a hair shy of your expectations and I'm wondering if you can say with any certainty what modification to your design would achieve that superior output rather than the equal output compared to the Tang Band TH you are describing.


----------



## Oklahoma Wolf

Here's the thing - the Tang Band horn does sound slightly better, at least for music. This is because the drivers are electrically more suited to tapped horn use. The drawback to that, however, is they need a whole of a lot of space to do the job. As a result, you'd be looking at 4 sheets of ply to build one. And that's assuming you get two good drivers from Tang Band - one of mine had debris in the gap.

The SDX driver, on the other hand, requires less space and is way better build quality but has a higher Qes than I'd like to see. As a result, it sounds just a mite on the sloppy side for music. That said, this thing wasn't designed for music. Movies. It's not that it sounds bad, because it doesn't. It's just that it's got tradeoffs, just like the Tang Band horn does. 

I personally prefer the SDX design. I could fit four of them behind my screen, the drivers are way better quality (and from a Canadian company), and a MiniDSP will take care of the stricter highpass needs the design has. 

The problem is, when you're designing a 16Hz tapped horn you start running low on drivers that will do the job. I've now used two of those drivers, and I only know of two more offhand - the TC Epic 10 and the Kicker CVX 15." Neither one of those were an option for me, mostly due to money and availability. Well, the DTS-10 drivers would work too, but good luck getting them.

As for greater output - the SDX design has the slight edge there on paper. Remember, the clattering coils were due to the highpass being set too low. My B-2 only gives me 24dB/octave, and it's hard to get it set up properly without multiple passes through REW. The SDX motors just have more strength past Xmax than the Tang Band motors do. So, you do have more protection from misconfigured highpasses on the TB design. But the design of that one is just... so... big! 850L is a lot of real estate for a subwoofer. Everyone who's asked me for the plans on that one has changed their mind when they realized how gigantic it is. 

Modifications? Well... a more ideal horn flare would add some output and sensitivity, but then you're back to monster 850L boxes and 4 sheets of ply. Not gonna happen in this house. More Xmech from the drivers is really what would help most. This is why you don't see many horn designs that go this low. Most are just too big to bother, and driver selection is extremely limited. 

Hope that makes sense - brain's a bit scattered today.


----------



## ironglen

Not at all- makes perfect sense. Thanks for all the patience answering questions from TH novices like myself.


----------



## Oklahoma Wolf

No problem - I please to aim to please 

Should mention - I had no idea the TB horn was going to turn out as well as it did. I completely by accident stumbled on a tapped horn that was better in reality than modeled. The SDX horn was my attempt to do it better on purpose this time. I'm satisfied with the result.

Both designs rival the DTS-10 in SPL abilities. One sounds slightly better and is more sensitive but is bigger with questionable quality drivers. The other is smaller with less electrically optimal drivers but with slightly more top end SPL capabilities. Neither really matches the DTS-10 in every conceivable way - the driver list gets really short by that point. Pick yer poison 

Before anyone asks - no plans on doing anything with the Epic 10. I'm done with the big tapped horns for a while, unless someone straight up gives me a pair. And the CVX is bigger than I want to work with. I have no need for more SPL in this home theater - I've already hurt the house with the two I have :R


----------



## hgoed

I'm cleaning out the garage to give this a go in the next few weeks...I just want to hear/feel it for myself. Anything you'd do differently in retrospect (given the same drivers and overall design)?

Maybe I missed something, but did you ever get a miniDSP for the steeper crossover?


----------



## Oklahoma Wolf

Nope - I'm satisfied. 

MiniDSP is not needed here... I have enough headroom that bottoming out the drivers is almost impossible even with a poorly configured highpass, and response is quite flat at LP. 

Since I don't make a lot of money, a MiniDSP is not a priority. A wise decision for those expecting to run the design wide open, but I'm not currently able to do that in this room without breaking pieces off the house.

Since my last post, two more Wolfhorn SDX's have been built... someone at AVS put together a couple of them a week or so ago. He hasn't posted much lately, but seems happy so far.


----------



## hgoed

I need to check AVS again. I'd been following it when you started your build, but got distracted over the summer. [It's suprisingly tough to get nice grass to grow in sand]

I still have a compulsion to turn the thing into a couch, but I'm pretty sure I'll never actually get around to doing that...maybe a waterbed:gulp:


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## Oklahoma Wolf

I totally forgot to mention - I now know of an alternate driver for this design in the Seas L26ROY. It is actually a better modeling driver than the SDX, and shares similar Xmax and Xmech numbers.

It is also, however, much more expensive than the SDX. Try it at your own risk... I will not be. It's not so good that I would recommend it over the SDX. And really... just those drivers alone will cost you what the SDX's and materials cost me in total.


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## hgoed

I saw you mentioned those drivers in that AVS thread. Personally, I'm much more comfortable with the SDX10 price point, besides the fact that I already have 4 of them. 

It'd be interesting to see what others do. I, for one, never would have felt like tackling a tapped horn without documentation/design like you have shown.


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## Oklahoma Wolf

Yeah - the price difference makes the decision an easy one. Just thought I'd mention it for the benefit of those who may have the Seas drivers and have no idea what to do with them


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## Oklahoma Wolf

Another video for interested peoples. Excursion on the SDX horn was starting to get a bit high again... I suspect the B-2 highpass setting has drifted off my desired settings. It's done that before. Not a big worry for me as I do have that other horn helping out, but once again this shows why a MiniDSP is the better option for the SDX design.

Even so, my LFE was set above reference here... not a problem for either horn. This is way above my usual listening levels. It was so loud, the horns had the dogs thinking there was a thunderstorm coming. The dogs were outside.






Edit - no drift on the highpass, says REW. After re-watching the video, SDX excursion was nowhere near high enough to worry about. An inch peak to peak.


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## hgoed

Hey, I've got a couple more questions--

First, I just wanted to make sure, since my dimensions are a bit different--that piece at the throat is placed to make the start of the horn 300 mm from the center of the two drivers and the mouth needs to be 390mm, correct?

Second, do you think there is any need to compensate for the volume of the dual drivers when calculating the volume at the mouth?

Also, why did you put the batting where you did and not anywhere else? 

Finally, do you think there would be any benefit to adding pieces in the corners of the largest turns?

I know some of this probably gets into miniscule differences, but until I can run to pick up a large enough sheet of ply, I'm just stewing.


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## Oklahoma Wolf

hgoed said:


> First, I just wanted to make sure, since my dimensions are a bit different--that piece at the throat is placed to make the start of the horn 300 mm from the center of the two drivers and the mouth needs to be 390mm, correct?


Yup.



> Second, do you think there is any need to compensate for the volume of the dual drivers when calculating the volume at the mouth?


Nope.



> Also, why did you put the batting where you did and not anywhere else?


Thought it would help with standing waves in the horn and cut down ringing. It does... kind of. Not sure the benefit is large enough to bother.



> Finally, do you think there would be any benefit to adding pieces in the corners of the largest turns?


Nope.


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## hgoed

Well, after fruitlessly trying all sorts of alternative dimensions, here is the plan I've decided to try. It's a little thicker but not as wide as the original. The calculations were re-done today basically as a pencil-doodle while I was bored out of my mind during a teleconference. As such, there may be a slight error, but the math should be much more accurate than my woodworking anyway.

Just under 14" x 77-1/4" x 38-1/4"

My basic goal was to keep the dimensions such that I could build a back and arms, add some padding and fit a pre-made couch slip-cover from Ikea over it. Well, that and the obvious--some nice bass.


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## Oklahoma Wolf

It's not too far off. Biggest difference is a raising of the low corner due to shorter length. It's probably up to about 17Hz there. Acoustic impedance and reactance is still good, as is compression ratio. 

Don't really see a reason not to build it that way, unless you absolutely must have that last 1Hz extension or so.


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## Oklahoma Wolf

Just a quick December update - there are now two alternate drivers for this horn: the Seas L26ROY and the Fi X10.

Note that I have tried neither of these, so can't say for sure whether they cooperate with the horn. It was designed for the SDX10... that's all I can guarantee unless and until these alternates are tried.


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## Oklahoma Wolf

Another alternate driver found - the Dayton Titanic TIT280C-4. It's not quite an ideal match for this design, but it's close enough to work. The horn flare of the design is actually a little more ideal for the Dayton than the SDX, as long as the specs on the driver are accurate.

Standard disclaimer: I haven't tried it so I don't know for sure how it does. It should work fine. Not as good as the Seas driver would likely be, but way cheaper.

Hornresp file attached.


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## Creative Sound

Hi,

For a variety of reasons, which I won't go into, the current SDX10 will continue though we will likely run out of stock before the next shipment arrives.

Thanks for you support
Bob


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## Oklahoma Wolf

Good to know. The SDX10 will always be the preferred driver for this design.

Incidentally, I have a new video I forgot to post:






That's both horns, but it gives you some idea on how these handle info below the designed F3. Remember, mine are also highpassed at 12Hz via the Reckhorn B-2.

Current number of these designs out in the wild is at 5, mine included. Everyone seems happy so far.


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## Oklahoma Wolf

Updating this thread again due the fact that I now have actual electrical impedance measurements for this beast. This will show how close I got to the model. I did a lot better on this one than my last TH design, I have to say. My dual Tang Band horn measures nothing like the model as far as electrical impedance.

Hornresp model:










Impedance measurement with phase:


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## robbo266317

That is impressive. It's always good to have the model confirmed and know you have done it properly.


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## Oklahoma Wolf

Thanks 

I have one more update - found a very small leak today. Here's the updated impedance measurement:


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## favelle

Insane build...impressive! CSS isn't far from where I live and I have been running a couple Trio12's for a while now, so maybe an SDX build is in the cards!!

Question though....does having the back end of the drivers sticking out into the "horn" affect sound quality at all? I do know that when I was making my ported subs, I was always told to keep the ports clean to avoid port noise and whistling.

Does the same not apply to horn configurations?


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## Zeitgeist

favelle said:


> Insane build...impressive! CSS isn't far from where I live and I have been running a couple Trio12's for a while now, so maybe an SDX build is in the cards!!
> 
> Question though....does having the back end of the drivers sticking out into the "horn" affect sound quality at all? I do know that when I was making my ported subs, I was always told to keep the ports clean to avoid port noise and whistling.
> 
> Does the same not apply to horn configurations?


Not really. It blocks some of the surface area, but relatively little compared to total size. Having a driver in path is common for horn designs.


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## Oklahoma Wolf

favelle said:


> Question though....does having the back end of the drivers sticking out into the "horn" affect sound quality at all? I do know that when I was making my ported subs, I was always told to keep the ports clean to avoid port noise and whistling.


Yes... that's the whole idea of the tapped horn configuration, or whatever else you want to call it. Use both sides of the diaphragm to contribute to output.

That said, you do have to be careful about choking the horn with the drivers. That was something I paid special attention to. You choke the horn with the drivers, it can cause all kinds of annoying noises; not to mention restrict the SPL output and increase distortion. Also, it's possible for the folds themselves to cause enough turbulence to ruin the sound. Too much air moving too fast around the bends gives you noises and distortion. Thankfully, I seem to have avoided that one too.

Me, I'm broke. That meant I had to be extra careful, because I had to nail it the first time. No do-overs for me. So, I left as much space under the drivers as I thought would be needed, and then I left a little more. I like to err on the side of caution, even if it ends up making the final box bigger than it could have been made had I pushed the limits a bit more.


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## DrDyna

I've been looking around for my next project, this looks pretty awesome. I've wanted a pair of monster THs to add to the collection.

I've noticed reading through the thread that a number of alternate driver possibilities have been mentioned and I wonder if anyone has put any thought into the TC Sounds Epic 10?

This project looks great though, so far, it's at the top of my short list.


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## Oklahoma Wolf

The Epic 10 won't work well in this design... you'd have to start from scratch.


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## DrDyna

Oklahoma Wolf said:


> The Epic 10 won't work well in this design... you'd have to start from scratch.


SDX10s it is then!


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## Oklahoma Wolf

Good choice 

Really, the SDXs are the only drivers confirmed beyond a doubt to work with the design. And you wouldn't get much if any more SPL from the TC Sounds drivers anyway. The design could be made a little smaller, but that's about it. There's really only so much you can do with a couple 10" drivers, and I really think I've gotten about as much out of them as I'm likely to get.


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## DrDyna

So, now that I've had a chance to go back and read through the whole thread, I did have a couple of questions about something you touched on, that these subs won't do music particularly well.

Could you elaborate a bit more?


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## Oklahoma Wolf

They'll do music just fine... just not as well as a tapped horn using more optimal drivers with a more optimal horn flare, like my older dual Tang Band design. There's a slight audible difference to me, but it's very slight. And since the drivers I used in the TB horn are no longer available, it's a moot point anyway.

Watched Project X with the two last week... there's lots of party music in that movie that uses subharmonic synths to drop the bassline an octave. The horns had no problem kicking me in the chest when needed, while at the same time rumbling away at high levels down below 20Hz until stuff started falling off the walls. Sounded excellent. And loud.

That said, in theory, the Seas L26ROY should sound a little better in this design. But, I haven't tried them and haven't measured them to know that they would work as well. And they're more expensive. It's up to you if you want to gamble with them. I'd like to get my hands on a pair of those to see how they do, but I'm broke. It's not happening anytime soon.


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## DrDyna

Oklahoma Wolf said:


> They'll do music just fine... just not as well as a tapped horn using more optimal drivers with a more optimal horn flare, like my older dual Tang Band design. There's a slight audible difference to me, but it's very slight. And since the drivers I used in the TB horn are no longer available, it's a moot point anyway.
> 
> Watched Project X with the two last week... there's lots of party music in that movie that uses subharmonic synths to drop the bassline an octave. The horns had no problem kicking me in the chest when needed, while at the same time rumbling away at high levels down below 20Hz until stuff started falling off the walls. Sounded excellent. And loud.
> 
> That said, in theory, the Seas L26ROY should sound a little better in this design. But, I haven't tried them and haven't measured them to know that they would work as well. And they're more expensive. It's up to you if you want to gamble with them. I'd like to get my hands on a pair of those to see how they do, but I'm broke. It's not happening anytime soon.


Sounds good, puts me at ease. One of my favorite things to do after a couple of beers is put on some Feed Me or deadmau5 and have a little party, I'm thinking these will fit right in.

I'd be happy to try the L26ROY but that'd blow my budget and I'd only be able to make one, plus according to the specs from Madisound, they don't look like their power handling is quite as rugged and I'm planning on hitting these pretty hard with an EP2000.

Once I get a long enough stretch of spare time and get everything ordered (so far I've only ordered speakon connectors and I don't want to order parts till I know I can devote some build time or it'll make me nuts) I'll throw up some contruction pics into the mix.


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## Oklahoma Wolf

Sounds good. One channel of the EP is more than enough to power one horn at 8 ohms each channel (2 total) or two horns at 2 ohms each channel (4 total). Because they'll be getting more than 350W each, it's important to highpass properly if you're going to hit them hard. My usual recommendation is a MiniDSP.

The design is excursion limited with both the L26ROY and the SDX10. If you give them enough power to blow the coils, you will have long since bounced them off the backplate and roached the drivers. But the EP4K is a good match for the design... one of these running in 8 ohms off each channel should keep most people very happy. One guy's pushing 200W to each of his and even that's more than enough SPL for him. I always suggest building another one if one at 400W isn't enough SPL. There's too much risk for not enough gain above that number.

deadmau5? I have Meowingtons Hax 2011 live on DVD. Not a challenge for the horns at all


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## DrDyna

Oklahoma Wolf said:


> The design is excursion limited with both the L26ROY and the SDX10. If you give them enough power to blow the coils, you will have long since bounced them off the backplate and roached the drivers.


Aha, this makes sense. I suppose the best way to do it then would be to wire them in series so each cab is 8 ohms. A miniDSP is a great idea for doing the HPF as it has the side benefit of doing a little room EQ as well.



Oklahoma Wolf said:


> deadmau5? I have Meowingtons Hax 2011 live on DVD. Not a challenge for the horns at all


Awesome, I love that dvd. You should check out this guy too:






Careful though, it starts pretty tame but takes off on some pretty nasty bass drops after about the 1 minute mark.


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## Oklahoma Wolf

Yeah, do 8 ohms unless you're building 3 or 4 of these.

Not worried about Feed Me. The horns can push 125dB at LP if I let them, and the room gives up before that point


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## Oklahoma Wolf

Hmm... apparently I posted this update to the wrong thread. Doh! I knew things were getting too hectic in this house. Mods, feel free to delete the other post. Sorry about that, folks.

Anyway... I wanted to do a quick update to the _proper_ thread with some bracing suggestions. If you do brace this horn, here's how I would currently do it:










Light colored wood is the vertical bracing, green is the horizontal bracing. Blue is removable horizontal bracing in the mouth... this will allow you to pull the brace out so you can install the drivers. I'd window the horizontal braces the same way the vertical ones are, just to tie them all together.

You don't have to do it exactly as I have... you can make it stronger as desired (like adding a removable vertical brace right at the mouth in front of the drivers, or corner bracing), but I wouldn't make it weaker. Don't add too much of it, or the response will deviate too much from the model. If you brace _nothing else_, get the mouth and throat segment done... in other words the areas on either side of the drivers. 1/2" plywood should be enough... that's all I used in my Tang Band horn. 

Attached is the revised Sketchup file.


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## Kgveteran

Well, its been three years.... Any new builds. My thought is four of these. Two up front corners and two in the back of the room. The room has a vaulted ceiling so i might fly all four in the ceiling corners..... Probably will enlist a couple structural engineers for this. Do you think i would lose anything doing this, other than my life if one falls Lol


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## Oklahoma Wolf

As far as I know, only two people at AVS other than myself have built these. I personally haven't felt the urge to do anything else... the two beasts still give me way more bass than I need. Not sure you would lose anything flying them unless they ended up too far from walls or corners, but if you're building four of them SPL shouldn't be a problem.


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## anup_modak

Are you willing to share your designs ?


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## Oklahoma Wolf

Plans are in my AVS thread. I haven't done anything since this design... there's just been no need to. This thing is a beast.

Edit - due to Photobucket nonsense, the pics in there may no longer be there. Will attach the folding plans to this post. These use 18mm plywood. Bracing should be added, but mine's been fine without it.


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