# DIY software



## Exocer (Apr 19, 2006)

Hey guys. I would like to ask everyone which is their favorite program to model their drivers in? Right now, my favorite program is Unibox (actually, a cool excel file). It seems hella accurate and is more than helpful, with a very simple user interface. Currently Unibox is aiding in the designing of my 2nd enclosure for a Rythmik Audio DirectServo kit. This one will be a vented enclosure tuned to 20hz. Check out the graph thus far


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## Exocer (Apr 19, 2006)

I accidentily deleted the rest of that post...at it was Long too :laugh: Ah well, Just wanted to mention if anyone needs help using unibox I am here to try and help. It'll take a little while to understand the graphs, and to understand how to convert from the metric system to ours and vice versa. But with help from google's conversion feature you will be suprised how fast you can design speakers :T


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## Sonnie (Apr 11, 2006)

Gee, I'm glad you understand all those lines... they make me drunk. :dizzy:


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## JCD (Apr 20, 2006)

If I remember correctly, Unibox is for designing subs?

One quick question (note -- I'm a rank amateur at speaker design) 
How can you come up with a SPL for leaks? Wouldn't you assume leaks=0?

Also, what other programs have you tried? The only one I've really played with was WinISD.

JCD


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## Exocer (Apr 19, 2006)

Sonie, LOL.
Jcd,I haven't tried any other programs.Well I did open winisd and it confused the poo out of me. Probably chose a bad time to try and understand the user interface. But I definitely know Unibox can be used to design more than just subs. I've actually modeled up an MTM speaker with two dayton da 175 7" drivers (Some dude was generous enough to send me two for free) and things looks pretty good with a 3" port. 

There are three choices of leak options in unibox to simulate output in situations where there will be: no leaks, minimal, or minor leaks. The program derives the output for leaks automatically based on variables I don't even know and which option of the three i mentioned previously you've chosen. It is nothing more than theoretical data that accounts for little or barely any change in the overall frequency response in most cases.

Jcd, you're a rank amateur at speaker design...maybe you can give me a few tips?


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## bobgpsr (Apr 20, 2006)

I started out last Feb with UniBox and modeled this:










But I added a lot more bracing thereby cutting down the internal volume. Still got a good listening position plot (using a LinearX M31 cal mike with TrueRTA software) of the result:









The top trace was the result of smoothing to 1/6 octave and shifted up 10 dB.

The Tumult sub was tuned (as measured with close mike) to 15 Hz:









This is my downstairs basement system and I do not have a BFD there. Thankfully it is fairly flat, but I want to get the new BFD that Sonnie is pushing for to use with this. Then I will use REW and MIDI like I did upstairs with the PC-Ultra and old BFD.

Bob


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## Exocer (Apr 19, 2006)

That tumult is a monster. Puts my Rythmik driver to shame. How big is your listening space bob?


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## Sonnie (Apr 11, 2006)

I just thought I was drunk... I think it's past that.

I might (read "might") learn a little something from you guys.

I've heard of people using that Tumult in there cars before... totally awesome sub.


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## bobgpsr (Apr 20, 2006)

Exocer said:


> How big is your listening space bob?


Around 7000 ft^3 now. It is a full basement room. I knew I needed something extreme to try to fill it with decent SPL. That is why I went with the 15" Tumult plus two 18" PRs. I drive it with a Mackie M1400 pro amp that gives 1400 watts bridged into 4 ohms. Got up to 110 dB SPL using a 30 Hz sine before the circuit feeding the Mackie popped.

The nice thing about the Tumult is its very low distortion of 2% @ 13Hz 102 dB SPL as measured with this:








Just a bit of a SWAG looking at the second and third harmonics and the table in the TrueRTA help file.

Bob


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## Exocer (Apr 19, 2006)

Awesome job bob! For me to move that much air, I would need about 2.5 Rythmik servo kits ****. Somewhere down the line when my listening space is larger than 10'x13' i'll upgrade to a second Rythmik kit. I haven't really decided if ported is my cup of tea yet...may go with PR's like you. How is transient response effected by a PR allignment? Would you say it is an improvement over ported but not quite as good as a sealed allignment?


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## bobgpsr (Apr 20, 2006)

Actually transient and group delay response is supposed to be worst for PRs over normal ported. But once you tune well below 20 Hz, say 15 Hz, I can't see how it matters for music. You don't hear it anymore, just FEEL its effects. :dizzy: The big advantage to my mind, of PRs is the very low tune with absolutely no port resonances, no port noise or port distortion. Of course you have to stay well within the linear Xmax of the PRs to keep distortion down.

Bob


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## Exocer (Apr 19, 2006)

Got it! So PR's must be for all out HT buffs looking for nothing but the best extension without all the downsides of ports. Sounds like your project is comming along smoothly, or is it already complete??


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## bobgpsr (Apr 20, 2006)

Exocer said:


> ...or is it already complete??


Well :blush: it is glued and working. But not outside finished (kind of a Jack Gilvey look).
Been enjoying it anyway since it is in an unfinished basement since I verified its mechanical and electrical performance. Thinking about testing it outside with Ground Plane (GP) measurements. Need to line up a laptop (from my son) and adequate electrical power for the pro amp (I think I need a 20 amp service and extension cords).

Future plans are to pull the PRs and driver to sink the bolts properly through the outer part of the included rubber gaskets. Doing a proper lining of the enclosure interior wall with dampening fiber (may not be able to tell if that really helps), doubling up the 12 gauge wire inside. Doing a roundover on the Baltic Birch corners with the router. Sanding, staining and sealing. Lots of little things to do. Fortunately no rush.

Bob


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## Exocer (Apr 19, 2006)

No rush here either! my first enclosure is far from done. Last I've done is glue everything up and go over the edges with a flush trim bit. I still have to paint it and am thinking about gluing some interior re-inforcement for the rear part of the enclosure. The rear seems to fail the knuckle rap test while the front doesn't. It's only 1 measly layer of MDF, while my front is 2.25" thick..I may glue some small MDF slices to connect the rear wall with the closest circle brace in a few places. Hopefully that helps...


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## Danny (May 3, 2006)

http://www.diysubwoofers.org/prt/ Is an excel spreadsheet with many features if anyone finds it helpful. Give me a yell if you need help with it


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## Exocer (Apr 19, 2006)

Danny, cool. I'll check it out.
When/if you get and chance swing on over to the member introduction, let us know a little bit more about you  Welcome aboard!


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## Exocer (Apr 19, 2006)

bob, my enclosure edges are sorta "rounded" because of sanding. Would it be possible to still apply veneer or is painting my only route now?


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## bobgpsr (Apr 20, 2006)

Exocer said:


> bob, my enclosure edges are sorta "rounded" because of sanding. Would it be possible to still apply veneer or is painting my only route now?


Hmmm...stiff veneer? Might be a problem IMO but I am not experienced with this. Might best be asked over at HTGuide in the DIY section. steve nn seems to be the expert.

Bob


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## Exocer (Apr 19, 2006)

Yeah it'd definitely be a problem. Looks like i'll be buying a can of spray paint...or maybe go with some good Truck Bed Liner. At this point I may nix the vented enclosure Idea. I am enjoying the sub again as is (sealed). Maybe a project for the living room (where no critical listening occures) would be a good place for a vented sub, it'll need the increased output.

ANyway, I am still a bit unclear about how the amount of air a given driver can push @ a given input power will effect the FR of the design. Does a higher Sd x (2(xmax)) value always equate to higher SPL when compared to a driver with similar efficiency fed with the same amount of power?


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## Brian Bunge (Apr 21, 2006)

Man, if Steve's an expert at veneering then what does that make me? 

I've been veneering for about 5 years or so and have gotten excellent results veneering around rounded corners. You could technically still veneer the cabinet if you actually rounded over the edges with a router and at least a 1/2" roundover bit. That's assuming you only round over the edges running one direction (either all the vertical edges or all the horizontal edges, but not both). Otherwise, you are probably better off just painting the enclosure.

Concerning your question about Vd, if drivers have similar sensitivities but one displaces more air, then it is capable of producing higher SPL's.


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## bobgpsr (Apr 20, 2006)

Nicely answered Brian. I had not hung around HTGuide long enought to know better. :huh: 

Bob


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## Exocer (Apr 19, 2006)

Well good news bears! May go Vinyl afterall...but that would have to wait a long long while! I don't even own a roundover bit for the old Ryobi yet :laugh: 

And thanks for confirming my theory about Vd. I've been modeling only 12" drivers in unibox lol no wonder they all look so similar. :T


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## Brian Bunge (Apr 21, 2006)

Bob,

Steve and I go back a ways so I had to take the opportunity to poke fun at him! 

Exocer, did you say vinyl? Just the thought makes me shudder. I'd honestly rather use wood veneer and contact cement any day of the week over that stuff.

Concerning router bits, I've found the best place for router bit both from a cost and performance standpoint is www.mlcswoodworking.com . They have a great selection and the prices can't be beat!


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## Exocer (Apr 19, 2006)

Good question...Definitely used the wrong word there. I meant to say veneer :R
Just what I needed, cheap quality bits. Great post Brian.


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## Brian Bunge (Apr 21, 2006)

Thanks!

Oh, and my one and only choice for veneer (10 mil, paper-backed): www.tapeease.com


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## Exocer (Apr 19, 2006)

Since i'll have an extra receiver lying around as of a week from now, I may as well use those Dayton Da 175's I have lying around to build a pair of MTM mains. This is what I am thinking about doing.








Haven't decided on a tweeter yet. Also if down the road I decide to buid a center channel it would preferably be a WTMW design. Has anyone seen an WTMW design with the Dayton Da 175's? I do not even know if one can consider this driver a Woofer or a Midwoofer but I guess that depends on its application and crossover used?








NHT driver next to two DA 175's


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## Brian Bunge (Apr 21, 2006)

Well, Parts Express has a kit using that driver in an MTM configuration and a Vifa aluminum dome tweeter. There's also a design on the PE Project showcase using these drivers along with the 5.25" drivers and a Vifa soft dome in a MTMWW tower and an WTMW 3-way center channel. Both of these designs are sealed IIRC.

I built a variation of the MTMWW towers with the aluminum Vifa tweeter in ported enclosures and they have very very good bass. I also built a center with the same drivers. 

Here are the towers in figured cherry:










Here are my dad's in ribbon mahogany:










And here's his center:


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## Exocer (Apr 19, 2006)

Doh, i forgot about those MTM designs...They even have kits ont he PE site with these exact drivers...Too bad the kit is4ohms. I could go as low as 6ohms with Onkyo receiver.

I definitely haven't seen that WTMW center though. That seems right up my alley.


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## JCD (Apr 20, 2006)

Holy moly Brian, those are beautiful! :hail: 
Did you veneer the outside yourself? 

The obvious next question is how do they sound?

Sorry if I'm hijacking a thread..:blush: 

JCD


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## Sthrndream (Apr 21, 2006)

Those really do *pop* Brian...if you could build a couple hundred cabinets a week...man...we'd have to talk...

Tom V.
SVS


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## Sonnie (Apr 11, 2006)

:yikes: Good gorgeous amighty! You really made those? Amazing!

I agree.... you could sell those Brian... you should start your own speaker company.

"Bunge Speakers" :yes:


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## Exocer (Apr 19, 2006)

How selfish of me...So wrapped up in my own project I failed to see the beauty in those speakers :duh: Job well done Brian, and if you'd like to help me build mine i'll pay for your ticket over to NYC :laugh:

Edit:If you guys haven't already seen check out his matching sub in the Guide to DIY sub box design thread as well.


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## Brian Bunge (Apr 21, 2006)

Thanks guys. I appreciate the compliment. As a matter of fact, these are a pair or speakers that I built for a customer (I also have a pair of cabinets in birds eye maple). My dad and I used to build custom speakers and subwoofers for customers when I was living in GA (some of you guys may have seen my website). I will probably do it on the side again (getting my woodshop setup in my garage here in FL) but it's hard when everyone wants something for nothing or are used to a handful of available finishes from someone like Tom and the guys at SVS but want you to go all out with something completely custom as far design, finish, etc. and still be competitive with the SVS' of the world. Not an easy undertaking, let me tell you!

As far as the sound, they have a nice flat response (no BBC dip) and decent midbass punch for a 3" driver. But they're really best used with a subwoofer and crossed over around 100Hz or so. They work quite well with a small 8" subwoofer. I've done full 5.1 systems like this with only the 3" driver running full range and the sound was very good. The tweeter adds some nice top end to the sound and I much prefer this design.


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## Exocer (Apr 19, 2006)

Heres something I thought about persuing before getting sidetracked into the Nat P's


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## Brian Bunge (Apr 21, 2006)

Your tuning is too high (60Hz?), which is what's giving you that peak in the response. I think 21L tuned to 35Hz or 28L tuned to 30Hz both look much better if you want to use this driver in a ported enclosure.


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## Exocer (Apr 19, 2006)

Yeah, that is one reason I scrapped that design. I have a few other variations of that design with larger and smaller enclosures. The Dayton DA175 itself isn't efficient enough for me. Ultimitalely i'd end up with a similar sensitivity as my current sealed bookshelfs, the whole point of this project was to build a more efficient speaker to be friendlier on my not so powerful amp. Also, listening loud is a major priority 

Edit: Brian I'll need you to take a look at my shopping cart over @ PE regarding the Natalie P crossover. It can be found over at HTguide's Natalie P sticky. I might've gotten some extra capacitors or left some out...


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## Brian Bunge (Apr 21, 2006)

Well, then you should build a nice 3-way tower using them, the 5.25" driver and a tweet. Like my MTMWW or the one posted in the PE Project Showcase. Works great with my dad's entry-level Sherwood Newcastle receiver, has great bass, and plays plenty loud.

I'll take a look at your BOM.

EDIT: I looked at your PE order and responded in the thread on HTGuide.


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## Exocer (Apr 19, 2006)

I read ur response  
And I could see why the drivers would go plenty loud in those configurations. Makes a lot of sense.


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## Exocer (Apr 19, 2006)

My Nat P's









I've ordered my BOM yesterday. I decided to use the bypass .22uF Dayton foil and film cap in addition to the Solen 1.0uF cap to make the C 11. Also decided to go with Mills resistors since I could afford it. I haven't decided whether to buy the Dayton 1.0cu.ft. enclosure or build my own. If building my own is the only option i'll go with Baltic Birch


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## Brian Bunge (Apr 21, 2006)

I've not used the PE enclosures but I have seen them in person and can tell you that they are absolutely gorgeous and well worth the money. But I really like building my own cabinets.


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## Exocer (Apr 19, 2006)

Brian Bunge said:


> I've not used the PE enclosures but I have seen them in person and can tell you that they are absolutely gorgeous and well worth the money. But I really like building my own cabinets.


You're **** good at it too :T

thanks for looking over the BOM.
This is my bootleg crossover sketch


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