# What is my best option for sdx15 with the bash 500?



## MatthewNixon

What are some good ideas to build if I use a sdx15 along with a Bash 500w plate amp? Any ideas?

Thanks


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## Mike P.

For Ht it would be 8 cu.ft. tuned to 20 hz with a 6" port 19.5" long. The default hi-pass filter on the Bash 500 is 30 hz, it would have to be modified to 13.9 hz according to the amps documentation. CSS will do it for you for a nominal charge.


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## dboff01

MatthewNixon said:


> What are some good ideas to build if I use a sdx15 along with a Bash 500w plate amp? Any ideas?
> 
> Thanks


If the 8 ft^3 optimal enclosure suggested by Mike P. is too large for you, here is a smaller enclosure I drew up for a 15" driver like the SDX15.

The enclosure is approximately 5.3 ft^3, tuned to 21 Hz, with the BASH 500 modded for an 18 Hz HPF. Slot port size is 1.5"H x 18.5"W x 27"D and a max port velocity of approx 17 m/s. It won't dig quite as deep as the 8 ft^3 but perhaps it is a more manageable size.

Steve


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## Mike P.

Nice design! :T


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## MatthewNixon

Awesome! Thanks guys!! Just what kind of info I was looking for! Huge kudos to you. Have either of you built either if these designs? 8^ft is a little big but I'll measure the room in case I can fit it. I'm just itching to build my sub!!!!!
_Posted via Mobile Device_


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## Mike P.

I built a 8 cu.ft sub years ago, my current HT subs are a pair of 10 cu.ft and a pair of 12 cu.ft. subs.


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## dboff01

MatthewNixon said:


> Awesome! Thanks guys!! Just what kind of info I was looking for! Huge kudos to you. Have either of you built either if these designs? 8^ft is a little big but I'll measure the room in case I can fit it. I'm just itching to build my sub!!!!!
> _Posted via Mobile Device_


I have not built the 5.3 ft^3 sub ... I am looking more at the enclosure below (for either Exodus Tempest-X2 or CSS SDX-15) with similar external dimensions but with a larger 2" port better suited to 1000W external amplifier. Note that the port velocity shown below (17 m/s) is for the Tempest-X2. 

I'm not sure when I will get to build as my wife is nagging me to renovate a bathroom first. My current sub is an Epik Valor (15" sealed with 350W BASH amp).

Steve


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## MatthewNixon

What would be some approx dimensions for the 8ft^3 box? Is there any advantage to a slot port besides easier to build? Thanks again!


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## dboff01

MatthewNixon said:


> What would be some approx dimensions for the 8ft^3 box? Is there any advantage to a slot port besides easier to build? Thanks again!


I ran a quick enclosure volume calculator and WinISD Pro. For a similar design style that I posted (slot port @ 2"H x 22.5"W x 35"D), a 28"H x 24"W x 32"D enclosure tuned for 19 Hz, after bracing (2 verticals + double baffle), slot port volume, and driver volume is approximately 8.5 ft^3, just to give you an idea. I didn't include the plate amp volume so I would expect with it you are approaching the 8 ft^3 size.

You should learn to use the Volume Enclosure Calculator here at hometheathershack.com and WinISD Pro and you can determine all these parameters and trade-offs yourself. Its well worth the time investment.

Steve


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## MatthewNixon

Can I use Winisd on a mac? Thanks


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## Mike P.

I don't think so. I can do any comparison you want.


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## MatthewNixon

I think I will order my sdx15 tomorrow from solen. Now it's time to decide on how much power.!


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## Mike P.

1000 watts would be nice if it's in your budget.


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## MatthewNixon

Is there that much of an audible difference between 500 and 1000 watts? I'm sure there is, but it would be great to be able to a/b the difference. Would 500 watts barely move the cone on the sdx15? I'm just asking because I spend time watching my speakers move! haha. Of course I'm always open for upgrades on the amp down the road. Thanks


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## Mike P.

Theoretically there's a 3 db difference when you double the power. The advantage of more power is you'll have some headroom for demanding situations. You'll have o decide now if the amp will be upgraded in the future as the port needs to be designed to handle the increased airspeed a bigger amp would cause.


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## MatthewNixon

Well I just took the plunge and finally ordered my sdx15!!! Can't wait! Now while building the enclosure, I have time to save for the amp. I'm leaning towards the dayton standalone sa1000 from css. For now I don't want to play with a pro amp (until I get more into this hobby!) and stick with something that will yeild great results with minimal effort. Down the road I'm sure I'll be itching to shatter my windows!! haha So would it be wise to spend little and play around with 500 watts in a vented enclosure or wait longer to save and play with a kilowatt? I like the sound of sealed subs from what I've heard at our local audio store (NOT BIGBOX). Keep in mind I'm making a HUGE step up from my puny 100 watt 10 inch sub i have now, so being modest now will still seem like a great step up in lfe quality! Thanks!:sn:


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## Mike P.

Is the sub strictly for music or for HT too?


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## MatthewNixon

Well I'll have to say that I watch tv most of the time, but the reason for upgrading is for the lfe in movies I watch that terrorize my current sub. I have a huge collection of vinyl records that I play very often too, so I do enjoy music. I don't need copious amounts of spl's (I think) but would rather have bass that sounds quick and not sloppy if that could be a description. Now having said that, I was considering starting with a sealed system and eq the lower bass, and if that didn't cut the mustard then go with a ported enclosure. That's a reason I am eyeballing the dayton sa1000, since it has the options to eq and turn on/off the high pass filter. Then again the Bash 500 amp may have more than enough "oomph" for the time being until I can get my hands into this more.

To answer you question! Yes I would say priority is for movies. Music a close second. Is there any desing out there that you can build that allows the user to block the port(s) for music? Maybe that would be ideal for me?

Thanks for your help Mike

Matthew


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## Mike P.

Here's 7 cu.ft tuned to 20 hz with two 4" flared ports 22" long each compared to 7 cu. ft. sealed. This was modeled with the Dayton stand alone which has a hi-pass filter at 18 hz.


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## MatthewNixon

That looks good. A quick question....if I am to build that model you just gave me (thanks by the way!) I can obviously plug the ports and cut the filter on the dayton and play around with placement of the sub if I feel like it right? I like the idea of that option, for now! Also when you look at the curve for the sealed configuration, can you make that curve closer to the vented curve with eq? 

Thanks again!

Another question, I need to get a router still, so I'm asking is it necessary to flare the port tubes? Is the difference only audible to a "bassophile" (ya made up word hehe)

I just can't WAIT to get the sub in the mail!!!!!!!!


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## MatthewNixon

Would a sub like this be too much if I wanted to build an aquarium stand? I really don't know what to expect once i get this set up!


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## Mike P.

You can't cut the hi-pass filter on the Dayton amp, it's set at 18 hz. 



> can you make that curve closer to the vented curve with eq?


Yes but at a price. If you boost a frequency 3 db it requires twice as much power. You would have to turn the amp down so it wouldn't clip at that frequency. End result is you have less overall SPL.

You need flared ports but not home made. Due to the port air speed of this setup you need "real" flared ports like these:

http://www.creativesound.ca/details.php?model=4FP

Fish don't like vibrations if my memory serves me correctly.


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## davidburn

Mike P. said:


> You can't cut the hi-pass filter on the Dayton amp, it's set at 18 hz.
> 
> 
> 
> Yes but at a price. If you boost a frequency 3 db it requires twice as much power. You would have to turn the amp down so it wouldn't clip at that frequency. End result is you have less overall SPL.
> 
> You need flared ports but not home made. Due to the port air speed of this setup you need "real" flared ports like these:
> 
> http://www.creativesound.ca/details.php?model=4FP
> 
> Fish don't like vibrations if my memory serves me correctly.


Mike is right, fish and sub-woofer's don't mix well at all. Separate cabinet next to a fish talk would be fine. I don't think your tank would last very long even with the best bracing and thickest timber.


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## MatthewNixon

Ok I just had to ask in case it's been done. Ya I wouldn't want to put my fish that kind of torture! 

Lastnight I did some testing with mycurrent cheapo sub and plugged it's port and didn't like the sound so I'm going to do a ported design for sure. Once I get my driver in my hands I'll be starting a build thread asap
_Posted via Mobile Device_


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## MatthewNixon

Ok i ressurected my old Windows computer so I can try using Winisd pro. It seems like evrything I put in the program makes the curves look good:huh: so I read the tutorial and still the same. Wow I need practise! Is 1000 watts good enough for decent spl's in my 1950ft^3 room? There are three doorways, one in the front wall, and two on either side. Hopefully I haven't been asking the same questions twice! Thanks


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## MatthewNixon

Well I just got my sdx15!! What an awesome looking driver. Can the sdx be pushed close to xmax with only 500 watts? Is there a design out there that can acheive that? I'm probably going to go with one of the designs you guys showed me in previous posts. Can't decide about how much wattage to pay for. I'm trying to keep this a cheap as possible for now with good results too. Can't wait!


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## Mike P.

> Can the sdx be pushed close to xmax with only 500 watts?


That would take a really big box to do so. 

500 watts with this sub in 8 cu.ft. tuned to 20 hz will give you excellent results.


​


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## MatthewNixon

What is the driver volume for sdx15? Thanks


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## Creative Sound

MatthewNixon said:


> What is the driver volume for sdx15? Thanks


Hi,

About 7 litres.

Bob


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## MatthewNixon

Ah thanks! Trying to get some box dimensions lined up! Since you don't have the ideal box dimensions still on your website, could you possibly give those to me? I've tried searching, and can only get the pdf files


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## Mike P.

If you're building 7 cu.ft. tuned to 20 hz there's a cabinet calculator in my signature. It takes into account the bracing, porting and driver displacement.


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## MatthewNixon

I just mean the ideal enclosure volumes, so I can use that link you showed me to see if I can come up with a box around 8 cubic feet that can work in my living room. Otherwise i may need to make some compromises and go with a smaller enclosure. For some reason I remember the recommended HT ported box size to be 6.5 cu feet.? I should have written that stuff down. Ok going to mess with that calculator! ttyl


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## MatthewNixon

So would a box 24 h by 20 w by 33 deep be 7 cu feet with the two 4 inch 22 in long flared ports? I think I have it right?!!!


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## Mike P.

You got it!


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## MatthewNixon

What is the acceptable margin off error when it comes to dimensions? I think i read that 10 percent is acceptable. So a 7.7 or a 6.3 cu ft box would still be in the same ballpark as a 7 cu ft box? 

Another question, the standalone 1000 watt dayton amp has a switch on the back to disable the subsonic filter (so they say...). Mike i know you said that the hpf can't be disabled on that amp. Isn't the subsonic filter the same as a hpf? I think that may be the amp I'm going to aim for, otherwise it will be the bash 500. I have time to decide because I'm trying to convince my wife that an 8 cu ft box wont look all that bad! Our room is only 1800 cu ft.

Sorry for all the new guy questions! I appreciate your answers. They're helping out big time!

Matt


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## Mike P.

10 per cent over the volume you need is a rule of thumb, but not 10 per cent under. I'm not aware of the amp having a switch to disable the subsonic filter (HPF). The manual would say so if it does. Go for 8 cu.ft. and the 1000 watt amp if you can.


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## paulspencer

8 cu ft looks ideal, but you can trim it down slightly. 7 cu ft tuned to 20 Hz is a good balance if a 2nd order highpass at 18 Hz is used. Keep in mind there is a close relationship between these factors:


box size and tuning
HPF settings
vent velocity
flare radius

Change one and they must all change. They all have to balance out. 

So let's start with 7 cu ft - not much different in performance to 8 but a bit smaller. We'll use a rumble filter as it will be essential to keep vent velocity down and excursion under control. So we tune it at 20 Hz and that bumps the response up a bit until we use the rumble filter and so we get a low -3db point at 21 Hz. We put on a 2nd order low pass at 80 Hz and the top -3 db point comes in at 80 Hz (it doesn't usually work this way). So here we have a nice textbook response. 

Now let's look at power. With 1kw we are safely below xmax, with 22mm one way peaking at 30 Hz. Now if we had a 3rd order rumble filter, the excursion would never be greater than this below tuning, but if we have the 2nd order that I've modelled then it's a bit higher at 25 mm but we're still safe because this is as much power as you are considering. It will never bottom out and in reality the excursion will be less due to increased stiffness of the suspension at high excursion that we haven't allowed for. If you use 500w then you give up 3db of output, or possible a bit less due to compression. That doesn't sound like much but in the bass range that is actually about 50% reduction in perceived output. Normally 10 db is perceived as double volume, but for bass the figure is only 6db. Having more power for a sub isn't just about loudness, but authority. You can't tell when the amp is clipping, but when you compare side by side, the more powerful amp + sub combination will sound as if it has more authority where the lesser is clipping significantly. 

About xmax - don't design a box to use all of it. Ideally we want to have some margin for safety. If you use up all the xmax often, then you need more subs.

Now let's look at the vent design. This is the hard part. Firstly, we need this to determine when it will chuff:

http://www.subwoofer-builder.com/flare-it.htm

Vent velocity with a 4" vent is a problem. With just one it gets up to 67m/s - there is no port that can handle that much velocity. The vent itself can only handle 20 m/s and if the flare has a radius of less than 50mm then it will chuff. To get the velocity down to 20 m/s we need 4 vents of this size, each over a metre long! This isn't very practical and we're better off using a bigger size that will let us have a higher velocity. 

So we step up to 6" PVC - now we can go up to 25m/s with two vents, but due to the size we actually only get 15 m/s so the flare only needs to be 20mm. You could achieve this with a roundover bit on 1" MDF. Now we have a very high performance vent, but the cost is that these two vents must be 1.2m long!

The alternative is to use a slot port which might make it easier to fit in the box, but also adds other challenges. The slot port is a bit more flexible in getting the desired area, as we don't have to jump up in size in segments, but can make it what we want.

You can relax the standard as most do, since this approach will get a sub that won't chuff even with sine waves. Real material is less demanding so you don't have to be quite this rigorous, however, the performance of a port goes down as velocity goes up. We want the velocity as low as it can be to avoid compression. 

If you are putting this in a corner, you could build a tall slender cabinet with the driver down the bottom and the vent up the top, ideally with no bends. 7 cu ft tuned to 20 Hz with a rumble filter at 18 Hz 2nd order and 1kw plate amp. All that together should work pretty well - 2 x 6" vents with a 20mm roundover on 1" MDF. If you make the box bigger then the extra volume will allow the vents to be shorter for the tuning point.


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## Mike P.

> Now let's look at the vent design. This is the hard part. Firstly, we need this to determine when it will chuff:


Collo's port chuffing experiments were based on a music application with his ear right next to the port. A percentage of air speed increase was then added for HT applications. Many subs have been designed with 4" flared ports with air speeds in the 25 - 26 m/s range. I'm not aware of one complaint about port chuffing from the listening position in a HT application.


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## paulspencer

Yes but it's also important to consider that compression begins long before the onset of audible chuffing. The absence of complaints isn't necessarily the basis of good design.


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## Mike P.

Compression can restrict output at high levels which I don't think is an issue from the results Ilkka's testing has shown. People build subs, sit back and enjoy the experience. The bottom line is the performance of the sub, just my opinion.


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## Ricci

Mike. You can see the effects of vent compression in Illka's tests. Most ported subs will exhibit some at the extremes. Even my 10" power port does this. It's not the end of the world though. 

The OP should be fine with a single 6" flared vent. If he's really concerned with the port overloading then he can step up to an 8" port or a slot port of some 50sq inches. That should do it.


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## Mike P.

Josh, I've seen the effects of vent compression in Illka's tests, I just don't think it's to big of an issue with a port speed of 26 m/s.


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## MatthewNixon

Thanks for the replies. Some interesting info. Since there's sooooo much information out there, how did you guys first decide on the design of your first diy sub? I wish I could have the opportunity to hear some of these subs to determine how much output I can be happy with for at least a few years! I'm definitely learning a whole lot! 

Am I interpreting the spl graphs right, because I see the 8 cu ft with 500w that mike showed me looks like it has the same spl's as some of the higher powered designs. So basically with a large box you can use less wattage and get spl's pretty high (with loss of headroom?), and if you design a smaller box, more wattage is needed to make up for less cu ft? 

The only way I can fit a 7-8 cu ft box in my room would be a sonotube sub. Unfortunately....

Thanks again.


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## MatthewNixon

I just checked again, and if you look closely on the back picture of the sa1000, there's a switch for subsonic filter (on/off). Correct me if I am wrong!


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## paulspencer

Personally I'd make the vent as big as possible within practical limits and as aerodynamic as possible. This may result in considerably more than is essential, but isn't that the whole idea of these kinds of subs? Things get easier as the vent gets bigger as the velocity goes down. Everything is less critical at lower velocity. As the velocity climbs up greater care is needed with every join and turn. The flaring also becomes more critical. To those who say "why" I say "why not!" 

Matthew, 
I picked up a few scraps of MDF and threw together a box on a Sat afternoon! 1 x 1 x 3 ft (70L) was good enough for a first version. I hooked up 1m of 4" PVC and started testing different flares, 18/36/72mm flare radius turned up on the lathe. The driver AE speakers AV12 was running at 46mm p-p with about 40m/s vent velocity. At about that time I had some discussions with Collo who then went on to make flareit.exe. I think it's a pretty good tool and I'd be reluctant to build a vent with a lower standard. Sure you can probably get away with it, depends how fussy you are.

The flares made a huge difference. At 40m/s the vent itself would already have considerable compression. We are talking about 144 km/h or 90 m/h. Each doubling of the flare was an obvious improvement. The 72mm radius flare was very big, you can see them here:

http://redspade-audio.blogspot.com/2009/08/diy-omni-loudspeakers.html

(Scroll down to the pic)

40m/s is extreme and suggests the need for a rumble filter and/or more vent area. 25m/s is still very high and about the limit for a 6" vent. There is a very interesting AES paper on vent design where they show that a vent ideally should have two flares, one which extends along the entire length based on a large radius, where the centre has the lowest CSA increasing out to each end, then another flare radius. This is beyond the capability of DIYers to build, although it can quite easily be done with a slot port with 3mm MDF curved into shape. As drivers keep offering more excursion and better motors, the design of the vent increasingly becomes something we need to work on a bit more.

Mike,
You've got me looking back at those sub tests. A quick look suggests a few are showing 3 - 4 db of compression around the vent tuning. Considering ~6db is subjective doubling in the bass range, that's a significant loss. I don't really have time to look at it properly now, but it would be interesting to look into it more, estimate from sims how much vent velocity to get some idea of measurements vs predictions in this area.

For this driver in an 8 cu ft box, I'd probably go with an 8" vent with a flare as big as you can make. You only need about 18mm according to flareit and the vent velocity is only about 17 m/s with a HPF on. That kind of flare is easily done with a roundover bit on the router and the bit will also come in handy for baffle edges if building speakers. In a big box like this that vent should fit without too much trouble. That would be my choice even though Mike is probably right and the smaller vent would probably be enough.


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## Mike P.

> The only way I can fit a 7-8 cu ft box in my room would be a sonotube sub.


So what's the maximum box size you can use?


​


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## paulspencer

or a tall rectangular box - cylinders waste a bit of space ... or a triangular shaped box ... or an IB style install ...

Like this:
http://www.sgraudio.com.au/products/sv/sv.html


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## MatthewNixon

Well, I'd like to keep the height to 24 inches IF it's going to end up being a piece of furniture (eg table between two couches). I don't have the room for much more than 20 inches wide, but the depth can be the measurement I have room for. I don't think that leaves much for a good ported sub.? I'm really upset because I'd like to build a sub that's going to satisfy me for a long time, but now I realize for that to happen I need to build it BIG! What a fight between space and performance! I'm actually been leaning towards a sealed build lately, only because I don't think I can fit such a big box to maximize the benefits of a ported design. I still have time before I decide on the amp (saving pennies)! 

I know this may be a stupid question but, I don't have the means of comparing the spl graphs to real world levels (my own ears), so what I am asking is how loud is 100 db when sitting near-field? Is it plenty of extension for most tastes? I wish I had a spl meter (will buy one in the future) to determine what my listening levels are, and attempt to compare what my sub is producing now to what I want and need. 

I'm terribly sorry if I'm dragging on the same questions on over and over again, but through all the reading I've been doing online and in magazines, I just keep teetering on the line between size and performance!! 

I've heard the paradigm servo 15 version 2. Is there a similar design that I could compare the my sdx15 to that sub? Then I can get a vague baseline to convince my wife for a big box(if I need to)! I enjoyed the sound of that sub (sealed). I know that the sound of each sub is completely dependent on room size and shape, but to compare a design like that sub (in an imaginary perfect room) would give me some sort of idea. 

Keeping cost down and simplicity are my goals since this is my first build from scratch.

If I'm asking questions that are already answered out there on the net, then I'd most appreciate it if you guys could point me to some more reading that can help. Otherwise, sorry again for the newbie questions! I like to ramble!!!!!!!

Matthew


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## paulspencer

Matthew, I think if you build a sealed box with that driver you'll get similar output to the Paradigm being a 15" sealed design. The Exodus driver probably has a bit more excursion, but the Paradigm has 1.2kw of power in a box of around 100L. That translates to (probably) a bit more midbass output from the Paradigm for music but (probably) a bit more low bass for HT from the Exodus if using a bigger box, as long as you can use the extra excursion. If the Paradigm has enough for you, then a modest sealed box probably does as well.

What if you were to build it tall and slim, put it in a corner and make it look like it's built into the space ie that it's a duct. You could even paint the same colour as the walls in the house. That can get around the size issue. You could even go so far as putting skirting board around the base to keep up the appearance of being built in!


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## looneybomber

Mike P. said:


> Fish don't like vibrations if my memory serves me correctly.


Neither do ant farms.


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## Mike P.

> but the depth can be the measurement I have room for.


Give us a number and we'll see what best suits your situation.


​


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## MatthewNixon

Give or take 36 inches deep. Does that sound like it could be done? Or should I just stick with a simple sealed design and wait until my ears need more bass to upgrade to ported??? Thanks soo much for the help!!

Does anybody make a plate amp that has no hpf built in? Or one that can be defeatable?


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## Mike P.

24" H x 20" W x 36 "D would give you a net volume of about 7 cu.ft if you use a slot port 2" high by the internal width (18.5") by 30" long. Shown with 1000 watts with a HPF at 18 hz compared to a 4 cu.ft. sealed with 1000 watts and no HPF.


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## Moonfly

If you would like a 3D model of the sub design you eventually settle on let me know, if I can find the time I'll model it to give you something to look at.


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## MatthewNixon

I think I may end up going with the elemental designs lt1300 plate amp to build a sealed enclosure now(only because I've never owned a sealed sub, and want to try one), and then eventually end up with a ported once I need more output. The lt1300 has a HPF at 20hz so down the road would that be ok with a ported sub design?

Thanks!

Matthew


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## MatthewNixon

Another quick question......I read somewhere that you shouldn't combine ported main speakers with a sealed sub and vice versa! Does that hold any truth?


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## Mike P.

> The lt1300 has a HPF at 20hz so down the road would that be ok with a ported sub design?


Yes.



> I read somewhere that you shouldn't combine ported main speakers with a sealed sub and vice versa! Does that hold any truth?


Not in my opinion.


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## MatthewNixon

Is there a design program to design a box that fits in the corner like the attached website shows? That design may work out in my room given the dimensions aren't too obtrusive. 

I wish it was easier to make a final decision!


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## MatthewNixon

Well I ordered the SA1000 standalone amp. Should be here soon. Is 3/4 inch plywood just as good as 3/4 inch mdf? I'm going to build the sealed version first and then build the box for a ported after so I can switch the driver to find what I like best. Can't wait!


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## Mike P.

As long as the plywood is void free. What box size sealed are you going with?


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## MatthewNixon

Im going to start off with a 3.4 cubic foot box as per css flat plans. That's just my starting point. It's my first build
_Posted via Mobile Device_


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## Mike P.

What box size will the ported be?


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## MatthewNixon

I think I'm going to build a corner box like the older post with the attached website picture shows. Id like to go big with that one. Basically a 45 degree back and a flat front with angled edges. How big should I go? I've got a corner in my room that can handle a bigger box. I can't model it with the design programs, but with some geometry I'll eventually get it. It could be four feet high. Perfect for holding a plant! I'm almost considering buying ANOTHER sdx15 for that. Gotta finish the first project though!! Any ideas? Thanks


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## Mike P.

> I think I'm going to build a corner box like the older post with the attached website picture shows.


Not sure which one you mean. Post a link.


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## MatthewNixon

Check out the link on page five that paulspencer gave. It has a picture of my idea. I can't post links on my phone which I'm using right now. I can when I get home from work.
_Posted via Mobile Device_


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## MatthewNixon

Click on the picture ofthe sv15. That's the design I'm talking about. Feasible??
_Posted via Mobile Device_


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## Mike P.

Ill wait for a link.


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## Moonfly

This one?

























and IMO, it is feasible, but not as straight forward as a typical box.


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## MatthewNixon

Ya thanks for the pictures. I was just retrieving them and saw your post. thats going to be the best design for my room


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## Moonfly

I dont see any problems with the design itself, but you need to ensure you get your calculation correct, ad that you build it well.


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## MatthewNixon

This is my crude design I drew up. So far the box is 11.5 cubic feet before taking into consideration the driver, braces and port(s) volumes. If someone could model it so I can find out my port sizes to put into the design. How many braces should I put in?

Thanks for the help


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## MatthewNixon

Nevermind, I guess the file is too large. I'll try myself to model it

My measurements are sor far: 

Height 4 ft.
The two back sides 2 ft.
Front baffle 2.12 ft.
Two small sides will be .5 ft


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## Mike P.

> So far the box is 11.5 cubic feet before taking into consideration the driver, braces and port(s) volumes.


Are you sure?


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## MatthewNixon

I'm pretty sure. Once I get the scanned plans I drew to work with this website, then I can show you. I divided the box up into geometrical shapes that I can measure with a little math. I hope I'm not too rusty with that!! One "shape" was the 6 inch by 24 inch by 4 foot box, and then the other is 6 inch by 1.5 foot by 4 foot. And the last is the triangular shape which I think is 2.12(base) by 1.5 ft by 1.5 ft(other two sides) by 4 ft(height).

Question: How do you wire the Dayton sa1000? I have the sdx15 wired fine, but before I hook anything up, I want to know how to wire the amp to bridge the two 8 ohm outputs (the manual doesn't show it).

Thanks!


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## Mike P.

The Dayton is a single channel 1000 watt 4 ohm as far as I know.


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## MatthewNixon

On the back of the amp there's four binding posts! Both labelled 8 ohms. I'm assuming one positive from the speaker to the positive of one channel and the negative from the speaker to the other negative on the other channel? I think thats how it's done. I don't know why it isn't in the manual


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## Mike P.

After deductions there should be about 10.5 cu.ft. Tuned to 18 hz with a 6" diameter port 18" long should produce the most output from the Dayton amp that has a hi-pass filter at 18 hz.


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## MatthewNixon

Any ideas on how to wire the amp?
_Posted via Mobile Device_


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## Creative Sound

MatthewNixon said:


> Any ideas on how to wire the amp?
> _Posted via Mobile Device_


Matt,

My take is that you wire the 2 voice coils on the driver in series which would give a 4 ohm load and then you hook up that one set of wires to either speaker output on the amp. It isn't 2 channels but would allow 2 8 ohm speakers to be driven with the same signal.

I sent this to you privately on Saturday but I guess you didn't get it.

Bob


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## MatthewNixon

Thanks bob, I agree with you on the wiring, but I emailed Dayton for a response. I'll post the diagram they send me for anybody else in the future. Thanks for the help!
_Posted via Mobile Device_


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## MatthewNixon

*Going to build a ported design now*

Hey guys, been a while since i built my first sealed sub and have been enjoying it. I did a search for a ported 8 cubic foot design using my dayton sa1000 amp and haven't had much luck yet. I see I have some dimensions for a 7 cuboc foot one, but I think it's time to go nice and real big! Ideas? or links to some designs?
Thanks


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## MatthewNixon

I want to build an enclosure that is tall with the sub being front-firing and the ports on the top of the sub. In the "projects" section here I couldn't find anything similar to what I want to build. I need a design that will complement my dayton sa1000. hpf @ 18hz, 1000 watts


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## Mike P.

Have you tried using the enclosure volume calculator?

http://www.hometheatershack.com/forums/enclosure-volume-calculator/


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## MatthewNixon

I'm going to play around with the calculator today. I'd like to find a design to be able to havemultiple ports come out the top of the box. Maybe a design with 2-3 four inch ports? Or two six inch ports? The calculations with the air speed etc. are where i start getting confused.


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## Mike P.

In 8 cu.ft. tuned to 20 hz with the SA1000 amp you'll need three 4" round ports each being 29 inches long. Maximum port air speed is 24 m/s peak which is fine.


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## MatthewNixon

I appreciate yoyr help! Does a 90 bend in the ports affect the air speed or sound? Should i i have aflare on the inside and outside of the port? Or just the outside? Ill post pics of the build once i start


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## Mike P.

Precision Ports are the best to use, they have flares at both ends. CSS in Canada sells them:

http://creativesound.ca/details.php?model=4FP

It's not a problem using elbows, 4" Schedule 40 PVC 90 degree elbows are about $4 each. To get the proper length you measure the port and elbow through the middle. And remember the port intake should be at least 4" away from any cabinet wall. (ideally)


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