DIY subwoofers - plans and ports?

McLoki

Where do you suggest purchasing parts for building a DIY subwoofer? I am mainly looking for the ports. (A 5" port based on the plans I am looking at)

Also is there anything obvious that I should know about port lengths. Many of the plans I have seen indicate a port that is longer than the box it is going in.

I assume that you just go to the end of the box and then angle the port (90 or 45 degrees) to get the desired length. Is there a certain number of degrees angle (for the turn) or number of turns that you should stay under?

What are your favorite sites for plans to build subs? (Mainly looking at boxes, not cylinders right now.)

I can go vented or sealed. I have the amp to run it (one of the channels from my cinepro) but need to purchase the actual woofer (looking at 12") and make the box. -

BTW - it is for 90-95% HT.

Michael

gatemplin

I have built a few DIY subs so I can try to help you out.
First, I recommend you do not try and design the box yourself. I thought I could and I was wrong. You will have better results copying a tried and true design.
Check out www.adireaudio.com They have some reference designs for their Shiva and Tempest drivers. I built the EBS Tempest. Some other sites to check out for parts are www.partsexpress.com and www.acoustic-visions.com
Consider some of the plate amps from PE and AV, 270W for about $150.

If you tell me what drivers you are looking at and the size of the sub I can help you out more.

Edit: Never mind about the amp comment, 500w good lord!!! :eek:

McLoki

I was thinking of the 12" titanic driver from Parts Express. (that is where the 5" port came from - http://www.partsexpress.com/pdf/295-404vented.pdf )

I was thinking of a 12" - 15" woofer and for the project trying to stay under $400.00 (keep in mind I can build the box and I already have the amp, so I just need ports, woofers, Speaker Terminals and some MDF)

Just as an FYI I am trying to compete with an SVS 25-31 CSplus (I can get one b-stock for $450) I would like to end up at least as good as that based on the price.

I think building a box subwoofer would be easier than trying to convince my wife that a 16" cylinder that looks like a cat scratching post gone out of control, would look good in my living room.

Anyway - I will appreciate any ideas oir advice that you can give me.

gatemplin

For that level of performance and at that price, I think you should step up to the Tempest. Check out the designs here
http://www.adireaudio.com/Files/VentedTempestApplications.PDF

The Adire Alignment is the most popular choice. As you can see the construction plans are very detailed and they were done by Dan Wiggins. It uses flared ports which produce no chuffing. If you choose to go this route, follow the design to the letter and you are guaranteed good results. Do some searches on the AA Tempest.

McLoki

Have you heard of anyone building this design before? http://www.adireaudio.com/Files/Monolith.PDF It looks promising and I should be able to build it for under $400. (169 for 2 PR kit and 150 for the tempest - rest for wood, fill, etc)

gatemplin

I'm sure it would be great, never heard of anyone building it. PR's have no advantage over a ported design except for a smaller enclosure. As you said before, to tune a sub low, the port gets longer than the sub. Thats where PR's come in. An AA alignment should be just as impressive and more efficient, cheaper but much larger. Some other sites to check out are the DIY section at home theater forum, www.diyaudio.com and to learn more about diy subs in general check out www.diysubwoofers.org

goingganzo

dude av15 kicks the tempest butt olny 50 more

gatemplin

Yes, the AV15 will displace more air per dollar, but as far as I know, you cant get them anymore. And some of the ones out there are Stryke rejects sold by TC sounds, according to John. Stryke has parted ways with TC sounds and John plans on building his own woofers but who knows when that will happen. Last I heard he was still working on getting the funds.

Of course there are other good drivers besides the Tempest, like the Blueprints, Titanics, DPL12, etc but they dont have the extensive and detailed construction plans available from the same guy who designed the driver. I think that is pretty important for a first time sub builder, but to each his own.

McLoki

I noticed that many of the plans from Adire are HUGE.... (2x2x4 or larger) Do the subs from parts express need a much smaller enclosure than the ones from Adire? (as the plans would suggest) Is this just a difference of opinion on design or are the subs that much different?

Based on this, should I always match the enclosure with the exact sub recommended?

Michael

gatemplin

You use the T/S specs for the driver (ie Vas and Qts) when designing an enclosure. Different designers have different goals for the different drivers. For example, the Tempest was designed for large, high efficiency enclosures. The Tumult was designed for small boxes and lots of power. The PE and Adire subs only look similar. The designs were not done by the same people.

You design a sealed box with a driver to have a specific Q. If the box is too big (low Q), it will be underdamped and you will lose output. If it is too small (high Q), it is overdamped and you end up with a boomy sub. A flat Q is 0.707 and that is what most want.
So in other words, the box needs to be designed with a specific driver in mind. Ported boxes are even more complex and there is an even greater need to design the box for the specific driver and application.

That is why I recommend the Adire plans. You pick the driver and Q you desire, then copy the plan that matches. The SBB4 is a 0.707 Q design which is maximally flat. The EBS is more efficient but has less overall output. The AA is a combination of both.

Edit: I recommend you download a copy of LSPcad from Adire and you can see for yourself the reponse of different alignments.

brody05

Dont just get hung up on the box and port. The amp plays a huge part in how good it will sound as well. I built a sub that was a copy of one I had and ran it with a much better amp and the home grown outperfomed the original by far, if you want to go lower in the freqs you will need plenty of power and current, I get 10hz out of mine (original was cut off at 16hz) and run it with 1200 watts of class A power. In the end you can also get drivers tuned to the port and enclosure at a specialist shop once built, if you copy one this wont be necessary providing you use the same drivers and internal dimensions.
Hope this helps

bknauss

Originally posted by gatemplin
Yes, the AV15 will displace more air per dollar, but as far as I know, you cant get them anymore. And some of the ones out there are Stryke rejects sold by TC sounds, according to John. Stryke has parted ways with TC sounds and John plans on building his own woofers but who knows when that will happen. Last I heard he was still working on getting the funds.

Of course there are other good drivers besides the Tempest, like the Blueprints, Titanics, DPL12, etc but they dont have the extensive and detailed construction plans available from the same guy who designed the driver. I think that is pretty important for a first time sub builder, but to each his own.

diysubwoofers is definitely a good site to start out with. Although diyaudio has a ton of amazing info, you usually need a degree in some sort of engineering to understand what they're talking about.

I also suggest hometheaterforum.com (the DIY section). The design software programs I would suggest looking at are WinISD, LspCAD lite for windows, and unibox (assuming you have excel). WinISD is generally one big error, but its easy to use and is a nice stepping stone to understanding some of the other stuff. The other two programs are more accurate.

cornerstone

try this link on for sizehttp://kahuna.sdsu.edu/~tucker/diyaudio/sonotube/

McLoki

Has anyone seen or heard this combo - http://www.adireaudio.com/Files/PR15andDPL12ComboKit.pdf

This is about the size I was looking for and looks to be able to hit about 20hz. Only questions is, will it be fairly tight/fast bass (for a sub anyway) and what level of output will I be able to hit with a 500 watt amp?

Should be able to build the whole thing for about $250 or so - I guess if I really like it and want more output, I could always build another one and run 2 of them?

I am still looking at other designs, just wondering what you think of this one? - simple build, no ports to deal with, cheap, etc.

Michael

McLoki

Here is something that should have been asked much earlier....

For someone that wants bass with the least amout of boom possible (fast/tight) and 90% use as HT - would you recommend a 12" or 15" sub or is there really that much difference between them? (are they close and does it just come down to the enclosure they are in?)

The 15" designs all seem to be HUGE compared to the 12" designs seem closer to what I wanted to try and build. (size wise)

This might really help me get to a good starting point....

Michael

gatemplin

The DPL12 combo looks great. I think someone at diyaudio.com built it.

The key to fast tight bass (good transient response) is low inductance, not mass and size of the woofer. Box and low frequency extension also have an affect.

Why not just squeeze a few more bucks out of the budget and buy the Tumult and be done with it. It's $500 shipped from acoustic visions. Put it in a small sealed box and it will have amazing ouput and still dig deep. Dan Wiggins has said it has the same clean output as about three Tempests! :eek:

McLoki

I did actually think of that, but cannot find any plans for the Tumult. What size box should it go in? If I want a basically flat response from 80-20hz should I go sealed, vented or PR?

I have seen a number PR-15/12" woofer setups that seem to vary by less than 2db from 20-80hz.

- I dont know if 500watts would be enough for the tumult anyway. It seems to want a 1000 or more. (I guess I could bridge 2 channels of my amp together - 1400watts @ 4 ohms RMS)

I have decided for my first sub to stay with the tried and true. (plans with a specific sub in mind...)

The EBS enclosure here http://www.adireaudio.com/Files/PRApplications.PDF - look at blue line resonse curve..... only a 12" woofer but damn.....

Michael

gatemplin

There are no published plans for the Tumult, and you are wise to stick with the tried and true. But, if you give Adire a call or drop them an e-mail they will help you design the enclosure for the Tumult to suit your tastes.

Any of those plans, Shiva, Tempest, DPL etc should give excellent performance as they were carefully engineered by Adire.

You are doing a good job with the research and I'm sure you'll end up with a great sub, or two.

bknauss

I've heard Adire is wonderful to their customers and non-customers alike. Dan Wiggins and Steve Kephart do a lot of rounds to visit message boards and give info whenever its needed.

Dennis Gardner

EBS designs will go the deepest but require alot of space. I use dual EBS 12" Shivas tuned to around 17hz. built into the bottom of a hideabed couch. 285 litres fit perfect in the base of the couch once the bed was removed. No need for a bass shaker or buttkicker here! It took 2-4 inchers at 19 inches in length to port it.

Powered with a 200 watt plate amp, I get more bass than my house can handle at times.

If 90% HT is your usage goal, I really think the ported alignments are better.

Just build it and enjoy!

DG

McLoki

At the risk of sounding like an idiot. What is the conversion factor for liters to cubic ft? (If a cabinet plan is for 142 liters, how many cubic feet is that?)

Thanks

Michael

BTW - I called aidre and they were very helpful. It sounds like the Tumult may be the way to go for my setup. (just plug and run in a 3cu ft. sealed box. Now I just have to figure out how to build one.)

I did find a site that looks awesome with the tumult. Now I just have to figure out how to reverse engineer what he has done.....

http://pages.infinit.net/remy/ (his enclosure is at the bottom of the page....)

Dennis Gardner

142 Liters is roughly 5 cu. ft.

The Tumult is such a monster that in a 3 cu. ft. sealed
box will give you tons of deep bass. Just make sure that you build the box sturdy enough to control the panel flex. Lots of bracing is in order.

gatemplin

That guy did a good job building that enclosure. All the panels are well braced. 85 L is about 3 cu ft. Check out the smallest sealed Shiva plans, maybe you can modify those for the Tumult too.

McLoki

Would most plans (modified to fit the woofer) at about 3cu. or 85 liters work? Do I have to end up at 3cu after taking into account the size of the woofer (65# worth of woofer) and all internal bracing or for sealed is close good enough?

Thanks again for all your help with these questions.....

Michael

Dennis Gardner

On a sealed box, 10% either way is considered acceptable.
With ported models, volume and port length is much touchier.

goingganzo

he is now hand bulding them now
http://yellow.mynethost.com/~bv126368/shop/catalog/product_info.php?cPath=21&products_id=37&osCsid=bf3d2b11e4133542cfa904eef8a08f24

check it out. i hope to be upgradeing stryke force. maybe by my birthday

McLoki

Do you have any links or sites listing enclosures for this woofer? (sealed, ported, plans, etc.)

It does seem like a good deal at $165 (limited time) but without the proper enclosure it would be $165 + alot of time wasted....

Michael

goingganzo

buld a big box tune it to 20 hz with dual 4 in ports your box size will determine your port lenth. lets say 150l box tuned to 20 hz with dual 4 in ports. i dont have program to dererman porth lenth but it will blow your mind

tryrrthg

If I remember correctly the original AV12 was suggested to be in around a 150 liter box with two three inch ports tuned to 18hz or something. I think Polk forum member Burdette built this design, but he doesn't chime in very often anymore...

goingganzo

thought we were talking about the av15 but box size will determane port lenth so get a free speaker moddleing software and it will help you pick a size of box and that will determan the port lenth.

tryrrthg

Originally posted by goingganzo
thought we were talking about the av15 but box size will determane port lenth so get a free speaker moddleing software and it will help you pick a size of box and that will determan the port lenth.

Yes, get WinISD Pro and play with it. But you can't just put a driver in a box and use the port length given. You have to make sure the port can handle the air speed so you don't get port chuffing. You also have to watch the driver's Xmax with the power you're running it with. Basically, you have to find a balance to all of these things to design a good sub.