Small DIY subwoofer - AVS | Home Theater Discussions And Reviews
Baselworld is only a few weeks away. Getting the latest news is easy, Click Here for info on how to join the Watchuseek.com newsletter list. Follow our team for updates featuring event coverage, new product unveilings, watch industry news & more!


Forum Jump: 
 
Thread Tools
post #1 of 17 Old 10-09-2006, 05:47 PM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Has anyone built a small powerful subwoofer? Something that would be like a Velodyne Mini-Vee or Carver Sunfire? Are the parts too expensive to make it worthwhile?
BoomieMCT is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 10-09-2006, 06:05 PM
IDW
Member
 
IDW's Avatar
 
Join Date: Jan 2006
Posts: 69
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
You can make something very small and very powerful...but it's very expensive to do it...

What do you consider small? Here's one that's around 21"x20"x25" that should be a serious beast. It's not DIY....but uses available (and soon to be available) DIY parts....so could be replicated.

http://www.tcsounds.com/ananda.htm


if you're looking for something less ridiculous, a rythmik audio kit packs a great bang for the size and buck.
IDW is offline  
post #3 of 17 Old 10-09-2006, 06:09 PM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
To get small enough for "wife acceptance" for this room we're talking roughly a cube foot (give or take). I did notice the name brand ones were very expensive and was wondering if there was any edge going the DIY route.
BoomieMCT is offline  
post #4 of 17 Old 10-09-2006, 06:28 PM
IDW
Member
 
IDW's Avatar
 
Join Date: Jan 2006
Posts: 69
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
A rythmik 12" takes from 1.5 to 2 ft. 15" cube should handle it.

If you really need very small...you could go with a Dayton RS HO or MkIII 10" You could then go with a Rythmik amp with LT circuit built in. All told around $400-$500. I'm not really sure of the commercial options available at that price point...so can't comment.

The MkIII looks like it can model in a 15l box (half a cubic foot, give or take) with a sub .6 QTC, and can output around 95db before reaching Xmax at 20HZ. seems pretty solid as a super small box choice to me.
IDW is offline  
post #5 of 17 Old 10-09-2006, 06:31 PM
Advanced Member
 
jmiyake's Avatar
 
Join Date: Mar 2000
Location: San Jose, Ca. USA
Posts: 631
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
You can take this woofer:

Dayton 12" High Output

Build a 13" x 13" or 14" x 14" sealed cube and add an amp similar to this:

Bash 300w plate amp

VOLLA :D !

"Your love of the halfling's leaf has clearly slowed your mind."
-------------------------------------------------------------------------
My DIY Line Array Speakers
My current subwoofer project
jmiyake is offline  
post #6 of 17 Old 10-09-2006, 06:47 PM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Hmm, some possibilities there. I'd probably use a smaller cone or multiple smaller cones. How hard is it to build a sub with multiple cones?

Or use something like this I suppose.
BoomieMCT is offline  
post #7 of 17 Old 10-09-2006, 07:16 PM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,301
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Liked: 22
Quote:
Originally Posted by BoomieMCT
How hard is it to build a sub with multiple cones?
Find the appropriate sized box for a single driver and multiple it by the number of drivers that you want. Then make sure you wire the voice coils to achieve a load that your amp will drive. As you can see from the MSRP of the Mpyre subs, having 2 or 4 of them would be the same as having a less expensive 10" or 12" sub.

And we refer to them as "drivers", not "cones". Some sub manufacturers use a flat surface to move air, therefore no cone is involved.

-Robert
rlj5242 is offline  
post #8 of 17 Old 10-09-2006, 11:41 PM
Member
 
jacoviii's Avatar
 
Join Date: Sep 2006
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
as far as all my time in car audio i've learned that multiple drivers in a common box work together
so you do not just multiply the boxes/ports
thast were the box software come in to play 6 drivers two 2" port per driver is 12 2" ports
does not work the best
it will look like swiss cheese
it will work but take 10 more min's and it will sound better and go lower
you will also have more control over the drivers
jacoviii is offline  
post #9 of 17 Old 10-10-2006, 05:33 AM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,301
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Liked: 22
Quote:
Originally Posted by jacoviii
as far as all my time in car audio i've learned that multiple drivers in a common box work together
so you do not just multiply the boxes/ports
Yes, my answer was over-simplified. I know that there is a slight bit of efficiency gained by having a pair of drivers working together in a single airspace. Either way, it's still easier to build a sub with a larger driver. Just cutting a bunch of 6" holes would be enough of a deterent for me.

-Robert
rlj5242 is offline  
post #10 of 17 Old 10-10-2006, 06:15 AM
Advanced Member
 
jmiyake's Avatar
 
Join Date: Mar 2000
Location: San Jose, Ca. USA
Posts: 631
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Hmm, some possibilities there. I'd probably use a smaller cone or multiple smaller cones. How hard is it to build a sub with multiple cones?

Or use something like this I suppose.
To create the required impact of the low frequencies of a subwoofer it is better to use a larger driver. Of course it is a compromise when you want a small enclosure. However it is not the best way to go to using multiple small drivers in a sub, compared to one large driver. The larger driver will move more air and require less movement to create lower frequencies which usually mean less distortion.

For example, one 12" driver provides about the same area of four 6.5 inch drivers.
Also the 6.5" inch drivers will never go as low, using 4 of them does not make the drivers go any lower. Using the Dayton 12" HO as an example, one 12" costs $122, and the four 6.5" cost $119 x 4, or $475. The 12" moves just as much air, goes lower, and does so with less distortion.

Oh BTW...
Those 6.5" don't look too good.

pyre audio 6.5"

Look at that itty bitty tiny magnet surrounded by all that metal to look like there is actually a big magnet there. Ha... Ha... ROTFL....

19mm xmax with a driver depth of 3.5 total inches! I don't think so! And look at that wussy surround, naw, that driver has like 1 or 2 mm xmax.

Looks like a rip-off to me.

"Your love of the halfling's leaf has clearly slowed your mind."
-------------------------------------------------------------------------
My DIY Line Array Speakers
My current subwoofer project
jmiyake is offline  
post #11 of 17 Old 10-10-2006, 06:30 AM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by jmiyake
To create the required impact of the low frequencies of a subwoofer it is better to use a larger driver. Of course it is a compromise when you want a small enclosure. However it is not the best way to go to using multiple small drivers in a sub, compared to one large driver.
I understand that but in my living room there is literally no way to put anything larger. I have always wanted to make a DIY subwoofer and after failing to win a bunch of small subs on ebay (Sunfire, Baby Boomer, etc.) I figured I'd see if I could just make my own small sub.

If I can't figure out how to do a small driver like the 65X (which I'm still researching), I'll probably just go with something like this.
BoomieMCT is offline  
post #12 of 17 Old 10-10-2006, 06:39 AM
Advanced Member
 
jmiyake's Avatar
 
Join Date: Mar 2000
Location: San Jose, Ca. USA
Posts: 631
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The Triska sub seems like a good way to go.
But you will recall, I initially stated that a 12" Dayton High output can also go into a 13" or 14" cube.

Anyway you have some good options that people have listed here.

"Your love of the halfling's leaf has clearly slowed your mind."
-------------------------------------------------------------------------
My DIY Line Array Speakers
My current subwoofer project
jmiyake is offline  
post #13 of 17 Old 10-10-2006, 06:54 AM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by jmiyake
The Triska sub seems like a good way to go.
But you will recall, I initially stated that a 12" Dayton High output can also go into a 13" or 14" cube.

Anyway you have some good options that people have listed here.
Yeah, I was originally thinking of putting the biggest driver into the smallest box I could get away with. Then I decided my goal is actually to make it as small as possible and I started looking at smaller drivers. However, since I want the amp built in and the amps themselves only get so small I may take your advice and start thinking about larger drivers again.

Here are my goals:
1. As small as possible. To fit where I want it to go depth can't be more then 10" and I'd like to keep the other dimensions at or below 12" if possible.
2. This is for music, not HT. I'm favoring a sealed box right now.
3. Must keep up with my HTD level 3 bookshelf speakers.

So much work, so much fun!
BoomieMCT is offline  
post #14 of 17 Old 10-10-2006, 06:59 AM
AVS Special Member
 
crackyflipside's Avatar
 
Join Date: Oct 2005
Location: Miami, FL
Posts: 2,186
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
crackyflipside is offline  
post #15 of 17 Old 10-10-2006, 07:00 AM
IDW
Member
 
IDW's Avatar
 
Join Date: Jan 2006
Posts: 69
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I guess you want to determine what you're going for in terms of output, and then make compromises on it down to your given size. Because the "smallest size possible" is nothing...and you could certainly do with no sub at all if size is THAT important.

If you are ok rolling it off at 30HZ you can go with a much smaller driver and be ok. If you require 20HZ, you're going to need a bigger speaker.


Below a certain size/capability level you're probably throwing your money away. Just my 2c.
IDW is offline  
post #16 of 17 Old 10-10-2006, 07:05 AM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
The Rhythmik looks cool but it is still too big and for $500 I could buy a used small Pinnacle on ebay.

So, I'll add to my list of parameters.

1. As small as possible. To fit where I want it to go depth can't be more then 10" and I'd like to keep the other dimensions at or below 12" if possible.
2. This is for music, not HT. I'm favoring a sealed box right now.
3. Must keep up with my HTD level 3 bookshelf speakers.
4. Must be cheaper then what I can get on ebay (say the $300 range).
5. I'd like frequency response down to 30Hz, but don't expect anything below that.


Is there any advantage to having it be shallow, short but wide (like a tube on its side)?
BoomieMCT is offline  
post #17 of 17 Old 10-11-2006, 10:15 AM - Thread Starter
Senior Member
 
BoomieMCT's Avatar
 
Join Date: Jul 2006
Location: Fairfax, Virginia
Posts: 378
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
So I did some research and played around with some of the design speadsheets on diysubwoofers.org. To meet my size goals I pretty much found out that a sealed box isn't going to cut it. Larger drivers also require larger boxes and more $$$. For my first subwoofer I don't want to get too expensive (consider it a learning experience).

Here are my top two so far - both are passive radiator designs. Each have about 12-14 liters of internal space (allowing me to make them small enough for my needs). Each has a peak SPL output of about 100 dB. I have attached my frequency plots below.

Parts for the Mpyre design will run me about $260. The Tang design is about $97.

Now, I have never designed a subwoofer before. Does anyone have experience translating this theoretical performance to the real world? Also, are there any tips or pitfalls anyone would like to share with me? Also, I have a bit of experience working with acrylic - is there any reason clear acrylic would make a bad enclosure?
BoomieMCT is offline  
Sponsored Links
Advertisement
 
Closed Thread DIY Speakers and Subs



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off