Behemoth Loudspeaker Project

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I'm working out a plan to build a pair of behemoth loudspeakers mostly with parts I have lying around. Becuase of this, I know I'm not going to get true audiophile sound, but since the drivers are here doing nothing, I don't mind. Perhaps it will turn out to have "frugal-phile" sound. :D This is basically a pair of real thumpers I can use for parties and such.

The plan so far:

I've got 8 Axon 6S3 6.5" drivers and Axon 4 T1S 1" tweeters. The upper portion of the speaker will consist of 4 of the 6.5" midbasses and two of the tweeters, in a ~2cu ft sealed box, with some woofers yet to be purchased to fill out the bottom end. For simplicity's sake I'm likely to use this crossover ( http://www.zalytron.com/Schematics/gerXO.jpg ) with another 16 or 24 db/octave crossover for the subwoofers.

I was looking at the Ultimate PS10 subwoofer (parts express part number 292-780) for the bottom end. They're designed for car use, and probably don't have the greatest sound. They do have good numbers for a ~3 cu ft vented enclosure with low frequency response and rather good SPL, though. Plus they're relatively inexpensive ($58 each). Two of them in series would hopefully give me enough volume to match the upper end without significant attenuation. Any alternative ideas are welcome.

Because of the rather bad low-end response of the 6S3's, I'll probably pick a crossover to the subs at > 100Hz, which is very much less then ideal.

I am interested in any comments or especially suggestions on the project. I'll be sure to post a few photos of the monsters when they're done.
 
Preliminary look of the thing.. I realize MTM doesn't work so well unless the drivers are as close together as possible, but this is the only asthetically pleasing look i can come up with. Perhaps I should do wwtwwt from bottom to top so there is wider dispersion. The circles in the bass bin are ports, of course.
 

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Hrm..
Reconsidering the woofers. Do I really believe a $60 car subwoofer is going to sound good?

Now searching for < $150 per speaker options that have good bass and fairly high SPL (92dB+)

Possibility: Peerless 831727 CC 10".. Too bad its 8 ohm. I could always ditch half of the midbasses and tweeters, make it a 4ohm speaker and use two of the peerless drivers, though. 3 cu ft enclosure with 2 of them tuned to 22Hz looks good, about 2dB extra bass with an f3 around 40Hz. 3dB of bass boost could give an f3 of almost 30Hz. That coupled with a bit of room gain is pretty respectable bass.

Thoughts?
 
Subs in your price range that you might like.

http://www.acoustic-visions.com/subdrivers.html

Just follow that link. I personally have purchased 2 of the Adire Tempest drivers but have not yet built cabinets for them due to a bad back and having had my fourth back surgery on the 31st of December. Kinda put a kink in my plans to build any speaker cabinets for a while. None the less, take a look and see for yourself. . A lot of Very nice subwoofers all on one page.

Hope that this helps a little.
 
Ex-Moderator
Joined 2002
Ignite,

There are a few ideas that come to mind with the combination of parts and the basic design you’ve posted.

The first thing I thought of was the Pass El-Pipe-O. The 6.5” drivers will work in a relatively small box. Take a look at what Tom has done with sono-tubes in this thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7709
My thought is to mount the MMTMM in the front baffle like Tom mounted his array, but put a thin box on the baffle inside the tube to house the mids. The 10” bass speakers would be mounted in the “base” as you’ve shown (although I would have one woofer on the front and one on the side), but it can be tuned as Mr. Pass did for the El-Pipe-O. The sono-tube used by Tom would instead be open on the top (hence the boxes for the mids).

Here in another of Tom’s threads dealing with El-Pipe-O type designs
http://www.diyaudio.com/forums/showthread.php?s=&threadid=9030&highlight=line+array+sono

Another thought was to use a single tweeter on the front and one on the rear of the sono-tube. This will also help with the height issue. Mounting one of the woofers on the side will also help lower the MMTMM to listening level.

Here is a Seas 10” woofer from Madisound. http://www.madisound.com/
CA25RE4X @ $54.50 ea.

I know it sounds kind of complicated, but I think it may be easier than building your enclosure as you’ve shown it.

Those are my thought,
Rodd Yamashita
 
AUDAX HT240G0

If you need two 4 ohm drivers to make an 8-ohm bass bin, use a pair of the Audax HT240G0 woofers from Parts Express. They look good. They don't plumb the depths the way a true subwoofer would (covering the range from 49-1150 Hz) but they go down at least as deep as a B@$# Acoustimass module, and since you're just lookng for thumpers, the Audax 4-ohm woofers I just listed should do you well. They will handle a lot of power and move a lot of air (double-stacked magnet structure) so your search for the big boom could end here if you want it to.

Another option is the Dayton Titanic drivers, but they may be more than you are willing to spend on a bass woofer.
 
My brief thought on the project are as follows.

MMTMM, with the T at the correct height for your ears when seated. Roll off the two outer Ms with a LPF at a frequency where the system will work as a D'Appolito still. Dunlavy, Montana, ProAc amongst others do this. One choke/channel will do.

I guess the Axons will work down to about 100Hz. If so, position the woofs at the sides of the enclosure, near the floor, in push-pull. Couples the bass to the floor well, increases putput, and the PP arrangement can reduce cabinet vibration, especially if you use threaded rod to link the driver's chassis. The woofs should be in a seperate enclosure.

The 12"Titanics would probably be a good match/value.

IME, car drivers are crap. Avoid.
 
First of all, thanks for all the comments.

The one thing I certainly want is separate bass bins. I move around a few times in a year, and having separate pieces is much easier to move around.

BAM, DIY subwoofer projects gave me a taste for the low bass, I want to get it if I can. Actually, I had looked at those specific drivers when considering this project. They're an option.

I had considered the titanic subwoofers, but they're a bit costly for the job. I do, however, have a tempest and 250W plate amp kicking around. I could puchase another tempest and amp (more then I want to spend, really) and bi-amp the monsters. It does mean gigantic bass bins, though.

I'll have to meditate on my options for a bit.
 
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