Opposed dual driver sub woofer.

[tade]

I have obtained a discarded helium canister of dimentions one foot in diameter and one foot in hight. giving it a volume of about .7 cubic feet. i intend to have a whole fashioned in each end to mount a ten inch DVC sub.
The goals of this project are:
For two opposed drivers to cancel vibration.
To have a large radiating area in a small space, for big sound.
To sound good.
To be inexpensive.

I plan on using Goldwood ten inch DVC drivers because they are cheap, and i have had good experiences with them.

The inspiration for this project came from B&W's compact sub.
http://www.bwspeakers.com/index.cfm/fuseactio,n/products.models/label/PV1

Does anyone see any potential difficulties with this plan as far as resonance, ringing or other coloration? i have scoured the internet for information on calculating values for dual driver sub woofers and have been unsuccessful. Any ideas?
Thanks guys!

 

[BassAwdyO]

As long as you cross over low, you should have no problems! I made a sub enclsoure out of a beer keg once, Still have it as a matter of fact. Cutting the speaker hole was sure a pain in the rear though!

 

[bwbass]

i have scoured the internet for information on calculating values for dual driver sub woofers and have been unsuccessful.

No problem, just double the airspace for a single driver box.

You might consider inverting one of the drivers (fire it into the canister and leave the basket exposed) and reversing its polarity to cancel suspension nonlinearities and reduce distortion while you're at it.

 

[tade]

sounds encouraging.
bwbass, if i invert one of the drivers, i should still get goo bass off of the back? will i have to worry about "port" noise around the basket?
well, those are probably foolish questions, and considering the small amount of money i intend to spend, i will build away!!!

Ill post pics as soon as i have em.

I intend on using a plasma cutter for the holes. it will either work really well, or not at all!

Thanks for the advise, and i am sorry for my errant and poorly though out replies. my mind is moving faster than my fingers!!
Thanks

 

[tade]

pic of B&W pv1

i realized thatr the link i had posted was one to B&W's general site. i hate it when people do that to me, so i appologize to you. Here is my sub's role model:
http://www.audiorevolution.com/news/0204/02.bw.gif

 

[audio-kraut]

dual subwoofer: isobarik loading. Google with that name.

 

[CBFryman]

why not have both drivers baskets facing out....you will gain even more volume for a lower enclosure Q....

 

[mike.e]

Copying a design concept for the sake of it,isnt a good idea.Instead study and learn about compromises and characteristics in audio so that you can design or get something decent.

Cheers

 

[audio-kraut]

Copying a design concept for the sake of it,isnt a good idea

No, but when the design - introduced by linn - makes sense - why is it objectionable to incorporate it into ones own design? My compound loaded subs go down to within -3db at 20Hz, using a back to front vented design that was propagated in speaker builder in the late '80s.

Very clean, non boomy and accurate bass reproduction.

 

[planet10]

why not have both drivers baskets facing out....you will gain even more volume for a lower enclosure Q....

If you want to really get the Q down, you go for a push-pull, push-push isobarik design using 4 woofers -- it requires the sane net volume of a single driver.

dave

 

[tade]

great advice friends! I am still gathering information, but i will sure keep you informed!
peace