Ultra Low Bass Sub?

[Yeha-Noha]

Hey guys, I'm thinking about getting a new 12" sub woofer driver for my DIY sub that I built about ten years ago to extend the ultra low bass (ULB) in my current setup. Right now it's just sitting in my living room doing nothing (see pic Smokey and the sub in my gallery). What I plan to do is add a third sub woofer to use with my dual PA 120 subs. Those have an f3 at 24 Hz. Thus the ULB sub will overlap the PA 120s a little but not their entire range. The LP crossover will be at 30 Hz. That's why I'm calling it an ULB sub to distinguish it from my main pair of subwoofers. The range above 30 HZ however is pretty smooth and well covered by the PA 120s. The ULB sub will handle just the lower octave from 15 Hz (f10) to 30 Hz.

What I don't know is will it be worth the expense ($170 for the driver) and the tiny bit of effort (cutting a 4.25" diameter hole in the front baffle for the port)?

Any thoughts?

[ssabripo]

you are not gonna get good extension and headroom with a 12", even a ultra high excursion driver with a hefty motor.

subsonic frequencies require lots of air movement to produce visceral output. If you really wanna do sub 20hz extension correctly, I would suggest a pair of high excursion 15, or better yet, a pair of 18"s like a Maelstrom X18, in a sealed enclosure, throw some good power and a L/T circuit to extend the low end, and you should be in great shape, and you can merge them with your PA's to make a really nice sub setup in terms of response and undistorted output.

a pair of Maelstrom's will run you $600 or so, a marchand bassis or DEQ2496 around $200, some wood/paint around $80, and a good amp (QSC PLX3402 or similar).

[Yeha-Noha]

Well, my idea was to limit the project to a $200 budget and use the same enclosure. I really don't want to go beyond those constraints. I have no desire to build another enclosure either which a 15" or 18" driver would involve. Plus there's the WAF. The wife loves the PA 120s. She'll tolerate my old sub box but nothing other than that. Those are good suggestions though. Thanks!

I could then just forget about going ULB and place it in the back of the room in the corner to work with my two subs in the front. That's plan B anyway.

[ssabripo]

Originally Posted by rwojtalewicz

Well, my idea was to limit the project to a $200 budget and use the same enclosure. I really don't want to go beyond those constraints. I have no desire to build another enclosure either which a 15" or 18" driver would involve. Plus there's the WAF. The wife loves the PA 120s. She'll tolerate my old sub box but nothing other than that. Those are good suggestions though.

I could then just forget about going ULB and just put it in the back of the room in the corner to work with my two subs in the front. That's plan B anyway.

i think that would be the best option at this point unfortunately. It may be a nice exercise to go thru for your own personal knowledge, and put a nice 12" long excursion driver and see what results you can get... I can already safely tell you pretty much what the outcome will be.

at $200 for the driver, you will realistically not touch good amounts of sub 20hz output.

[Yeha-Noha]

Originally Posted by ssabripo

i think that would be the best option at this point unfortunately. It may be a nice exercise to go thru for your own personal knowledge, and put a nice 12" long excursion driver and see what results you can get... I can already safely tell you pretty much what the outcome will be.

at $200 for the driver, you will realistically not touch good amounts of sub 20hz output.

I wonder if I could find out which driver the eD A2 300 sub uses. It can get down to 18 Hz. Perhaps, Elemental Design sells them separately.

[Chris7277]

I know SVS sells their drivers seperately...might give them a look.

My ultra 13 plays subsonic.

[erict]

Originally Posted by rwojtalewicz

I wonder if I could find out which driver the eD A2 300 sub uses. It can get down to 18 Hz. Perhaps, Elemental Design sells them separately.

http://www.edesignaudio.com/product_...ducts_id=782:D

[Yeha-Noha]

Thanks erict and chris for those links. Those look very promising and in my price range. After I get home, I run the speaker parameters through my java speaker design apps.

[Yeha-Noha]

That 12" Elemental design subwoofer is not going to work well in my box with a vented design. The Qts being 0.31 is way to too low and is more suited for smaller boxes like those for car audio. In fact these speakers are listed under their car audio products.

The SVS subwoofer driver is an upgrade for one of their subs. They don't give any specifications for the speaker parameters.

The 12" subs from parts express have more suitable Qts ratings ranging from 0.40 to 0.45 which are perfect for my 4.3 cu. ft. box if the Vas is in the 80 to 100 liter range. The Fs must be in the 20 - 25 Hz before I can get an f3 around 18 Hz to 20 Hz. So, it still looks like I'll end up ordering one of theirs.

Thanks for your suggestions though.

[Big Daddy]

You will not be able to find a better driver than Exodus Shiva 12" driver. Its Xmax is 26mm and can easily go under 20Hz in the right enclosure. I used one of these drivers in my cylindrical Hsu subwoofer. The magnet is so massive that I had to modify the box to fit it.

http://www.diycable.com/main/product...roducts_id=693


If you want to use a bigger driver, they have 15", 18", and 21" drivers. They have a 15" for $170.

http://www.diycable.com/main/default.php?cPath=24

[Yeha-Noha]

Yes BD, that Shiva X2 12" driver will do exceptionally well in my subwoofer box with the voice coils wired in series to give 4 ohms. My Dayton 1000W sub amp is rated at 4 ohms and has the built in 18 hz subsonic filter that Shiva recommends. The 26 mm max excursion is phenomenal. It'll do perfect with my 1000 W in 4 ohms amp.

I am going to give this driver serious consideration. It will exceed my budget by $50 with shipping, but worth it. That is one massive driver weighing over 30 lbs!

Thanks BD. You really rock!