Exciting new subwoofer

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2008-07-23 4:57 am
I heard some really excellent bass today, and I would like to duplicate it.

My friend was crossing over from small Maggies to a single subwoofer at 80Hz. The sub was a stack of eight 5 ¼” woofers (equivalent to about a pair of 11” woofers). Each woofer was in its own sealed compartment. He equalized the heck out of them to get bass to about 25Hz. They had speed, impact, texture and no overhang. They also mated extremely well with his Maggies.
His cabinets were trapezoidal, with narrow fronts and wider backs.

Problem is, the woofers were the last of the Dahlquist production run bought up by Parts ConneXion and sold for about $8 each. AFAIK there are no more.

I would like to build a similar configuration, but I need some advice on what woofers to use (and where to get them). No, I don’t expect to get by for $8 each.
Thanks much
 
There have been a number of products like this in the marketplace. In fact, I worked on a subwoofer based on 4" woofers with THX, at my former employer.

You need something with reasonable displacement capabilities, as swept volume, not cone area is what you need to consider. Peerless SLS would be a good option. You can purchase these at madisound or parts express. Peerless 830946 6-1/2" Paper Cone Woofer Speaker 4 Ohm 264-1148
 
sealed Dahl's

I heard some really excellent bass today, and I would like to duplicate it.

My friend was crossing over from small Maggies to a single subwoofer at 80Hz. The sub was a stack of eight 5 ¼” woofers (equivalent to about a pair of 11” woofers). Each woofer was in its own sealed compartment. He equalized the heck out of them to get bass to about 25Hz. They had speed, impact, texture and no overhang. They also mated extremely well with his Maggies.

His cabinets were trapezoidal, with narrow fronts and wider backs.

Problem is, the woofers were the last of the Dahlquist production run bought up by Parts ConneXion and sold for about $8 each. AFAIK there are no more.

I would like to build a similar configuration, but I need some advice on what woofers to use (and where to get them). No, I don’t expect to get by for $8 each.
Thanks much

Hi there: Thanks for the post on the Dahliquests. Can you post the size of the trapezoidal boxes, (or a best estimate to use as a starting pont for a simulation)?I have 4 of the Dahl's and would like to try this out. The posted T/S parameters were: Fs=51.81, Sd=122.22, Qts=0.33, Qes=0.55, Qms=5.37, Vas=10.57L, BL=10.50, Xm=6.5, Le=2.5, Re=9.90, Imp=12ohms. (these are 6.5-inch nominal diameter not 5.25). Have you looked-up Partsexpress and looke for drivers of this size? Also you may want to look at some 6.5-inch drivers at Electronmavin.com with Fs about 37hz which should also work.
...regards, Michael
 
sealed Dahl's

Thanks, cbrunhaver. I'll check those out. I might have a problem hooking up eight on a side with their low impedance. Any ideas?...Michael, I will try to get the dimensions for you. The Dahls really sounded good.

Hi there T: The eight Dahl's in sealed enclosures seems to be an extnsion of Rod Elliott's Electronicly Assisted Sbwoofer (EAS) concept. While R. Elliott used a 15-inch driver, he stated: "or a larger number of smaller drivers". You may wish to google-up Elliott Sound Products, loudspeakers, subwoofer controller project P48A for history and a discussion "Extended Low Frequency" operation of drivers. ....regards, Michael
 
Dahlquist 7''

Michael (@post #5),
Dahlquist 17 cm/7'', ideal with VB = 15 L, FB = 34 Hz tunned. Best BR's internal volume between 11 and 25L. I guess this helps...
With a max. Vol. box tunned Dahlquist, VB = 25.0 L, FB = 35 Hz you have some control of the 30 Hz low frequency (F-5 dB free field). This can be the low effect that originally the OP is talking about. This and room gain. :cool:

They are great candidates for quarter waves too.
mh-audio Tapered Quarter Wave Tube
 

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Michael (@post #5),
Dahlquist 17 cm/7'', ideal with VB = 15 L, FB = 34 Hz tunned. Best BR's internal volume between 11 and 25L. I guess this helps...
With a max. Vol. box tunned Dahlquist, VB = 25.0 L, FB = 35 Hz you have some control of the 30 Hz low frequency (F-5 dB free field). This can be the low effect that originally the OP is talking about. This and room gain. :cool:

Michael,
The reference seemed to call for a bass reflex cabinet. I am looking to build a stack of small woofers in sealed compartments.

Also, do you know where I could get the Dahlquist woofers?
Thanks,
Chuck
 
Do your math... post your constraints

The reference seemed to call for a bass reflex cabinet. I am looking to build a stack of small woofers in sealed compartments.
Chuck, none of the drivers linked above is for a sealed enclosure. If that is your objective please post more details... (like the desired Volume/sealed for each driver, ~F3,...)
and much less...
...to get bass to about 25Hz

  • The GR RESEARCH M165X is asking for an ideal box of 30-60 L (BR), so do your math with multiple compartments/drivers.
  • The PEERLESS SLS 830946 between 3-10 L (BR), higher F3 close to 40/50Hz.
  • The TANGBAND W5-876SE between 2-9 L (BR) and much higher F3 close to 50/70Hz. :cannotbe: