DQ 20 and LA woofers the same?

[Carlspeak]

A customer bought some DQ 20 woofers on Ebay and was surprised to find out they weren't Large Advent masonite types although they look pretty much the same on the surface.

Someone at Regnor told me the voice coils are different. How different? Does anybody know?

Customer would like to simply drop these DQ 20's which I've refoamed into his LA's but isn't sure what the outcome will be.

Looking for wisdom.......

[Pete B]

A customer bought some DQ 20 woofers on Ebay and was surprised to find out they weren't Large Advent masonite types although they look pretty much the same on the surface.

Someone at Regnor told me the voice coils are different. How different? Does anybody know?

Customer would like to simply drop these DQ 20's which I've refoamed into his LA's but isn't sure what the outcome will be.

Looking for wisdom.......

They probably look like these:

http://www.classicspeakerpages.net/IP.Boar...ost&p=72351

Don't know anything about the DQ20s.

Are they going into early LAs that were original with the masonite type woofer?

I'd offer to trade if I had an extra set of masonite types, do you think he'd be interested?

[Carlspeak]

They probably look like these:

http://www.classicspeakerpages.net/IP.Boar...ost&p=72351

Don't know anything about the DQ20s.

Are they going into early LAs that were original with the masonite type woofer?

I'd offer to trade if I had an extra set of masonite types, do you think he'd be interested?

Pete.

They not only look like those - they ARE those! The writing on them is exactly what's on mine.

I've posted at AK and the Yahoo DQ forums and can't seem to get a consistent answer.

I"ve run some impedance and phase curves on the refoamed woofers I have, but my impedance isn't right. It needs calibration.

However, I could get a close VOM impedance if need be.

The answer to your first question is yes. You say "IF you had some" on the trade deal. Do you have any to trade?

[Pete B]

Pete.

They not only look like those - they ARE those! The writing on them is exactly what's on mine.

I've posted at AK and the Yahoo DQ forums and can't seem to get a consistent answer.

I"ve run some impedance and phase curves on the refoamed woofers I have, but my impedance isn't right. It needs calibration.

However, I could get a close VOM impedance if need be.

The answer to your first question is yes. You say "IF you had some" on the trade deal. Do you have any to trade?

No, but they're fairly common on ebay and I could get a pair obviously.

I'm very curious about those DQ-20 woofers, want to measure the T&S parameters.

[Carlspeak]

No, but they're fairly common on ebay and I could get a pair obviously.

I'm very curious about those DQ-20 woofers, want to measure the T&S parameters.

I've done that with the impedance/phase plots I mentioned before via WT2 tester. All is not lost however, regarding impedance. I believe the readings I'm getting now with the bad calibration (need to contact software guy for help) are about 1/2 of what they should be. Haven't done the VAS scan yet. Here's what I have so far.

Look anything like LA woofer characteristics?

Ooops! sorry about uploading 2 of the same pics

[Pete B]

I've done that with the impedance/phase plots I mentioned before via WT2 tester. All is not lost however, regarding impedance. I believe the readings I'm getting now with the bad calibration (need to contact software guy for help) are about 1/2 of what they should be. Haven't done the VAS scan yet. Here's what I have so far.

Look anything like LA woofer characteristics?

Ooops! sorry about uploading 2 of the same pics

Hi Carl that Fs is rather high, it is hard to tell more since the calibration is off

and I don't think you did the Vas test. Cone mass is what you want to look at.

You could test them in the box and see what the Fc is, it should be about 41

as I think you know. I'd just use the correct drivers if it was up to me.

Fascinating that Advent stopped making those in about 1976, yet those are

from 1987. I wonder where they were manufactured?

[Carlspeak]

Hi Carl that Fs is rather high, it is hard to tell more since the calibration is off

and I don't think you did the Vas test. Cone mass is what you want to look at.

You could test them in the box and see what the Fc is, it should be about 41

as I think you know. I'd just use the correct drivers if it was up to me.

Fascinating that Advent stopped making those in about 1976, yet those are

from 1987. I wonder where they were manufactured?

I was told by Regnor (official DQ repair shop) that the cone on the DQ woofer is the same as was used on the LA. The cone isn't the difference. Regnor said the VC's were different be didn't elaborate. Maybe DQ bought up a large left-over inventory of frames and cones when Advent stopped production?

[Guest Audiomark]

Just re-foamed a pair of DQ20 woofers. They measure 27 hz, probably that would drop a little with some use.

Curious driver, 10 inch cone in a 12 inch chassis, fibreboard annulus making up the gap. I wonder why they did that?

[Pete B]

Just re-foamed a pair of DQ20 woofers. They measure 27 hz, probably that would drop a little with some use.

Curious driver, 10 inch cone in a 12 inch chassis, fibreboard annulus making up the gap. I wonder why they did that?

This woofer is a copy of the early Large Advent (LA) woofer designed by Henry Kloss. The story is told in the LA owners manual that HK wanted to have a very large excursion capability and could not obtain it with the normal 10" woofer frames available at the time.