Distortion from Dahlquist DQ-20...


I have a pair of mid 80's DQ 20's which have developed distortion from both speakers at anything above normal speech levels. When the volume is turned up on either the NAD amp or Denon receiver, there is a "scratchy" type noise that emanates, which becomes intolerable even at reasonable listening levels. I switched the wiring to a small pair of bookshelf speakers which sound fine. Is this a reconing issue or some other problem? I'm debating the worth of sending them to Regnar in N.Y. for a full overhaul vs. just buying a new set of speakers. Any advice is appreciated!
blitz72
Oops pasted in the same link twice, here's the DQ's again:

http://cgi.ebay.com/DAHLQUIST-DQ-20i-DQ-20-DQ20-10-FLOORSTANDING-SPEAKERS_W0QQitemZ5877272349QQcategoryZ14993QQrdZ1QQcmdZViewItem

Anyway - if you do want to replace yours, they come up on Ebay fairly often.
Whether they're 20's or 20i's (bi-wirable), you can isolate the woofers by removing the mid/tweeter fuse.
1. Play the offending music with those fuses out and if you hear the same scratchiness, it's likely that the woofers are your problem.
2. To be sure - REVERSE: Remove the Woofer fuses and replace the tweeter/mid fuses. If you hear the same scratchiness coming from the mids, it's likely your problem is NOT the speakers but somewhere else.
3. If it appears to be only the woofers, remove the grills and have a look at the foam surrounds. If they are torn, you can replace them yourself fairly easily. It's about a 4 hour job start to finish. IMO Regnar's prices (and their attitude) is total ripoff. If you want someone else to do it, pull the woofers and send them to MillerSound (215-412-7700):

http://www.6moons.com/industryfeatures/forbidden/forbidden_9.html

4. My guess is it's the woofer surrounds, because at their age, they're definitely overdue (atmospheric ozone breaks them down) - but the odd thing is that they both went simultaneously. Possible but unusual, unless you went from chamber music to '70's disco at high volume.

5. IMO, the DQ's are worth saving - once you're used to the sweet DQ midrange and imaging it's hard to find anything that's as nice in the recent crop of speakers. Either that or find a pair of DQ-20i's on Ebay so you can biwire. A friend of mine just bought a pair a couple of days ago:

http://cgi.ebay.com/DAHLQUIST-DQ-20i-DQ-20-DQ20-10-FLOORSTANDING-SPEAKERS_W0QQitemZ5877272349QQcategoryZ14993QQrdZ1QQcmdZViewItem

Hope this helps - if you need advice about doing a refoaming yourself, email me. I've done a number of them and can direct you to the source for PROPER surrounds - there are some being sold on Ebay that aren't good.
If they need reconing that would be something you could see, are the cones or surrounds damaged? If not it sounds like the voice coils are rubbing, not a good sign. I would have them checked out by a professional and be prepared to replace the bad drivers. Can you tell which drivers are making the noise? If they can be biwired it will help determine which driver is faulty. "Scratchy" is not a good sound to have, I think you will be buying drivers. If you liked the sound before the problem get them repaired. You might not be happy with anything less than "fullrange" speakers after living with the 3-way 20s. New 3-way "fullrange" speakers will not be cheap. Good Luck.