Dahlquist DQ-20 help

Superbengosh

New Member
I just picked up a pair of DQ-20’s for $100 off of CL. The price was dropped from $350 because one speaker did not sound as good as the other according to the seller. They look great by the way and I did not demo them. I was thinking they need to be recapped and $100 bucks is just a few happy meals, so I grabbed them.

I got them home and hooked them up to my McIntosh MA 6200 which I use to stream music from my iPhone via a HLLY DAC. I plugged the speakers into my amp making sure the red went to red and black went to black. The DAC is plugged into AUX 1. The iPhone is plugged into the DAC via the headphone port. When I try to play music I get static over what sounds like crystal clear music. This “sound” eventually cuts off.

Where do I begin to fix this? Any suggestions for a repair shop in LA? Any help would be appreciated.
 
Well I will say you did very well for yourself! What you describe isn't coming from the speaker, is this from both speakers? Forget the DAC for now, feed a CD signal into it.
 
Yeah, I agree, if you don't have a CD player, just plug the output from your phones headphone jack directly into the amp. Do you have any other components you can test with, like a tuner or a turntable?
 
Thanks for your interest in helping. I removed the dac and plugged straight into the amp. This substantially improved one speaker but not the other. I have no other components.

The speaker that sounds the better of the two still has static and the sound comes on after about a 15 second delay. The worse speaker I am suspecting has a problem with the woofer. The static is much worse but maybe because of a bad woofer. The sound comes on right away with that speaker. I am going to try different speaker cables later tonight. Any suggestions for a repair shop in LA? I figure I need to recap both speakers and reform the one woofer - might as well do both woofers I suspect. By the way, if you cannot tell, I am a complete newbie with no soldering or electrical skills.
 
Very odd that a speaker would not make sound as soon as power is applied to it. Are you 100% sure your amp is fully functional? Try swapping the two speakers to the opposite amp channels (you can just swap leads where they connect to the amp, rather than moving speakers). If the problem follows the speaker, then it's the speaker. If it says on the same side, it's the amp or something else.

A channel that takes a few seconds to come on, or only pops in after cranking up the volume a bit, is a common problem with amps and preamps.

Also when you're checking for odd sounds, use a paper towel tube or something similar to listen to each driver by itself, to make sure each is playing, and where the static is coming from.

Scratchy and staticy sounds can also come from bad connections or corroded/dirty contacts. Or internal breaks in cables. Wiggle or slightly turn your cables and connectors a bit when it's happening to see if you find a bad spot. BUT be careful NOT to unplug and plug in cables completely when things are on and turned up, or else the big thumps can damage speakers.

Edit: You already have the Mac and DAC, do you have other speakers already that work 100%? If so it is probably not your equipment and cables, but it's still odd that the one DQ20 didn't come on for a few seconds.
 
Have they been refoamed? If not they will need it. I've never heard a misaligned speaker making that noise but you never know
 
Speakers do not make static bad connections and electronics do. Rubbing voice coils make noise, but not static. If you have no experience, get some help, those speakers are too good to mess up!!!!!
 
Pio1981 - Yes, they have fuses - two fuses each. I was going to order them from Dahlquist. would the speakers have any sound if a fuse was bad or the incorrect fuse?

FreddyMan - I don’t want to touch them. I am looking for recomendations in the LA area for a good repair shop.

I would like to take a look to see what I have under the hood. Is there a way to remove the grill covers withou destroying them?
 
Check fuses for proper type and rating, replace if necessary and clean the ends if not.
 
You don't have to get fuses from Dahlquist. If they are the right rating, and they are still good, leave em alone. If they are burnt, there will be zero sound, and you can replace with standard fuses the correct rating from the hardware store.
 
Ok, so I changed the old, frayed, and spliced speaker wire that came with the speakers and was able to clear up some noise. It seems what I thought was static is more of a slight buzz when music is playing and is accentuated on the beat. I think it’s a vibration coming from the woofer. That’s the good speaker. Have not tried the bad speaker yet as I assume it has the same issue with the woofer only more advanced. I am guessing reforming is in order or rebuilding.

Questions:
1. How do I remove the speaker grills to visually inspect the damage? Is the replacement fabric easy to install? Is it easy to remove s woofer?

2. Does anyone have a recommendation for a repair shop in LA where I can have the woofers evaluated and reformed, or sent to Dahlquist for rebuild?

3. Is it better to bring the whole speaker to a repair shop and let them evaluate and repair? I will probably want to recap when I fix the woofers.

4. How much should I invest in these before I scrap them maybe save them for parts and get a working pair? I paid $100 and I am very pleased with the cabinets. So cosmetically they are very good.

Thanks for all your help
 
The rear grills come off first, then the side screws are removed and the fronts should come away, iirc.
 
Thanks, Pio. One last observation. I just tested the worse of the two speakers with the new speaker cable. The buzz is significantly worse than the other speaker but curiously the volume is much lower than the other speaker. There is some sound coming from the tweeter, mid, and woofer. It is just not as loud as the good speaker. Any ideas?
 
If all the drivers are playing, then I agree on refoaming the woofers, and recap that old crossover before doing anything else. Bad caps, drifted resistors, etc. can cause low volumes from drivers.

I know Orange County Speaker used to do refoaming and reconing, have never used them, but if they are still in that biz it might be a start.

Other CA dwellers may not be seeing this thread so you may have to search the forum and/or post a request for speaker refurbishing services and include the location in the title so everyone sees it.

Definitely a pair of speakers worth putting some $ into considering what you paid for them.
 
If you don't mind pulling and shipping the woofers, I recommend Bill LeGall at Millersound. Bill is the best in the business, when it comes to speaker refoaming. Cheap too.

Millersound

Good luck.

Oh yea, DQ-20's like tube amps. Awesome sound. I've heard them on conrad johnson and Audio Research all tubed systems, and it was some of the best sound I've ever heard! :)
 
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