Dahlquist DQ-10 Information - Design Discussion - Mods

[Pete B]

aroostookme wrote:

>I am looking for a schematic for the classic DQ-10's.

>Anyone have one or a place I can get one?

>Thanks

I've made some comments about the DQ-10 a while back here on this forum, and also here where you'll find the schematic:

http://www.diyhifi.org/forums/viewtopic.php?p=5673

While a few people e-mailed me off list, none commented on the public forum so I dropped the discussion.

Pete B.

[Guest wank]

Well, I've lurked long enough, I thought I'd actually register and comment after more than a year.

Nice to see at least the genesis of a board for the Dahlquists. Hopefully there will be some discussion and sharing. It's not really easy to find any info on these. Maybe some will come out of the woodwork.

I was a little confused by your linked thread, in that your second post seems to be much more negative about the DQ-10s than the first.

- What measurements do you have that would indicate ways to improve the speakers? Especially, any info on the .75 dome tweeter?

- Do you have the specs on the AD5060, and would a dome replacement be a better choice?

- If I recall, the volume of the woofer enclosure is very clost to the Large Advent (same stuffing too) - doesn't this limit replacement options to something similar? I don't know much about speaker design, but I wouldn't think the volume could support a 12" driver there.

-And wasn't the DQ-10 intended to go with a sub, so that low bass performance isn't much of an issue?

[Pete B]

Well, since people are so sensitive about their favored products I tried to make the first post positive. There was little response, so I just gave the honest comments in the second post. I do like the speakers for what they are, but they're far from perfect. Their marketing claims were rather optimistic which is a bit irritating, but they all do it.

Yes I have AD5060 specs.

No, dome is not better, larger cone is better.

Isn't the AR-11 an example of a 12" that works in about that volume?

Doesn't the DQ-10 have enough drivers already?

Yes one could add a sub, I think if one is cloning a better woofer

is the way to go, just my opinion.

I do plan to get to the DQ-10s someday.

Pete B.

>I was a little confused by your linked thread, in that your

>second post seems to be much more negative about the DQ-10s

>than the first.

>- What measurements do you have that would indicate ways to

>improve the speakers? Especially, any info on the .75 dome

>tweeter?

>- Do you have the specs on the AD5060, and would a dome

>replacement be a better choice?

>- If I recall, the volume of the woofer enclosure is very

>clost to the Large Advent (same stuffing too) - doesn't this

>limit replacement options to something similar? I don't know

>much about speaker design, but I wouldn't think the volume

>could support a 12" driver there.

>-And wasn't the DQ-10 intended to go with a sub, so that low

>bass performance isn't much of an issue?

[dynaco_dan]

Hi Pete;

I just went to that site, thank you.

Another great write-up by you.

[Pete B]

Thank you Vern, always nice to hear from you.

Pete B.

[Guest wank]

Gosh Pete, I didn't expect my questions to irritate you so. I'm just looking for objective ways to measure the weaknesses, and if/when it becomes necessary when a driver fails, to remedy those deficiencies. I've long believed that it is more important to know your weaknesses than to know your strengths. I made polite inquiries and took no shots, as your post on the other forum suggested.

Of course you are absolutely right - DQ10s are not perfect - but I've never met a perfect speaker yet. To be perfect you'd think it would have to have a perfectly flat response curve in any room with any amplification and would please everyone that heard them. None of those is going to happen. Personally, I think that if you like it - you like it, and if you like it - it's good and good enough. I'm more than comfortable with other people not liking gear I'm fond of or pointing out its objective weaknesses.

But 8 minutes (1:47p to 1:55p) seems an awfully short time to expect significant response and to then switch gears in your tone on a product. I guess that's the part that made me curious.

So, back to follow ups or refined versions of the questions I raised initially:

- Has anyone seen a response curve for these speakers? I'm guessing it drops off drastically around 45-50 at the bottom, and goes up 3-5 dB in the 6k or 8k range. What does it do up top? I've not been chased out of the room by the piezo.

- I asked if you were suggesting a dome because you said "if you want to stick with a paper cone" - sounded like not using a paper cone was a good idea.

- What happens if you pull that 8 Ohm resistor and replace it with a better 4 Ohm, or is it there for impedance reasons? For that matter, assume ignoring the piezo - how should the XO be designed?

- I assume the AR-11 IS a 12" in the same volume. Is it the same woofer as the 3s 3as, etc? I might have to try dropping one in. Right now my AR3s are doing subwoofer duty. Or I could find any other 12" 4 ohm that has an affinity for that volume - I'm sure there are a wide assortment of budget 12s that could do the job.

(Quick side note - since the Advent masonite woofer is a 12" basket, has anyone ever removed the masonite and re-coned with a 12"cone but the same motor?)

-Yeah, the DQ-10s have enough drivers. More than. I like 2-ways, like M100s, AR7s, Large Advents, smaller Infinities with the EMIT. But then, I'm not sure I'm able to correctly evaluate speakers, so 2-ways may stink.

If you do plan to get to the DQ-10s some day, feel free to stop by if you're ever in Indiana.

[Pete B]

I'm not irritated at all, sorry if it came across that way. Short yes, because often I take the time to answer and get no response in return, OK your different. Also, I'm much more busy with work. And, I don't have a pair of DQ-10s, yet, which limits how much I can do.

I'll say your observant about those times, that's good paying attention to detail. Those posts, were cross posted from another list, I waited days for responses as I recall, and there were some negative ones, which is fine, and I just offered my view of the negatives.

I've never seen curves for the DQ-10 and you ask some good questions. I'm curious as to how the .75" and the piezo horn interact. The bass might go a bit lower, the Advents should be about -2 dB at 42 Hz into half space re the woofers piston band, which is quite good. Like double Advents, I'd want more, or a better woofer. I'm not suggesting hacking up a DQ-10, thinking of something from scratch.

About paper cones, I have no problem with them and even prefer them over a poorly designed poly or metal cone. However, some poly drivers are outstanding, so for me either is fine paper or poly. Might want to stick with paper just to follow the original intent. I'm speaking here of replacements for the AD5060, not the domes which I believe are fabric. I suggest bigger because the 1.5" dome can come down low, so the 5060/replacement doesn't have to go high at all. A 6-7" makes more sense, especially since it's a dipole that needs a lot of VD.

You say pull the 8ohm resistor and replace it with 4 ohm, do you mean the woofer which might make some sense since it, in parallel with the resistor makes roughly 4. Yes, absolutely a 4 ohm woofer buys a lot, but the driver is inductive, so a zobel would probably be needed to keep the series connected midbass crossover working right. But the woofer would have to be matched in terms of voltage sensitivity so as to not overpower the rest of the system. A high mass long throw driver would do the trick and we have Advent woofer measurements to get the exact dB/2.83V sensitivity number.

I'd simulate the current series connected crossover, and then design a parallel type with the same transfer function to each driver. I reserve the right to provide better stop band attenuation which lowers distortion but should not otherwise change the tonal character.

Yes the AR-11 woofer is very similar to the AR-3, it's been modernized and probably has a few differences, many like the 3 better.

Well, I don't want to encourage hacking up a DQ-10, but you remind me that the Advent woofer is really a 12" so if you find one that fits - maybe it's worth a try. I do think that a 4 ohm 12" would be the way to go and yes there are many available, it would help if you calculated the internal volume. I'm also assuming for a clone/variant that the enclosure could be made larger/deeper if necessary. Yes there are some real nice budget drivers out there, not as easy to find a 4 ohm 12" that works in a small volume, but it's possible.

I do like 2-ways also, rather have a well done 2-way than a poorly done 3-way. I'm starting to want to hear stacked Advents with BSC.

Thanks very much for the invite but I don't get out to Indiana, I was about to say that in person, actually listening to some music is much more enjoyable than the bickering that goes on on these forums, not you by the way.

Don't know when I'll have time for the DQ-10s, lots of other projects as much as I'd like to.

Take care interesting thoughts and questions,

Pete B.

>Gosh Pete, I didn't expect my questions to irritate you so.

>I'm just looking for objective ways to measure the weaknesses,

>and if/when it becomes necessary when a driver fails, to

>remedy those deficiencies. I've long believed that it is more

>important to know your weaknesses than to know your strengths.

> I made polite inquiries and took no shots, as your post on

>the other forum suggested.

>

>Of course you are absolutely right - DQ10s are not perfect -

>but I've never met a perfect speaker yet. To be perfect you'd

>think it would have to have a perfectly flat response curve in

>any room with any amplification and would please everyone that

>heard them. None of those is going to happen. Personally, I

>think that if you like it - you like it, and if you like it -

>it's good and good enough. I'm more than comfortable with

>other people not liking gear I'm fond of or pointing out its

>objective weaknesses.

>

>But 8 minutes (1:47p to 1:55p) seems an awfully short time to

>expect significant response and to then switch gears in your

>tone on a product. I guess that's the part that made me

>curious.

>

>So, back to follow ups or refined versions of the questions I

>raised initially:

>- Has anyone seen a response curve for these speakers? I'm

>guessing it drops off drastically around 45-50 at the bottom,

>and goes up 3-5 dB in the 6k or 8k range. What does it do up

>top? I've not been chased out of the room by the piezo.

>- I asked if you were suggesting a dome because you said

>"if you want to stick with a paper cone" - sounded

>like not using a paper cone was a good idea.

>- What happens if you pull that 8 Ohm resistor and replace it

>with a better 4 Ohm, or is it there for impedance reasons?

>For that matter, assume ignoring the piezo - how should the XO

>be designed?

>- I assume the AR-11 IS a 12" in the same volume. Is it

>the same woofer as the 3s 3as, etc? I might have to try

>dropping one in. Right now my AR3s are doing subwoofer duty.

>Or I could find any other 12" 4 ohm that has an affinity

>for that volume - I'm sure there are a wide assortment of

>budget 12s that could do the job.

>

>(Quick side note - since the Advent masonite woofer is a

>12" basket, has anyone ever removed the masonite and

>re-coned with a 12"cone but the same motor?)

>

>-Yeah, the DQ-10s have enough drivers. More than. I like

>2-ways, like M100s, AR7s, Large Advents, smaller Infinities

>with the EMIT. But then, I'm not sure I'm able to correctly

>evaluate speakers, so 2-ways may stink.

>

>If you do plan to get to the DQ-10s some day, feel free to

>stop by if you're ever in Indiana.

[Pete B]

I've not checked the specs carefully or sampled them, but they're a bargain: http://www.ascendantaudio.com/assassin12specs.html

http://www.ascendantaudio.com/Images/Assassin-12-Side.jpg

Pete B.

[Guest wank]

>I'll say your observant about those times, that's good paying

>attention to detail. Those posts, were cross posted from

>another list, I waited days for responses as I recall, and

>there were some negative ones, which is fine, and I just

>offered my view of the negatives.

Ah - that explains it. I think tried to convey that on the other forum and my attention to detail didn't overpower my dense nature to get me to understand that. He said with a grin.

>I've never seen curves for the DQ-10 and you ask some good

>questions. I'm curious as to how the .75" and the piezo

>horn interact. The bass might go a bit lower, the Advents

>should be about -2 dB at 42 Hz into half space re the woofers

>piston band, which is quite good. Like double Advents, I'd

>want more, or a better woofer. I'm not suggesting hacking up

>a DQ-10, thinking of something from scratch.

Still haven't seen a curve, but I found published numbers that say:

Frequency Response: 37Hz - 27kHz +/-3dB

Efficiency: 86dB/1W/1M

Crossover Frequencies: 400Hz, 1K, 5K, and 12.5K

Which is interesting, however accurate it may be. Though I suppose you already knew the XO freqs. I'm surprised the XO from the woofer is that low.

I knew they were inefficient, and wow are they. They really start to open up at volume, but don't make superior low level speakers.

The 37 is a little lower than I expected for the -3dB at the bottom, and it doesn't tell the whole story in that it sounds like there's a peak in the tweeter.

>You say pull the 8ohm resistor and replace it with 4 ohm, do

>you mean the woofer which might make some sense since it, in

>parallel with the resistor makes roughly 4...

>Well, I don't want to encourage hacking up a DQ-10, but you

>remind me that the Advent woofer is really a 12" so if

>you find one that fits - maybe it's worth a try. I do think

>that a 4 ohm 12" would be the way to go and yes there are

>many available, it would help if you calculated the internal

>volume. I'm also assuming for a clone/variant that the

>enclosure could be made larger/deeper if necessary. Yes there

>are some real nice budget drivers out there, not as easy to

>find a 4 ohm 12" that works in a small volume, but it's

>possible.

I certainly don't want to hack these things, but I might have to think carefully about replacing the woofer - or at least giving it a try. Though I do like the sound of the Advent woofer. I'll measure and calculate next time I go through the nightmare of removing the grills. It might just be better to break down and get a sub.

>I do like 2-ways also, rather have a well done 2-way than a

>poorly done 3-way. I'm starting to want to hear stacked

>Advents with BSC.

Funny - the stacked Advents are my next project. They're here (1 walnut ALS, 1 utility "New"), but I'll have to clear some space (34" x 34" without stands on the DQ-10s is a lot of real estate) before I can do it, but maybe that gives me time to build your BSC circuit to compare.

I know what you mean about forum tone. This is the disadvantage of text. That's why I make sure to insert frequent self-deprecation. That way no one takes anything I say too seriously, whether offended or not.

[Guest aroostookme]

Hello.

Thanks for the DQ-10 schematic.

I love these speakers.

I own a set of ESL-57's and a couple of Snell A's and these all together are my favorites for listening.

The DQ-10's are like the Quads in another respect. I have seen online that some people are mirroring the DQ-10s so they appear to look like the doubled up Quads.

Does anyone know how to do this? If it sounds great? Pluses and minuses?

Also, are the speakers now using two amps and have their original crossovers or are these modded in some way.

It's a fascinating idea for a DQ-10 lover.

Anyone?