Hi thanks a lot for the valuable advice I have the feeling that a very wide dispersion in an usual domestic room can be a problem
I was looking at some monitoring speakers and i see that lenses and felts around tweeters are quite popular
Clearly i listen perfectly in the sweet spot I tend to prefer a controlled and limited dispersion
For sure Mr Dahlquist has made a great project Very challenging indeed However the latter models have been 3 way ... the dq 30 and more
Less drivers used i mean I dont know the rationale behind the decision of reducing the number of drivers But could be for a easier integration between drivers ?
First of all I should have said that a 4 way -or 5- combines good dispersion with driver's integration, or perhaps I should have said nothing since I'm not the most knowledgeable around here, but anyway, here is my humble opinion. Although you could achieve a very nice dispersion pattern with a 2 way system using a tweeter crossed at 1kHz, a 1" dome does not compete a 8" mid driver down there. It is the transition between drivers' sizes that determines the integration. All that provided that you won't mess phase integrity with a non optimal XO network... It is a challenge, no doubt. Another thing I have found empirically is that beaming and the resulting sweet spot is more like forced sound rather than controlled. It's not only about the missing soundstage dimensions, it comes with distortion and details loss. Room interaction is another thing. Treatment, lenses, all work as well as box-less or baffle-less designs.
Hi thank you very much indeed for the very valuable advice.
I don't want to sound too emphatic but I could say that the dq10s were my first love at first sight (in hifi of course)
Never before that day had I experienced the so-called virtual 3D soundstage listening to speakers
However I wonder if all this complication is really necessary as I can't help it note that later models were all 3-way except the smallest one the dq8 only 2-way
I don't know if anyone has ever been able to compare the old and the newer models but it would really surprise me if a later model sounds worse than an earlier one
I'm no crossover expert but I would try to crank the Philips midrange (a really good component) up to 3kHz and then finish the range with the dome tweeter taking away the dome mid and the piezo driver (I've never really understood the use of the piezo driver. Seems like a surplus to me)
Old xover cuts > 400, 1.000, 6.000, 12.500Hz
New xover cuts > 400 and around 3 kHz ... and stop
Another option could be to ask the woofer to do all the job up to 1kHz (i am quite sure it can as it was used in the famous Advent 2 way ) and then using the dom mid and the tweeter only conserving the cut freq at 1000 and 6000 (maybe lowering 6kHz to 3 or 4kHz. Any good tweeter around can cover decently from 3 to 20kHz)
I've never listened to the DQ-10. It is what members here are stating about this holographic soundstage that gives me a clue about their design principle. Cut drivers before they start beaming and move gradually from one cone size to the next. Any chance I have guessed wrong is not unlikely. 
The choice of drivers is a matter of availability and trend especially for a commercial product. The "better" drivers lent for a less complex design. Adding more drivers makes their individual characteristics less important. For a multiple way speaker, what you hear in the end is the XO network. Personally, I take that. YMMV.
The choice of drivers is a matter of availability and trend especially for a commercial product. The "better" drivers lent for a less complex design. Adding more drivers makes their individual characteristics less important. For a multiple way speaker, what you hear in the end is the XO network. Personally, I take that. YMMV.The speaker was designed circa 1969-1970. Back then they did have available .75" tweeters which could give you good dispersion up above the 14440 Hz max you get from a 1" but the power handling wasn't there. So Jon Dahlquist (JD) decided on a piezo for the top end up to 27k I believe, and i 1" dome under that. At that time there were no commercially available ribbon tweeters AFAIK.Hi ! plese forgive me if i take up this old thread
I listened to the DQ10 driven by Audio Research electronics many many years ago for the 1st time ... i guess it was in the 1978 ?
I was immediately hit but what i still think is the most fascinating effect with stereo ... a nice 3D soundstage.
As the drivers used are very nice but quite "normal" i tried to study the crossover ... without any real understanding of it
My question is the following
I have found a FR of the Philips midrange cone in another thread
https://files.diyaudio.com/forums/gallery/data/1935/medium/fr.jpg
It goes unbelievably flat up to almost 10kHz
In the DQ10 if i am not wrong is cut at about 1kHz ?
Why on the earth do not stretch it up to let's say 3kHz ? in this way just a very good dome tweeter would be needed to cover the remaing highs
I mean ... why not make a 3 ways DQ10 ?
I am sure that the cabinet is not the secret of its so coeherent sound .... probably the xover is but i am very ignorant on the matter.
When i see so many drivers i always wonder if they are all really needed And i am skeptical
Thank you very much and best regards,
gino
I think he got very enamored of the 2.5" dome mid driver which had to be cut well over 500 hz and well under 6k. so now 3 drivers over 1k. While you could find a nice woofer like the Cizek 1 8" woofer that could play over 1k, the problem is with a 10" woofer there is going to be a lot of IM distortion in the higher range. So the xover was set at 400, and the 4" cone was added.
By the end of the run, JD did go to a cheap JVC ribbon and turned it into a 4 way, which is what I did per the available plan. It resulted in a much better treble - more natural and acoustically neutral IMO, not to mention faster with more detail like harmonics coming through better.
Some folks got hold of the Sequerra ribbon and used that, never heard it, but it was a big step up from the JVC as I understand it.
Also for coherency JD chose a 12 db slope between drivers. Compare that to a very fine current speakers like the BMR Philharmonic - which has 18 db and maybe even a 24 db slope. Understanding, modeling, and implementation of Xovers is well ahead of 50+ years ago.
My mods were:
woofer: doping the paper so it would play lower Hz, and adding a pair of internal baffles to break up standing waves. Then I turned it on its side, with the woofer at the top side. I also integrated a cut piece of solid oak under both so they would be slightly angled up to the listening position, and appear to be a single square at the base.
I replaced the caps with the Solens - best reasonably upgraded priced caps then. Got rid of the coffin resistors, but left the inductors alone.
I oriented the drivers in a straight vertical line, spacing them at the 1/2 wavelength length on two very ridgid metal poles on the woofer cabinet above the woofer. The mid was actually in front of the woofer as it tapered off to the edge, and added more damping because you could hear the cabinet behind it.
I tossed away the entire metal frame in front of the drivers, and the cloth, but saved the two side pieces of wood with the baffles attached. I build a metal flange inside the wood/baffles to hold a new black fabric in front of the drivers , and a thin strip of wood below the woofers and painted the remaining part of the woofer cabinet a deep gloss black. Later I faux painted them a red marble/black marble finish which looked excellent
After a bit I realized that the OG baffle pieces were at a tuned distance, so I added felt to them and another wider flange piece for the short side (turned sideways the woofers were not centered. They looked decent but obviously home brewed, but they sounded well better than a stock DQ-10. People dinged them for visuals so I stuck them behind a curtain, and blindfolded my friend that sold them to me to 3 years earlier, and he was convinced that they were a pair of Verity Parsifal 1's because we had both heard them shortly before and I in particular were struck by them - they were $12.5k I believe then. I ended up buying a used pair of the Parsifals 3's about 13 years later. My 10's were 97% as good, I wish I kept them. Using the best amp I ever heard on the DQ-10's was the Threshold Stasis 3 - another piece I wish I never sold. I went through a lot of stuff since, and it wasn't worth it.
Yes, JD was a huge fan of the Quad ESL-57. The DQ-10 stock could player louder and deeper. It could not pass a test tone as cleanly.
The DQ-20 I believe was not totally JD's design. Its a good speaker, with upgraded parts today well worth having, but after the Home Run that was the DQ-10, nothing was ever going to top it.
Hi thanks a lot for the valuable advice. He was trying to get a constant dispersion throughout the audio range.I've never listened to the DQ-10. It is what members here are stating about this holographic soundstage that gives me a clue about their design principle. Cut drivers before they start beaming and move gradually from one cone size to the next. Any chance I have guessed wrong is not unlikely.
Adding more drivers makes their individual characteristics less important. For a multiple way speaker, what you hear in the end is the XO network. Personally, I take that. YMMV.
I understand now from a post above that the tweeter had limited range I tend to be worried about complexity. While most talented people see it as a challenge i see it as a nightmare. One of the best speaker i have listened to many years ago was a 3 way ... Pro Ac EBS
But what really shock me is the complexity of the crossover ... i look at it and i am completely confused. Never seen something similar. Never
The 20 was not a match for the 10 sonically. Veiled, homoginized.
The OG dome 1" tweeter and piezo are very well replaced by a solid ribbon tweeter, there was a plan, and it cuts the xover complexity and load on the amp.
The Philips midrange at a 12 db slope would blow - that means -24 db at 100, and -36 at 50. Good luck with well recorded bass music at realistic levels. Pull up the sheet on it, bet it behaves badly under 400 Hz.
You'd be much better off with the drivers in the BMR Philharmonic - Raal ribbon, BMR mid, Scanspeak woofer - $1200 kit, another $450 for the flatpack. Blows the stock DQ-10 out of the water. Even better than my modded DQ-10's.
Woofers that can woof at 32 Hz in a sealed cabinet do not produce good mids into the female contralto+ range, not in the least if you are talking purity.
Hi thank you very much indeed for this very valuable advice and experience. For sure the drivers were good ... no doubt about that But they are not coming from an alien manufecturer So i tend to think that the magic is in the xover as i said above it looks to me like something completely different from the usual xover I have never seen series of drivers covering different ranges ... never Woofers in series yes ... but not a woofer and a mid
I am completely lost with this design And intrigued I would like to understand more of it
Is there a thread describing the theory behind it ? i would love to read it
Seen and heard the stacked ESL 57's with the Hartley 24" woof and the Sequerra ribbons. without the side flange/baffles the sound could be problematic at some point. The
No sir. They were released in 1973. Harry Pearson of the Absolute Sound turned them into an instant legend with his watershed review in Issue #4 of the The Absolute Sound in Spring 1974. That review was probably the spark that ignited the High End more than any other review published in all of the 1970's. I heard them in September 1974 for the first time.
He debuted a prototype at the NYC Hi-Fi Show in 1972. So he probably developed them from 1970-72.
From 1966-1974 my father had a system built around the Quad ESL-57. They were more pure than the DQ-10, but forget playing Led Zeppelin II on them at any real rock volume. I bought my first real speaker in Spring '74 - the ADS 810. Later tried the Lg Advent, KLH-5, Cizek 1, the DCM Time Window, (then got out of the college dorms) and went with the MG-1, MG-II (stacked hanging off of ceiling beams driven by two Dyna 410's), and didn't finally buy a pair of used DQ-10's until 1985 when I had the room and the time to mod them. Sold them and my stacked MG's when I had the room for the ML CLS-IIz.
the great: a package deal: drivers, xover, sized baffles for the drivers, side flange tuned for the drivers, time aligned,... the OG woofer - serial number under #340 had a sloppy Q and didn't match the other drivers, but went down to about 34 Hz.. The new one was a nice quick woofer, but in that small box was pretty much done at about 42 Hz, with some life to about 35. Given the xover I think they could have increased the woofer to a 12" with a box about 40% bigger and got to 25 Hz flat for maybe $100 more. The next two products they made were a sub-woofer and crossover to try and make up for it,
the meh: I know from taking off the metal screen in front of the drivers that it caused a lot of diffraction and cancellations, added cost and weight too. The stock caps - mylar - needed replacement. The resistors and caps were not matched very well. After that the 4" low mid voice coil would go out of the alignment easily when pushed and make a scraping sound over about 94 db at 1 meter - which was annoying as heck.
As for the xover - I only modded the caps and resistors and wires to the originals, but not changed values - except the cap and resistor for the ribbon using a SPL meter and test tones to be sure I was flat after tossing the tweeter and piezo. Later on I upgraded to a really nice cap with a .01 cap in series which really cleaned up treble hash.
FWI remember i was listening exactly in the sweet spot I did not move L to R The room being the listening room of a major audio shop in my city i think it was treated adequately Someone say that almost ANY speaker with a decent FR in the RIGHT listening room will image quite wellI've never listened to the DQ-10. It is what members here are stating about this holographic soundstage that gives me a clue about their design principle. Cut drivers before they start beaming and move gradually from one cone size to the next. Any chance I have guessed wrong is not unlikely.
This is not what worries me What worries me is that ANY speaker even the best one in the WRONG room will not image well That is a problem
At the moment i cannot treat the room ... anyway this is a very important question i have
Usually people change speakers much more easily than treat the listening room Maybe they are making a mistake ?
thanks a lot again Clearly there are points for upgrading Like almost always Starting from the drivers i guess They are good but better ones are available now
It's the whole design that i have never seen in any other commercial speakers And strangely i did not find any discussion about it
Maybe the coeherence in the emission comes from it ? after all the reference was a speaker the Quad ESL 57 that has an excellent coeherence
If i am not wrong it was used for the Mr Mark Levinson personal system ?
Currently, my open baffles live in a completely untreated room with plaster walls, concrete floor and zero soft furniture. However, I enjoy pinpoint imaging within a soundstage well extended beyond rear and side walls.
Yes they are. I was very fortunate to have good to superb rooms from 1981-2016. Most rooms can be easily adjusted for reflections and absorption - but the key is to balance those factors - and add diffusion which is the hardest and most expensive factor needed to mimic a sizable acoustic setting. Its important because delay between the initial note and the trailing notes convey the sense of space. All direct or too much reflected sound ruins that sense. I was mostly listening to planars and other well known imaging speakers. I built two rooms for myself, supervised the construction of 3 other rooms and modified dozens of others - as a sideline business in the middle of that period.
If you could find a pair of Spica TC-80 (from the 80's) or the current KEF mini speaker and give them the sort of env I describe here you will hear a very large soundstage indeed. But a Magnepan MG-20 or 30 with the true ribbon tweeters, or a M-L CLS IIz will give you a well larger one.
Easy things to change: Get the equipment rack out of the back wall between the speakers! Nice for the ego - death for the staging. Listen with eyes closed. If turntable: damp the contact to the table and consider putting weight on it, or get the dust cover off entirely. Getting it into an adjacent room or closet is better. If floor wood - get table mounted on wall - into the Get speakers with any real bass on spikes. If on wooden floor try to have them over the floor joists. If too much glass, cover most with blinds mixed with drapes but vary the covering of the drapes and visible glass with folded drapes. I used a large number of ASC bass traps/diffusion traps, sound flags.
Wall to wall carpeting is very bad, bare floors are also bad. Small scatter (2'x3' range) rugs are good to cover roughly half. I like them in the path of the speaker to cut down early reflections. Heavy chairs or couches are very bad for listening - to sit on. They are good in other areas as long as they do not sit on the speaker wall, I always have them on the back wall and sit forward of them by at least 2'. And yes, there is always just one best seat. There should be nothing above the neck behind and the chair. The chair padding should be minimal or none with no carpeting or couch under your head area. Think thats crazy? Sit back on a couch with a lively treble recording on as loud as your normal volume, then lean forward until you head is over a bare floor - right - amazing change. You want lively, but not bright, and dead is no good at all.
Avoid speakers in corners unless they are horns, or others that are wall loaded. Measure the distance from the woofer magnet to the 3 intersecting surfaces, and try for a ratio of 1, 1,67, 2.5 to avoid bass nulls and peaks. Also set up speakers on long wall, avoid narrow rooms with speakers on short wall - mid bass peaks will happen.
If you are stuck in a room where you do not control these sorts of things - consider moving the system or getting headphones and lowering your hopes.
But you are getting early reflections, probably nulls and peaks as well - do you have windows or doors that can be opened?
Yes the best system of the 70's was either stacked Quads with Hartley sub and Sequerra ribbons - or the Infinity Servo-Statik.
I have been around the highest of high fidelity for 56 years now, and when I say that many current speakers in the $1500-5000 range would crush a stock DQ-10 today in a good room with a good system. Cheapest? The BMR Philharmonic kit plus the flatpack is about $1700 US, and easily top the DQ-10. Focal, Falcon, Triangle, Vandersteen, ProAc, and about 15 more brands will do it.
Now a modded DQ-10 with a Fountek ribbon or better and much more expensive a Raal ribbon, and all new 1% matched metal film caps, mills resistors, and get the metal screen from the front of the drivers... now its a hot speaker, and will do battle up to something like a Maggie 3.7i.
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