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As I mentioned in my introductory post, I'm the new owner of a pair
of DQ-10s. However, the 2" midrange dome and 3/4" dome tweeter on
mine are bad.

For the midrange, the tinsel wire has been burnt up or broken inside
its protective resin right where it enters the cloth dome. The voice
coil is in good condition with no evidence of being overheated and
the like loosening of wires, continuity there also checks fine. So,
it must have been a mechanical breakage. In the past, I have
repaired similar breaks in similar drivers (the 2" dome midranges of
a pair of Infinity Quantum 2s), however the proximity of the break
to the dome makes such a repair too difficult to undertake. And so,
I am in need of a company that might be able to affect a repair of
this driver or a source for good, but used equivalents. I am aware
of Regnar, but so too am I that their prices are above and beyond my
range.

As to the tweeter, the aluminum tinsel leads have corroded from
exposure resulting in one breaking just as it passes beneath the
magnet cover. Unlike the midrange, this driver appears to be glued
together rather than screwed and so I cannot take it apart for
repairs. Nevermind that my success at resoldering aluminum VC wires
even with the appropriate solder has been minuscule. So, I need one
of these as well.

Another issue I discovered while tracking down the above problems is
that the woofers, while largely the original Advent woofers with the
masonite ring, have been reconed in the very recent past. The foams
and cones are spotless, but rather than the dark, almost purplish
cone with annulae, I find that mine have light grey and very plain
cones. The foam surrounds, however, were reglued appropriately.
Anyone know how I might identify whether the woofers were reconed
appropriately with the correct cone mass and VC replacements? There
is a number printed on the back of the cone that I do not remember
nor wrote down, but that I can retrieve if it might point to the
answer. If need be, I do have a pair of Advent/1s on loan to some
friends that I might retrieve and sacrifice for a woofer transplant.
The drivers in these speakers I believe are the same as found in the
New Large Advent and thus are the same that Simply Speakers sells as
replacements for the DQ-10.

While I have mine apart and am working on them, I do plan on
eventually recapping the crossover as per the schematic in the files
section. I'll likely also affect the mirror imaging project shortly
after I can locate the needed replacement drivers. So, I might as
well implement any modifications at the same time. Does anybody have
experience with various modifications or suggestions for what I
might do to improve these speakers? Since half my midranges and
tweeters are shot, perhaps there are better options available that I
should install rather than direct replacements? Any and all
information would be greatly appreciated.

Thank you for your time.
- JP

--- In Dahlquist@..., "hrothgar1982" <hrothgar1982@...>
wrote:

As I mentioned in my introductory post, I'm the new owner of a pair
of DQ-10s. However, the 2" midrange dome and 3/4" dome tweeter on
mine are bad.

For the midrange, the tinsel wire has been burnt up or broken

inside

its protective resin right where it enters the cloth dome. The

voice

coil is in good condition with no evidence of being overheated and
the like loosening of wires, continuity there also checks fine. So,
it must have been a mechanical breakage. In the past, I have
repaired similar breaks in similar drivers (the 2" dome midranges

of

a pair of Infinity Quantum 2s), however the proximity of the break
to the dome makes such a repair too difficult to undertake. And so,
I am in need of a company that might be able to affect a repair of
this driver or a source for good, but used equivalents. I am aware
of Regnar, but so too am I that their prices are above and beyond

my

range.

As to the tweeter, the aluminum tinsel leads have corroded from
exposure resulting in one breaking just as it passes beneath the
magnet cover. Unlike the midrange, this driver appears to be glued
together rather than screwed and so I cannot take it apart for
repairs. Nevermind that my success at resoldering aluminum VC wires
even with the appropriate solder has been minuscule. So, I need one
of these as well.

Another issue I discovered while tracking down the above problems

is

that the woofers, while largely the original Advent woofers with

the

masonite ring, have been reconed in the very recent past. The foams
and cones are spotless, but rather than the dark, almost purplish
cone with annulae, I find that mine have light grey and very plain
cones. The foam surrounds, however, were reglued appropriately.
Anyone know how I might identify whether the woofers were reconed
appropriately with the correct cone mass and VC replacements? There
is a number printed on the back of the cone that I do not remember
nor wrote down, but that I can retrieve if it might point to the
answer. If need be, I do have a pair of Advent/1s on loan to some
friends that I might retrieve and sacrifice for a woofer

transplant.

The drivers in these speakers I believe are the same as found in

the

New Large Advent and thus are the same that Simply Speakers sells

as

replacements for the DQ-10.

While I have mine apart and am working on them, I do plan on
eventually recapping the crossover as per the schematic in the

files

section. I'll likely also affect the mirror imaging project shortly
after I can locate the needed replacement drivers. So, I might as
well implement any modifications at the same time. Does anybody

have

experience with various modifications or suggestions for what I
might do to improve these speakers? Since half my midranges and
tweeters are shot, perhaps there are better options available that

I

should install rather than direct replacements? Any and all
information would be greatly appreciated.

Thank you for your time.
- JP

I for one would love to see photos documenting your restoration. It
might be a valuable resource for others attemping similar projects.

cubdog

---

PC-to-Phone calls for ridiculously low rates.

John,

I believe you were responding to my post concerning the burnt tinsel
on the midrange dome and broken tinsel on the tweeter. I do
appreciate the information on a possible replacement and I may very
well look into the Vifa domes when I pursue improvements. On
Wednesday, however, I discovered that I have more patience than
dollars and managed to affect a repair on the two broken drivers.

For the midrange, I completely removed the bad tinsel and replaced it
with my own made of 32 gauge magnet wire and soldered to the VC
inside. Of course, the task was more difficult than it should've been
thanks to that ubiquitous orange/brown resin used on tinsels around
this time that's impossible to dissolve with acetone, alcohol,
lacquer thinner, or even with dilute HCl (Muriatic acid). Hence why I
had to cut away the lead altogether and scrape away as much of the
coating as possible. To that end, does anybody know of a good modern
replacement for the resin so that I might coat my new tinsel for
improved mechanical durability?

For the tweeter, the task was much more of a hassle thanks to the
magnet cover being glued on. After spending the better part of an
hour attempting to open the driver housing so that I might have
better access to what remained of the tinsel, I had to abort that
approach and instead scrape away bits of superfluous plastic to
expose the tinsel. Afterwards, the repair was fairly straight forward
in soldering a short length of the fore-mentioned magnet wire to the
stub using a 15 watt iron with a fine tip that I've filed down to be
even finer for this type of repair and silver solder. The tinsel was
extremely fragile and fine, being finer than a hair (when I tired of
opening the magnet cover, I did the comparison directly). Fortunately
for me, the tinsel wasn't aluminum as I had feared, but rather had
merely been tinned way up into the driver when the leads were
soldered to the contact -- that small of wire heats up extremly fast
allowing for distant flow of solder.

After reassembling the drivers (ensuring the midrange dome was not
experiencing VC rub due to any magnet shift) and replacing them in
the questionable DQ-10, they proved to work just fine and are singing
quite well. Of course, that's when I discovered that the midbass and
supertweeter weren't working anymore. They were when I first picked
up the speakers, so more work was needed. The cap had simply gone bad
on the midbass (or is just very questionable and subsequently
intermittent), so I jury-rigged a test replacement daisy-chaining a
batch of spare polyprops I had to match the 80uF value. Now it's
working, but still nothing on the supertweeter.

I'm hoping the issue with the piezo is that the caps have simply gone
bad and that a fix will be equally simple. If not, I might as well
forward my question again of what the possible problems and fixes
might be for this driver? Anyone know of a good, cheap source of
replacement drivers with the proper part number? I understand that
the piezos came with different PNs to indicate how well the driver
fared with quality control testing and those used in the DQ-10 were
the best.

No pictures yet, I'm afraid as my digital camera makes the output of
camera phones seem like Ansel Adams works in comparison. More
information about my progress will be forth-coming as I get further
along in this project.

- JP



--- In Dahlquist@..., John Gilronan <old.fatboy@...>
wrote:

Cubdog,
I'm sure we have been on the same posts on AK, When I got my 10's

about three years back I had the same prob with my domed mid. I
substituted a Vifa 3" dome mid-off the top of my head I can't recall
the mod. # but they only make one in shielded and unsheilded. I put a
12 ohm resistor in paralell with it to attain th proper Ohmage.. i
got the Vifa from PartsExpress so check their website. I can't
remember his AK handle but the "twangophile" put the same Vifa driver
in for his domed mid and the 5" mid with happy results

If you haven't done so yet REBUILD the Xover with all new

inductors,caps and a new L-pad(Regnar is the only source for the L-
pad with a proper resistance) all the rest came from PE. I used Solen
caps and foil inductors-All I can say is WOW unbelievably fast with a
HUGE bass improvement.

Glad to find a forum to my all time favorite speaker-$300 of TLC

makes this beauty compete against the modern $5000 big boys

Old Fatboy on AA and
The Fatboy on AK
to my friends I'm just John


---------------------------------
Yahoo! Messenger with Voice. PC-to-Phone calls for ridiculously low

rates.

Piezos bad ?let me know-took mine out of the equation on my first
tweak, reverse the polarity on the tweeter and completely disconnect
the harsh piezo,at the Xover(just clip the lead at the 35 ohm
resitor)
the ScanSpeak 2010 seems to be a standard replacement for the
tweeter-once again with a 12 ohm resitor in parallel.

OK time for the tweak list, this is not all mine but a compilation
from other DQ10 fans must notably DMAN from AudioAsylum ( great
mentor when I began my project)


As for tweaks you can do spending little or NO money, here's a few.

1. REMOVE the super-tweeter and its associated crossover stuff. On
the
schematic, that's parts labeled R6 and 7, C7 and 8, and L5 (and the
driver,
of course). this yields a MUCH better top end with less hash in the
frequency extremes.

2. Change the phase of the tweeter. If you find the top end becomes
rather
edgy after removing the parts described in #1, then try flipping the
wires
on the tweeter. Whatever gives you the most listenable treble is the
right
way around!

3. (okay, this costs a bit of money and requires disassembly of the
crossover and most of the speaker system). Add bi-wire capability to
the
system. as you can see on the schematic (and rather obviously!), the
crossover seems to be divided between the bass/midbass and the
mid/tweeter
layouts! The lines between C2 and L1 can be split, and L1 and C2 can
be set
up their own + terminals. At the bottom of the schematic, the trace
between
each set of drivers (line joining the junction of L4, R5 and C6 can
be sent
to the - terminal of the C2 hook up, while the junction of L2 and the
midwoofer can be sent to the - terminal next to L1's + hookup.).
Got it? I
hope so! I've done this to my system, and it allows me to use a pair
of amps
(top and bottom, or vertical bi-amping) when I need "crazy loud"
volumes,
which is rare, but still, its nice to have...

4. Restuff the woofer enclosure with "acousta-stuff" dacron acoustic
stuffing,cheap and helps the bass response.
One lb per enclosure

5. Mirror imaging older non-mirrored DQ-10's.You don't nee a kit to
mirror image your DQ10's. Just remove the midrange and piezo tweeter
from the panel,drill out the rivets,turn the panel around,and put it
back together. then swap positions of the two panels,making sure to
keep everything aligned properly

6. Stands to raise the speakers up to ear level for the mids and
tweets. Mine are homemade and stand 22".

A link to Frank Van Alstines news letter-magazine ,the Jan 1982 has
info on damping,
Frank is an opiionated old curmudgeon but is knowledgable.




Well thats all folks
John

John,

Thank you much for the write-up of the modifications you have done
to your DQ-10s. I have copied the pertinent text into a text file
and posted it in the Files section for future reference by others.

As to my pair, I did some more troubleshooting earlier today and
determined that the piezo is still good on the one (makes noise with
the good ol' meter lead scrape across the contacts), so it's likely
the caps that are bad. As cubdog suggested on AK, this one DQ-10
must've taken one heckuva shock from a dying amp to have two drivers
with burnt tinsels and the capacitors to the other two drivers go
bad.

Interestingly, the resistors also measure about 10ohms lower than
their label on my trusty, calibrated Simpson 206 Series 6. That's a
fair bit greater than the 10% tolerance, so maybe these old
wirewounds don't age all that gracefully. Perhaps future crossover
upgrades will also include replacement resistors in addition to new
caps and inductors.

As I don't have the appropriate capacitors on hand, I followed your
modification suggestion and just disconnected the supertweeter
altogether on both Dahlquists. The treble is a bit suppressed and
definitely rolled off on the higher end -- my guess by ear is around
15-16kHz. When I switched the tweeter leads, the output was greater
(though the roll-off was still present). However, there was a weird
phasing thing happening at the lower crossover frequency where the
midrange ends. It was very subtle and I may have overlooked it were
I not accustomed to other phase coherent speakers, but it was a
detraction and interfered with the coherence of the sound. So, I
returned the meter leads to their previous position and instead
upped the potentiometer to adjust for the reduced output.

To that end, I've figured out why the one working DQ-10 was 2-3dB
louder than the one I've repaired -- someone in the past removed the
adjustment knob on the good '10 and mispositioned it so the arrow
was not in the same position as the other. A very simple issue and
even simpler fix, but I was so obsessing over bad caps and drifting
resistors that I overlooked it for too long.

At any rate, the resultant sound is very pleasant and reminds me a
great deal of the Magnepans that drew me into audio in the first
place (though without the added joys of dipolar sound that the DQ-
10s lack everywhere but in the midbass).

Right now, I'm debating whether it's worth my scrounging up the cash
to completely rebuild the crossovers (nearly broke college student
here) and subsequently be out $100-150. The question is whether such
an outlay of money could be recouped were I to sell these speakers
eventually.

Thanks all for the help. I love trouble-shooting and repairing
speakers and these DQ-10s have been ideal for that (easiest access
to the drivers and crossover I've ever encountered).

- JP

--- In Dahlquist@..., "old.fatboy" <old.fatboy@...>
wrote:

Piezos bad ?let me know-took mine out of the equation on my first
tweak, reverse the polarity on the tweeter and completely

disconnect

the harsh piezo,at the Xover(just clip the lead at the 35 ohm
resitor)
the ScanSpeak 2010 seems to be a standard replacement for the
tweeter-once again with a 12 ohm resitor in parallel.

OK time for the tweak list, this is not all mine but a compilation
from other DQ10 fans must notably DMAN from AudioAsylum ( great
mentor when I began my project)


As for tweaks you can do spending little or NO money, here's a

few.

1. REMOVE the super-tweeter and its associated crossover stuff. On
the
schematic, that's parts labeled R6 and 7, C7 and 8, and L5 (and

the

driver,
of course). this yields a MUCH better top end with less hash in the
frequency extremes.

2. Change the phase of the tweeter. If you find the top end

becomes

rather
edgy after removing the parts described in #1, then try flipping

the

wires
on the tweeter. Whatever gives you the most listenable treble is

the

right
way around!

3. (okay, this costs a bit of money and requires disassembly of the
crossover and most of the speaker system). Add bi-wire capability

to

the
system. as you can see on the schematic (and rather obviously!),

the

crossover seems to be divided between the bass/midbass and the
mid/tweeter
layouts! The lines between C2 and L1 can be split, and L1 and C2

can

be set
up their own + terminals. At the bottom of the schematic, the

trace

between
each set of drivers (line joining the junction of L4, R5 and C6

can

be sent
to the - terminal of the C2 hook up, while the junction of L2 and

the

midwoofer can be sent to the - terminal next to L1's + hookup.).
Got it? I
hope so! I've done this to my system, and it allows me to use a

pair

of amps
(top and bottom, or vertical bi-amping) when I need "crazy loud"
volumes,
which is rare, but still, its nice to have...

4. Restuff the woofer enclosure with "acousta-stuff" dacron

acoustic

stuffing,cheap and helps the bass response.
One lb per enclosure

5. Mirror imaging older non-mirrored DQ-10's.You don't nee a kit

to

mirror image your DQ10's. Just remove the midrange and piezo

tweeter

from the panel,drill out the rivets,turn the panel around,and put

it

back together. then swap positions of the two panels,making sure

to

keep everything aligned properly

6. Stands to raise the speakers up to ear level for the mids and
tweets. Mine are homemade and stand 22".

A link to Frank Van Alstines news letter-magazine ,the Jan 1982

has

info on damping,
Frank is an opiionated old curmudgeon but is knowledgable.




Well thats all folks
John

Charivari??
Well- how many DQ 10 folks can there be in Eburg? This is amazing
how many are from WA-indeed Magnolia did a great marketing job for
Dahlquist-I remember the radio adds in the 70's and 80's(old and fat
is not just a moniker it is now a way of life)
Sounds like a recap is beyond necessary for your 10's-fortunately
that is the cheap part of the start,Solen's would be nice but you
can go cheap with the basics- Dayton's or RatShack specials.

Me thinks your 10's were under powered and over driven, a hard
thing to beleive in a college town. A good friend suffered his
college age daughter's friends for springbreak(while out of town)-
They smoked his bi-amped Vandersteen 2C's,250 watts per speaker-
well my ears would be bleeding.

So What are you using to power your 10's, me an old PhaseLinear 400
series I- Is this a NW forum or what? had a pioneer SX1250 reciever
but was just too thin at 160wpc(now used as just a tuna) The proper
power is the most important with these hogs,200wpc ss or 80 wpc tube

Let me know how I can help-A DQ10 gives a lifetime of enjoyment
John

--- In Dahlquist@..., "old.fatboy" <old.fatboy@...>
wrote:

Charivari??
Well- how many DQ 10 folks can there be in Eburg? This is amazing
how many are from WA-indeed Magnolia did a great marketing job for
Dahlquist-I remember the radio adds in the 70's and 80's(old and

fat

is not just a moniker it is now a way of life)
Sounds like a recap is beyond necessary for your 10's-fortunately
that is the cheap part of the start,Solen's would be nice but you
can go cheap with the basics- Dayton's or RatShack specials.

Me thinks your 10's were under powered and over driven, a hard
thing to beleive in a college town. A good friend suffered his
college age daughter's friends for springbreak(while out of town)-
They smoked his bi-amped Vandersteen 2C's,250 watts per speaker-
well my ears would be bleeding.

So What are you using to power your 10's, me an old PhaseLinear

400

series I- Is this a NW forum or what? had a pioneer SX1250

reciever

but was just too thin at 160wpc(now used as just a tuna) The

proper

power is the most important with these hogs,200wpc ss or 80 wpc

tube

Let me know how I can help-A DQ10 gives a lifetime of enjoyment
John

Yep, I go by Charivari on AudioKarma. Hrothgar is an artifact from
years back when I needed a quick email address name and had
memorized (but not yet forgotten) the first couple of pages
of "Beowulf" in the original Old English.

For recapping, I'm hoping to go with Solens for most everything, but
the midbass ($20 per cap!!). The price isn't significantly more than
the Daytons (Madisound vs. Parts Express), but the sound improvement
appears to be worth it. You're right of course, the rest is looking
like it'll be expensive such as switching to foil inductors and the
like.

My DQ-10s aren't actually from Ellensburg, originally. The guy I
traded for them from (who mislead me by saying they were fully
functional) was near Wenatchee and said he had bought them off of a
gent in Seattle. So, these are traveling Dahlquists at least. His
system did consist of some BPC, so it could be that his receiver
wasn't up to the task.

As to what I have to power them, that's a good question. My main
speakers are borderline high-efficiency, so I've been pursueing
lower powered amps as of late. I have a Radio Shack MPA-250 – much
better than you'd expect of that brand – and it appears to have
enough oomph for my listening room and preferred levels. If not, I
also have a Kenwood KR-1000 Galaxy Commander that has a fair bit of
power itself, so some biamping possibilities exist, at least for
fool's biamping (using fullrange power and the passive crossovers).

At any rate, I have a new reason to pursue a larger amp. Just a few
days ago, I snagged a pair of Sound Lab A-2 elecrostatic
loudspeakers. As I'm looking at the possibility of a sensitivity
rating as low as ~74dB, a hefty amp is now high on my list of
priorities. No worries, I'm not planning on abandoning the DQ-10s
just yet, so you'll hear more from me as I finish the
repair/upgrades of these speaks.

- JP

JP
sounds like Eburg might be the place for great vintage-who'da thunk
it. I knew that name struck an old college chord,though I always
liked Gardner's take in "Grendal". a great DQ10 is a slow rebuild,took
me 3 years to cough up the coin-spend more than you should but less
than you can and you will be successful.It's a great speaker to build
around, every system improvement will show. If the bucks are there a
Dynaco PAS3 pre is a great starter tube setup, for real sweetness.
You're a year late or you could of had one on a long term loan. So
what's your major? Beowulf is not a common thread-me now I'm just an
old fat finish carpenter, but every day is new and a challenge and I
enjoy it
John