Some were upset by my last Repair / Rebuild.
So all I will say is this.
They sounded like rubbish before.
No treble, and one side had almost no mid-range.
I investigated, found many issues, and it was decided to do a full rebuild.
These are factory original. Matching serial numbers. Never touched before now.
Did you notice one side using different parts ? From the factory.
After the rebuild using far superior parts, everything is now working as it should.
Plus some.
To head off all the old worn out arguments.
A lot of the capacitors are in parallel banks. The capacitance of each bank was matched to the original.
The old inductors were measured, and the new inductors were selected for correct inductance AND dcr.
If the owner wishes to comment further (they are a member here) then that is up to them.
So all I will say is this.
They sounded like rubbish before.
No treble, and one side had almost no mid-range.
I investigated, found many issues, and it was decided to do a full rebuild.
These are factory original. Matching serial numbers. Never touched before now.
Did you notice one side using different parts ? From the factory.
After the rebuild using far superior parts, everything is now working as it should.
Plus some.
To head off all the old worn out arguments.
A lot of the capacitors are in parallel banks. The capacitance of each bank was matched to the original.
The old inductors were measured, and the new inductors were selected for correct inductance AND dcr.
If the owner wishes to comment further (they are a member here) then that is up to them.
WOW.
Nice rebuild.
Australian made resistors.
This speaker must be from the last century... LOL
One day I must build a 4 way SWMTMWS using modern transducers.
Nice rebuild.
Australian made resistors.
This speaker must be from the last century... LOL
One day I must build a 4 way SWMTMWS using modern transducers.
How do they sound? I breifly heard a set of smaller ones (3-way). Not enuff to really get a feel.
dave
dave
I love Duntechs. Heard several pairs in various settings and was always amazed how lifelike they can sound.
The mismatch of parts isn't anything new to me as are the way parts were added / subtracted for "voicing".
I would love to see your corrected crossover schematic. I bet they sound great now.
The mismatch of parts isn't anything new to me as are the way parts were added / subtracted for "voicing".
I would love to see your corrected crossover schematic. I bet they sound great now.
Thanks all.
Built roughly around 1990 as the cap date codes are 1989.
Sound. Hard to answer.
Originally they were terrible due to dead / drifted parts.
Now they have a very extended response.
The bass goes way down, but its not the thumpy boomy bass that others resort to to sell speakers.
Very clean and clear through the range.
Maybe a touch more treble than I'm used to.
Overall one of the closest I've heard to what music should be.
Imaging and sound stage is spot on.
No real sense of them lacking dynamic range.
It's more that they do less wrong than they do right.
Having said that.
I've also heard JBL 4350's in the same house.
Maybe not as technically accurate as the sovereigns.
But their dynamic reserves are beyond insane.
I for one have no trouble believing their brochure that warns of their ability to permanently damage your hearing.
And well, horns with compression drivers. If I have to explain that, then you need to go hear a good set.
For the foreseeable future trying to draw up a schematic isn't on the cards.
So here's a bunch of pics to help anyone that wants to work it out.
I will post an overlay pic at some stage to help out as I have a few hand scrawled notes that covers things the pics don't.
Built roughly around 1990 as the cap date codes are 1989.
Sound. Hard to answer.
Originally they were terrible due to dead / drifted parts.
Now they have a very extended response.
The bass goes way down, but its not the thumpy boomy bass that others resort to to sell speakers.
Very clean and clear through the range.
Maybe a touch more treble than I'm used to.
Overall one of the closest I've heard to what music should be.
Imaging and sound stage is spot on.
No real sense of them lacking dynamic range.
It's more that they do less wrong than they do right.
Having said that.
I've also heard JBL 4350's in the same house.
Maybe not as technically accurate as the sovereigns.
But their dynamic reserves are beyond insane.
I for one have no trouble believing their brochure that warns of their ability to permanently damage your hearing.
And well, horns with compression drivers. If I have to explain that, then you need to go hear a good set.
For the foreseeable future trying to draw up a schematic isn't on the cards.
So here's a bunch of pics to help anyone that wants to work it out.
I will post an overlay pic at some stage to help out as I have a few hand scrawled notes that covers things the pics don't.
Ouch. Too much metal for me. Those are some of the worst binding posts i have ever used.
The rest looks very nice.
dave
Your summation of the way they sound is exactly why I love most Duntechs. Thats also why quite a few mastering studios use them. I don't recall the bright sound, but everything else you describe is right on point. They do more right than wrong, but need alot of amplifier to shine.
I agree with you on the CD + horn thing. The bug bit me hard recently and I'm learning alot fast. Getting it right isn't easy and much less forgiving than your typical multi way direct radiating systems. I can only imagine how a set of JBL 4350s would sound with good amplification and analog source material.
I agree with you on the CD + horn thing. The bug bit me hard recently and I'm learning alot fast. Getting it right isn't easy and much less forgiving than your typical multi way direct radiating systems. I can only imagine how a set of JBL 4350s would sound with good amplification and analog source material.
From the blurry picture looks like a mixture of old Dynaudio and Vifa drivers, but what exactly were the driver models in this speaker?
Shhhh. He did get me to swap one pair of input binding posts for WBTs.
Being slightly bright I suspect was due to the parts being fresh and not broken in.
I imagine they will have settled down by now and opened up and smoothed out.
Sorry yes. I only had the potato camera in my phone when I went to reinstall the crossovers.
I'm sure there's plenty of way better 'product' pics on the net.
I don't know what the exact drivers are.
And here's the parts values overlay for those wanting to play at home.
It's a BIG image so it can be zoomed in with clarity.
IF, anyone does draw up a proper schematic, Please share it here.
The interesting (and sad) thing is, the left side terminals are completely undocumented.
No body seems to know anything about them.
At a quick glance they seem to just insert or remove a little extra filtering to the tweeter/mid/bass drivers (Not the sub bass drivers)
Being slightly bright I suspect was due to the parts being fresh and not broken in.
I imagine they will have settled down by now and opened up and smoothed out.
Sorry yes. I only had the potato camera in my phone when I went to reinstall the crossovers.
I'm sure there's plenty of way better 'product' pics on the net.
I don't know what the exact drivers are.
And here's the parts values overlay for those wanting to play at home.
It's a BIG image so it can be zoomed in with clarity.
IF, anyone does draw up a proper schematic, Please share it here.
The interesting (and sad) thing is, the left side terminals are completely undocumented.
No body seems to know anything about them.
At a quick glance they seem to just insert or remove a little extra filtering to the tweeter/mid/bass drivers (Not the sub bass drivers)
Last edited by a moderator:
As an owner of these speakers I just wanted to say a big THANKS for posting this info. Although my crossovers look somewhat different being an earlier revision you have inspired me to investigate doing the same
At a Quick glance It seems that the active---passive links are there for separating the three branches of the crossover.
Mr Bells of Tubes 😉
I can assure you they will leap into a far better place with a rebuild.
I was honestly shocked when I found quite a few PP caps had drifted not only in value but also esr.
And yes, I've experienced the different versions of crossovers in the same model with previous dunlavey/duntech repairs I've done.
Pico.
Uncoupling the different driver sections is what I was expecting too.
But in use, they make very minor alterations to the overall sound.
The lead wires from those connectors go off to sections of crossover on the board.
The speakers have 'upper' and 'lower' terminals to bi amp and bi wire.
I was more concentrated on getting them done so the gent can have them back up and running.
I can assure you they will leap into a far better place with a rebuild.
I was honestly shocked when I found quite a few PP caps had drifted not only in value but also esr.
And yes, I've experienced the different versions of crossovers in the same model with previous dunlavey/duntech repairs I've done.
Pico.
Uncoupling the different driver sections is what I was expecting too.
But in use, they make very minor alterations to the overall sound.
The lead wires from those connectors go off to sections of crossover on the board.
The speakers have 'upper' and 'lower' terminals to bi amp and bi wire.
I was more concentrated on getting them done so the gent can have them back up and running.
