Anyone in the SF Bay Area with Dunlavy SC-IV/a Speakers I can listen to?

[destinationsound]

Hello all! I'm coming back to update. I'm still not ready to do any component testing with meters or impedance or whatever. For now I'm doing audio-only testing.

Two questions:
1. Does anyone know at what frequency range the midrange speakers and the tweeters are set to on the crossover? At what frequency should the tweeters start to produce sound?

2. If I hear a DC hum and some subtle white noise hiss coming from the midrange speakers when idled, should I be able to hear some of that from the tweeters as well?

The reason I ask is the midrange speakers produce the quiet white noise when idled, however the tweeters on both speakers are dead quiet.

Furthermore, when I play pink noise and use a high pass EQ set to 12kHz and higher, I get ZERO sound from the tweeters on either speaker.... from what I can tell.

It's hard to tell because the midrange speakers make sound at 12kHz, so I try to cover them up with my hands and try to listen to the tweeters only. From what I can tell the tweeters aren't producing any sound.

For reference, my ears can hear a sign wave up to 15.8kHz.

 

[MAB]

Hello all! I'm coming back to update. I'm still not ready to do any component testing with meters or impedance or whatever. For now I'm doing audio-only testing.

Two questions:
1. Does anyone know at what frequency range the midrange speakers and the tweeters are set to on the crossover? At what frequency should the tweeters start to produce sound?

2. If I hear a DC hum and some subtle white noise hiss coming from the midrange speakers when idled, should I be able to hear some of that from the tweeters as well?

The reason I ask is the midrange speakers produce the quiet white noise when idled, however the tweeters on both speakers are dead quiet.

Furthermore, when I play pink noise and use a high pass EQ set to 12kHz and higher, I get ZERO sound from the tweeters on either speaker.... from what I can tell.

It's hard to tell because the midrange speakers make sound at 12kHz, so I try to cover them up with my hands and try to listen to the tweeters only. From what I can tell the tweeters aren't producing any sound.

For reference, my ears can hear a sign wave up to 15.8kHz.

I don't know the crossover frequencies, and can't find any mention of the frequencies. All I know is they are 6dB/oct (shallow), and as a result you will have significant treble energy sent to the midranges. Which explains why you hear the midranges up to 12kHz... for instance if the crossover is at 3kHz the electrical signal to the midrange would only be 12dB down at 12kHz. That combined with the mid's natural rolloff and you will still get audible output.

I really think the tweeters are blown. There are some additional steps to confirm.

Also, I would reach out to the party that sold them. It seems they sold you broken speakers.

If you want to repair the tweeter, this Peerless is a possibility which comes up often in various forums as a replacement:

Peerless by Tymphany D27TG35-06 1" Silk Dome Tweeter

Peerless by Tymphany D27TG35-06 1" Silk Dome TweeterPeerless by Tymphany D27TG35-06 1" Silk Dome TweeterThe Perfect Drop-in Replacement Tweeter to Upgrade Your High EndThe Tymphany high performance D27TG35-06 1" coated silk dome tweeter features ferrofluid cooling, linear response faceplate...

www.parts-express.com

Perfect

Or this Scan Speak::

ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter

ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter. High-quality tweeter in stock. Crossover and system matching advice available. Contact Madisound.

www.madisoundspeakerstore.com

Both Peerless and Scan Speak have dramatically similar responses to each other, on-axis and off, and similar specs by their spec sheet. It would be good to see what the model is of your original tweeter. That's if they are original. It would help to see if these are indeed drop-in compatible.

The tweeter (and mid for that matter) are going to be easy to blow if overdriven. If the Peerless or Tympany are adequate drop-in replacements, you can get spares!

 

[MAB]

For reference, my ears can hear a sign wave up to 15.8kHz

Oh by the way, just rub it in won't you.

 

[destinationsound]

I don't know the crossover frequencies, and can't find any mention of the frequencies. All I know is they are 6dB/oct (shallow), and as a result you will have significant treble energy sent to the midranges. Which explains why you hear the midranges up to 12kHz... for instance if the crossover is at 3kHz the electrical signal to the midrange would only be 12dB down at 12kHz. That combined with the mid's natural rolloff and you will still get audible output.

I really think the tweeters are blown. There are some additional steps to confirm.

Also, I would reach out to the party that sold them. It seems they sold you broken speakers.

If you want to repair the tweeter, this Peerless is a possibility which comes up often in various forums as a replacement:

Peerless by Tymphany D27TG35-06 1" Silk Dome Tweeter

Peerless by Tymphany D27TG35-06 1" Silk Dome TweeterPeerless by Tymphany D27TG35-06 1" Silk Dome TweeterThe Perfect Drop-in Replacement Tweeter to Upgrade Your High EndThe Tymphany high performance D27TG35-06 1" coated silk dome tweeter features ferrofluid cooling, linear response faceplate...

www.parts-express.com

View attachment 424352
Perfect

Or this Scan Speak::

ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter

ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter. High-quality tweeter in stock. Crossover and system matching advice available. Contact Madisound.

www.madisoundspeakerstore.com

Both Peerless and Scan Speak have dramatically similar responses to each other, on-axis and off, and similar specs by their spec sheet. It would be good to see what the model is of your original tweeter. That's if they are original. It would help to see if these are indeed drop-in compatible.

The tweeter (and mid for that matter) are going to be easy to blow if overdriven. If the Peerless or Tympany are adequate drop-in replacements, you can get spares!

Thanks for the leads.

Ive heard people talk about scan speak as a replacement option. The sad part is John Dunlavy hand picked tweeters and tuned the crossover to match.

I sent a preliminary email to the seller stating "I think tweeters are blown. Doing more testing. Will let you know and discuss financials once I'm certain."

I'd still keep the speakers with replaced tweeters if the price discount was correct. It's a shame they won't be tuned to JD original specs but beggars can't be choosers with 23 year old "custom" speakers.

 

[MAB]

Thanks for the leads.

Ive heard people talk about scan speak as a replacement option. The sad part is John Dunlavy hand picked tweeters and tuned the crossover to match.

I sent a preliminary email to the seller stating "I think tweeters are blown. Doing more testing. Will let you know and discuss financials once I'm certain."

I'd still keep the speakers with replaced tweeters if the price discount was correct. It's a shame they won't be tuned to JD original specs but beggars can't be choosers with 23 year old "custom" speakers.

Good luck, whichever approach you take.

If the Peerless and Scan Speak tweeters are truly drop-in replacements, I wouldn't worry too much about the hand-tuning part. That last 0.1 or 0.01dB is not particularly audible.

I'm eager to hear how it goes.

 

[destinationsound]

I found these new old stock. Never know if they're actually new.

NEW PAIR VIFA D27TG-05-06 SILK DOME TWEETERS -6 ohm DENMARK | eBay

Find many great new & used options and get the best deals for NEW PAIR VIFA D27TG-05-06 SILK DOME TWEETERS -6 ohm DENMARK at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I'll probably get them and test

 

[MAB]

I found these new old stock. Never know if they're actually new.

NEW PAIR VIFA D27TG-05-06 SILK DOME TWEETERS -6 ohm DENMARK | eBay

Find many great new & used options and get the best deals for NEW PAIR VIFA D27TG-05-06 SILK DOME TWEETERS -6 ohm DENMARK at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I'll probably get them and test

Good start.
The D27TG05-06 have response that is almost identical to the current Peerless D27TG35-06 and the D2606 Scan Speak.

If and when you demount the existing tweeters, you can also remove the diaphragm and look inside to see if Dunlavy added additional absorption material in the cavity behind the dome (it says he did in some of the reviews). It likely won't be a big difference from the stock tweeter's response, but may be worth considering transferring any modifications to a pair of new tweeters. Or even getting replacement diaphragms for the existing magnets.

I forgot to mention, these are all ferrofluid tweeters, it is possible the tweeter is dead not because of a burned voice coil, but because the ferrofluid has dried up and turned to varnish in the gap. In any case, in your communications with the seller, please ask if the tweeters are original. Will be nice to understand if they are the original Dunlavy-modified pieces if only to understand the if he is doing some special treatment in the cavity. Note, if the ferrofluid is indeed dried completely, it is exceptionally difficult to remove from the gap and you likely just need to replace the entire tweeter.

I would make keeping these contingent on figuring out first that you can order equivalent tweeters, which will likely involve you demounting at least one of the existing drivers to check model numbers and likely sourcing a replacement unit to check fit. I actually think this is doable, not expensive, you might end up with a collection of tweeters and some new confidence on fixing things if that helps. And likely see how a great sounding set of speakers is constructed from pretty average drivers (despite the woo woo stuff about esoteric bespoke drivers fabricated from rare and exotic materials). And I am hoping for lots of pictures, including potentially the crossover so we can figure out the actual crossover frequencies!

But first, you have some business to sort out with the seller.

 

[destinationsound]

Good start.
The D27TG05-06 have response that is almost identical to the current Peerless D27TG35-06 and the D2606 Scan Speak.

If and when you demount the existing tweeters, you can also remove the diaphragm and look inside to see if Dunlavy added additional absorption material in the cavity behind the dome (it says he did in some of the reviews). It likely won't be a big difference from the stock tweeter's response, but may be worth considering transferring any modifications to a pair of new tweeters. Or even getting replacement diaphragms for the existing magnets.

I forgot to mention, these are all ferrofluid tweeters, it is possible the tweeter is dead not because of a burned voice coil, but because the ferrofluid has dried up and turned to varnish in the gap. In any case, in your communications with the seller, please ask if the tweeters are original. Will be nice to understand if they are the original Dunlavy-modified pieces if only to understand the if he is doing some special treatment in the cavity. Note, if the ferrofluid is indeed dried completely, it is exceptionally difficult to remove from the gap and you likely just need to replace the entire tweeter.

I would make keeping these contingent on figuring out first that you can order equivalent tweeters, which will likely involve you demounting at least one of the existing drivers to check model numbers and likely sourcing a replacement unit to check fit. I actually think this is doable, not expensive, you might end up with a collection of tweeters and some new confidence on fixing things if that helps. And likely see how a great sounding set of speakers is constructed from pretty average drivers (despite the woo woo stuff about esoteric bespoke drivers fabricated from rare and exotic materials). And I am hoping for lots of pictures, including potentially the crossover so we can figure out the actual crossover frequencies!

But first, you have some business to sort out with the seller.

I don't have many repair techs in my area (SF Bay Area)...surprising I know except a place called SerTech. I'll try to consult with them. See if they know anything

 

[MAB]

I don't have many repair techs in my area (SF Bay Area)...surprising I know except a place called SerTech. I'll try to consult with them. See if they know anything

The good news is, this repair may be as simple as removing the drivers with four screws, removing the spade lugs keeping the polarity in mind, reattaching the lugs on new driver with correct polarity, and remounting the drivers. The hardest part may be the felt over the tweeter flange.

 

[destinationsound]

The good news is, this repair may be as simple as removing the drivers with four screws, removing the spade lugs keeping the polarity in mind, reattaching the lugs on new driver with correct polarity, and remounting the drivers. The hardest part may be the felt over the tweeter flange.

I've got a tech coming within the next week.

He said the even easier first fix would be replacing fuses if they exist. fingers crossed it'll be that simple.

Either way he's going to do a checkup on speakers and amp (Pass Labs X5). I'll be sure to take many pictures and relay all findings to the group.

 

[MAB]

I've got a tech coming within the next week.

He said the even easier first fix would be replacing fuses if they exist. fingers crossed it'll be that simple.

Either way he's going to do a checkup on speakers and amp (Pass Labs X5). I'll be sure to take many pictures and relay all findings to the group.

This is great. Keep us posted!

 

[Grenadine]

Any updates on this?!

 

[MattHooper]

Just chiming in to say:

@MAB Has been a terrific source of knowledge and help in this thread for the OP. This is what can make ASR so useful.

 

[MAB]

Just chiming in to say:

@MAB Has been a terrific source of knowledge and help in this thread for the OP. This is what can make ASR so useful.

Thank you.

 

[materialbasis]

Looking for updates on this as well! I'm really curious as to what the tech had to say and what troubleshooting was done. Hope all is well with your speakers!