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What to do with unsaleable speakers?


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Recently, my system developed a severe channel imbalance, with the left speaker being louder than the right.  I have been troubleshooting to find the source of the imbalance by swapping cables and sources.  After switching the speaker cables at my amp, I concluded that the issue almost certainly is with my 15 year-old Revel F32 Concerta speakers because the imbalance did not change.  

 

Reading a bit online, I concluded that the problem likely is with the crossovers or with one of the drivers.  It might be my hearing to blame, although there aren't huge differences between ears that would explain the shift in imaging.  My recent hearing exam discloses that I no longer hear anything in either ear above 10khz, so I can't really hear tweeter-only information with my ears near the tweeters, but I ended up suspecting a tweeter failure.  After coming to that conclusion, I called Revel, which confirmed that, in the F32 model, it's likely to be the tweeter that failed. 

 

Unfortunately, Revel no longer stocks parts for speakers this old and it doesn't have a factory-authorized service facility within 400 miles of here.  If parts were available and affordable, I might drag these 75 pound things down the stairs and into the van so I could take them to an independent facility to have them evaluated and repaired, but that can't happen without parts to fix them.

 

I now am reluctant to try selling these things because I can't guarantee they work properly.  I think I have the original boxes buried somewhere at the back of a storage unit.  Shipping two 85 pound boxes runs about $250 each way, so I can't see sending them anywhere from which they might have to be returned.  I could list them "as is" on Craigslist for a few hundred bucks, I suppose - they would be worth at least $1000 if healthy - but my wife is reluctant to admit Craigslist purchasers to our premises after being voir dired for a jury trying a murder that occurred during a Craigslist electronics sale.  I guess that leaves Goodwill, which could either sell them at retail or to an electronics recycler.   

 

Any other venues for disposal that I am overlooking?

 

I am not looking forward to replacing these, especially with compromised hearing.

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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I would have though that there was a local expert/enthusiast who could do the evaluation and find a way to repair such a speaker. Admittedly it could be hard to find a useful tweeter, but it's also possible that a standard crossover component (or something else easily obtainable) could be causing the problem.

 

Even if it's the tweeter, with your high-end hearing loss, close might be good enough--providing that you still like the sound.

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2 hours ago, GregWormald said:

I would have though that there was a local expert/enthusiast who could do the evaluation and find a way to repair such a speaker. Admittedly it could be hard to find a useful tweeter, but it's also possible that a standard crossover component (or something else easily obtainable) could be causing the problem.

 

Even if it's the tweeter, with your high-end hearing loss, close might be good enough--providing that you still like the sound.

I have zero doubt that sort of expertise exists, but I don't know how to find it, unfortunately.

 

You are right about the hearing loss. The speakers still sound listenable.  The concern at this point is about the effects on the imaging.  Maybe I should just spend some time rearranging placement so that the balance issues are minimized.

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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18 hours ago, Mike Rubin said:
23 hours ago, Mike Rubin said:

Recently, my system developed a severe channel imbalance, with the left speaker being louder than the right.  I have been troubleshooting to find the source of the imbalance by swapping cables and sources.  After switching the speaker cables at my amp, I concluded that the issue almost certainly is with my 15 year-old Revel F32 Concerta speakers because the imbalance did not change.  

 

Reading a bit online, I concluded that the problem likely is with the crossovers or with one of the drivers.  It might be my hearing to blame, although there aren't huge differences between ears that would explain the shift in imaging.  My recent hearing exam discloses that I no longer hear anything in either ear above 10khz, so I can't really hear tweeter-only information with my ears near the tweeters, but I ended up suspecting a tweeter failure.  After coming to that conclusion, I called Revel, which confirmed that, in the F32 model, it's likely to be the tweeter that failed. 

 

Unfortunately, Revel no longer stocks parts for speakers this old and it doesn't have a factory-authorized service facility within 400 miles of here.  If parts were available and affordable, I might drag these 75 pound things down the stairs and into the van so I could take them to an independent facility to have them evaluated and repaired, but that can't happen without parts to fix them.

 

I now am reluctant to try selling these things because I can't guarantee they work properly.  I think I have the original boxes buried somewhere at the back of a storage unit.  Shipping two 85 pound boxes runs about $250 each way, so I can't see sending them anywhere from which they might have to be returned.  I could list them "as is" on Craigslist for a few hundred bucks, I suppose - they would be worth at least $1000 if healthy - but my wife is reluctant to admit Craigslist purchasers to our premises after being voir dired for a jury trying a murder that occurred during a Craigslist electronics sale.  I guess that leaves Goodwill, which could either sell them at retail or to an electronics recycler.   

 

Any other venues for disposal that I am overlooking?

 

I am not looking forward to replacing these, especially with compromised hearing.

I have zero doubt that sort of expertise exists, but I don't know how to find it, unfortunately.

 

You are right about the hearing loss. The speakers still sound listenable.  The concern at this point is about the effects on the imaging.  Maybe I should just spend some time rearranging placement so that the balance issues are minimized.

 

Boy I understand that!  I have a n old pair of Dahlquist DQM 909 with Magnat drivers.  One speaker has a  mid not working right, and needs to be replaced.  Where on earth would one go to find these drivers that no longer exist, with a manufacturer that no longer exists?  

 

Working in the industry, drivers go obsolete all the time.  I know some folks who own older ProAc Studio 100s and the woofers are no longer available.  There is no solution.  You want to know that person out there who is sitting on a few spare parts, that must exist, but how would you find them?

 

Brad

Brad Lunde

www.LoneMountainAudio.com (High End Consumer Importer to the Trade) and www.TransAudioGroup.com (High End Pro Audio Importer to the Trade)

Brands we import to the US are ATC, Tube Tech, Drawmer, MUTEC, Bettermaker 

Brands from the US we distribute are A Designs, Auratone, Daking, LatchLake and Mojave   

 

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1 minute ago, Lone Mountain Audio said:

 

Boy I understand that!  I have a n old pair of Dahlquist DQM 909 with Magnat drivers.  One speaker has a  mid not working right, and needs to be replaced.  Where on earth would one go to find these drivers that no longer exist, with a manufacturer that no longer exists?  

 

Working in the industry, drivers go obsolete all the time.  I know some folks who own older ProAc Studio 100s and the woofers are no longer available.  There is no solution.  You want to know that person out there who is sitting on a few spare parts, that must exist, but how would you find them?

 

Brad

There might be some Revel parts at one of its distributors, I found out, although I am not holding my breath.


I have been mitigating the issue.  I switched the two speakers and the louder left is now the right.  (I can’t lift the speakers, but I was able to get a blanket under them and drag them along the hardwood floor.)  The louder speaker now plays in a less-enclosed space and the softer one is being reinforced by the proximity of an armoire where I keep the electronics.  The channels now are almost balanced, actually, so that much is good for the moment.

 

At some point, I will have to get serious about repairing or disposing of these speakers.  Until then, this change will help me limp along. 

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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3 minutes ago, GregWormald said:

I'd be trying internet searches (Google, DuckDuckGo...), asking questions at hi-fi forums, consulting local dealers/repairers, any FAQs for Revel, etc. Good luck.

Thanks!  Good tips.

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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You may be able to find tweeters that are a good match for what you have and change them out. There are probably lots of substitutions that will work well. Ditto the crossovers. Look at the later Revel models for which parts are still available.

 

Aurender N10, Esoteric F-05 Integrated Amplifier, Synergistic Active USB, Oppo 203, Synergistic Atmosphere Level 3 UEF Speaker cables, Legacy Audio Focus SE, Rega Planar 10 turntable with Aphelion 2 cartridge.

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1 hour ago, rwwjr44 said:

You may be able to find tweeters that are a good match for what you have and change them out. There are probably lots of substitutions that will work well. Ditto the crossovers. Look at the later Revel models for which parts are still available.

 

Thank you. 

 

During my conversation with the Revel tech support guy, I got the impression that this isn't a great idea, but maybe he just wanted me to buy new speakers. 

 

If I did this, I assume I would need to buy two of these, so that the two speakers are configured identically? 

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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1 hour ago, Mike Rubin said:

Thank you. 

 

During my conversation with the Revel tech support guy, I got the impression that this isn't a great idea, but maybe he just wanted me to buy new speakers. 

 

If I did this, I assume I would need to buy two of these, so that the two speakers are configured identically? 

 

 

Yes, you would need to maintain channel consistency but I would also imagine you need crossover adjustments, as the "new" tweeters would most likely not be the same identical sensitivity off the old ones.  Even a very small difference in sensitivity would be audible as more sensitivity means brighter if its a tweeter or darker if's lower sensitivity.  And its not the Tweeter's fault or the factory's as no production method offers precision in "adjusting" driver sensitivity without changing something else.  So it is what it is and the adjustments happen through crossover parts.  

 

It is important to account for this as the smallest change in sensitivity will make the entire driver band louder (the whole speaker sounds brighter in the case of a tweeter) or "darker" (less top end across the entire tweeter band).  This is MUCH more obvious than a small change in EQ.

 

I know this to be true as my company just went though all these issues in upgrading some later model ATC's to a new in house ATC built tweeter (replacing an externally supplied OEM one).  It thew me for a loop in how much change a 1/4 dB difference in sensitivity can make when I know a 1/4dB boost in EQ is almost impossible to hear.

 

SO it's not just tweeters, you must account for the change in driver sensitivity.

Brad    

Brad Lunde

www.LoneMountainAudio.com (High End Consumer Importer to the Trade) and www.TransAudioGroup.com (High End Pro Audio Importer to the Trade)

Brands we import to the US are ATC, Tube Tech, Drawmer, MUTEC, Bettermaker 

Brands from the US we distribute are A Designs, Auratone, Daking, LatchLake and Mojave   

 

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HARMAN LUX-A USA Return_Repair Form REV 10.11.16.pdf

 

Hi Mike, 

 

When my Revel subwoofer went out, I was able to just remove the rear panel and then I mailed the panel to Pyramid Audio (Revel authorized service provider).   They fixed it and mailed it back to me at very reasonable price.  Could you just remove the tweeter and mail it for service?

 

P.S. I understand the Performa F32, C32, and M22 speakers share the same tweeter.

Speaker Room: Lumin U1X | Lampizator Pacific 2 | Viva Linea | Constellation Inspiration Stereo 1.0 | FinkTeam Kim | Revel subs  

Office Headphone System: Lumin U1X | Lampizator Golden Gate 3 | Viva Egoista | Abyss AB1266 Phi TC 

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59 minutes ago, Blake said:

HARMAN LUX-A USA Return_Repair Form REV 10.11.16.pdf 495.15 kB · 1 download

 

Hi Mike, 

 

When my Revel subwoofer went out, I was able to just remove the rear panel and then I mailed the panel to Pyramid Audio (Revel authorized service provider).   They fixed it and mailed it back to me at very reasonable price.  Could you just remove the tweeter and mail it for service?

 

P.S. I understand the Performa F32, C32, and M22 speakers share the same tweeter.

Nope!  The Revel support guy checked and said there are no repair parts available.  He told me that they stop carrying repair inventory after about 15 years from start of production (although I suspect that it's really the industry-standard seven years from end of production, given the dates of start, end, and inventory discontinuance that he gave me.)

 

At this point, I think I will live with what I have until I replace these. With at least 20 years of speaker development since these came to market, I probably can find their equal at less than what I paid for these. 

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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I don’t think you know exactly what’s wrong yet - you’re trying to treat an unknown disease on the basis of guesswork, but you need facts to make the diagnosis. The fact that tweeters “often fail” in that model does not mean that yours did.  You describe the imbalance as “severe” but say you can’t hear anything over 10k.  Your tweeters start putting out at close to 3k, as I recall, and that’s where timbre, brilliance, “air” etc start to be defined but none of the fundamentals and major harmonics are that high.

 

It’s a bit hard to believe that you can easily hear a gross imbalance in SPL from lack of output above 3k, especially if you truly have no functional hearing sensitivity above 10k. It’s a truly rare audiogram that breaks sharply at a specific frequency and even rarer if it’s bilaterally symmetric - so you almost certainly have a progressive loss of threshold sensitivity that starts at or below 1k.


All you know for sure (assuming that it’s constantly on the same side despite swapping input or output channels/cables) is that there’s a problem in one of your speakers.  There are several things you can do to get a more accurate diagnosis.

 

  1. A simple, cheap SPL meter is very useful, but if the imbalance is truly big, just download a free SPL “meter” for your smartphone 
  2. You can use recorded music as a test source, but you might want to use an online sine wave generator to ensure consistency of input levels and signal between channels. You can use the audio out jack on your phone or computer - SQ is irrelevant here.  Obviously an external DAC is also fine to use.
  3. I’m pretty sure your speakers are designed for biamping.  Remove the jumpers and connect your amplifier’s outputs to the bass input terminals ONLY.  Listen to and measure the SPL from each channel from a close, fixed distance on the axis of each driven speaker.
  4. Move your speaker leads to the high frequency terminals and do it all again.  If using a tone generator, start at 1k and go up from there.

I don’t know where those terminals are in the crossover chain, i.e. whether there’s any filtration between them and the drivers or if they’re direct (which I doubt). You’ll need to find out from Revel, because it will affect the information this test will give you.  If those terminals are inputs to the crossover, any imbalance could still be caused by a driver or a component in the crossover.


If the imbalance is audible only through the bass terminals, the problem is almost certainly not your tweeter.  If it becomes audible at some point while sweeping the frequency upward using a tone generator into the full frequency inputs (with jumpers in place), you’ll know where it starts and that should narrow the search.  Just for completeness, you might also want to check the jumpers themselves and the terminals to which they connect.

 

And if it really is a tweeter, you can simply remove the jumpers and wire up to a pair of external add-on tweeters. There used to be many on the market.  You could even use a good, small, inexpensive passive “monitor” as your new tweeter - there are many excellent ones for less than $100/pair.  If your HF hearing is that compromised, this should be fine - just sit them on top of the Revels.  To the inevitable critics about to post how terrible this solution is, I don’t think the phase and sensitivity differences will matter much to someone with poor high frequency hearing - especially when the stated alternative is to use boundary effect as a fix and listen to them as they are now.

 

Good luck!

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14 minutes ago, bluesman said:

I don’t think you know exactly what’s wrong yet - you’re trying to treat an unknown disease on the basis of guesswork, but you need facts to make the diagnosis. The fact that tweeters “often fail” in that model does not mean that yours did.  You describe the imbalance as “severe” but say you can’t hear anything over 10k.  Your tweeters start putting out at close to 3k, as I recall, and that’s where timbre, brilliance, “air” etc start to be defined but none of the fundamentals and major harmonics are that high.

 

It’s a bit hard to believe that you can easily hear a gross imbalance in SPL from lack of output above 3k, especially if you truly have no functional hearing sensitivity above 10k. It’s a truly rare audiogram that breaks sharply at a specific frequency and even rarer if it’s bilaterally symmetric - so you almost certainly have a progressive loss of threshold sensitivity that starts at or below 1k.


All you know for sure (assuming that it’s constantly on the same side despite swapping input or output channels/cables) is that there’s a problem in one of your speakers.  There are several things you can do to get a more accurate diagnosis.

 

  1. A simple, cheap SPL meter is very useful, but if the imbalance is truly big, just download a free SPL “meter” for your smartphone 
  2. You can use recorded music as a test source, but you might want to use an online sine wave generator to ensure consistency of input levels and signal between channels. You can use the audio out jack on your phone or computer - SQ is irrelevant here.  Obviously an external DAC is also fine to use.
  3. I’m pretty sure your speakers are designed for biamping.  Remove the jumpers and connect your amplifier’s outputs to the bass input terminals ONLY.  Listen to and measure the SPL from each channel from a close, fixed distance on the axis of each driven speaker.
  4. Move your speaker leads to the high frequency terminals and do it all again.  If using a tone generator, start at 1k and go up from there.

I don’t know where those terminals are in the crossover chain, i.e. whether there’s any filtration between them and the drivers or if they’re direct (which I doubt). You’ll need to find out from Revel, because it will affect the information this test will give you.  If those terminals are inputs to the crossover, any imbalance could still be caused by a driver or a component in the crossover.


If the imbalance is audible only through the bass terminals, the problem is almost certainly not your tweeter.  If it becomes audible at some point while sweeping the frequency upward using a tone generator into the full frequency inputs (with jumpers in place), you’ll know where it starts and that should narrow the search.  Just for completeness, you might also want to check the jumpers themselves and the terminals to which they connect.

 

And if it really is a tweeter, you can simply remove the jumpers and wire up to a pair of external add-on tweeters. There used to be many on the market.  You could even use a good, small, inexpensive “monitor” as your new tweeter - the JBL 305s are excellent and have onboard adjustable attenuation.  If your HF hearing is that compromised, this should be fine - just sit them on top of the Revels.

 

Good luck!

Thank you very much for this detailed precis!  
 

I will be home a lot for the next few months - nearly all of us will- and this gives me a chance to undertake more detailed testing.

 

Just a few things:  

 

These are jumpered now, so I can play with the two sets of terminals that you suggest.  
 

I also have a system test record that plays tones at about 40 closely-spaced frequencies.  I haven’t had the patience to start at the bottom, but, beginning at about 2500 hz does reflect an audible imbalance, although the degree depends on the end of the couch that I occupy.  I will use my phone’s SPL app to verify more precisely; that hadn’t occurred to me.

 

Finally, if I end up having to mate outboard tweeters, I will just move on from these speakers.  Their market value isn’t really that high snd I’ve gotten my money’s worth ovr the more than 15 years I have had these.

 

Thanks again!

Living room:  Synology 218+ NAS > NUC 10 i7 > HQP Embedded > xfinity Xfi Router > Netgear GS348 Switch > Sonore Optical Module Deluxe > Sonore Signature Rendu SE Optical Tier 2 > Okto DAC 8 Stereo > Topping Pre90 Preamp > Apollon Audio 1ET400A Mini > Revel F32 Concertas

 

Computer Desk System: Synology DS-218+ NAS > Dell XPS 8930/NUC 10 i7  > HQP Desktop > xfinity Xfi Router > EtherRegen > ultraRendu > Topping D90 DAC > Audioengine A5+'s

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17 minutes ago, Mike Rubin said:

Thank you very much for this detailed precis!  
 

I will be home a lot for the next few months - nearly all of us will- and this gives me a chance to undertake more detailed testing.

 

Just a few things:  

 

These are jumpered now, so I can play with the two sets of terminals that you suggest.  
 

I also have a system test record that plays tones at about 40 closely-spaced frequencies.  I haven’t had the patience to start at the bottom, but, beginning at about 2500 hz does reflect an audible imbalance, although the degree depends on the end of the couch that I occupy.  I will use my phone’s SPL app to verify more precisely; that hadn’t occurred to me.

 

Finally, if I end up having to mate outboard tweeters, I will just move on from these speakers.  Their market value isn’t really that high snd I’ve gotten my money’s worth ovr the more than 15 years I have had these.

 

Thanks again!

You’re welcome - but to be honest, I suspect it’s not a tweeter and new speakers may be the best choice. Having said that, it’s always worth a thorough evaluation first.  Measure very close to each driver - you won’t learn much from the ends of the couch. Hold the microphone right in front of the cone. A fixed measured distance is best, and a tripod or other stable support to hold it at the same angle makes the measurement even more repeatable.
 

I still listen to the Rogers LS3/5a monitors I bought new in 1976, and my son uses my KLH 19s (circa 1969) in his home theater system. Age is just one factor for both speakers and for their owners :) 

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1 hour ago, Lone Mountain Audio said:

Another simple test is to swap tweeters from right to left/left to right.  Does the loss follow tweeters or stay the same with the crossovers?  That narrows it down fast. 

 

Brad 

It’s a lot easier to move wires between terminals than to swap tweeters, especially if you do it at the amplifier.

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32 minutes ago, bluesman said:

It’s a lot easier to move wires between terminals than to swap tweeters, especially if you do it at the amplifier.

 

If you are speaking of a biamp or triamp speaker input panels, many of these are not direct inputs to the tweeter.  They are usually inputs to the passive network and a HF section of a network still outputs something to the midrange; a passive biamp network is not a brick wall protecting the tweeter.  Plus there are many parts prior to the tweeter so if the network is bad (has bad parts) then you might think its the tweeter when its really the network.  

 

The only failsafe way to check is to physically disconnect and switch the tweeter between right and left.

 

Brad 

 

Brad Lunde

www.LoneMountainAudio.com (High End Consumer Importer to the Trade) and www.TransAudioGroup.com (High End Pro Audio Importer to the Trade)

Brands we import to the US are ATC, Tube Tech, Drawmer, MUTEC, Bettermaker 

Brands from the US we distribute are A Designs, Auratone, Daking, LatchLake and Mojave   

 

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2 hours ago, Lone Mountain Audio said:

 

If you are speaking of a biamp or triamp speaker input panels, many of these are not direct inputs to the tweeter.  They are usually inputs to the passive network and a HF section of a network still outputs something to the midrange; a passive biamp network is not a brick wall protecting the tweeter.  Plus there are many parts prior to the tweeter so if the network is bad (has bad parts) then you might think its the tweeter when its really the network.  

 

The only failsafe way to check is to physically disconnect and switch the tweeter between right and left.

 

Brad 

 

You might want to read my post above discussing this.  Here’s the relevant quote so you won’t have to search for it:

 

I don’t know where those terminals are in the crossover chain, i.e. whether there’s any filtration between them and the drivers or if they’re direct (which I doubt). You’ll need to find out from Revel, because it will affect the information this test will give you.  If those terminals are inputs to the crossover, any imbalance could still be caused by a driver or a component in the crossover.

 

So as I said above, start with the wires and go to the driver itself if the problem is tweeter-related. I think it’s probably not, based on the description.  A truly gross loudness discrepancy is unlikely if it’s the tweeter, which starts getting its drive at 2700 Hz in this system. This is especially true for a listener with what he describes as a severe high frequency hearing loss in both ears, unless he has a bizarre cochlear disorder with severe recruitment (which is also very unlikely).

 

I think he’s much more likely to find the problem driving only the midrange down and will never have to test the HF circuitry or driver. I could be wrong, but the only data we have suggest that I’m not.

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Sorry Bluesman, I missed that post and said the same thing you did.  Forgive me!  I agree tweeters are so small and delicate they usually either work or are dead- I've not seen them reduce level and stay consistent response wise.  I am with you, it is likely midrange crossover or some unusual failure.

 

Brad 

Brad Lunde

www.LoneMountainAudio.com (High End Consumer Importer to the Trade) and www.TransAudioGroup.com (High End Pro Audio Importer to the Trade)

Brands we import to the US are ATC, Tube Tech, Drawmer, MUTEC, Bettermaker 

Brands from the US we distribute are A Designs, Auratone, Daking, LatchLake and Mojave   

 

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36 minutes ago, Lone Mountain Audio said:

Sorry Bluesman, I missed that post and said the same thing you did.  Forgive me!  I agree tweeters are so small and delicate they usually either work or are dead- I've not seen them reduce level and stay consistent response wise.  I am with you, it is likely midrange crossover or some unusual failure.

 

Brad 

No worries, Brad.  But this isn’t a matter of opinion - the physics of sound tell the story. The combined SPL of two sound sources of equal levels is an additional 3 dB, which (although clearly audible to listeners whose hearing sensitivity to the frequency range in question is adequate) is not a major difference. And I assure you that a tweeter crossing over at 2700 Hz is not putting out an SPL equal to that of the other drivers in that system - so its contribution to the speaker system’s output is less than 3 dB above the output of the other drivers. Even if totally nonfunctional, it would simply not cause a gross level discrepancy in comparison with the functional side.

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Agreed.  ATC crosses over at 3800Hz as well, so we are well familiar with this idea.   A 3 dB boost at some frequency would eb heard to hear, but an entire band being down 3dB is audibly quite significant (to us).  

 

People's idea about what is "louder" or "softer" is often different to what we think and measure with our Audio Precision 515x.

 

Brad    

Brad Lunde

www.LoneMountainAudio.com (High End Consumer Importer to the Trade) and www.TransAudioGroup.com (High End Pro Audio Importer to the Trade)

Brands we import to the US are ATC, Tube Tech, Drawmer, MUTEC, Bettermaker 

Brands from the US we distribute are A Designs, Auratone, Daking, LatchLake and Mojave   

 

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I'd continue troubleshooting cause it could be a simple fix. It's 100% the crossover or the tweeter.

 

Going off old photos, the crossover PCB can be neatly detached with an allen key. It's going to be similar to the PCB from the F12 shown on the Stereophile website review, except the F32 also had funky variable resistors and switches to set different crossover values for bass and treble. Have you already tried adjusting the tweeter level dial? Maybe one of those resistors has shorted, or there's a discontinuity going from crossover input to the tweeter plus or minus terminals. You could check that with a multimeter if you can get at the crossover. 

 

If it's the tweeter, well the brochure says the F32 is a 3-way with crossover frequencies of 190hz and 2.7khz, 86.5db senstivity, 6.5ohms nominal impedance. Photos show the F32's tweeter uses a standard circular faceplate (rather than the proprietary recessed waveguided unit in the F12). Finding suitable replacements (for both speakers) that fit the basic specs from Seas/Scanspeak etc, could be easy, and given you have tweeter level adjustment controls on the crossover, it could well bring a very good change as well as a complete fix. To test if it's the tweeter, you could unscrew it, unplug it and test continuity again, plus swap in the one from the other speaker / vice versa.

 

If you wanted to dispose of them, you could make an ebay listing as "parts only" and "local pickup only" (there should be less crazies on Ebay, and well, you can make them pay beforehand).

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