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What to do with unsaleable speakers?


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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 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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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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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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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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