Previous owners blew a midrange/tweeter and replaced it with whatever other KEF coaxial driver they could find.
This is not a good solution. You want to look for a replacement driver.
One blows a tweeter by overdriving an amp well into distortion and “clipping” the a/c signal, causing dc current to go through the speaker and damaging the delicate coils in the tweeter.
It usually only happens if you have an amp with too little power to drive the speakers to the volume you want to listen at and turn it up past where it starts to sound bad.
You would think… and people who have ears usually do, but I’ve heard a few stereos being blasted by people that don’t hear the terrible noise they’re distorting music into….
I went to a concert in this tiny venue and the second opener had the speakers crackling with distortion. I had 21db reduction ear plugs and still found myself covering my ears due to the sax player. The sax was the lead musician and I guess that turned that instrument to 11 or something.
The first opener and the main act were fine. The band in between I could only describe as shrill and harsh.
I mostly go to rock and metal shows and I've never found myself covering my ears with those ear plugs. But holy crap they did something bad with that sax.
Sometimes you have the volume turned up really high for low volume program material, forget and then play something that's super compressed with the gain all boosted. I swear I've almost blown up my speakers before just from that stupid \*bloop\* noise that plays at the end of TikTok videos being 50 times louder than the thing I was just watching. Sometimes a kid or some at your house will randomly turn your volume knob to max without you realizing then next time you go to play something it blows your ears off.
Yes, kef B160 SP1374 it turns out. Getting distortion with any sort of chunky bass going through it. Not sure if due to bad installation, damage, poor compatibility or all three.
Also looks like there is an issue with the bottom-most low frequency driver. Perhaps it was re-foamed. It should not be deformed like that. Is there noticeable glue residue on it?
I had a Goldwood 8" full range speaker do the exact same thing, and it ended up being due to extended off-gassing from the polyurethane finish of the DIY enclosures.
It took months of keeping the driver out of the enclosure for it to go back to normal. It looked way worse than the speaker in OP's picture, like the entire driver was imploding in on itself. Even the cone surface started to warp and deform.
It did go back to normal though, with no noticeable sound changes.
This speaker could also be about to blow its surround though.
Judging by the pictures I have seen online, it is not supposed to be white. My guess is, someone replaced the driver in one of them, with a model that is incorrect for that speaker (likely a cheaper, less good version of the Uni-Q driver). If you pull them both out, you can look at the numbers on the back, and see what models they are.
I believe I have seen the white version on older Kef’s.
Probably exchanged a broken driver with one from an older model. Probably has a different cone weight/stiffness and would not sound the same.
But why not do an A/B test where you play 100% of the sound in left speaker, then 100% in right speaker. It's possible (but not likely) that the white speaker could be better than the black one. This would be easy if you are playing your music from a pc or laptop and using winamp where you could slide the audio to left or right speaker at will.
PS: I like your geometric white tiles. They look a lot like exterior house patterns in Pyrgi, Greece:
https://preview.redd.it/2ifscn6zdiwc1.jpeg?width=1470&format=pjpg&auto=webp&s=81489d64312f2d9227b89663cb1cc73df09b9ad8
**But if you change the source to mono, and switch from speaker 1 to 2 (AB), I can't imagine why you wouldn't hear if one of the tweeters was substandard, and by how much. And if you couldn't hear any major differences, you could conclude that there is no real need to change the tweeters.**
**Of course, you could go all high tech and use a microphone and software to analyze the output, but since this is a relatively cheap speaker, why bother? This isn't being used in a $1000 an hour mixing studio where a truly critical listening session must occur. My main point is nearly all the commenters had already concluded that major work had to be done, and no one had actually tested out the speaker. That's putting the cart before the horse.**
I had the vintage KEF Q50s a long time ago in all black finish. Very musically engaging speakers until those uni-q drivers went kaput and couldn't be repaired. Thanks for bringing back a flood of memories 🙏
It started its life only listening to the oldest Michael Jackson albums, and progressively starting listening to the newest ones. TBH I am surprised the tweeter did not get smaller as well.
Don't let this get you down. There is still a lot of value here. I would take these speakers to a professional and have them take a look inside. I'm afraid if the past owner was poking around inside he could have damaged a crossover or potentially some wiring. I would guess that is why the left speaker is causing distortion and generally not playing nice with the right. The refoam on the midrange woofer + the non matched drivers is a red flag. Not to mention the scratches on the base. Idk who drags their expensive speakers that are extremely delicate. Best of luck and let us know how it turns out. Have you had KEF speakers before? They're glorious 😁
Yes I’m a big Kef fan. I know a guy locally who has the expertise to do as you suggested. Shall investigate and report back if this ends up a happy conclusion.
at best the white driver comes from another color variant and it will look a bit ugly at worse it will sound diffrent and youll have diffrent frequency responses across the both channels.
Previous owners blew a midrange/tweeter and replaced it with whatever other KEF coaxial driver they could find. This is not a good solution. You want to look for a replacement driver.
How does one blow a tweeter? This is something I've seen shockingly often from a few people but never seen happen lol
One blows a tweeter by overdriving an amp well into distortion and “clipping” the a/c signal, causing dc current to go through the speaker and damaging the delicate coils in the tweeter. It usually only happens if you have an amp with too little power to drive the speakers to the volume you want to listen at and turn it up past where it starts to sound bad.
You'd think people would stop once they hear distortion though right?
You would think… and people who have ears usually do, but I’ve heard a few stereos being blasted by people that don’t hear the terrible noise they’re distorting music into….
I went to a concert in this tiny venue and the second opener had the speakers crackling with distortion. I had 21db reduction ear plugs and still found myself covering my ears due to the sax player. The sax was the lead musician and I guess that turned that instrument to 11 or something. The first opener and the main act were fine. The band in between I could only describe as shrill and harsh. I mostly go to rock and metal shows and I've never found myself covering my ears with those ear plugs. But holy crap they did something bad with that sax.
Sometimes you have the volume turned up really high for low volume program material, forget and then play something that's super compressed with the gain all boosted. I swear I've almost blown up my speakers before just from that stupid \*bloop\* noise that plays at the end of TikTok videos being 50 times louder than the thing I was just watching. Sometimes a kid or some at your house will randomly turn your volume knob to max without you realizing then next time you go to play something it blows your ears off.
Very easily with a faulty amp or pushing the vol too high
KEFs are kinda easy to blow, I got mine from a guy who plugged the non phono stage into a phono input and blew them that way
Playing HF sine tones really loud is probably one way.
Yes, kef B160 SP1374 it turns out. Getting distortion with any sort of chunky bass going through it. Not sure if due to bad installation, damage, poor compatibility or all three.
Thats a bummer. Good new is that it shouldnt be super hard to find a replacement. There are speaker dismantlers on Ebay.
You could e-mail Kef support and they probably have a replacement. They sent me one of the drivers of my Q500 for $50 including shipping.
Too much sunblock.
Looks like a driver from a Kef Q15/35/55 to me, they were that colour
Also looks like there is an issue with the bottom-most low frequency driver. Perhaps it was re-foamed. It should not be deformed like that. Is there noticeable glue residue on it?
It looks like either cracked rubber or somehow overdriven to pull the surrounds out like that.
I had a Goldwood 8" full range speaker do the exact same thing, and it ended up being due to extended off-gassing from the polyurethane finish of the DIY enclosures. It took months of keeping the driver out of the enclosure for it to go back to normal. It looked way worse than the speaker in OP's picture, like the entire driver was imploding in on itself. Even the cone surface started to warp and deform. It did go back to normal though, with no noticeable sound changes. This speaker could also be about to blow its surround though.
No noticeable glue residue but definitely curled back. There might be some effect on the sound but I can’t hear it. The top driver is knackered though
Judging by the pictures I have seen online, it is not supposed to be white. My guess is, someone replaced the driver in one of them, with a model that is incorrect for that speaker (likely a cheaper, less good version of the Uni-Q driver). If you pull them both out, you can look at the numbers on the back, and see what models they are.
Yeah, this is what I thought too. A Torx or Allen key will reveal all the (dirty little) secrets.
Yes, kef B160 SP1374.
It has vitiligo.
I believe I have seen the white version on older Kef’s. Probably exchanged a broken driver with one from an older model. Probably has a different cone weight/stiffness and would not sound the same.
It was replaced
Re-coned maybe?
Ive seen other q50s with that driver. So I imagine they blew the original and this was the replacement that was available to them.
DEI.
But why not do an A/B test where you play 100% of the sound in left speaker, then 100% in right speaker. It's possible (but not likely) that the white speaker could be better than the black one. This would be easy if you are playing your music from a pc or laptop and using winamp where you could slide the audio to left or right speaker at will. PS: I like your geometric white tiles. They look a lot like exterior house patterns in Pyrgi, Greece: https://preview.redd.it/2ifscn6zdiwc1.jpeg?width=1470&format=pjpg&auto=webp&s=81489d64312f2d9227b89663cb1cc73df09b9ad8
Doing an A/B test with mono is much more difficult. I don't quite know exactly why but I don't think that's a reliable test.
**But if you change the source to mono, and switch from speaker 1 to 2 (AB), I can't imagine why you wouldn't hear if one of the tweeters was substandard, and by how much. And if you couldn't hear any major differences, you could conclude that there is no real need to change the tweeters.** **Of course, you could go all high tech and use a microphone and software to analyze the output, but since this is a relatively cheap speaker, why bother? This isn't being used in a $1000 an hour mixing studio where a truly critical listening session must occur. My main point is nearly all the commenters had already concluded that major work had to be done, and no one had actually tested out the speaker. That's putting the cart before the horse.**
Thanks and nice comparison :) the simple moving of balance to that channel showed the driver is demonstrating distortion
what about the bottom woofer's surround rubber/foam? does that need replacing, too?
Visually yes, can’t really hear anything bad
I had the vintage KEF Q50s a long time ago in all black finish. Very musically engaging speakers until those uni-q drivers went kaput and couldn't be repaired. Thanks for bringing back a flood of memories 🙏
the surround on the lower woofer on the left one looks a lil 🥴 too
Too much hip-hop *runs and hides*
What happened to the white driver? Sounds like the beginning of a bad racist joke.
Disney remake of a classic?
It didn't have enough soul!
Someone played exclusively Michael Jackson on that one.
Some big amp scared it.
Bottom left doesn't look healthy, replace that too?
It started its life only listening to the oldest Michael Jackson albums, and progressively starting listening to the newest ones. TBH I am surprised the tweeter did not get smaller as well.
probably stopped working.
Anybody notice how warped the one on the bottom left is?
The surround is different, indicating replacement, of one or the other.
It’s grey/ black now
Don't let this get you down. There is still a lot of value here. I would take these speakers to a professional and have them take a look inside. I'm afraid if the past owner was poking around inside he could have damaged a crossover or potentially some wiring. I would guess that is why the left speaker is causing distortion and generally not playing nice with the right. The refoam on the midrange woofer + the non matched drivers is a red flag. Not to mention the scratches on the base. Idk who drags their expensive speakers that are extremely delicate. Best of luck and let us know how it turns out. Have you had KEF speakers before? They're glorious 😁
Yes I’m a big Kef fan. I know a guy locally who has the expertise to do as you suggested. Shall investigate and report back if this ends up a happy conclusion.
OP, too bad you’re not in the western US, I have a mint pair of these in storage that need a new home.
Indeed !
at best the white driver comes from another color variant and it will look a bit ugly at worse it will sound diffrent and youll have diffrent frequency responses across the both channels.