So I’ve had mine boxed up for a week or so ready to send back. A slight delay on that and, without any sound system now (I’ve sold my Naim kit), I decided to plug them back in. No distortion. After about 15mins I get distortion. Like you I think this indicates that a component is overheating. The fact that we both get this suggests three things: 1. We are using our Kefs in a manner that propagates this fault; 2. We happen to of received speakers from a bad manufacturing batch or a bad component; or 3. the thermal design of the LS50W is somehow inadequate.
With regard to 1) the only use case I can think of is to do with whether the speaker is always on (this is how I have been using the ls50w l) or whether it is turned off when notnin use. Tell me - prior to the fault developing did you power the speakers off when you were not using them?
I had them powered off (from the mains) up to the firmware update. After doing that the fault was awful and worse (voice distortion and a new one: ‘ticking’ when on AUX). I powered them off for an hour or more and the fault was then not apparent for some time when I listened to them again. KEF have got back to me, after I sent them a recording of the fault in full ‘bloom’ (it’s really horrible!), but shipping has yet to be arranged (I need the packing boxes). I use the KEFS, on a stand, with small room set and with the treble enhanced (for a damped room) using the KEF Android app. I also set standby to never occur when they are on (using the back-button trick) and I reset the speakers immediately after the update.
They are now ‘off-the-mains’ again while I listen to lovely stuff on headphones…to recalibrate my ears!
When I get home I will check what firmware I have. If a new one just came out it will be interesting to see what happens. Kinda nervous about updating.
Mine are in rural USA 120V from a power conditioner with UPS due to flaky power grid.
Mine are USA as well and I also use a power conditioner although my power is pretty good in Carlsbad, Ca.
I updated the firmware in May and the issue happened many months later so it was never my feeling the firmware impacted it.
I use these speakers many hours in the day.
Well I appreciate your contributions. For consideration I will report that I have had IDENTICAL problems in Treble as posted here. I noticed my speakers were MFGR’d in Nov 2016 and i purchased in Jan17, 2017 USA. I noticed a problem In January/ February and it was extremely intermittent, after playing for several hours, I contacted KEF, and they said there were no reports as mine; I figured it was something in my chain. I upgraded some other system components; but from the start had a Panamax Filtered power set-up; and all non-oem premium cables.
Recently, say the last 4 months have been extremely busy with work, and mostly played the speakers, under 4 hours a day, and not every day as before. Then I bought a new TT, and set it up, and upon hearing the distortion, this was on the pre-October Firmware; thought it had a problem, the TT, that is, never thinking it could possibly be the speakers, and bought a new cartridge, to test out the TT. In the process I broke a lead on the TT, and sent that out; and then started playing the KEFs more. The Distortion was present on vocals and Treble, about 30+ minutes into playing. Made several files; sent them to KEF in NJ, and they confirmed a defect, and after "receiving my old KEFs this past Thursday, will be sending me a new pair. The white are on backorder, and I was told it may be next week. I paid shipping and insurance to KEF ~$47 + 22 or $69. to ship! I searched the internet, and did not find these posts before tonight. I pressed KEF if this was a reliability issue and got NO Reply on that. I felt bad because I ruined a new TT set-up, and spent 1 1/2 days testing, trying to isolate the problem, never thinking it was the speakers. I did apply the October 9, Firmware update, and there was no improvement. my warranty will expire in 3 months. If there must be a problem, and we should be “protected” from it as consumers; and also sorry i bought them, NEVER thinking that their company might have a design flaw, after having experience with the 300W and going through 2 iterations, and apparently solving heat issues with those in the second generation. Please keep us up to date as I will you all. Chip Bayko The defect seemed to get worse, immediately before i sent them; i.e. no warm-up required, so I was thinking a hardware failure.
PPSS although i hadn’t seen these posts, I thought the problem might be more isolated, as I couldn’t find anything in other forums or on the Facebook KEF Owners Group. If there is a more widespread problem, it would seem to surface on Social media?
I had the ticking also, thought it might be a Hz interference, never thinking was speakers. I just sent a follow-up to KEF on my ticket, citing this forum; will let you know what i hear.
Heard for KEF US Support today, and they said: 10_23_2017
“We have learned of some rare occurrences of this issue. We have sent these units back to manufacturing, so that they can be evaluated on a case by case basis. It is extremely unlikely that you would encounter the same problem with a replacement set.”
The LS50W are a Flagship /Statement product for KEF, I believe because of that and their quality and reliability on all their products, that these are isolated issues, and not major design, hardware or software issues. chip Bayko
Besides my issue Chester, I have seen others report issues requiring a replacement. Some people more than one replacement. Check the Amazon reviews and comments in the Roon forum and computer audiophile forum. We are far from the only ones whose Kefs required replacement. The one year warranty is a concern for something like this. I wonder if its the same in Europe as they typically require longer warranties.
My replacement set just died and I’ve only had them a month.
Many people have been through several sets already.
There are many many reports of failed speakers.
This is systemic and Kef has a quality and reliability problem on their hands.
my replacement pair have now had four occurences of a ‘system failure’ (flashing lights and no sound from the left or right speaker solved by cucling the power).
my dealer has very kindly offered to give me a full refund. i am undecided as i love the sound of the Kefs but their reliability is certainly a cause of anxiety. partly tempted to take the offer and go for dynaudio.
No the 1st time the right speaker developed really loud static which I have heard has happened to others too. The lights flashed then too.
This time the left speaker stopped playing and starting making a loud clicking sound which sounds like a hardware failure.
That is not good news. I would certainly consider a refund. Partially because of you guys I decided against the KEF’s or any integrated devices and went oldschool (passive speakers, regular dac, no apps except Roon).
I just got them to work again. I left them off for awhile and unplugged. Then I did yet another hard reset. I had already done both of those things multiple times. This time they came up and started working with no more flashing lights.
The reset still didn’t work because they connected via the Kef app and a reset would have wiped out that connection.
So now my choice is to continue to live with them hoping it doesn’t happen again or sell them. The warranty expires in three months.
I don’t care how good the sound is nothing is worth this.
I had the first set 8 months and these 1 month so I’m sure I would not be able to get a refund from the dealer.
I’ve had other powered speakers that had no issues. I’d say this is a Kef issue. They clearly aren’t ready in either manufacturing or software development for this sort of thing.
What’s really frustratings is the Roon integration is so good.
I’ve had the Dynaudio Focus XD 200/20 (active speakers) placed on their own Dynaudio Stand 6 for about 16 months now with zero problems. They have a beautiful rich neutral warm tone.
They are not inexpensive.They are audiophile quality and Dynaudio manufactures their own drivers/housings etc…except for DAC chipset.
They have 2 other models in the Focus XD range.
Thinking about getting the XD600/60 (4 drivers and 150 watt amp per driver including tweeter).
Thinking about selling mine to help finance these.