KEF Subwoofer Problem


New member
Aug 10, 2019
Hi all

Having problems with my KEF PSW2010 SUB. It makes a constant hum when on and will not not play sound.

Any help would be apprecaited.

KEF want £116 to replace the unit. I hear though that this is an updated unit.

Again comments on this would be good too.

Ravey Gravey Davy

Well-known member
Apr 28, 2008
If you google kef subwoofer problem you will find a few threads on this same issue.If left on auto and there is no input ,it will go into quiet mode,and people have left it like this meaning it is permanantly fired up .As a consequence some of the circuit board overheats and melts.It's up to you whether you get it fixed or buy a replacement.If you get it fixed always switch it right off by the main on/off switch.

I've got the same one and it is pretty good.You could always buy the new Kube 2 if you are feeling flush.It has good reviews.


Well-known member
Dec 23, 2007
Hi David

I'm not sure what help anyone can be - clearly it's knackered so needs replacing or repairing... if it's under warranty you should be fine, if not, then sadly you'll have to pay

For what it's worth though my sub has always hummed!!


I had the same problem. No matter what you connect, or even if you disconnect everything, it still hums.

I got my repaired, apparently it is easier to just replace the entire board in a sub and as I was told that there is only the board and the drive unit in there then you effectively get a new sub when they replace the board - if you see what I mean.

I always thought that the sub powered down when not in use, but the standby on the sub is actually quite a warm standby, so it is basically on all the time which accelerates the demise of the internal bits.

Anyway, once the board is replaced then it's fine. So, choice is - new sub or repair old one.


Just re-read your post. KEF said £116 to replace it - Hmm new sub for £116, bargain.


Thanks all for the reply's, that is what happened silly me!

Do any of you have a contact for repair nearer to West Yorkshire or is back to KEF only???




Hi all,

I've just had exactly the same failiure with my psw2010 a couple of weeks ago(although from what I've now seen about the poor reliability of these kef products I've had a good run s mine is 3 years almost to the day!), the buzz or hum is from the power relay(basically an on off power switch) which when it fails constantly switches from on and off when powered .

I assume, like me those who have experienced this fault may have noticed that the noise starts when the sub is on auto and switces on (red LED to green LED) a closer listen to the driver on mine i could still hear the sound signal aurally strobed if you like as well as the noise from the relay!

I like David contacted Kef asking if they could provide me with just the relay(cost should be no more than £15) as being 3 years old and well outside warranty I wanted to try to repair it myself, but got the same £116 repair quote also stating 12 months warranty on any parts replaced, what about the rest of it if next month an unrelated part fails...another £116? As I only paid £199 for it 3 years ago for me its simply not worth it!

I then contacted the uk office of the manufacterer of the relay but was told that relay is'nt held in the uk(note the made in china label on amp plate!) and could only be ordered in 500 pieces!

Right now I can't afford the £200 to buy a new sub so my interim solution has been to turn my active sub into a passive one i've stripped out the power transformer and amplifier pcb left the control knob pcb in place disconnected, just purchased a 120khz 8ohm 600w peak subwoofer crossover on ebay for £5.99 + £3.00 p+p and will just double up speaker cable to main L + R channels on my Yamaha amp and solder to the input on the crossover and voila, I still have working sub with a less than £10 repair cost!

P.S. I won't buy any Kef products in the future!


Thank you Djdanc for this infomation. I too have spoken to various speaker/electronics speacilist locally who all say the KEF will not release any workshop manuals and are not repairers but speaker folk who buy in amps to fit.

I wish somebody would be able to repair because the cost would be negligble for us poor credit crunch hit owners!!!!!!!!


Well if this helps anyone with a failed kef active sub and doesn't have £200 or so spare for a replacement or £116 for kef to put a new amp in it!

If you have a decent Amp/Receiver(mine's aYAMAHA DSP-AX757SE) and decent/floorstanding main/front speaker(i've got MISSION M35i's) here's my solution you can try (if you can handle a screwdriver, pliers and some wire cutters) that cost me less than £10 and a couple of hours of my time installing and tuning in!

Go to this link to see the back panel removed from the cabinet,

I removed all the components up to the top PCB that is for the knob and swich controls on the back panel.

Then i bought a crossover see link below

I then connected the wires red(+) and black(-) that come out of the cabinet straight on to the + and - output terminals on the crossover

Next I cut speaker cable to length from receiver to sub, pushed through the hole left by the 110/240 volt switch, crimped on a couple of female connectors and pushed those on to the input terminals on the crossover.

Then connect the + speaker cable from the sub to one of the + terminals (L or R channel) together with the main speakers cable then connect the - speaker cable from the sub to the opposite channel - terminal together with the main speakers, e.g.sub + to R +. sub - to L -.

or sub + L +. sub - to R -.

Have to say so far i'm delighted with the results, which stands to reason as the sub is now powered by a much better quality amplifier and fed better frequency's by this bargain priced crossover!(if you have home cine amp/receiver makes sure lfe/low freq's are set to front or both not sub only!)

It sounds better balanced, again makes sense all the speakers are powered by the YAMAHA and makes me think that if you have larger main speakers instead of a small/satallite set up, a passive sub driven by a quality amp is a better balanced set up!


Hi all again,

Just to confirm, for anyone interested below is the reply email i received from Kef and to point out that you do not get a new sub for £116, but the amplifier section is repaired/replaced and don't forget it will be a few quid postage on top of that to send back to Kef as it weighs a few kilos!

Also if the driver in the cabinet failed that wouldn't be covered by the new warranty

I have a PSW2010 subwoofer that has
developed what I believe to be a faulty relay,(see attached pics) makes a
horrible buzzing noise when running after switching in from standby(LED red) to
on(LED green).
As I have had the speaker for 3 years I understand I'm well
outside any warranty period, but if the cost of a replacement relay isn't
prohibitve and is available I would like to buy one and any sundries
required(the white paste/mastic? that is applied the base of the relay and some
of the other components on the PCB) to repair.
Any advice on repairing my PSW2010
would also be much appreciated!

I am sorry to hear that you are experiencing problems with your

By the description you have given, it sounds like the relays on the amplifier
have developed a fault.

We are unable to send out repair kits to non electronic engineers as it is
very easy to damage the amplifier further so we do recommend that you return the
unit to us.

You can return the amplifier section to us by removing the eight screws on
the outer edge of the back of the unit and disconnecting the two cables inside.
Once removed, carefully package the amplifier and send it to the following
address with a covering letter. When sending the parcel, please make sure that
you send it recorded delivery or get a tracking number if sending by courier.
The repair charge will cost £116.33 inclusive of VAT and carriage back to you,
and you will also receive a new twelve month warranty on the replaced parts.

The address is as follows:


GP Acoustics

Eccleston Road




ME15 6QP

Best regards,​
Richard Coleman​
Technical Support and
Service Dept​
GP Acoustics (UK)
Tel : 01622 766631​

Try my solution if funds are tight!
Jan 1, 2015
Pls, I need somebody to help me with my KEF R400b Subwoofer. It keeps tripping off after about 1minute when swiched on. The indicator changes from green to red and their is no sound from the subwoffer afterward. When it is switched-off and switched-on again the green light comes up for about 1 minute a with the sound and switched-off again.

I will be happy to hear from the oneone with solution as soon as possible.


Frank Harvey

Well-known member
Jun 27, 2008
hybridauth_Facebook_100000014654164 said:
Pls, I need somebody to help me with my KEF R400b Subwoofer. It keeps tripping off after about 1minute when swiched on. The indicator changes from green to red and their is no sound from the subwoffer afterward. When it is switched-off and switched-on again the green light comes up for about 1 minute a with the sound and switched-off again.

I will be happy to hear from the oneone with solution as soon as possible.


You'll need to speak to your retailer, as there isn't really anything that anybody can do for you on here. Your unit will be repaired (if) under warranty, or replaced if you've just bought it.


New member
Jul 24, 2016
My old KEF subwoofer did the same thing and I ended up throwing in the bin. I bought a new one a few years back and it started buzzing last week!! I started researching it and found a youtube video where a guy put a magnetic screwdtriver on the small black relay box and it stopped. I happened to have some industrial magnetics in the house and taped one down to the top of the relay box and WALLA it stopped and its working fine now. It needs to be taped to the left side. Here is the video with the screwdriver demonstrating where to put the magnet. the magnet should be about a centimeter in diameter and should only be placed on the left side of the relay. Good Luck!!


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