Subwoofer Failures - Have I just been unlucky?

THX1138UK

Well-known Member
I've had several KEF and Monitor Audio Subwoofers, and at some point, they all seem to fail due to power supply / capacitor problems.
Sometimes the manufacturer will repair these at no cost (even though they are out of warranty), and other times it's cost a couple of hundred pounds in repair and shipping fees.

My current subwoofers in the living room are KEF 400b (pair) and in the Home Cinema they are Monitor Audio AW12 (pair).
I tend to hold onto stuff, so my Monitor Audio subwoofers are from 2012, and the KEFs are from 2016.

I'd be interested to hear about other people's experience with subwoofers and expectations regarding longevity and component failure.

I connect my subs to Denon X6200W AV Receivers via the dedicated LFE connections. The (UK) mains plug sockets are protected with Belkin surge protectors.
I leave the subwoofers permanently powered-on, in 'Auto' mode.


I hear great things about the SVS SB-1000 Pro - but are the power supplies and capacitor actually better than their rivals?


Thanks & regards,
James.
 

rccarguy2

Well-known Member
If you're concerned I'd look into passive subs, that way of the amp blows it doesn't effect the use of the sub

Got a blown svs sub and it's useless now, can't get replacement amp
 

THX1138UK

Well-known Member
If you're concerned I'd look into passive subs, that way of the amp blows it doesn't effect the use of the sub

Got a blown svs sub and it's useless now, can't get replacement amp

When you say passive, do you mean without it’s own powered amplification?

I’m not familiar with passive subwoofers. I’d rather not put too much load on my AVR, as I am already powering 7 surround-sound speakers and two overhead speakers.

What model of SVS do you have? I thought their service & support was supposed to be second to none? Certainly seems to be the case in the US.

Regards,
James.
 

Conrad

Moderator
You'd get a dedicated outboard sub amp. Behringer inukes are popular, lots of power and they support low impedance.

You can "convert" a sub with a failed amp plate to a passive amp. Wire up the driver to a pair of terminals mounted in a cover that's the same size as the amp plate, connect those terminals to said inuke and then connect the inuke to the sub out of the AVR. As long as the replacement plate is snug you should get similar performance.
 

rccarguy2

Well-known Member
Svs 20-39 pc plus
 

Ultrasonic

Well-known Member
How much do you use your subs? Personally I think you've probably been unlucky. Also bear in mind that modern subs increasingly use Class D amps and so failure modes/likelihood may be changing.

I wouldn't be considering a passive sub myself.
 

Mr Wolf

Well-known Member
I also suspect you've been unlucky. Either that or I've been very lucky as I've been in this hobby for 27 years and never had sub amp fail on me. I currently own a 1997 REL, a 2010 Velodyne, one 2016 SVS and two 2021 SVS subs that I've all owned from new without problems.

I hear great things about the SVS SB-1000 Pro - but are the power supplies and capacitor actually better than their rivals?

I wouldn't know if SVS subs are more reliable but I do like the fact that they come with a full 5-year warranty which is much longer than some other brands. Given that SVS also sells a huge volume of subs I would expect that this generous warranty policy would be unaffordable to them if the quality/reliability wasn't there to back it up.
 

THX1138UK

Well-known Member
How much do you use your subs? Personally I think you've probably been unlucky. Also bear in mind that modern subs increasingly use Class D amps and so failure modes/likelihood may be changing.

I wouldn't be considering a passive sub myself.

Home Cinema gets used for a few hours per week, but subs are left powered on (Monitor Audio)
Living-room subs get used for a few hours every day (KEF), and again are left on all the time.

We listen at quite low levels really -25, and we're certainly not cranking up the bass on the subs.


Regards,
James.
 

Ultrasonic

Well-known Member
Home Cinema gets used for a few hours per week, but subs are left powered on (Monitor Audio)
Living-room subs get used for a few hours every day (KEF), and again are left on all the time.

We listen at quite low levels really -25, and we're certainly not cranking up the bass on the subs.


Regards,
James.

One reason I personally always turn my subs off when not in use is that it protects them from possible damage via mains power spikes. There's every chance the failures you've experienced have nothing to do with this but it's something to bear in mind, as well as simply saving electricity.

Yes, before people mention this I am of course well aware that loads of people leave subs on all the time without issues :) .
 

Gasp3621

Distinguished Member
Home Cinema gets used for a few hours per week, but subs are left powered on (Monitor Audio)
Living-room subs get used for a few hours every day (KEF), and again are left on all the time.

We listen at quite low levels really -25, and we're certainly not cranking up the bass on the subs.


Regards,
James.

Well hanging about 10years on this board i have seen lot of these threads with issues on MA/Kef and other speaker manufacturer woofers. Kef had lot of amp issues with the Kube/HTB woofers. MA Silver subs have lasted from couple years to five. Not too long ago one member cursed as he bought amp for Silver RS/RX? sub but it died within 2year time. I think MA also gives 1year warranty for the new amp which is joke. I would steer away from these "package" subwoofers, also B&W is another one with the dirty expensive bowling ball, lot of amp issues . Kef R400 the dual woofer amp hasn`t been reported that much, i think last year one member had one amp failure on it.

I would stick with the companies that specialize in woofers. SVS, Arendal, XTZ (Edge), PSA etc. all those have 5year amp warranty and good support. REL has 3years and they seem to be quite robust too.
 

MI55ION

Distinguished Member
I have had 2 subs fail so far: a Corsair sub sold as part of a desktop 2.1 package. Failed twice, once within warranty then outside of the warranty. The second was a BK Gemini.

The Corsair was shoddy design/parts as it was a common problem. The BK I'm not too sure about but a lot of others have had issues on here with amp failures.

It might be bad luck for you but I suspect they've used poor quality parts. As a result I'd avoid certain manufacturers and stick with those who carry extended warranties of 3years+ and have a solid reputation for subs.
 

THX1138UK

Well-known Member
One reason I personally always turn my subs off when not in use is that it protects them from possible damage via mains power spikes. There's every chance the failures you've experienced have nothing to do with this but it's something to bear in mind, as well as simply saving electricity.

Yes, before people mention this I am of course well aware that loads of people leave subs on all the time without issues :) .

The subs are protected with mains surge protection from Belkin. All my other AV (and computer) equipment is protected with APC 1400 UPS units.

The subs were surge protected when they failed. I don’t think the failures are related to the mains supply quality. Also, just for context, we have a new build house, with a modern Consumer Unit, new wiring etc.

I’ve read that leaving the subs in Auto standby mode, doesn’t prevent Power Supply / Capacitor failures, because they are still energised, but the load must be minimal in this mode?

I would have expected prolonged heavy loading to be a (possible) trigger to failure?

It’s interesting that you turn your subs off when not it use… I don’t physically turn any off my equipment off, I just let it go into standby.

Regards,
James.
 
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Ultrasonic

Well-known Member
It’s interesting that you turn your subs off when not it use… I don’t physically turn any of my equipment off, I just let it go into standby.

In HiFi terms it's only my subwoofer (which does have a standby mode) and my power amp (which doesn't have a standby mode) that I switch off actually, leaving my miniDSP SHD (streamer/pre/DAC) in standby, principally because Volumio can sometimes fail to boot up properly from off. My previous sub didn't have a standby mode so in part I've just continued the same practice but I do think it offers an additional level of protection and does save a little electricity.

I do switch off things like my PS5 and blu-ray player when not in use as well though. My TV stays in standby though so I won't say I'm totally consistent :) .
 

Gasp3621

Distinguished Member
Svs 20-39 pc plus

"We'd need the amp's faceplate dimensions (L x W)" They might have amp for you if you are intrested. Take the dimensions so i will post them to SVS and see what they say. That is if you want new amp for it?
 

rccarguy2

Well-known Member
"We'd need the amp's faceplate dimensions (L x W)" They might have amp for you if you are intrested. Take the dimensions so i will post them to SVS and see what they say. That is if you want new amp for it?
His is the one with seperate heatsink/fet board. Bash amp
 

THX1138UK

Well-known Member
I thought I should post an update to my original post:

I contacted KEF, and they asked me to return both of my failed R400b subwoofer boards.
Upon testing, they said one board was OK, and fixed the other board at no cost, even though it was long outside of warranty.

Having had both of the boards back from KEF, both subwoofers are now working perfectly again. So I'm very pleased with the result (maybe the one they said was OK, had a bad connection? - whatever the reason, they are both working great now).


With regard to the Monitor Audio Apex AW-12 subwoofer. Monitor Audio didn't offer to repair it, but they said I could buy a brand new board for £302 inc VAT & Postage. Considering the subwoofer cost me £1,000 11 years ago, I decided this was a fair enough price to pay - it would cost a lot more to buy a new replacement sub....

Having received the new board, and fitting instructions I was quickly able to get it back up and running.


So I have gone from having 3 out of 4 subwoofers not working, to having all of my subwoofers working perfectly for a total of £302, which I think is a pretty good outcome.


I'd particularly like to thank KEF for the no cost repair. Monitor Audio were also very helpful and responsive.


Regards,
James.
 

password1

Distinguished Member
Thanks for the update. Did Kef and MA ask if you are the original owner and ask for the proof of purchase. ie reciept.

This information would be useful for buyers of used Kef and MA subs.

Personally I would stick to Rel or BK for reliability and good after sales support respectively. SVS have a good reputation for warranty repair support too After the warranty period, BK are excellent. Im not sure of the newcomer/newer subwooferspecialists yet.
 

THX1138UK

Well-known Member
Thanks for the update. Did Kef and MA ask if you are the original owner and ask for the proof of purchase. ie reciept.

This information would be useful for buyers of used Kef and MA subs.

Personally I would stick to Rel or BK for reliability and good after sales support respectively. SVS have a good reputation for warranty repair support too After the warranty period, BK are excellent. Im not sure of the newcomer/newer subwooferspecialists yet.

KEF and Monitor Audio asked for the serial numbers.

I provided them with the sales info, where I bought them & when. All the kit was purchased from independent, but authorised dealers.

Regarding Monitor Audio, I’m pretty sure they would sell a replacement board to someone regardless of whether they were the original purchaser or not.

I don’t know if KEF would have run the diagnostics and replaced the board at no cost, if I wasn’t the original purchaser.

Regards,
James.
 

Moviebuff

Well-known Member
I've purchased my PB13U's brand new, when they very first came out. Since that time, the original Bash amps gave up the ghost, so I replaced them with the first generation of Sledge. They too, have since passed, and I'm now on the latest Sledge amps.

To me, the hassle has been worth it - but also majorly unwanted!
 

password1

Distinguished Member
I've purchased my PB13U's brand new, when they very first came out. Since that time, the original Bash amps gave up the ghost, so I replaced them with the first generation of Sledge. They too, have since passed, and I'm now on the latest Sledge amps.

To me, the hassle has been worth it - but also majorly unwanted!
Ive been considering an SVS but the uncertainty of what happens if the amp develops a fault is one of the things tbat has put me off.

Did you send it back at your own cost and inconvenience..to the svs distributor or retailer? did you pay for all postage and packing? did you arrange delivery yourself? Did you have to dismantle the faulty amp and send it at your own risk and install the repaired or new amp yourself? or send the whole sub back to the US or somewhere?
 

rccarguy2

Well-known Member
Ive been considering an SVS but the uncertainty of what happens if the amp develops a fault is one of the things tbat has put me off.

Did you send it back at your own cost and inconvenience..to the svs distributor or retailer? did you pay for all postage and packing? did you arrange delivery yourself? Did you have to dismantle the faulty amp and send it at your own risk and install the repaired or new amp yourself? or send the whole sub back to the US or somewhere?

Why only SVS? All other active subs could fail.
Also have to be concerned if you had multiple subwoofers that means more likely fail.

I do see the appeal of passive subs, that way just use power amp and if that dies then just replace it. I wish active subs were replaced with passive subs, would be cheaper.
 

password1

Distinguished Member
Im also considering bk, elac and orhers. the svs sb1000pro appeals to me because it's one of the smallest if not smallest 12 inch subs.

Would a passive sub and separate amp be similar price and performance
 

rccarguy2

Well-known Member
Im also considering bk, elac and orhers. the svs sb1000pro appeals to me because it's one of the smallest if not smallest 12 inch subs.

Would a passive sub and separate amp be similar price and performance

If you can build a sub yourself, you'll get better value. However you'll need subwoofer EQ so that will add another couple of hundred.

Bk subs are good VFM and better finish than many other sub £400 subs, however they are pretty basic in features, also concern with buzzing and humming worries me.
 

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