Why is my sub buzzing?

[CraigVmax]

Hi all.

Just moved my kef sub from my living room not the kitchen where it's running through a denon av receiver. It's plugged in using a phono cable and I haven't changed the settings on the sub since removing it from my living room.

I'm aware of a slight hum from the sub although it is working properly, it's just annoying when watching tv on low volume.

Any ideas?

[OldSkoolRS]

Does the hum increase if you turn up the gain on the sub itself? If so then you could try turning the sub gain down and on the amplifier turn the sub output up (should give a higher signal to noise). However, there is a limit onto how high the amp output can be set as there is the possibility of clipping (overdriving) the sub input.

There are various possibilities such a an earth loop, bad cable or a fault with the sub itself, but if this solves the problem, then at least it's a quick fix.

[Ady1970]

Which sub is it? If it is a PSW2010 which comes with the 2005 series speakers(among others). There is a commmon problem with these subs. Some of the components fail cuasing a hum. Does your sub hum with no connection to the amp? See the link below.

http://www.avforums.com/forums/subwoofers-tactile-...

Send a message to Frank1471. He is a top bloke and fixed mine for me. He should be able to point you in the right direction.

Ady

[CraigVmax]

erm, it came with the 3005SE's. i'd have to check, thank you for the tip

[Ady1970]

It's probably the HTB2SE. This is essentially the same amplifier but with a bit more power. And afaik suffers from the same problems. I would still recommend dropping a line to the guy who fixed mine.
Apart from the problem with the subs, tese are a cracking set of speakers. I have been very happy with my 2005's for the last 8 years.
Hope you get a resolution soon.

Ady

[CraigVmax]

thx Ady, yeah i love mine. Ive only had prob with sub since moving it, was fine before.

[MadMark911]

It the amp on it's way out or is it a loose / crimped cable?

[The_Burg]

Take the top of the plug and disconnect the earth wire, worked on my Kef sub. It's an earth loop.

[CraigVmax]

yeah?

amp is brand new btw

[JimbobVFR]

The_Burg said:

Take the top of the plug and disconnect the earth wire, worked on my Kef sub. It's an earth loop.

You may be right about it being an earth loop but that's not the way to solve it and could potentially be very dangerous.

Craig what other kit do you have connected to the amp and how (type of cable)

Oh BTW forgot to say in your other thread nice room, like what you've done, the TV and speakers are a bit similar to my kitchen diner and very nicely done.

[CraigVmax]

thx matey.

The amp (denon) has sony lcd connected via hdmi, ps3 same way, 2 front speakers and the sub thats it. the speakers are on decent speaker cable and the sub on a phono lead. tbh it was meant to be on coax with proper connectors but the chap doing it used a normal phono lead and had run it through walls and plastered over it before I realised.

[HoHoHo]

I thought I read somewhere subs tend not to have an earth for this very reason.....it can make them buzz. My Sub came with a two pin plug with an adaptor to three pin.

Cables would be my best guess - check them and make sure you're not using cheap cables or connectors.

[TonyRPH]

If poorly screened phono cable was used for the cable run, then hum will be inevitable.

Cheap stuff simply doesn't cut it with sub woofers.

I suspect your phono cable is running adjacent to mains cables - in which case the potential for hum pickup is enormous.

[djtex]

I had this problem with mine, took back to Kef HQ in Maidstone, they fixed it under an our. Cost me about £100 I think. As others have said its a common fault, its a broken relay I think.