Sub Woofer buzzing

[admin_exported]

I need some advice please, my new system comprises of-

Sony KDL-46W2000 LCD

Sony RDR-HXD1065 DVD recorder

Sony STR-DA1200ES AV Receiver

KEF 2005.2 Surround speakers.

Now I have set all the above up the Sub has developed what I can only describe as a loud electrical buzz happening at various times and for varying lengths, it is similair to if you were to plug in the phono whilst powered up and at high volume, I have tweaked all the controls of the unit but this makes no differance.

Even with the input turned right down the noise is quite loud, now unfortunately I have no Manual for the sub as it was purchased second hand, I have all the box's and speaker info but no sub info.

The KEF sub has both a right and left phono in, not a single sub in, I am however feeding it from the single sub out on the DA1200ES into the Right Phono on the sub, is this OK ?.

It feel like it needs earthing or something but there is no ground point on the box, I am not sure if it makes any differance but just in case, my connections are as follows, DVD to LCD= HMDI, SKY Digi box to TV & DVD =both scart, DVD to AMP Digi Coax, and the amp is linked to the LCD Vis S Video.

Any help would be appreciatted as I have tried evrything I know apart from stripping the sub and cleaning the electronics.

Thanks in advance Neil.

 

[Andrew Everard]

Does the buzz go away when you unplug the connection from the receiver? If not, it may be a loose earth connection in the mains plug, or something internal. If it's the former, a change of mains lead may cure it, if not, then it may need servicing. But before you do that...

If the buzz is only there when the sub is connected to the receiver, you'll need to try a few things.

If there's a ground lift switch on the sub try changing the setting of this.

If the sub is plugged into the same wall socket as the rest of the system, try plugging it in somewhere else.

If none of that works, you could try a Y-adapter like this to connect the Sony's single sub output to both of the sub's inputs.



Or you could try making a shorting plug to use in the phono input you're not using on the sub - ie if you're connecting the sub output from the Sony into the sub's right channel input, you use the shorting plug on the sub's left input.

To make that plug, get one of those freebie interconnects that come with everything, and pull the two cables apart so you only have one cable with a plug on each end. Cut off the plug at one end, along with 3 - 4in of cable. Strip the cable insulator back, using a very sharp knife and minimal force, and you should reveal a braid, or mesh of cable, surrounding a central conductor inside a plastic shield.

Fold the braid back a little, and then cut off some of the inner insulation on the central conductor. When this inner conductor is revealed, twist it and the braid together, and tidy the whole thing up with some insulating tape - there's no need for the tape, as we're dealing with tiny signals here, but it keeps things tidy and stops the bare wires touching any metal part on the back of the sub.

Plug this shorting plug into the input you're not using on the sub.

If none of that works, it's time to get some servicing done on the sub.

 

[Anonymous]

As Andrew says, if that doesn't work, you need to take the sub back to KEF.

It just so happens that I had the same sub and satelite set from KEF and my subwoofer packed up. Not the same set of noises as you, my sub just stopped working but I took it to KEF in Maidstone in Kent and they swapped out the amplifer in the sub while I waited for £50.

All in all they were lovely and £50 is not too much for a new amp including labour. No fuss. I called in advance to make sure that it was ok to drop in. If you live within spitting distance of Kent and Andrew's tips don't help, then you'll find KEF very nice people if you call.

Good luck!

 

[Anonymous]

thats really interesting as I had the same with my old kef eggs. happened as soon as I plugged them in. tried different sockets etc with no effect.

I went back to sevenoaks hifi in bristol where I bought them and I was told this was a common problem with this KEF 5.1 set up. I was told the answer was to open up the plug and cut the earth wire out. I wasnt sure about this but they said that it was ok. I did it and the buzzing definitely improved.

A year later the sub died. It was now out of warranty. I took it to a local kef dealer " Paul Green Hifi" in Bath.

I left the sub with them and they informed me they would contact KEF to see if there was a solution.

I was informed that KEF said it was unrepairable and that I would need to purchase a new sub. In view of the fact I had been told that this was a problem with this model of sub I declined. I was thinking about upgrading anyway. I downgraded to 5.0 for a while before buying my new set up which has been trouble free with regard to the speakers.

Either KEF didnt offer this option or someone didnt contact them. I am also concerned about the original advice I received form Sevenoaks.

 

[Anonymous]

some of the advice you receive seems to be as reliable as taking your motor down the local garage.....

 

[Anonymous]

Thanks for all the tips, to confirm it was still buzzing when disconnected from any line input, I say was, as it has now stopped working altogethor, so a new amp is required, I phoned up my local KEF dealer and they did not know how much an amp would be but said if I pop it in they could have a look, as it could be just a capacitor that has gone, the charge, £45 for fault finding plus parts, so if as is suggested in an earlier post the amp is around £50 I may as well buy complete and fit myself.

They did mention though that this is a common fault with the KEF amps and that leaving the amp in "Auto on" mode (kicks in when it picks up a signal coming in) can reduce the life of the amp by as much as 70% in their opinion. So off at the plug in future.

Cheers again Neil.

 

[Anonymous]

Quotes for a replacement amp are coming back at just over the £200 mark, so what would be your advice as to how much to potentially spend fixing it, Taking into account it cost me £45 just to drop the blummin thing off, "standard investigation charge sir" they then asked how much I am willing to spend to get it repaired, £45 was my first thought, so what is reasonable and what is the point of kepp it mate I'll buy a new one.

Cheers Neil.

 

[Anonymous]

Hello,

I recall an Audioquest cable site mentioning this problem in relation to Subwoofers.

The reference appears with their Subwoofer cable description.

Apparently, to eliminate the "buzz" they included an extra little "spade" connector. This provides an earth by attaching it to the casing of the amp and the subwoofer respectively.

Perhaps check the Audioquest site and give it a read. Seems to address this problem of the buzzing specifically.

Cheers,

Robert.