KHT KEF 2005.2 speaker not working

trwynybwa

Standard Member
Hi, I've just resurrected my 6.1 set up comprising six KHT2005.2 eggs (which are all sticky and need cleaning as per other members' suggestions).

I recently bought a gloss black egg to give me a 7.1 set up that my recently bought DENON AVR-X2700H will drive. I've designated the speaker that used to be the centre speaker (one of the stickies and the only one with a cable clip at the back) as a rear surround because the new speaker has a different finish which is less obvious/looks less odd as the new centre speaker.

Unfortunately, the re-designated sticky centre egg no longer outputs any sound. I've eliminated the possibility that the receiver is at fault by swapping speakers/outputs/red and black wires and this is the only one that doesn't work at all (i.e. no popping, no distortion, just nothing).

The only thing I perhaps haven't eliminated is the possibility the old centre speaker is specifically configured to output the centre channel output - something I'd dismissed as the new speaker is playing that channel's audio perfectly well.

I can't remember whether it worked around three years ago when I last used the setup, but assuming there's something amiss inside the speaker is this something I can investigate/attempt to fix myself?

Many thanks in advance,

Ifan
 

trwynybwa

Standard Member
Thanks. l opened the casing and the attached photos reveal the innards. All the wire connections at the terminals and at the circuit board are secure. There seemed to be a burning smell but no sign (e.g. scorch marks) as to which of the components, if any, might have failed - I'd need to open another speaker to confirm whether the smell was burning or not. I didn't want to cut the cable ties securing the circuit board so I couldn't see if its underside was intact.

Although this centre speaker was always left alone on its base on a shelf (i.e. not as vulnerable to being toppled as my stand-mounted ones), the insulation of the speaker wires (QED Silver Anniversary) had degraded in the sun to the point where the bare wires may have touched each other over a period of time. Similar degradation had happened to the wires feeding three other speakers also, but they're all working fine.

If it's a case of testing/replacing components like a blown capacitor, I'm quite handy with a multimeter and soldering iron as long as I know what I'm trying to achieve, but if the circuit board is damaged I guess maybe buying a new speaker would be more economical than attempting a repair.
 

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trwynybwa

Standard Member
Just in case this knowledge might be of use to anyone else, I narrowed the problem down to the speaker itself rather than the crossover, although the crossover may also be faulty (capacitors haven't bulged in any way).
I swapped the crossover from a working speaker (just involved snipping the cable tie securing the circuit board to the speaker's bracket, de-soldering the small red and black wires to the driver, and gently working the circuit board off the two prongs soldered to the speaker's bracket) and placed it in the non-working speaker. I tested it on a couple of the amp's channels that were outputting sound through other speakers, but there was no sound at all. Incidentally, there was no burning smell in the working speaker.
I'm glad I tested it though, although I'd have been happier had it been a cheaper fix involving some new capacitors/resistors rather than a replacement speaker. I must thank the kind soul on eBay who sold me a replacement speaker for the advice he gave me regarding diagnosing the problem, and for giving me the confidence to have a look myself.
 

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