Squawker K55 distortion

[mr-b]

Hi

 

I've noticed that some tracks produce slight distortion on one of my Khorns (1987 with K55M squawkers, upgraded Crites CT-125 tweeters and B&K AK-3 crossovers).

The distortion is a slight harsh glassy sound on some piano tracks and, bizarrely, Kraftwerk. I tried Alan Parker's excellent Soundcheck CD but couldn't pinpoint the frequency. I then swapped crossovers, amps, cables etc. and the issue follows the K55 squawker driver.

 

Is it new driver time or is there some maintenance that might work - aka "Klipsch K55M Overhaul" at 

 

If it's new driver time then what are things that I could be looking at for possible upgrades (possibly horn too)?

Oh and I'm in the UK so shipping parts may be rather expensive than normal!

[Khornukopia]

14 minutes ago, mr-b said:

K55M squawkers

The black plastic cap on the back of the K-55M driver can sometimes buzz. The problem can usually be fixed by applying a bead of silicone around the edge of the black cap.

[jimjimbo]

I would check all of the horn to cabinet screws and make sure that they are nicely hand tight.

[OO1]

@mr-b   -could be a host of things  including static  , place the driver on a rubber mat , discharge yourself -

 

-worn  or loose gasket  between the horn and driver  -inspect - tighten

--loose top plate screws , would be odd , but it does not hurt  to check ...if all is tight , do not tighten any more  - if screws are loose , loosen all screws ,then  re-tighten in a cross pattern  and stop when you feel resistance , 

-same with the plastic bezel at the rear of the driver ,check it ,  they do come unglued

-dirt in the Voice coil  gap can  affect  the sound  , remove the top plate  gently   ,  blow air in the VC gap,  then use a sticky tape all around the gap and blow air at a distance from the VC  -then re-assemble

-worn diaphragm  , or  damaged leads  -check the solder on the diaphragm leads , and add if required .

-finally   inspect the  bug screen of the driver -