Odd speaker cabinet problem

[northstreet]

I've got a problem with a speaker cab and I'm hoping for some wise words from fellow chatters. A while back I bought a second hand Hartke VX115 cab to go with a new Hartke LH500 amp. From the start there was a slight 'clicking' noise when I played lower notes, but I put that down to wear and tear on the well used original driver. However, I've just replaced the driver with a new Eminence Kappa Pro unit and the noise is still there. The click comes just as a note is played (or slightly after). It only happens on lower notes on the E and A strings, and seems to be related to EQ - more bass = more clicking. But, it doesn't happen every time, only on about one in three notes. The click sounds almost like electrical interference rather than something mechanical - it's not really a noise I've ever associated with a driver fault. It's not the horn because I've by-passsed it - the driver is connected directly to the jack socket.

I've tried with different basses, cables, mains leads etc but no joy. And I get the problem when I drive the cab from my Create BT100 combo, although it's not as apparent - which I put down to the combo being less powerful.

I guess the next step is to take the driver out of the cab and run it that way just to ensure it's not the actual cabinet, but if anyone's got any bright ideas I'd appreciate any help.

[Mr. Foxen]

Something in the crossover sparking would be my guess. Really is an ill informed guess though. Maybe have it out and put full range to the main driver? Guessing this is a tweeter equipped cab.

[Bill Fitzmaurice]

Could be the driver exceeding its excursion limit, maybe even the coil hitting the backplate, it could be the amp out of headroom also. The added excursion and power demand that results from boosting the low EQ could cause both symptoms.