Amp Gurus: your help is required please!

[Moos3h]

Hi folks,

Got a Hartke VX1508 (2x8 and 1x15) cab but the 15 is crackling. All drivers are 8 ohm and the cab itself is 8 ohm. There is a fairly hefty looking crossover unit fitted inside.

My question is: i have a 16 ohm Celestion speaker, ignoring the fact that it's a crapshoot as to whether it'll work in the enclosure, will it change the load that the amp sees?

Thanks in advance!
James

[Mr. Foxen]

It will pretty much not be compatible with the crossover. How bad that will be is a whole other thing, likely scenario is the amp will see 16 ohm, but crossovers do some funny things. Aim to figure what the cracking is first, might just be a loose connection, plenty of connections with a crossover involved.

[Moos3h]

I think its the voice coil makes a gritty sound when the cone is gently pushed.

Damn. Time to buy a new 8 ohm unit then?

[Mr. Foxen]

Isn't the nominal impedance that has to agree with the crossover. The crossover is interactive with the actual impedance (as in the varying with frequency thing) of the driver. So basically, more to it than an 8 ohm driver. A similar driver might work similarly, but the crossover might not even have been that suited to the one in there. Its another crapshoot like sticking a speaker in a box, there are simulators and such to figure, pretty much the same deal. on't actually know how much difference it makes in practice.

Edit: Actually, it is pretty similar to the box tuning thing, because its another resonant resistive/inductive network thing.

Edited May 8, 2012 by Mr. Foxen