Originally posted by nfaguys:

Here's a simple question whose answer I should but do not know.

I bought some KEF tweeters just as backup since they are hard to get. Several ae 8 ohms. So......

If speaker systems with x-overs in cabinet are rated at 4 ohms, and you have a replacement driver at 8 ohms....any problem in using it, for example as a replacement?

TIA

The parts values in the crossover were arrived at with calculations using the 4 ohms impedance. If you use an 8 ohm driver in place of an original 4 ohm driver, the crossover frequency will change for that driver, and any voicing applied to that driver will be changed.

I would certainly not install a driver with a different impedance than the one being replaced.

However, I would check that the driver you're replacing is really 4 ohms. Just because the total system is 4 ohms doesn't mean the drivers are automatically 4 ohms.

If you have an ohm meter, check the DC resistance of the voice coils - an 8 ohm driver will measure about 6 ohms, and a 4 ohm driver will measure about 3 ohms.