My cab is 4 or 8 Ohm - how can I tell?

Azztoz

I'm looking to get a new cabinet at some point this summer, and I'm not sure whether to go for a 4 or 8 Ohm cab. I've currently got a Peavey Mk IV (300W) Bass Head, and a Peavey 115 Cab, and I want to get a Peavey 410. My head and cab about 24 years old, but I don't know whether my current cab is 4 or 8 Ohm - how can I tell? The plate on the back (with serial no, etc) has been scratched to an illegible state over the years! If I can't tell what my current cab is, would it be safe for me to use a 4 Ohm 410 alongside my x Ohm 115?

Thanks in advance!
Andrew

DaveBass

If you look inside the cab, if you're lucky the speaker(s) may be marked with the impedance.

If not, you could try measuring the resistance with an ohmmeter. A 4-ohm speaker will generally have a d.c. resistance somewhere around 3 ohms, an 8-ohm speaker twice that. But this is only a rough guide.

As for combining multiple cabs, it's best to go for equal impedances. Otherwise, assuming they're in parallel, the lower-impedance cab will be handling all the power while the other one is almost inaudible.

Dave

Azztoz

Thanks Dave! They are in parallel, I'll borrow my dad's ohmmeter when I'm next home (don't really want to start opening it up...).

I doubt I'd often use both cabs at the same time, its just that my 115 can struggle sometimes with projection.

Thanks
Andrew