Originally posted by okcomputer
Some (most?) amps that can drive an external speaker have an impedence switch.
My Laney has a switch from 8ohm to 4ohm. 8ohm is used for the internal speaker. I switch it to 4ohm when I connect an external cab. The volume is not noticably reduced.
I'm sure it goes down some though, since the amp is now powering more speakers.
Which amp are you talking about?
Peavey Prowler 1x12 combo.
The external speaker output impedance isn't adjustable, it's fixed at 8 ohms. The internal speaker is also 8 ohms, so the total impedance would be 4 ohms with an external cab.
But the thing I don't understand is whether the external output just puts a cab in parallel with the internal speaker, or if it's somehow some sort of isolated output that's only active when connected. Does that make any sense?
I'm kind of wondering if the internal speaker recieves a signal at 4 ohms until another cab is placed in parallel with it, or if the speaker out jack is a switching jack, that switches the overall impedance to 4 ohms when something is plugged into it...