OHMS.. can someone help me really quickly?

[nakleh]

Silly question, I know.

If I'm using a Marshll JCM800 50W head, and a Mesa 4x12 cabinet, with the following as the jack plate in the back- if I plug one cable from the output of the 800 to the bottom left jack, does that mean I set the amp to 4ohms? The amp has 4, 8 or 16.. the "split for stereo or bi amp" part confuses me..

[monroe]

Looks to me like it's an 8-ohm cab, and that if you use the stereo inputs, each half of the cab becomes 4-ohms so each 4-ohm input would be connected to only two speakers. If you're only using one amp, use the 8-ohm input and set the amp accordingly.

[drewbertca]

Originally Posted by monroe

Looks to me like it's an 8-ohm cab, and that if you use the stereo inputs, each half of the cab becomes 4-ohms so each 4-ohm input would be connected to only two speakers. If you're only using one amp, use the 8-ohm input and set the amp accordingly.

yep...+1

[Robster]

Set your amp to 8 ohms and use the jack on the lower right (8 ohm input). Just ignore the others, unless you plan to use this as a stereo cab (or plug 2 different amps into it, in which case you'd set each amp {or the stereo amp} to 4 ohms.) Does this make sense?

Rob

[stryker59]

yep on the descriptions above.......unless you would rather use just two of the speakers then do it the way you described!

[nakleh]

Here's why I'm asking..

It's a studio we go to once in a while, and this is the amp and cab setup. The right side of the inputs are taped off, not to be used. So I can't plug into the 8ohm side, only the left side. And the "split" part was confusing me..

I guess they don't want people using the 8ohm side for some reason?

Tonight at practice I set the amp to 4ohms and plugged into to the bottom left input. Sounded ok..

[xsouldriverx]

maybe get a y connector so that the one head plugs into both 4 ohm inputs. or maybe they only want 2 speakers to be used so its not as loud.

by the way i have an amp and cab that can do 4/8/16 ohms, whats the sound difference between them. and if there is no sound difference what is the best value to use.

[monroe]

Originally Posted by xsouldriverx

maybe get a y connector so that the one head plugs into both 4 ohm inputs.

Most Y connectors are parallel, and that will result in a 2-Ohm total load. If you choose to try a Y connector, make sure it's a series connector (may have to fab one) and then your amp will see 8-Ohms using both 4-Ohm inputs. Actually, all of the suggested schemes seem like overkill for a recording session....? My $.02