bass ohms...

bigdawg

OK been covered a ton of times probably but search isn't my friend today...

4 ohm amp (TC RH750) normally into my markbass (2x10)4 ohm cab, but someones just given me an 8 ohm 15inch, can I run this amp - markbass - 15 inch??

ICBM

No. You can only use one cab at a time since the Markbass is 4 ohm, so connecting both would take it below the minimum impedance for the amp - 2.66 ohms total load for both cabs together.

If you want to run both together, and not the Markbass on its own, you could rewire it to 16 ohms by reconnecting the speakers in series not parallel, which would then give a total impedance of 5.33 ohms, safe for the amp.

Bridgehouse

Worth noting that the amp would give a slightly lower output at 5.33 ohms. Tho the 15 would more than compensate for that tho...

bigdawg

what would that do soundwise . at the moment I love the tightness ofthe markbass cab?

ICBM

bigdawg said:

what would that do soundwise . at the moment I love the tightness ofthe markbass cab?

It would make it looser-sounding, both because the damping in a series-wired cab is lower than in a parallel-wired one, and because the 15 will be inherently looser-sounding.

Overall it would be better to get an 8-ohm 2x10" (with two 16-ohm speakers wired in parallel), then you could use either or both cabs without compromising the sound as much. The 8-ohm 2x10" on its own would not be as loud as the 4-ohm one though.