Mix of ohm numbers

Doelle · #1 12-29-2010, 12:49 PM

Hi Talkbass!

Long time reader, first time poster!

I currently have a Marshall MB450 with the matching 4x10 cab. I have found a Mesa Diesel 2x15 in my area and have been gassing for 2x15 for a while. But I am not sure that the 4 ohm of the 4x20 will match up with the 8 ohm of the 2x15.

I have done searches but my english is not good enough to underrstand the long explanations I found. I would like a simple answer on whether or not it is possible and/or responsible matching them and a fairly easily read explanation why

Hope you can help out a rig-newbie!

- Doelle

coreyfyfe · #2 12-29-2010, 12:54 PM

If the MB450 is 2 ohm stable then yes, you can do that. The 4x10 will receive more wattage than the 2x15 though due to the lower impedance.

I checked the manual on the marshall page, they are indeed 2 ohm capable, so it would work though may not be ideal.

Munjibunga · #3 12-29-2010, 12:57 PM

Since that amp is rated for 2-ohm operation, it will handle the 2.7-ohm load of the two speaker cabinets. The 4-ohm 410 will get twice the current (and twice the power) of the 8-ohm 215. This may work out OK, since each of the 6 speakers total will receive the same power. The 15s may be a little weaker than the 10s, but it might sound OK. Then again, it might not.

Stick_Player · #4 12-29-2010, 01:03 PM

Quote:

The 15s may be a little weaker than the 10s

Depending on the sensitivity of the 15 vs. the 10. And there are 'other' factors that can affect sensitivity.

Quote:

... it might sound OK. Then again, it might not.

True, just try it.

Doelle · #5 12-29-2010, 01:05 PM

Thanks for the quick replies!

I would like to just run the amp through the Mesa, but the amp is not rated for 8 ohm. Is that not possible then?

coreyfyfe · #6 12-29-2010, 01:34 PM

Quote:

Originally Posted by Doelle

Thanks for the quick replies!

I would like to just run the amp through the Mesa, but the amp is not rated for 8 ohm. Is that not possible then?

It's solidstate so it should be ok. With a solidstate head (without an output transformer) you can go higher, but not lower, than the rated impedance without issue.

Munjibunga · #7 12-29-2010, 01:49 PM

Quote:

Originally Posted by Doelle

Thanks for the quick replies!

I would like to just run the amp through the Mesa, but the amp is not rated for 8 ohm. Is that not possible then?

It'll be fine. You just won't get as much power.

Munjibunga · #8 12-29-2010, 01:50 PM

Quote:

Originally Posted by Stick_Player

Depending on the sensitivity of the 15 vs. the 10. And there are 'other' factors that can affect sensitivity.

True, just try it.

Yeah, I know, but he said he wanted simple answers.

Doelle · #9 12-29-2010, 02:15 PM

Thanks for your answers

Very appreciated!