Cabinet choice for Bassman silverface

[sibo]

I play guitar through my '70s Bassman silverface 100W and just decided to spoil my beloved amp with a new speaker. There are two outputs, speaker and extra speaker. The total load is 4ohms. Right now I'm using a low-end Laney cabinet with cheap celestion speakers running at 8ohms.

I kind of like the sound of the Marshall 1960A cab but I don't have the possibility of trying it with my amp. The input on the 1960A cab has mono/stereo mode with mono mode offering the possibility of 4/16ohms and the stereo 8+8ohm.

So

Just plugging it in with mono mode would actually give the amp the right impedance but how would that change the sound from 8 ohms? It would be louder of course but would anything else be affected, tone wise? Also, would there be any point in wiring it in stereo, using both preamps somehow (bass and normal)? Would the total load still be 4 ohms? This is some what confusing..

Other cabinet ideas are very welcome.

Thanks.

[Leo_Gnardo]

I play guitar through my '70s Bassman silverface 100W and just decided to spoil my beloved amp with a new speaker. There are two outputs, speaker and extra speaker. The total load is 4ohms. Right now I'm using a low-end Laney cabinet with cheap celestion speakers running at 8ohms.

I kind of like the sound of the Marshall 1960A cab but I don't have the possibility of trying it with my amp. The input on the 1960A cab has mono/stereo mode with mono mode offering the possibility of 4/16ohms and the stereo 8+8ohm.

So

Just plugging it in with mono mode would actually give the amp the right impedance but how would that change the sound from 8 ohms? It would be louder of course but would anything else be affected, tone wise? Also, would there be any point in wiring it in stereo, using both preamps somehow (bass and normal)? Would the total load still be 4 ohms? This is some what confusing..

Other cabinet ideas are very welcome.

Thanks.

Yes those Marshall "stereo" cabs with their confusomatic panels are a drag. I'd say select 4 ohms and just go for it. IF you go to one 'side' of the 'stereo' cab and drive only 2 speakers at 8 ohms, you'll be disappointed two ways. First, you're not getting all the power you should. That's not the worst. Drive two out of four speakers, and the air pressure in the cab will push the two un-driven speakers in the wrong direction. Almost as good as out-of-phase. Self-defeating. A sure fire formula for naff sound.

If you have some other cab that's 8 ohms and without a fancy panel, you'll be a little lacking in the power department but at least won't have half the speakers in the cab working against you. Tone will have more to do with what the speaker does than impedance match or non match, BUT there's something to be said positively for a proper match between amp and cab, more than just maximum power capability.

[sibo]

Thanks that helped!

[Tom Phillips]

...Also, would there be any point in wiring it in stereo, using both preamps somehow (bass and normal)? Would the total load still be 4 ohms? ...

No. Both of the Bassman pre-amp channels are summed together and then drive the mono Bassman power amp. The Bassman output impedance will remain unchanged at 4 Ohms no mater what signals you put into the pre-amps.

[sibo]

No. Both of the Bassman pre-amp channels are summed together and then drive the mono Bassman power amp. The Bassman output impedance will remain unchanged at 4 Ohms no mater what signals you put into the pre-amps.

Yeah that makes sense. I had to ask to know for sure. Thanks.

Any other ideas on cabinets?

[Joe L]

If only running two speakers out of 4, plug a shorted plug into the unused speakers to reduce the effect of back pressure.