Marshall 1960B as second cab ? Is another amp needed ?

[Sweeps]

Currently, playing a trace elliot elf amp through a Marshall AVT150 cab (the slanted version) it would be great to have a straight Marshall to compliment and Ive finally found one. However these marshalls are 4 ohms or only 8 ohms in stereo. Since the trace elliot elf is 8 ohms for two cabs would it be better to get a second amp to run to the second cab ? (I know these are guitar speakers and granted they do lack a bit of low end but for the tone I'm going for it suits me personally)

ps. thanks in advance

 

[Redbrangus]

Just to confirm: you currently have a TE amp and a 4Ω Marshall cab, and you want to add a second Marshall 4Ω cab? Two 4Ω cabs in parallel is a 2Ω load, which I don't believe your amp can safely drive. So yes, you're going to need another (or different) amp to drive those two cabs. Your amp could drive the two cabs safely if they were 8Ω cabs.

 

[Sweeps]

Just to confirm: you currently have a TE amp and a 4Ω Marshall cab, and you want to add a second Marshall 4Ω cab? Two 4Ω cabs in parallel is a 2Ω load, which I don't believe your amp can safely drive. So yes, you're going to need another (or different) amp to drive those two cabs. Your amp could drive the two cabs safely if they were 8Ω cabs.

the slanted cab (the one I already have) is 8 ohms, the 1960B cab is 4 ohms or 8 ohms in stereo but that'd mean you'd only be using the two speaker of the 4.

 

[agedhorse]

Guitar speakers for bass usually ends up ruining perfectly good guitar speakers.

 

[beans-on-toast]

It depends on the tone that you want. Lemmy for instance turned the mids up all the way and the bass and treble off. He played his bass with Marshall cabs like a guitar. It gave him his metal sound.

But the speaker cabinet impedance needs to be within the operating limits of your amp. Be careful with a used Marshall cab if this is what you are considering, determine what speakers are in it and what impedance it’s been wired for. Being stock makes it easier.

 

[Wasnex]

If I understand, a modern 1960B is either 16 ohms or 4 ohms mono. See jack panel below:

It's loaded with 16 ohm drivers (Celestion G12T-75)

Power handling is 300W mono. It will probably handle 300W of guitar fine. But mechanical power handling with bass will be significantly less. I think if you run it at 4 ohms with the ELF producing 200W, there is a good chance you will damage the drivers. It may get pretty darn loud, but I wouldn't expect strong lows.

Back in the 60s, it was fairly common to use a full stack with a 100W Marshall for bass. They still blew drivers, even with eight 12s sharing the power.

The ELF is 4 ohms minimum. If your current cab is 4 ohms, you can't run a second cab.

If your existing cab is 8 ohms, you could use the 16 ohm jack of the 1960B. 8 ohms and 16 ohms in parallel = 5.33 ohms, which would be safe for the ELF

My guess is the ELF can produce about 170W at 5.33 ohms. The power would be split into three shares. The 8 ohm cab will get two shares and the 16 ohm cab will get one share. So if the amp makes 170W at 5.33 ohms, the 8 ohm cab will get about 113W and the 16 ohm cab will get about 57W.

 

[B-string]

If your Trace has an effects send jack use that to go to the input of a second amp to drive the 4 ohm cab. This would also give more complete control over the tone shaping to keep the skinny string speakers alive and well in this world.

 

[Sweeps]

If I understand, a modern 1960B is either 16 ohms or 4 ohms mono. See jack panel below:
View attachment 6980286
It's loaded with 16 ohm drivers (Celestion G12T-75)

Power handling is 300W mono. It will probably handle 300W of guitar fine. But mechanical power handling with bass will be significantly less. I think if you run it at 4 ohms with the ELF producing 200W, there is a good chance you will damage the drivers. It may get pretty darn loud, but I wouldn't expect strong lows.

Back in the 60s, it was fairly common to use a full stack with a 100W Marshall for bass. They still blew drivers, even with eight 12s sharing the power.

The ELF is 4 ohms minimum. If your current cab is 4 ohms, you can't run a second cab.

If your existing cab is 8 ohms, you could use the 16 ohm jack of the 1960B. 8 ohms and 16 ohms in parallel = 5.33 ohms, which would be safe for the ELF

My guess is the ELF can produce about 170W at 5.33 ohms. The power would be split into three shares. The 8 ohm cab will get two shares and the 16 ohm cab will get one share. So if the amp makes 170W at 5.33 ohms, the 8 ohm cab will get about 113W and the 16 ohm cab will get about 57W.

great points. 57w of power is hardly worth having another 4x12 cab for . Maybe I should just keep the one cab ?

 

[Wasnex]

Maybe I should just keep the one cab ?

If one cab can safely play loud enough to meet your needs, yes.

Adding a cab usually gives you more headroom, fill out the lows a bit, and reduce the risk of blowing drivers. However you would probably be best using a pair of matching cabs that share power equally.

The amp is rated for 200W at 4 ohms and 130W at 8 ohms. FYI, this is less than a 2dB difference in power.

Log(200/130) x 10 = 1.87dB

 

[B-string]

great points. 57w of power is hardly worth having another 4x12 cab for . Maybe I should just keep the one cab ?

I thought your intension was a different tone from the guitar cab? If you want louder and deeper a second like cab beats raw wattage by a factor of 10 if the single amp can survive the load. This won't address driving a bass heavy instrument signal into guitar speakers with even 50-75 watts. They are just not designed to be driven that way so the "power rating" is useless when driven by bass guitar. That "input power rating" is for skinny string signal, not long and heavy string signals.