ohms and amp shit

[J3FF3R00]

Hey. I'm a dunce when it comes to anything technical involving numbers.

I'll cut to the chase...

 

I have a 100w Marshall JCM900 1x12 combo amp. I believe it is 8 ohms impedance.

I was wondering if it would be possible (and safe) to use an Ampeg 4x10 or 6x10 bass speaker cabinet @ 4 ohms as an expansion cab for the JCM900 combo.

The guitar amp is great and loud for it's size, but I'd like a little more low end and crunch.

Part of me says that this is a bad idea, but the other part says that if it works, it will be heavenly.

 

I've never been able to figure this shit out. I've googled soo much and it's always like reading someone's chemistry homework.

 

Help me out and I'll give you a reach-around. Promise.

[tontonz1]

can you just give me the reach around?

[Guest Blanket Fort Collapse]

I'm pretty confident it will be fine and will probably sound great. I guess you're going to match impedance, which I don't quite know much about but. I would imagine that the Ampegs can handle like 800 watts at 4ohms and isn't double the ohms means it can handle half? I'm thinking if the cab can handle 200 watts at 4ohms it can easily handle 100watts at 8ohms. Pretty sure that's how it works but I don't for sure. I've been playing guitar and bass for 16 years but never had to combine different ambs with cabs. I've seen quite a few bands where the guitarist had a bass cab in his rig and it sounded fucking thick but still defined.

[J3FF3R00]

Really. No one here knows about this shit?

 

*edit*

 

music makers my ass.

[Guest Blanket Fort Collapse]

Any quality bass cab beyond 2x10 should have no problem with a 100watt guitar amp but dude, you live in Los Angeles go to down to Sunset, go into Guitar Center, try out some guitars, amps, bass, synths, annoy people with your shitty drumming and ask people about matching watts and ohms for what your doing. If they don't have someone smart enough at GC walk across the street and I'm sure your luck would change.

[Guest MrSparkle666]

You have to match the impedance. Just plugging in a 4 ohm cab to the speaker extension jack could fry your amp. Are you planning on disconnecting the internal speaker? If not, you need to find out whether the external speaker jack puts the external cab in parallel or in series with the internal speaker. Many Marshall amps also have an impedance switch, so look for that. Once you are 100% certain of the impedance of your amp, and you know whether the ext. speaker jack is in series or parallel, come back here and I'll answer your question.