extension cab question

reaching hands

so..i have a harley benton ga5 combo (basically an epi valve junior 5 watt), it has an 8" speaker in it and its 4ohms

can i connect this into another speaker cab to beef its sound up for possible use in a band?....would it just go as far as a 12" speaker?

this bit about ohms always confuses me somehow? :(

mccreadyisgod

The short answer is yes, although it's subject to some serious reservations.

The first question is what resistance (ohms) your amp is ultimately rated for. You can run higher resistance than the amp is rated for, but NEVER lower resistance. So, if your amp is rated at 4 ohms, you never want the total speaker resistance load to be lower than 4 ohms.

The second question is if you have two speaker outputs, or just one. If you have two outputs, then it's designed to run the internal speaker PLUS another, external cabinet. It should say something about what resistance the external cab can be rated at. If there's only one speaker output, and the internal speaker is normally plugged into that output, then you can plug an external cabinet into that output INSTEAD of the internal speaker.

The third question is what resistance the internal speaker of the amp is. If the internal speaker is a 4 ohm speaker, then you would need to disconnect it before plugging in another speaker. If it's an 8 ohm speaker, then you can plug in another speaker cab rated at 8 ohms or greater.

The rule for this (don't worry, it's easy to forget it) is two speaker loads in parallel will halve the resistance of the speakers. So, two 8 ohm speakers in parallel will make a 4 ohm load. When an amp has two outputs, one for the internal speaker and one for an external speaker, then the outputs are wired in parallel.

The answer to the more basic question is, yes, you can plug your 5 watt amp into a much larger speaker cab. In fact, you could plug your amp into a full stack with 2 cabs, 4x12" speakers each, if the total resistance load is 4 ohms or more. And it would be pretty loud.

mccreadyisgod

So... I just looked up the amp, and it shows one speaker output, rated at 4 ohms. That means you can disconnect the internal speaker and essentially use your combo amp as an amp head, and plug an external speaker into that output, so long as your external cab is 4 ohms or greater (I'd stick with a 4 ohm or 8 ohm cab). It will make one heck of a difference. A single 12" would work nicely, but a 2x12" or 4x10" will be even better!

jcmark611

I think it should also be said that even hooked up to an ext. cab a 5 watt amp will be hard to hear over drummers.

mccreadyisgod

jcmark611 wrote:

I think it should also be said that even hooked up to an ext. cab a 5 watt amp will be hard to hear over drummers.

Yeah...


I'm gonna have to disagree with you on that. 5 watts is plenty of juice. Not a ton of clean headroom, maybe, but plenty loud.

ianvomsaal

uhmm, 5-watts probably won't cut it over a hard hitting drummer or full band. depending
on the band, sometimes 15 or 18-watts doesn't cut it. the crate v-18 18-watt tube amp
i recently bought had a hard time being heard over one band i recently played with (it was
a full on rock band, so my amp actually needed to be mic'd to be heard over the drummer,
vocalist, bassist, and other guitarist). i'm a firm believer in the 30-watt tube amp, which
can fairly easily be set quiet enough for small venues, yet is almost always loud enough
for any band/stage application - personally i think it's just the right amount of tube watts.

jcmark611

mccreadyisgod wrote:

Yeah...


I'm gonna have to disagree with you on that. 5 watts is plenty of juice. Not a ton of clean headroom, maybe, but plenty loud.

Oh, well I like to have lots of headroom. :-)

I can see a 5w with 4x12 working but, he is going to have to push it hard.

reaching hands

cheers guys!, (sorry been away from the net for a few days!), i use a class a tube 30 watt amp for main practice/gigs which is plenty loud at 10 o'clock.....i was just curious as i'm always intrested in getting different sounds and the little benton 5 watt has a sweet little sound and just wondering if it would work?

so top and bottom...yes a 2x12" would work but would just make the sound more 'full' and would strain it abit at full band level?

but if i was to use it with an extension cab it would sound nice for more 'stripped down, intimate' gigs?

thankyou for your help, guys

reaching hands

and also if my laney vc30 ever dies i could hook up my 5 watt to the speakers and use it in the same way if i need a quick fix?(obviously using the right ohm input)

mccreadyisgod

reaching hands wrote:

so top and bottom...yes a 2x12" would work but would just make the sound more 'full' and would strain it abit at full band level?

but if i was to use it with an extension cab it would sound nice for more 'stripped down, intimate' gigs?

You'll get more beefy tone overall from a 2x12" cab compared to the internal single 8" speaker, definitely. And you'll get more perceived volume from your amp at the same settings. You would have to push it to play with the band, depending on how loud the band is (if the band was similar to Pearl Jam, you'd have to crank it, and put it through the PA with a mic). But if you play in a stripped-down, mostly acoustic band, then it would probably work great. It's all a matter of dynamics. I used a 12-watt tube amp with a 12" speaker for a summer's-worth of bar band gigs, and it was great. I've also played with groups where my 45-watt tube amp with a 4x10" cab wasn't loud enough.

You just need to be as loud as the loudest thing in the group. That's usually the drummer (who doesn't have the convenience of a volume knob). If your drummer plays with brushes, rods, or just plays with less punch, your 5-watt job will probably be just fine. If your drummer thinks he's Lars Ulrich and Alex Van Halen put together, you'll be straining.

reaching hands wrote:

and also if my laney vc30 ever dies i could hook up my 5 watt to the speakers and use it in the same way if i need a quick fix?(obviously using the right ohm input)?

I've pretty much answered the question as best I can above... Yes, but you won't have the clean headroom (which means you won't be able to turn it up loud and still have a great "clean" tone) and you may even need to mic up for gigs, but if you're at a gig and that's your back-up, it'll be better than playing unplugged. Who knows, maybe you'll want to have that pure tube distortion tone of a cranked amp, and you'll start using the little bugger for all your gigs. I say try it out sometime, and see what the limits are.

reaching hands

thanks man......:)