Adding a Cab to a Combo - Can it be done?

[Garth]

Evening all,

I highly doubt I'm the first to ask this...

I've got an Ampeg BA115HP and I was wondering if I could hook up another Cab (another 15" Ampeg) to it.

If so, would it be easier on the Combo/better sound?

Or should I just save up and get a head and Cab?

Thanks in advance - Very new still

Garth

[Lozz196]

On some combos they have a jack-plug socket for adding in another extension cab but looking at the manual for the BA115HP it doesn`t appear that there is one, so the answer would be no. Adding in another speaker makes the sound a lot better - especially if adding in the same speaker again - as you`re essentially doubling up so whilst not necessarily louder the sound is much "bigger/fuller". A head and cab is a good idea (or possibly two identical cabs, one for rehearsals, both for gigs), as is a combo and a matching extension speaker cab. It all depends on your needs really, so many different parameters to choose from.

[chris_b]

Adding another speaker cab would probably improve the sound but that amp is already running at 4 ohms and has no extension socket so you can't add a speaker.

At over 80lbs for a pretty low rated 115 combo I'd definitely be investigating other options.

[Dan Dare]

Most combos have a preamp out, so you could add a power amp and cab.

[kiat]

I'd like to do the same but with another combo acting as a cab. I've a 4 Ohm speaker in the combo and would like to use this without any invasive electricians work. For example speaker cable from cab jack on combo A into (say Effects Recv by passing the amp of) combo B. Could it work?

OP sounds like you're best off getting a combo with a line out to a cab.

[chris_b]

Your cheapest option is to find a used Ampeg BA115HP and daisy chain them, but 2 80lb amps in this day and age (of D Class and Neo) is totally unnecessary.

I'd get separates and my preference would be 2 112's and a 500 watt amp.

[Dan Dare]

If you use another combo, it makes no sense not to use the onboard amplification (which will also enable you to equalise volume, tone, etc between the two).

[Japhet]

The amp section in your combo will run at a max of 4ohms. Adding another speaker would increase this to 2ohms (counter intuitive I know, but that's how it works), and would blow your amp up. The industry standard is that most combos/heads run at 8ohms and have a speaker extension socket to run an additional cab. Yours doesn't have an extension socket because it can't power another cabinet.

[Opticaleye]

[quote name='kiat' timestamp='1481881090' post='3195863']
I'd like to do the same but with another combo acting as a cab. I've a 4 Ohm speaker in the combo and would like to use this without any invasive electricians work. For example speaker cable from cab jack on combo A into (say Effects Recv by passing the amp of) combo B. Could it work?

OP sounds like you're best off getting a combo with a line out to a cab.
[/quote]

You can't take a speaker out and connect it to an effects return The speaker voltage would damage the other combos head.
You also couldn't connect the speaker out to another speaker connection in the other combo without disconnecting the 2nd combo's head from its speaker, You would, again, run the risk of damaging the head otherwise.

Running tuner out to a second combo's input might be the best option but there may be phase implications.

[chris_b]

You can use an A/B splitter box.

Run your bass into a box and then 2 cables, one to each combo.

[Jack]

In theory it would be possible to drill into your combo, connect some wires, install a jack socket and then run a second cab in series rather than parallel. But this is one of those questions where the answer is Can you? Yes! Should you? No.

As most everyone else has said it's too much hassle for not really any gain, especially as in series you'd actually be reducing the power output from your amp. If you're not yet weight-adverse when it comes to gear then Ebay and the classifieds here are full of heavyweight gear that people are selling for a song as they move to lightweight gear. It wold be a great way to pick up a rig for cheap until you get more invested in the hobby.

[JPJ]

Years ago, I had an Ohm combo, can't remember now if it 80 or 120 watts 1x15, with a five band eq, sort of graphic but using knobs rather than sliders. Anyway, not knowing anything about impedence etc I added a 1/4" jack socket 'in parallel' with the integral speaker and ran a second no name 1x15 cabinet underneath it.
That was my gig/rehearsal rig (more rehearsals than gigs if truth be told) and the second speaker never bothered the all transistor amp one jot. Now I might have just been exceptionally lucky, and the fact that the internal speaker farted out at anything more than half volume might have been the saving grace, but that amp ran that way for years.
I'm not suggesting this is something we should all try, but sometimes, the maths and reality don't exactly align and you can get away with something the science says you can't.

[Phil Starr]

[quote name='JPJ' timestamp='1482793312' post='3202797']
Years ago, I had an Ohm combo, can't remember now if it 80 or 120 watts 1x15, with a five band eq, sort of graphic but using knobs rather than sliders. Anyway, not knowing anything about impedence etc I added a 1/4" jack socket 'in parallel' with the integral speaker and ran a second no name 1x15 cabinet underneath it
I'm not suggesting this is something we should all try, but sometimes, the maths and reality don't exactly align and you can get away with something the science says you can't.
[/quote]

Not really, the science worked perfectly. You lucked out in that you (probably) had two eight ohm speakers and an amp which was happy with a four ohm load. It wasn't that lucky, the majority of speakers are eight ohms and just about all solid state amps are happy with four ohms. The OP knows they won't be lucky in this case as the internal speaker is four ohms.