Using combo speaker as ext cab

[Replica101]

I promise I researched this but couldn’t find a specific example. I purchased an ampeg RB210 combo and love it. I also have an old BA 115 with a bad preamp but good speaker. I’d love to be able to use the 15 from the old combo in addition to the 2 10’s in the new combo, as an ext can. The speaker out on the RB210 is for an 8ohm speaker but I the BA115 speaker is 4ohm. I’m an idiot when it comes to ohms, impedance etc (and electronics in general). I was hoping someone could tell me a) if it’s possible, and b) how hard it is to attach a 1/4” input jack to my old speaker.

 

[gtirard]

No you can't. It's not a question of ohm. Combo amps never have a connector to allow using their speaker as an external cab for another amp.

 

[Nebadon2000]

No you can't. It's not a question of ohm. Combo amps never have a connector to allow using their speaker as an external cab for another amp.

That is correct for most; My Markbass Combo has a short 1/4" speaker cable that connects Cab to one of the Speaker outs on amp. So I used male to female Speaker Cable

You may be able to get Service person to install and wire a Jack

 

[2strings2frets]

As an experiment I once deconstructed a Peavey combo and used it to try to power a 2/10 cab. Sound quality was lacking as well as volume. Probably because of mismatched amp and speakers? Check the impedance, try to avoid the blue smoke

 

[WRM]

You probably do not want to do that. If the RB210 Ext speaker wants to see an 8 Ohm load, don't hook up your 4 Ohm BA 115 to it. That might let the magic blue smoke out of the RB210....

Cheers,

 

[abarson]

Here's the BA series manual:
https://ampeg.com/data/6/0a020a3f1440d5e0ba7b4d7bd9/application/pdf/Owner’s Manual - English .pdf

The speaker in the BA115 is 8 ohms, not 4.
The internal speaker load of the BA210 is 8 ohms, and will accommodate an external 8 ohms speaker, as its minimum load is 4 ohms.
It would be possible to add a jack, but it isn't straightforward. When used as an extension cabinet, the amplifier in the BA115 must be entirely isolated from the speaker. I don't recommend this path unless you know what you're doing.
You might want to try using a patch cable between the Effects Send on the BA210 to the Effects Return on the BA115, bypassing its preamp and using it as a slave combo. But this depends on what is actually wrong with the BA115.

 

[Replica101]

Thanks for the replies. My BA115 is actually the older version:

https://ampeg.com/pdf/BA-115.pdf

I am seeing that the general consensus is that it’s more trouble than it’s worth. I should probably just invest in a new ext cab - I just hate seeing gear go to waste

 

[MCF]

Here's the BA series manual:
https://ampeg.com/data/6/0a020a3f1440d5e0ba7b4d7bd9/application/pdf/Owner’s Manual - English .pdf


You might want to try using a patch cable between the Effects Send on the BA210 to the Effects Return on the BA115, bypassing its preamp and using it as a slave combo. But this depends on what is actually wrong with the BA115.

This is the best and safest solution. I master/slave a couple old combos and it works great in one of my practice ares.

 

[abarson]

Thanks for the replies. My BA115 is actually the older version:

https://ampeg.com/pdf/BA-115.pdf

I am seeing that the general consensus is that it’s more trouble than it’s worth. I should probably just invest in a new ext cab - I just hate seeing gear go to waste

Yep, the older model is a 4 ohms speaker and can’t be used with the BA210 as an external. No effects loop so can’t use it as master/slave. Best to get a 8 ohms extension.

 

[Rip Van Dan]

I promise I researched this but couldn’t find a specific example. I purchased an ampeg RB210 combo and love it. I also have an old BA 115 with a bad preamp but good speaker. I’d love to be able to use the 15 from the old combo in addition to the 2 10’s in the new combo, as an ext can. The speaker out on the RB210 is for an 8ohm speaker but I the BA115 speaker is 4ohm. I’m an idiot when it comes to ohms, impedance etc (and electronics in general). I was hoping someone could tell me a) if it’s possible, and b) how hard it is to attach a 1/4” input jack to my old speaker.

DO NOT try to hook up a 4Ω cab to your RB210. Your amp has a minimum ohms load of 4 ohms. Notice on the back of your combo where the external speaker output is that it says "250 watts @8Ω - 8Ω minimum". Using an 8Ω extension cab with the 8Ω internal speakers of your combo puts a 4Ω load on the amp. That is the lowest it can handle. If you hook up a 4Ω cab to your RB210, that will drop the ohms load to 2.67Ω and can turn you amp into a giant paperweight if the protection circuits don't kick in soon enough. Regardless of whether or not you can jury rig your BA115 speaker to hook up to your RB210, DON'T DO IT!

 

[Skip Chucker]

Thanks for the replies. My BA115 is actually the older version:

https://ampeg.com/pdf/BA-115.pdf

I am seeing that the general consensus is that it’s more trouble than it’s worth. I should probably just invest in a new ext cab - I just hate seeing gear go to waste

This is something I struggle with as well- "entry" level gear (though at 500 bucks, is it really entry level?) is designed to be cheaply produced, used for a year, and then discarded to the landfill.

 

[eric_B]

Check my signature, I have done something similar so it can be done.
You have to be careful though, you might damage your amp (or speakers) as your combo was not build for this kind of usage.

BTW: mine is still working fine but I don't push up the volume as I use it for home practice only.

 

[swink]

Use the line out (FX send) on your BA-210 Put it in the -15dB of your BA-115 Clip the signal out with the gain and you're good to go.
I have had no problems with this type of setup to date. Perhaps a more electronically gifted person can chime in on this?

 

[-Asdfgh-]

No you can't. It's not a question of ohm. Combo amps never have a connector to allow using their speaker as an external cab for another amp.

No, sometimes combo amps do exactly have such a connector. I have in fact done as the OP suggests. It's not where I'd suggest starting, though.

 

[abarson]

Use the line out (FX send) on your BA-210 Put it in the -15dB of your BA-115 Clip the signal out with the gain and you're good to go.
I have had no problems with this type of setup to date. Perhaps a more electronically gifted person can chime in on this?

The OP stated that the preamp in the BA115 isn’t working so your plan doesn’t apply.

 

[BassFalcon]

I feel like this feature is the fabled Philosopher’s Stone or some sort of Bass Player’s Forbidden Fruit. Everyone at some point after they have “graduated” to a head & cab thinks to themselves “this is awesome…but it would be more awesome if I could also use this cab that I already have in my old combo”. Because that’s a reasonable assumption. Your new head needs speakers in boxes and you happen to have a speaker in a box, BUT NO!!!!! It’s not possible, lol. Can’t get there from here.

 

[agedhorse]

Why not get the 115 combo fixed?

 

[themickster]

No you can't. It's not a question of ohm. Combo amps never have a connector to allow using their speaker as an external cab for another amp.

Don’t say 'never' too quickly. I could unplug the driver jack from its jack in the head of my Markbass combo and plug it into another head or speaker, through a jack coupler. That's what I'd do, if the MB head stopped working.

 

[Replica101]

I’m thinking I could just buy a new 15” 8ohm speaker and stick it in the combo cab, hook up an input jack and see how it sounds as an ext cab. The two 10’s in the RB210 sound great, but having an additional 15 might give it a bit of extra punch.

 

[abarson]

I’m thinking I could just buy a new 15” 8ohm speaker and stick it in the combo cab, hook up an input jack and see how it sounds as an ext cab. The two 10’s in the RB210 sound great, but having an additional 15 might give it a bit of extra punch.

Random modifications will lead to random results. Your money is better spent on a used cabinet.