# SWR Amp and Math Problem..fill in the gaps

Discussion in 'Amps and Cabs [BG]' started by schackattack, Mar 2, 2008.

1. ### schackattack

Mar 10, 2005
Sandy Hook, CT
Okay.

I have an SWR 350 with the following cabinets

2x10 8ohm
1x15 8ohm
1x18 8ohm

without changing cabinents, I want to add an amp of about the same power. What should the second amp be, and how should I configure it?

Not interested "replacing the whole set-up" with a different combination.

Anybody have ideas?

2. ### projectMalamute

Jan 9, 2008
Westfield, MA, USA
Google says the 350 gives you 350 watts at 4 ohms or 240 watts at 8 ohms. So I suppose you either run 2 of the cabs with the 350 and get something that will put 350 watts in to an 8 ohm load for the third, or you run one of the cabs with the 350 and get something that will put 240 watts in to a 4 ohm load to run the other 2. I guess. Not sure I am understanding the question. If you wanted more volume out of the same setup I would get a good sized power amp to run the 18 and power the other 2 boxes with the 350.

3. ### leftymike

Sep 23, 2006
Austin Tejas
Also, the 350 will run around 450 watts into a 2ohm load. So you could run all 3 cabs.

4. ### schackattack

Mar 10, 2005
Sandy Hook, CT
Questions for both projectmalamute and leftymike...

with the poweramp idea...how would I get the signal from the SWR to the poweramp? an aux out?

with the 2 ohm setup....any danger of blowing speakers?...I think each cab is rated at 350...never understood how that translated into how much the cabs could actually take

5. ### anderbass

Dec 20, 2005
Phoenix. Az.
You could safely run all three 8 ohm cabs, (2.67 combined load) with your 2 ohm amp. Its not the optimum solution but it would be safe for all until you pushed your amp past its limits. (listen closely, you'll hear it)

You could drive your second amp/18" cab by connecting to your 350's effects send (or line out) jack, but these outputs will have already been eq-ed (post eq) to a setting that happens to work best with your 2x10/1x15 pairing.
(I wouldn't necessarily want my 18" cab amp receiving this pre eq-ed input signal)

You could split your basses signal with an ABY pedal, or also use your amps "tuner-out" jack. (its basically the same output as your bass). I successfully drove a secondary head/Big Ben using this output with my old SWR Bass 350/750 models.

I'd want the secondary amp to be fairly powerful (more the better)
and have a really good eq (and possibly a crossover) somehow involved to have the option of fully cutting mids/highs to have the ability to dial in the 18 for use mainly as a subwoofer but also full range or anywhere in-between.

If you could locate a secondary two channel bass head with two individual eqs, you could then connect each sides outputs to your 15 and 18. (you'd still be powering/EQ-ing your 2x10 directly from your Bass 350) Each cab could now have fully individualised settings.

If you decide to go with the stereo poweramp method using the tuner-out/ABY pedal out method, you'll probably have to add two channels of preamps w/eqs also.