Dual Amp setup. What do I need to look out for?

nothing. absolutely nothing.

seriously: i've bi-amped, tri-amped, double-amped...i've probably tried all of the various combinations at one time or another. i think the only thing you'll find out is: whether it's worth the effort. IME: it seldom was! YMMV. good luck tonight!

 

Label your speaker cable ends. Go ahead, we'll wait. There was a sad thread a few months ago where an experienced bassist on a dimly lit stage plugged one amp output into another. Poof. The smoke got out and you can't get it back in.

If your amps and cabs all use common connectors, this is especially important. Like if they all have speakon jacks. If you grab two ends from a mass of cables and accidentally plug one amp into the other, rather than the intended amp->cab connection, this thread will have a very sad ending. One amp trying to drive the output of another is a sure path to an expensive repair bill!

 

Are you trying to do stereo?
Or are you just looking to get louder?
If you prefer one pre-amp, Send the preamp out of one amp to the effects return, aux in of the other amp.
It won't be the same as a power-amp, but a lot less knobs and interference to keep track of.

 

The resultant phase responses to the bass input may become unpleasant by small or large degree. Individual perception may differ.

 

Not just the amps but the effects also.

 

To me it's fun to experiment with stuff like this. If worse comes to worse, you could power them both off and plug your cabs into one of the two heads. If you like it, check out the Crown XLS power amps. Each channel has independent HPF and LPF filters, so you can send clean to one channel, dirty to the other, and enjoy the yummy goodness I think I'll be heading in that direction. Something is really appealing to me to be able to just plug in a different preamp to change things up.

Crown XLS 1502 Power Amplifier I'm pretty sure Sam Ash Castleton stocks these if you wanted to plug in and try it. Very nice people in that store.

There was a very sad thread, maybe last fall or summer, where someone plugged one amp output into another on a dimly lit stage. Ate both amps It was a sad thread That's why I mentioned labeling the ends of the cables. It would really suck to kill two nice amps and be left with nothing I already labeled my cables... I'm kinda thick. You know how Purdue employees are BTW: just noticed your location, I'm just down the street from you... an hour N. on 65.

 

Your back? The paint in the stairwell? Your very small and underfoot dog? Just trying to think of everything that would go wrong if I tried this.

 

I would say, nothing. My live rig was two Eden WT-300's. One into an SWR 8x8 and one into an SWR 2x12. I plugged my Zon bass into the heads at the same time via a Y-cord and EQ'd each cabinet separately. Never ran into any issues.

 

generally, i think one amp is supposed to sound clean through 12s or 15s, while the other is supposed to be distorted through 10s, or at least that's what i've read

 

Using matching cabs should eliminate most phase related problems, but keep in mind EQ introduces phase shift as well. Greater boost or cut means greater phase shift. Probably minimal impact such as reduced clarity and uneven tone.

Some pedals invert signal polarity 180 degrees which can result in cancellation in the low end and comb filtering across the audio spectrum. This would likely produce a quite noticeable loss of low end and volume.

Digital effects have latency that equates to a slight signal delay which can cause comb filtering. Impact would probably vary with the type of effect used. Perhaps perceived as a slightly annoying mid range resonance.

If you have FOH support an additional channel will be required for bass.

If you are using several effects it could be quite time consuming to dial them in given you haven't used this sort of setup before. I would play around with the setup at home, work out the kinks in rehearsal, and use it live after I had a good feel for how to dial in the various sounds. YMMV

Additional Ideas for later
If you have the option, consider experimenting with pre distortion EQ and post distortion high pass and low pass filtering on your wet rig. Ideal EQ and band pass settings could vary from one effect to another.

It is likely, some effects will sound better running parallel wet/dry amps, and some will sound better running wet on both amps. The range of possibilities with signal switching is endless, so have fun and good luck.

 

I am sure everyone looks forward to the gig report

 

I do this all the time! My second amp is called "the PA system"...

 

Can put bright colored tape around the cable ends too as a backup.

EDIT: I initially thought above-referenced post said 'label the cabs'.