Is there anything wrong with my setup?

[Downunderwonder]

Btw, Billy doesn't have to be concerned about the substandard dispersion of his 15 on the distorted high end because it's going out through the PA.

 

[Bassnomer]

Biamp mode gives you level control over the highs and lows, whatever the 4x10 can dish out before farting the 15 will fill in the mids and highs. Tweak the crossover frequency for best result, somewhere between 200 and 500hz I expect you will find a sweetspot where the crossover and cab phases sum well.

Interesting you noticed it sounding hokey with the last test. Did you try to eq down the higher frequencies duplicated by the 15 to at least get some balance? If you did and it was still hokey that would tell me those cabs weren't meant for running together full range ever.

Separating frequencies for applying effects is a whole 'nuther ballgame. Some biamping amps have separate effect loops, but they are vulnerable to phase twisting causing a cancellation in the summed sounds. Yours might be in that boat?

My effects are run high and low with phase adjustment for my phase inverting fuzz. Putting overdrive and fuzz on highs while leaving lows clean is badarse.

Then there is Billy. There is a world of difficulty in getting dual amp rig sound out through a PA. When you're Billy you probably have a dedicated soundman just for your rig. Doing it with effects and a mono amp is very much easier. I digress.

Bring on the biamp test!

As I was expecting, the sound was lacking with the low and high frequencies going through separate cabs. I think it would be best to sell one of them and use two of the one I keep.

Here's the thing; I love the sound of the 115xl on its own. To me it sounds much warmer than the 410. If I were to stack up 2 115's, would the 4 Pro be too powerful for them?

 

[Jim Carr]

IMHO, more to the point is the question "Will the 2x115s be enough for you?" You have to try it to tell.

 

[Downunderwonder]

Yeah, a smaller amp could also overpower a pair, but at a higher knob position. Either way you only get into that situation if the cabs were incapable of what you wanted.

I'm surprised you couldn't tweak the biamped stack to sound like the 15 on steroids. I'm guessing you must have had crossover set too high.