Quote Originally Posted by GM View Post
FWIW, I did a bunch of empirical testing of a single 604E in one of my ex DIY 825 cabs [3/4" no void marine ply, mucho bracing/damping] and among other tests, used a 500 Hz/2nd order [autoformer] XO to blend the 511 perched on top to it and with just the XO and both horns disconnected we [me and its owner] couldn't tell anything useful compared to the 416 in his other cab or even my dual 515Bs in 210 cabs, i.e., they all sounded like 'mud' sloshing around inside, with no definition/tone/whatever you want to call it 'cause we sure couldn't hear anything like music.
I hadn't thought about using a 604 as a 515. It makes sense since its the same woofer besides the horn in place of the dust cap.

So you are saying that at the 500hz xover point there was no noticable difference between the different drivers? I bet if they were run up to 1.2khz there might be more differences.