410 vs 215 dispersion

[DukeLeJeune]

I might be off topic here, but it reminds me of a tale I was told many years ago. If you take a 1x15 with 4x10 combination and compare it to just two of the same spec ( 2x1x15 or 2x4x10) the two later configs will have a natural boost?? I don't remember the details but for some reason I've stuck to it blindly. Any thoughts?

Might have something to do with this:

At low frequencies, the output of two closely-spaced drivers will add in-phase. As we go up in frequency, the distance between the drivers starts to be a significant fraction of a wavelength, so instead of perfect in-phase summing we get summing at some angles and cancellation at others (these angles change with frequency). The higher we go in frequency, the more cancellations we get, approaching the theoretical limit where we have'd have just as much cancellation as summing.

What this means is, as you cluster more drivers on the front of a cabinet, you're losing more off-axis upper frequency energy because of cancellation. So the in-room tonal balance (which comes from both the direct and reverberant energy) will become more bass-heavy.

These cancellations occur in the plane that the drivers are stacked in, because that's the plane in which they are spaced apart. So a vertical stack of drivers will have cancellations in the vertical plane, but in the horizontal plane (where the audience is) the direct sound's frequency response will hold up much better - and this is the reason for the argument in favor of vertically stacking drivers.

 

[greasyogre]

Sorry...I didn't know Ampeg was the only company that made cabs

Around here, about 2/3rds of all bass cabinets are Ampeg. The other third is made up of Hartke and GK cabinets, but once in a long while you might see SWR or Mesa stuff.

 

[JimmyM]

Ampeg dominates, yeah. It's a reflection of the marketplace. But this place gives a lot of cabs play, especially new builders. And there's a lot of talk about how to improve cab designs as well, which is building the audience for new builders.