Not completely the same thing, but this:

http://www.tactaudio.com/web-files/RCS 2.0/RCS 20.htm

is by far the best tweak to any super High-end system I've ever heard (and I've heard a few!). Even with systems that were already damn near perfect really benefitted from this device.

Apart from being able to tailor frequency response exactly to a preset, it also corrects for time differences with incredible resolution.

In time, I'm sure this sort of stuff will find its way into cars as well.

There's another unit on the site, the RCS 2.2, that actually has a separate subwoofer output; of course time-aligned separately as well.

(as it so happens, that truly digital amp Millenium is equally incredible, I'm saving up for one...; wouldn't mind a car version of it).


Cas