Hi Dylan,

As a fellow owner of 604's, I have often thought of putting them in something like Imperials.  I think in terms of parameters they should be a good match, although the Altec "crowd" is more in favour of large bass reflex approaches.  The one drag is that the drivers are more than 11" deep, and the majority of horn designs don't allow for that in the depth of the compression chamber.  Actually, mine are "E's" and I think "C's" might be deeper slightly.  Anyway, it looks like the Decware (fullrange) Imperials might be able to accomodate them if you just cut the support boards that go behind the drivers differently.  But then you're talking two per side, and these are not exactly "cheap" drivers.  You could also use something like a 515 for the other one, again not much cheaper.  I have also heard of cutting a hole in the back of the compression chamber to allow for the driver, and then sealing it once you have it installed, but that sounds rather difficult to do properly.

Dave

Hi Dylan,

I guess I'm assuming you have the plans for the "regular" Decware Imperial and not the "SO (sub-only)" Imperial.  The regular one uses two 15" drivers per side, while the SO uses a single 15".  I'm not sure how the SO would work with something like a 604, perhaps not so bad?

FWIW Steve does recommend using mismatched drivers in the regular Imperials, or at least that's how he had them set up originally.  Having said that it seems to me that if not a coaxial something like a 515 or an 803/416 would be a logical choice.

If you have the plans, you could probably tell me if the braces behind the drivers will accomodate the magnet structures of your drivers, but either way it appears to me to be a simple fix if they don't of just cutting the shape different.

I'll take your Onken cabinets once you make the Imperials  

Dave