I'm running my 604's at a crossover point of 1150.

[donaldpatten]

Cradeldorf
I never did think of the 1600 XO freq as golden.To me the magic was how it sounds. If you would like to do some listening tests PM me.
Don

[cradeldorf]

A buddy stopped over today and confirmed that they sound better than he's ever heard. Like I said over on AK if a 515 is indeed what the woofer section is, they are rated at 20-1000hz why they mated that with a horn that shouldn't be driven below 1600 is beyond me. Juniper All I'm gonna say is mine go well into the ear splitting level without batting an eye. I can almost hear them laughing.
Don they sound much more like they should this way.

[zelgall]

I've read that 604 E to the last sectoral before the CD types were only providing driver loading to about 1900 Hz but the Altec standard Xover is 1600 Hz

[cradeldorf]

I've read that 604 E to the last sectoral before the CD types were only providing driver loading to about 1900 Hz but the Altec standard Xover is 1600 Hz

I could never grasp the concept of loading since the phragm is barely moving in the first place and then every bit of air it is moving has to pass through 3 little human hair sized slits in the phase plug?
I can't imagine I could load the horn if I put my lips on the phase plug and blew as hard as I could. That is if my definition of loading means building some kind of back pressure from the air trapped in the horn tube and horn assembly itself. I would surely think the phase plug is what provides loading if there is to be any.

[Altec Best]

I could never grasp the concept of loading since the phragm is barely moving in the first place and then every bit of air it is moving has to pass through 3 little human hair sized slits in the phase plug?

Think of the diaphragm that is like a tuning fork.When you wrap on the edge of the tuning fork it puts out a lot of sound but you won't see it moving much.It is the tremendous amount of vibrations in such a short time that creates the output or (SPL).Or something like that.

[cradeldorf]

Think of the diaphragm that is like a tuning fork.When you wrap on the edge of the tuning fork it puts out a lot of sound but you won't see it moving much.It is the tremendous amount of vibrations in such a short time that creates the output or (SPL).Or something like that.

Okay, that draws a better picture in my head. Thanks.

[alancohen]

I still haven't built my XOs yet. After reading this thread I might try bi-amping my 604Ds with my Behringer DCX2496 first. Problem is I don't have enough amps and don't want to cannibalize my daily system to experiment. I might build another one of these: Transcendent Sound Cathode Follower Tube Amp and use it along with the one I have running my BR TV system to play with the 604s. They are a really sweet 3W/ch and I think I had around $500 all up into the scratch build of the first one. That's pretty cheap for a pure SE tubey.