Bi-amping

[Foxman]

Just curious if anyone hear has ever Bi-amped their speakers using an active crossover. I know there are some mods on the Klipsch RF-7 for an improved crossover, but I am more curious if anyone has tried this.

If so, what active crossover network did you choose and how did you find your crossover points.

Right now I am just gathering info on the idea.

Thanks for your input.

[Davey]

Bi-amping with active or passive line-level crossovers is something I've done for many years. There are a number of forum members here who also use this approach. I am not familiar with the Klipsch RF-7 but, generally, any speaker can be converted to bi-amp operation. However, it might not make a lot of sense in certain situations.

The term "bi-amping" has taken on new meanings/labels in the last few years with configurations that don't follow the tradition bi-amping configuration that dates back many many years. You might see the term "passive bi-amping" used which is not much more than bi-wiring, but in my view the only true bi-amping configuration is one in which the drivers are connnected directly to the amplifiers and the crossover is shifted completely upstream of the amplifiers.

Rod Elliot has a couple of nice articles on this subject on his website. Good reading.

http://sound.westhost.com/bi-amp.htm

http://sound.westhost.com/biamp-vs-passive.htm

"Converting" a conventional passively-crossed speaker to bi-amp operation is not a trivial task in most instances. The commercial, active crossovers that are available usually have fixed 24db/octave slopes which are probably much different than your speakers existing crossover. Not to say that it won't work better, but is essentially a redesign of the system, and unless measuring equipment and some know-how is available you might not get good results.

The best active-crossover, bi-amp speaker systems are those designed from square one with dedicated crossovers/EQ for the drivers/configuration used.

Cheers,

Davey.

[Foxman]

Thanks for the info and links, I will have to take some time and digest all of that. Yeah, I don't see much point in passive Bi-amping so I had been thinking of using a crossover from Behringer (can't recall the model right off).

I have read on the Klipsch forum that some people have come up with a modification of the original crossover's using better materials and supposedly getting great results although for the $500.00 they charge I would have to demo them first and that doesnt appear to be an option. I also read that Klipsch is coming out with a revised RF-7 to sell in addition to the current series that inlcudes a better crossover network. I don't have a problem with the sound, I just am striving for maximizing the speakers I have. I may be heading down the wrong path though, not sure yet.

It seems to me that several people that has done this type of thing really enjoys the results, although I am aware that there is a ton I do not know about the process and thus do not want to rip open my cabinets just yet.

[Dennis H]

The biggest problem with "generic" active crossovers is they don't provide any baffle step compensation (BSC). Without it, the speakers will sound too weak in the bass. That's because high frequencies mostly project forward from the speaker but low frequencies go in all directions. Since the lows are filling more area in the room, they are quieter than the highs when you're in front of the speaker. The speaker designer boosts the lows in the crossover to compensate but a generic active crossover can't do that. Even with the digital crossovers that let you apply EQ for things like the baffle step, you have to be able to measure the speaker to know how to set the thing and doing it right is about as hard as designing a crossover from scratch.

That was a long-winded way of saying don't bother unless you are unhappy with the sound and/or you really know what you are doing.