Another biamp thread.

08-16-11: Drew_eckhardt
08-15-11: Hifihvn
>The pros have the high dollar test equipment to work with, and see the after results too.

The few few hundred dollars to buy a personal ARTA license for gated measurements, microphone preamp, and calibrated measurement mic are no longer a big deal.

Reading a couple of books doesn't turn you into an expert. I guess you could test them outside instead of an anechoic chamber. But that aside, there are all kinds of things that you learn from experience and Electrical Engineering school to decipher what some things mean, if this equipment can give you everything the experts use. It sort of reminds me of these ISF certified guys that come out to your house to calibrate your TV for D6500. A lot of TV's look terrible after. They don't understand what is going on, and that is the way it is, since the equipment shows it's close to D6500. Also THX certified equipment. Definitely not a sure thing for hi-end. There is a real science to crossovers, and how much different they can act just with a different wood used for a speaker. The same goes for different materials used for speaker cones with the same specs..

They're fourth order crossovers, and they are probably complicated. The marketing materials for the speakers included a few proud sentences about their computer designed crossovers. I suppose this may have been novel in the late 90's? Anyway, some sources suggest that actively biamping is the only way to fly, completely disparaging passive biamping. So then, what's the best use, generally speaking, of two sets of speaker posts on a pair two way speakers?

08-15-11: Hifihvn
>The pros have the high dollar test equipment to work with, and see the after results too.

The few few hundred dollars to buy a personal ARTA license for gated measurements, microphone preamp, and calibrated measurement mic are no longer a big deal.

Products like MiniDSP mean rapid iteration over cross-over functions doesn't involve a lot of bread boarding and making speaker cabinets isn't hard either.

The main issue is knowing what to do.

Read and understand

Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms by Floyd Toole

and

Loud Speaker Design Cookbook by Vance Dickason

and either get to work (because you're still interested) or decide you don't have that much free time and build other peoples' designs.

The project is ill-advised.

To at least match the performance you have now will require duplicating the transfer functions at the driver terminals (duplicating compensations for rising response, baffle step, driver resonances, etc). If you're willing to invest that much time you're better off building better speakers designed by someone else.

To beat it you'll need to learn what you're shooting for, make gated measurements of the speaker's polar response, and come up with more ideal cross-over functions. At this point you've decided to make speaker design a hobby and with all the time going into the effort you're better off starting from scratch.

Crossovers are indeed complicated. It's hard to out do an Engineer/Designer as an experimenter. It's hit or miss. If you miss, you could end up with blown drivers fairly easy. A lot are hard to get. Especially tweeters that blow easily. If there is a proven upgrade, then you have a better chance. After experimenting with speakers years ago, the best I found was to leave it to the pros.

Possibly change to better grade caps in the passive crossovers (same value) in there now would be an option.

As far as keeping it all analog, I don't know if that could be done with something like the Behringer you mentioned. It has a time delay in it, and that most likely does it in digital. Could it be bypassed? Also, all the op amps, capacitors, and who knows how much other active electronics added to the mix, that could add something else sonically.

The pros have the high dollar test equipment to work with, and see the after results too.

If you're going to remove the passive crossovers I would do some research on the speakers you may be interested in and see how complicated the passive crossover network is designed. The more complicated the crossover design harder it will be to incorporate an active crossover. The active crossover will need to be very flexible. I would stay away from 3 4 or 5 way designed speakers.

A simple well built two way design or dual concentric design would be good candidates. Maybe a DIY project from Madisound with high quality tight tolerance drivers would be a great option.

Or you could choose a speaker that has an active bi-amp option like a Magnepan Apogee or something in the horn loaded arena.

Plenty of options but research about the drivers and cabinet design you are actively bi-amping will be key