Odd that you would spend all the extra time and money to bi-amp and change the signal when once it arrives at your speakers IT IS GOING TO GET CROSSED OVER ANYWAY! seems like a waste to me. bi-amping just sums the power inputs, you could achieve that with one, more powerful amp (if passive speaker network). i guess if you like it thats cool for you, but there is no way to get around your passive crossover unless you take it out. so regardless of what you do to the signal prior, it is going to end up the same in the end. i used to do some manufacturing analysis (not really audio design, but how to more efficiently make speakers get them to retailers, etc.) for polk audio and while on that project i had the chance to ask them about why would one bi-amp and then said its pointless for passiver crossover speakers. you could instead of buying two lesser amps for price A, instead buy one better one for price A and be better off. obviously i asked them more questions about it than that and they said more than that, but that sums up what they said. YOU ONLY BI-AMP ACTIVE CROSSOVER NETWORKS (NOT PASSIVE SPEAKERS), UNLESS YOU JUST WANT MORE POWER AND WANT TO UTILIZE EXISTING AMPS.

if you are only getting low frequency signal of 400Hz then why is it necessary to further "limit" it with a 600Hz low pass filter that is doing nothing since the freaking signal is already 400 or below. that is just plain dumb. btw i wouldnt consider 400-600Hz as bass, perhaps you should label it more correctly as low frequency sound, or mid-range. "bass" i.e. what one would expect from a subwoofer is WAY lower than 400Hz...
[This message has been edited by curegeorg (edited May 15, 2004).]

[This message has been edited by curegeorg (edited May 15, 2004).]

I don't quite understand how you can say something like this:



yet still say something like this:



It sounds like you're saying bi-amping doesn't do a thing with the passive crossovers in place yet bi-wiring does? I would venture to guess that what you mean is that bi-amping isn't worth the time over just bi-wiring.

A big thing that might help some of us understand the issue better is to know how the passive crossovers receive the signal when it comes from two different lines be it via bi-amp or bi-wire. How does the crossover handle two input signals instead of one? Does it do anything different?

I see what curgeorg is saying about the passive crossover still being in the way, but it is absolutely imperative to answer the question I just posed before being able to answer that. Maybe it was and I just didn't see it? There is a LOT of information here.

[This message has been edited by JT Clark (edited May 15, 2004).]

yes i mean it is no better than bi-wiring, however it is not as good because it costs a lot more (from that standpoint at least). i am not exactly sure how a signal is dealt with as soon as it enters the speaker, i.e. is the input combined if you connect high and low frequency or what... it seems to me like it has to be since it is only going through one crossover, however i think feedback is fed back through each individual input (high or low). another advantage to bi-wiring is the removal of the cheap p.o.s. jumper used to connect the two posts, granted you could just use a short segment of wire.

Not all jumpers are cheap POS's. Mine are big and strong enough to tear a nasty hole in someone. Not that I have any experience with that.

My car speakers have the ability to be bi-amped. They have two inputs and have a switch for a single input or bi-amp/bi-wiring. I doubt they would spend all that time and money putting it in for nothing. That's what led me to think the passive crossovers might do something different with 2 signals entering vs 1. I haven't tested out how effective it is though. It just doesn't seem very wise to say they don't do anything without actually testing it. Those without a switch may have some sort of automatic detection built in. I don't know.

It is not rocket science to make a 4" long jumper bar to short together two sets of terminals on the back of a speaker. Just how "expensive" does such a bar have to be? Pure gold perhaps? Plated with silver and platinum? Blessed by the Pope? Maybe 4" long by 3" thick, and pure silver - then blessed by the Pope?

That bar does nothing but join the two sections of the crossover network - the section that feeds the woofer, and the section that feeds the tweeter (or midrange and tweeter combined in a 3 way system). That connection could just as easily be done inside the speaker cabinet and routed to a single + and - terminal set on the back of the cabinet. Before the bi-wiring fad reared it's ugly head, this is exactly how all speakers with passive crossovers were configured. The bar just gives you the "option" of feeding the two crossover sections independently from two amplifiers or one amplifier. Either way, the electrical configuration is identical as far as the crossover network is concerned, and the performance will be identical whether you bi-wire or not.




[This message has been edited by soundhound (edited May 15, 2004).]

If someone understands enough about active bi-amping to convert their passive system, I’m sure that person would know better to open up the speakers and rewire it to bypass the stock crossover circuit. They can always reattach them if passive crossover is desired. Only possible compromise (cosmetic) may be drilling two extra holes on the back for additional pair of binding posts if the speaker only came with 1 pair.

So if the you can feed the two crossover sections independently that means that if you had dedicated wiring for each section there would be a benefit. i.e. the inputs are not summed and then split up, but instead that the high terminals connect to the mid/tweeter assembly and the low terminals connect to the woofer assembly? that cannot be what you are saying...

For the sake of simplicity, let's just say each speaker size has it's own input terminal available, ie biwire a 2 way or triwire a 3 way. That way whether you're talking about a 2-way setup or 3-way speaker it wouldn't matter. No partial garbage going on, like figuring out biwiring a 3-way. Or just stick with a 2-way only.

georg, I don't quite understand what you're getting at?

[This message has been edited by JT Clark (edited May 15, 2004).]

I bi-amp my mains by removing the straps which allows you to feed each section of the passive crossover independently. Bi-amping allows me more control over the sub section of the speaker by using the right type of amp with it. If you use an integrated sub amp you can effectivly tune the sub section by being able to adjust volume, phase and bass rolloff independently of the mids and tweet section. The amp I use also allows you to high pass the signal thru to the amp supplying the upper range. My next step will be to remove the woofer passive crossover and control it completely form the sub amp.

As for biwiring I see no advantage at all unless you are stuck with a lot of wire at to small of a gauge and you want to use it up. SH's logic and explanations (numerous) are perfect in explaining this, I just don't understand the reluctance of some to see it.