Bi-amping....

[myriad1973]

I just wanted to get an idea of how many of you bi-amp your speakers?

I just got my pair of TSi500's this past weekend and bi-amped them (man they're HUGE towers!). They sound great with 260 watts per channel, but they tend to drown out my sub and surrounds without any tweaking. I'm going to have to re-calibrate with Audyessy to compensate.

 

[highfigh]

I just wanted to get an idea of how many of you bi-amp your speakers?

I just got my pair of TSi500's this past weekend and bi-amped them (man they're HUGE towers!). They sound great with 260 watts per channel, but they tend to drown out my sub and surrounds without any tweaking. I'm going to have to re-calibrate with Audyessy to compensate.

Define 'bi-amp'. If you mean run one channel to the high pass and low pass, through their existing passive crossovers, the most difference you'll ever see is 3dB, assuming both channels are capable of the same power output. If you never play at full power or anywhere near that, it's pointless unless you just want more headroom than you need. If they already drown out your sub and surrounds, it will only make that problem worse.

 

[jinjuku]

Sounds like you are feeding them enough power.

Bi (or multi amping) comes from the pro-audio realm where each monitor has its' own amplification. That way you could assign a channel of EQ as well as X-Over. You don't get to do this so much with a home audio setup.

Bi-amping isn't really about power delivery, it is about electrically isolating the passive crossovers so they are on there own circuit.

Me? I just feed my speakers with an Adcom 5503 and don't worry about Bi-amping. If I was to multi-amp a speaker setup then I would go full blown active x-over and eq.

 

[j_garcia]

Let me just add: biamping with a receiver is about as far removed from biamping as you can get since all of the channels feed from the same receiver sized power supply. A single channel from a decent external amp will provide you with more power than biamping from a receiver IMO.

 

[highfigh]

Sounds like you are feeding them enough power.

Bi (or multi amping) comes from the pro-audio realm where each monitor has its' own amplification. That way you could assign a channel of EQ as well as X-Over. You don't get to do this so much with a home audio setup.

Bi-amping isn't really about power delivery, it is about electrically isolating the passive crossovers so they are on there own circuit.

Me? I just feed my speakers with an Adcom 5503 and don't worry about Bi-amping. If I was to multi-amp a speaker setup then I would go full blown active x-over and eq.

Actually, biamping at the pro level is about power and efficiency- when a PA system needs to be able to deliver a specific output level, it's much better to cross over actively, because the insertion loss from passive crossovers means the amplifiers need to be more powerful. It costs more for more powerful amps and they weigh more. This isn't a problem for a fixed installation but it is for a touring rig. It's often less expensive to add an amp and active crossover than to use a more powerful amp. It also offers much more control over the sound- if the acoustical space has a problem that coincides with the crossover frequency, it's possible to use the F3 or F6 to cause a dip in the response and that can tame the problem.

Another problem that can occur with excessive power input to one speaker or another is thermal compression. That's when so much voltage/current is applied to a voice coil that the winding heats up- since temperature increase in a conductor increases resistance, increases in voltage (power) cause little/no increase in SPL.

 

[jamie2112]

What Hi Fi said ..........

 

[jinjuku]

Actually, biamping at the pro level is about power and efficiency- when a PA system needs to be able to deliver a specific output level, it's much better to cross over actively, because the insertion loss from passive crossovers means the amplifiers need to be more powerful. It costs more for more powerful amps and they weigh more. This isn't a problem for a fixed installation but it is for a touring rig. It's often less expensive to add an amp and active crossover than to use a more powerful amp. It also offers much more control over the sound- if the acoustical space has a problem that coincides with the crossover frequency, it's possible to use the F3 or F6 to cause a dip in the response and that can tame the problem.

Another problem that can occur with excessive power input to one speaker or another is thermal compression. That's when so much voltage/current is applied to a voice coil that the winding heats up- since temperature increase in a conductor increases resistance, increases in voltage (power) cause little/no increase in SPL.

I should have been clearer: When I see home 'audiophiles' bi-amping they are trying to electrically isolate passive crossovers. At least that is one of the main reasons I have seen (that of 'purity').

Bi-amping at the pro audio level is done for different reasons than the home. Both for reasons that you and I mentioned.

 

[highfigh]

I should have been clearer: When I see home 'audiophiles' bi-amping they are trying to electrically isolate passive crossovers. At least that is one of the main reasons I have seen (that of 'purity').

Bi-amping at the pro audio level is done for different reasons than the home. Both for reasons that you and I mentioned.

Yeah, there is that, too. What a bunch of loonies.

 

[lsiberian]

I will be bi-amping or tri-amping my mains, but they are custom built speakers. So it's a different ball of wax.

 

[myriad1973]

Well I wasn't expecting to start a debate over bi-amping. I just wanted to know who else does it regardless of the technical aspects. I did it to add some dynamic range and clarity to my speakers.

 

[ichigo]

Well I wasn't expecting to start a debate over bi-amping. I just wanted to know who else does it regardless of the technical aspects. I did it to add some dynamic range and clarity to my speakers.

You get slightly more power at the cost of more speaker wire. And I've heard that it causes a lot of wasted energy onto the passive crossover that turns into heat.

 

[PENG]

Well I wasn't expecting to start a debate over bi-amping. I just wanted to know who else does it regardless of the technical aspects. I did it to add some dynamic range and clarity to my speakers.

That's a good thing, because around here you will end up getting a lot of opinion based on hearsays and myths based on a few articles (at least one that comes complete with bunch of formula put together based on misconceptions) on the web. While it may not make any audible difference at all, the theory behind passive biamping and even biwiring can be proven scientifically and visibly displayed with the appropriate intrument, but people would just tell you it is no different than using thicker wires unless you do active biamping. And you can't argue with them because you would need to be in a class room to show the math and hope everyone knows their advanced math and electrical theory well; and a lab to show the signal spectrum in each pair of wires.

So you are very wise to not starting a debate.

 

[myriad1973]

The way I figured, I had two extra available channels, and I can't run a 7.1 system in the apartment I live in, so why not use them in a bi-amp 5.1 configuration? It made more sense to me.

 

[Pure_Brew]

Interesting option! I haven't used a receiver to bi-amp but I have used separate amps to do this before. If I had the 805 I would have tried the very same thing, and I'm not surprised you find the sound better overall (although I wouldn't be surprised if you got no benefit either). I also have found that higher quality single amplifiers can yield better sound then lower quality amps used in horizontal/vertical bi-amp configurations. However, I work with what I have, and after experimentation, a better result exists then I stick with it until I can make another improvement - naturally.

 

[blueone]

You get slightly more power at the cost of more speaker wire. And I've heard that it causes a lot of wasted energy onto the passive crossover that turns into heat.

Hmmm, I would have said it differently. With bi-amping you get twice the power (assuming equal amplifiers), theoretically resulting in 3db of additional loudness in the audible frequencies, at a cost of extra channels of amplification, extra electricity, extra interconnects (or a y-splitter), and twice the speaker cable.

Since the average input power to most speakers is less than 4 watts, and often less than 2 watts, I wouldn't worry much about heating up the crossover.

Whether or not bi-amping is an audible benefit seems to depend on some pretty subtle variables. For example, some speakers present rather punishing loads in some frequency ranges but not others. My old Legacy Audio Focus were like that, since it seemed like the designer just hooked three 8-ohm woofers in parallel for the lowest three octaves. (I know he probably didn't, but looking at the measured impedance curve for that speaker one might think he did...) Some people also like to convince themselves that multi-driver woofer arrays generate a lot of back-EMF that negatively affects the amp, or that arrays of mid-range drivers and tweeters complicate loads, and that separating these arrays from the woofer arrays through a passive crossover somehow improves the sound. I have no idea if it does, but my gut feel would be that it mostly doesn't, for amps that perform well into both high-impedance and low-impedance loads. With some speakers with complex driver configurations and lower power amps you might get better sound with bi-amping, but when I see folks that want to vertically bi-amp a two-way, two-driver speaker using 200w/ch amps, well, I just have to shake my head.

One other thought, your ears work logarithmically, but your sense of touch doesn't. A 3db increase in power causes a small increase in loudness at 40Hz, but you feel about twice the slam, because it's twice the delivered power.

Bi-wiring looks to be a complete waste of money if you use wires of the proper gauge. The audibility of bi-wiring must be one of the biggest lies in the audio world.

 

[myriad1973]

I guess I should clarify something for all of you that are not aware of if you do not own an Onkyo receiver. The amplifier has the capability of not only being a 7 channel amp. It can also assign the surround back channels for bi-amping the front channels, if you do not use surround back speakers. So regardless of it not being true bi-amping, why not use the extra channels in that way if it's available?

 

[Pure_Brew]

I guess I should clarify something for all of you that are not aware of if you do not own an Onkyo receiver. The amplifier has the capability of not only being a 7 channel amp. It can also assign the surround back channels for bi-amping the front channels, if you do not use surround back speakers. So regardless of it not being true bi-amping, why not use it anyway if it's available?

Exactly. If you get a benefit out of it, there's no reason not to do it.

 

[adwilk]

Hmmm, I would have said it differently. With bi-amping you get twice the power (assuming equal amplifiers), theoretically resulting in 3db of additional loudness in the audible frequencies, at a cost of extra channels of amplification, extra electricity, extra interconnects (or a y-splitter), and twice the speaker cable.

Since the average input power to most speakers is less than 4 watts, and often less than 2 watts, I wouldn't worry much about heating up the crossover.

Whether or not bi-amping is an audible benefit seems to depend on some pretty subtle variables. For example, some speakers present rather punishing loads in some frequency ranges but not others. My old Legacy Audio Focus were like that, since it seemed like the designer just hooked three 8-ohm woofers in parallel for the lowest three octaves. (I know he probably didn't, but looking at the measured impedance curve for that speaker one might think he did...) Some people also like to convince themselves that multi-driver woofer arrays generate a lot of back-EMF that negatively affects the amp, or that arrays of mid-range drivers and tweeters complicate loads, and that separating these arrays from the woofer arrays through a passive crossover somehow improves the sound. I have no idea if it does, but my gut feel would be that it mostly doesn't, for amps that perform well into both high-impedance and low-impedance loads. With some speakers with complex driver configurations and lower power amps you might get better sound with bi-amping, but when I see folks that want to vertically bi-amp a two-way, two-driver speaker using 200w/ch amps, well, I just have to shake my head.

One other thought, your ears work logarithmically, but your sense of touch doesn't. A 3db increase in power causes a small increase in loudness at 40Hz, but you feel about twice the slam, because it's twice the delivered power.

Bi-wiring looks to be a complete waste of money if you use wires of the proper gauge. The audibility of bi-wiring must be one of the biggest lies in the audio world.

Strong first post, Blueone. I concur.

 

[PENG]

I guess I should clarify something for all of you that are not aware of if you do not own an Onkyo receiver. The amplifier has the capability of not only being a 7 channel amp. It can also assign the surround back channels for bi-amping the front channels, if you do not use surround back speakers. So regardless of it not being true bi-amping, why not use the extra channels in that way if it's available?

It is good that you clarify this but I am pretty sure most who responded to your post so far know it already. I do not own an Onkyo receiver but I know many of the 800 series and up models can do it. My Denon 4308 can do the same but so can the < $1,000 AVR-3310. I suspect it is a common feature nowadays among mid to upper range AVRs, not just Onkyos and Denons.

You are absolutely correct about "Why not?", as long as your goal is to find out if you can get better SQ by separating out the high/low frequency signal paths and not trying to gain more power output.

 

[JerryLove]

I'm quad amped, but then again I'm using an active crossover, so it's basically a neccessity.