Another Bi-Amp Question


I have B&W 805's for front speakers and a Pioneer Elite A/V Receiver (VSX92THX). The speakers max power handling is 120W and the Receiver max output is 130 watts into all channels. Here is my question- I can biamp the fronts using the surround rear speaker outputs. Would I need to worry about frying my speakers? In otherwords, would the B&W handle max 120W into each driver? Or, would I be putting out (max ) 130w X 2 into each speaker?). Sounds awesome the way it is but if I can grab a bit more power w/o damaging anything, why not? (It is an HT system only).

Thanks,
128x128cerrot
130 watts into your speakers isn't an issue so long as you don't over drive them.

That said, you need to make sure your speakers are wired such that they can be biamped. The mfg will tell you this.

That said, the only way you could do this with your Elite is IF you can independently configure your surround amps to be driven by the Front/Main preamp outs - such that they get the exact same signal as the front amps would get. I'm not familiar with your Elite, so unless you know how to do this I wouldn't try it.

That said, I frankly doubt you'll find it makes much difference, but if you can meet all of the above criteria, it may still be fund to try. I've tried to passively biamp many different amp/speaker configs, and have only had luck (ie a materially favorable result) with one setup.
Thanks. The speakers are capable and I do know how to configure them. I do play my movies LOUD. Is it 2 times 130 watts into one speaker rated at $120 watts? Does someone know? That's my question.
You can try it but why? Assuming(!) the quoted numbers are accurate, you have speakers with a max power handling of 120w connected to amp channels with 130w output. How could or why would you think that biamping would get you any more volume output (without distortion)?

Kal
If this could be done,you will have a power loss and lower volume.If your speakers are 8 ohm and you split them,each half will be about 16 ohms.Hooking the 16 ohm half to the receiver will cause the power output to drop to approximately 65 watts since it will be driving a 16 ohms load.This will cause about a 3 db loss in sound.You'll have about 65 watts x 4,if your equipment allows bi-amping.I could only see a volume loss doing this.
I don't need to increase volume output, nor was I aksing if hey would play louder. As I said, system sounds great. Advantage of biamping isn't necessarilly to play louder. If I wanted louder, I would get more effecient speakers and larger amps - and a larger room.

Theoretically, is it 260 watts into the speaker?..are biampable speakers rated by the entire speaker or the biampable inputs? I thought a simple question. Not aksing for opinions or why I should.

Thanks for your help.
Cerrot: The only possible reason for bi-amping (without replacing the built-in crossover with a custom external one) is to increase the power output to the speaker. However, any such increase is minimal. There is no reason to expect any other difference for the bother. (Gratuitous opinion.)

Hifitime: That is simply false. Impedance analysis will demonstrate that each leg of a crossover will still show the same impedance as the combination since each leg will have a very high impedance outside of the pass-band for that leg. The individual and combined pass-band impedances are the same. Thus, with biamping there is no loss of output and any power increase is real but minimal (<3dB).

Kal
The speakers are rated as "Recommended amplifier power 50W - 120W into 8Ω on unclipped programme." That means 120W on typical musical material. Typical musical material has much lower energy levels at treble frequencies than at lower frequencies. Therefore the 120W rating applies only to the low frequency driver, especially in view of the relatively high crossover frequency (4kHz).

Tweeter power handling capability is usually far less than woofer power handling capability. However, speaker damage occurs most frequently as a result of high volume bass peaks causing the amplifier to clip. The clipped waveform contains high frequency spectral components that are not present in the original music waveform, and the speaker's crossover routes that extraneous high frequency energy to the tweeter, causing it to have to handle more power than a music waveform would normally require it to.

None of that will change as a result of the bi-amping scheme you propose, apart from a probably inconsequential reduction in the amount of current each amplifier channel will be required to supply. And keep in mind that the power delivered to the speaker is determined not by the amplifier power, but by the music and by the volume control setting (as long as the amplifier's voltage and current capabilities are not exceeded).

HiFiTime -- Respectfully, I don't think that is true. The impedance that the speaker has at low frequencies (below the crossover region) will be the same regardless of whether or not the tweeter and its crossover elements are connected. Likewise the impedance at high frequencies (above the crossover region) will be the same regardless of whether or not the woofer and its crossover elements are connected.

Regards,
-- Al
Cerrot, I think I understand your question and the answer is- that even if you biamp using the two rear channels it will not double the power but will still be 130 watts to each driver and will not hurt your speakers. I can't say if you will notice a difference or not, but hey give it a try and see. Good Luck!
I believe you guys are correct for the frequency range it will be driven at.I'm thinking of full range drivers.
Hifitime wrote:
I believe you guys are correct for the frequency range it will be driven at.I'm thinking of full range drivers.
And what is the relevance of biamping for full-range drivers? Why not simply use a better, more appropriate amp?
Theoretically, is it 260 watts into the speaker?
no, it's 130 watts into each speaker. Not theoretical. Actual.

Given your responses so far - if I were you I'd try it. it'll cost you nothing but your time (except you'll need another speaker run unless you already are using biwire shotgun cables), and it will do no harm.
Thanks. I do already have the cables. Just didn't want to fry the speaker. Thanks, everybody.