Bi-amp with rear of subwoofer connection

Bloodeagle

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hey ladies and gents. Forum newbie, but a half way decent techy....


My thought is, id like to finally biamp my speakers. My sc97 is located in a nook. I currently only have 2 leads being sent to my bw 704s. That will soon change as i intend to buy a 5 channel separate to run biamp to fronts and 1 lead to center.

This is where my crazy thought comes in....

As many would note, some subs come with rear hpf and lpf speaker terminals in order to integrate and blend their speakers to their woofers.....

Can I purchase and use 2 subs (not my main woofers) connected by said left and right channel bi amped leads (both left leads for left woofer and vice versa) using the subs rear hpf and lpf in order to extend the bass response of my 704s? Would this inherently null the bi-amp? Unaffect it?

Would be something like this:

Left and right analog out of sc97 to nameless separate. Left two leads of separate in bi-amp ran to left and right leads in of left subwoofer. Both lead outs sent to bw 704. Do the same for the right.

Would i now have not only a bi-amped set of 704s, but a bi-amped pair of 704s with an independent subwoofer for each? Then with a much lower hitting and powerful main woofer tucked away elsewhere....

Or does this somehow get botched along the way????

I have a strong suspicion that many an audiophile already sets things up this way, but from an eager-minded guys point of view, this seems perfect. Correct me if I am wrong, please.



Sorry for drawn out post. Thanks in advance for any assistance.
 
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Why bother? The b&w designers have spent a lot of time and engineering effort in developing a well balanced speaker. And they have a good wide frequency response matched speakers etc. I think it would be a kludge to start sticking third party speakers on in the hope of getting another octave of frequency.
 
And your considering an AV amp just to add extra channels of amplification - you would be better off sticking with a stereo amp. Much better sound quality than an AV amp pound for pound
 
There's nothing to stop you biamping via the sub, but bear in mind that any filtering puts some phase shift onto the signal, so if you were to use the HPF to limit the bass to your B&Ws, the treble unit would not get the same degree of phase shift and this would change the behavior, particularly around the crossover point.

If you want to add in some sub, why not? It's not normal in audiophile setups, where really deep bass below 30Hz or so is not really required (Instruments rarely get this low), but it can give more punch around the 60 - 80Hz area, which is good for EDM and other bass heavy genres.

Sub bass in the home is much more relevant to home cinema, where LF effects contain gut wrenching amounts of LF. In this case however, a dedicated sub channel is better, with the AV amp controlling the bass distribution.
 
I have never seen a sub with biamp INPUTS, not have I ever heard of a subwoofer with separate HPF and LPF IN.

Since you didn't identify any in your post I can't check, but I do rather wonder if you're confusing IN and OUT. If so, the answer is that you cannot biamp into the subwoofer, so the question is of no relevance. Connecting both leads from both amp channels into a single input will cause a big bang, a lot of smoke and a non functional amplifier.
 
I have never seen a sub with biamp INPUTS, not have I ever heard of a subwoofer with separate HPF and LPF IN.

Since you didn't identify any in your post I can't check, but I do rather wonder if you're confusing IN and OUT. If so, the answer is that you cannot biamp into the subwoofer, so the question is of no relevance. Connecting both leads from both amp channels into a single input will cause a big bang, a lot of smoke and a non functional amplifier.

I am not sure the OP is suggesting that the sub has biamp inputs but has left and right inputs and therefore two distinct channels.

An older sub I had for example had both High and Low inputs

1352399-bampw-asw1000-subwoofer.jpg


So in theory what I think the OP is saying, is take say the pre-out left channel out of the AVR. Split to two to feed two channels of the 5 channel power amp. Take those speaker outputs and run one to the left channel of the sub high input, the other to the right high input. Set the sub filters appropriately and then the output of the left high would go to the HF input on the speaker. The right high would go to the LF input on the speaker. Rinse and repeat for the right channel.

So you end up with a lot of cabling, 3 subwoofers and a power amp. As @noiseboy72 states, I can't help but feel its going to end up with a muddle.

How much power can the subs handle through their High Inputs.
How is that signal changed?
Who still does one that is capable of being partnered with the speakers at a similar quality\performance level?
Risk of getting it wrong and frying stuff?
Noise\hum level introduced on circuits?

If you think your speakers are not performing in the way you would want then I would look at possibly using either a power amplifier or an integrated amp with HT bypass. That will quite possibly tighten the bass up. Alternatively look at changing the front speakers for something with more bass?

I can't help but thinking you are going up spending an awful lot of money for little if any gain, in fact it will probably sound worse.
 
I meant to put depending on how your setup your AVR up it could well be limiting the amount of bass its sending to the front pair. Have you checked these settings? If these are restricting, adding the subs as you describe won't help anyway till you change the settings.
 
I know of no subwoofer that will amplify a line level input to a speaker level output. Since the OP definitely says biamp and also that he wants to use a subwoofer to provide the other channel, I remain with my assumption that the OP is asking for something based on a misunderstanding.
 
I know of no subwoofer that will amplify a line level input to a speaker level output. Since the OP definitely says biamp and also that he wants to use a subwoofer to provide the other channel, I remain with my assumption that the OP is asking for something based on a misunderstanding.

We will have to agree to disagree then :)

His original post states he is buying a 5 channel power amp to provide centre plus bi-amp front right and left. So that provides all the power requirements for his speakers, nothing else required from the sub.

His slightly unconventional idea is to bring in two subs into the mix and allow those to pass through the high level signal with the tweak to the bass.

Is that doable yes, it will technically work as @noiseboy72 and I describe. Will it sound any good that's the million dollar question... IMO not sure it will.
 

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