[Closed] Bi-amping speakers

I have old Cambridge Audio stuff bi-amped, with treble and bass separately.

It improved matters noticeably. Hard to say exactly how but everything is clearer and the different parts of the music are less likely to blend together even when there's lots going on. But it was a long time ago when I contrasted and compared.

Dunno about bi-amping, but bi-wiring my speakers definitely made a difference.

Even my ever sceptical Dad who laughed at the thought of it, admitted he could hear a definite improvement in clarity when swapping between the two....

Does the amp have separate outputs too? And make sure you remove bridges (if there are any present) between the speaker input terminals are removed before you wire it up otherwise it won't work as intended.

^^^ Speakers with bi-wire bridges in place for a traditional (non bi-wired) set-up.

Does the amp have separate outputs too?

He's talking about bi amping, so either he needs an integrated amp (the normal kind) with pre-amp outputs to wire to a second power amp, or he has a separate pre-amp and two power amps (like I have).

He’s talking about bi amping, so either he needs an integrated amp (the normal kind) with pre-amp outputs to wire to a second power amp, or he has a separate pre-amp and two power amps (like I have).

or he could have an integrated amp (the normal kind) with spare speaker outs (ie a 7.1 setup but 5.1 speakers) that can be set to bi-amp a pair of front speakers (like I have)

its worth noting that on some lesser yamaha amps (other brand may vary) the overall power available is apparently the limiting factor (rather than the power per channel) so bi-amping doesn't help.

fwiw I don't see any reason why you *have* to bi-wire to also get the advantages of bi-amping. I would think you could run both amp channels together over a single wire pair, and still get the benefits of twice the power, but without the separation of one amp doing the lower cones (specifically) and one doing the higher cones (specifically)

I haven’t tried it but don’t understand the physics, as they’re both combining at the crossover anyway. I doubt people could tell the difference in a blind test

are they combining at the crossover? I would have thought that bi-wirable speakers have two separate crossovers in them (or no crossover and full range sent to each cone?)

Bi-amping I can see a point to, though I'd probably never bother.

Bi-wiring is hi-fi snake oil. Aside from anything else, your speaker manufacturers know more about your speakers' characteristics than your amp manufacturers.

YMMV.

I make use of the 2 sets of terminals on my speakers by connecting one set to my AV surround amp and the other set to my Hi-Fi amp. Not used at the same time, obviously 🙂

Like others I haven't heard any noticeable difference with bi-wiring, but I have with bi-amping. One of my systems uses an active crossover and 2 power amps and that was a very big improvement over passive with a single power amp.

I'm deeply skeptical for two reasons.

1- If you really just use an amplifier for the tweeter alone you're presenting a very very small load to the amplifier, and through a crossover which means all the bass frequencies are rejected making a very uneven and high impedance load.

2- If you're going to do it, you should cross the signal over before the amplifiers or you're retaining the main source of distortion etc in the system

My suggestion, and indeed what I use, is a minidsp in the digital domain as a crossover and then satellite and sub.

fwiw I don’t see any reason why you *have* to bi-wire to also get the advantages of bi-amping. I would think you could run both amp channels together over a single wire pair, and still get the benefits of twice the power, but without the separation of one amp doing the lower cones (specifically) and one doing the higher cones (specifically)

So just connect two amp channels outputs together? No. The amps will have a little fight about who thinks who is right about the voltage at their output terminals, deliver maximum current into one another and go pop or hit an Overcurrent protection.

are they combining at the crossover? I would have thought that bi-wirable speakers have two separate crossovers in them (or no crossover and full range sent to each cone?)

A two-way speaker crossover is really two separate filters. One is a high-pass filter with its output connected to the tweeter. The other is a low-pass to the woofer. In normal speaker wire the two filters inputs are connected together, and connected to the amp. When you remove the bi-wire links, you gain access to each filter individually.
In bi-amping, the HF amp will be driving a high pass filter connected to the tweeter. It will therefore experience a very high impedance (and therefore deliver a small amount of power) for low frequencies. This reduction in loading for low frequency content may help it deliver an improved output for the High Frequency material it is now tasked with. It may help reduce distortion for example. The opposite is true for the amplifier driving the low frequency section, it is untaxed by HF. That’s the basis for bi-amping. Share the load in terms of frequency. I’m not up to date on the thinking about whether this is successful, I’m writing the above from my knowledge as an electronics engineer rather than a knowledgable hi folks enthusiast. I can see that reducing low frequency loading (which usually demands the most power output) could help reduce THD in the amplifier driving the HF end, so the principle seems sound. Even in an a multichannel amp where the total power budget is limited. If OP has the ability to do that, may as well try it for the sakes of some relatively inexpensive cable.

I would think you could run both amp channels together over a single wire pair, and still get the benefits of twice the power

That's different, it's "bridging" - combining two power amps to increase output. What is referred to here is having separate amps for low and high drivers.

Also sceptical gofasterstripes, but there’s some merit to the idea as above. On point 1 I disagree, a high impedance load is always helpful, even when it’s just part of the spectrum. The input impedance to a two-way speaker with crossover (or even a one way without) is all over the place anyway.
Point 2 - absolutely yes crossover before amp is way better. Ideally this would be at the tweeter/mid frequency rather than just satellite/sub, though that’s still an improvement.

I would think you could run both amp channels together over a single wire pair, and still get the benefits of twice the power

That’s different, it’s “bridging” – combining two power amps to increase output. What is referred to here is having separate amps for low and high drivers.

And just to be sure no one blows their amp, bridging is not connecting two amps in parallel to a load (pos of both amps to the pos of speaker etc) it means using one amp to drive the positive side of the speaker, and the other amp to drive the negative terminal in anti phase, so that the peak voltage across the speaker is doubled and the peak power therefore quadrupled (if the power supply can deliver it). The power amp must be designed for this and the pre amp stage must be able to deliver the anti-phase signal. Takes a bit to get your head round, but don’t go connecting two amps in parallel to one speaker and expecting it not to go pop!

I guess to do it properly, for stereo speakers you'd need a preamp and 4x mono block power amps?

out of interest, is bi-wiring (and thus bi-amping) available on 2-way speakers? I've only seen it on larger things (I have it on my BR6's, which I assume have separate crossovers for each cone, and 2 cones fed off each circuit, but who knows..) - but I haven't bought many smaller speakers in my time (most of those I have are surround/centre speakers, on which I haven't seen bi-wiring, regardless of cone count).

Incidentally I'd also agree with the 'don't do what I suggested and just wire two together' - I was just throwing a thought in my head out there. I obviously don't know enough about circuits to know how they'd interact correctly

My speakers are 2 way.

I've also heard that the only bi amping that makes sense is to have one for the left channel and one for the right, to improve separation.

I think you would be better off spending any extra money on a better single amplifier rather than bi-amping, unless you are getting into the realm of monoblocks and crossovers.

I’ve done extensive blind testing with bi-wire and bi amping.

It’s only worth doing if you go for an active crossover and have separate amps for each speaker.

Otherwise, it’s a complete waste of time and money.

I have gone down the route of two monoblocs per speaker on my hifi setup.

It sounds amazing.

My second power amp was £50 on eBay, didn't cost a lot and I'm satisfied it delivered benefits. I'd be surprised if you could find a better sounding system made out of such cheap old kit.

Some scientific work from QA (on bi-wiring): https://www.qacoustics.co.uk/blog/2016/06/08/bi-wiring-speakers-exploration-benefits/

I had a pair of Tannoy P40 speakers that were tri wire/amp capable - just too expensive to try , they sounded great anyway - just too big.

Some scientific work from QA (on bi-wiring):

... from a company selling speaker cables.

"My second power amp was £50 on eBay, didn’t cost a lot and I’m satisfied it delivered benefits. I’d be surprised if you could find a better sounding system made out of such cheap old kit."

As I have 4 power amps and one pre-amp I did spend more than Moly bit it is all second hand and a fraction of the costs it would be to buy new.

… from a company selling speaker cables.

Yeah, I'm a bit sceptical about bi-wire but bi-amp kind-of makes sense. I've contacted QA to see what they think too.
At the end of the day, it'll only cost me about £6 to try...

There is some techinical reason why bi-wiring can make a difference - I can't remember it but I do remember being told the reason by Derek Hughes, who is arguably one of the most knowledgeable designers of passive crossovers in the industry...

However whether the difference is correct as, as he pointed out, when the speaker is voiced the designer will highly probably not be bi-wiring or bi-amping.

https://www.hifiplus.com/articles/a-night-at-the-opera/

https://www.grahamaudio.co.uk/news/royal-opera-house-chooses-graham-audio-ls35/

IME, both bi wiring and bi-amping offer very slight benefits. You are usually far better just buying a better amp. Using a line level crossover before the amplifiers (like Linn do with their active stuff) is worth doing, but again, you have to think about how much you end up spending in total and how the results compare with flogging what you have and spending the money on better gear. The hifi industry loves people who make small upgrades.