Bi-amping

I love my Siegfried Linkwitz designed LX521.4 speakers. The a Precision ASP! Each speaker has 6 drivers, two opposed 10” woofers, lower midrange and upper midrange and two opposed tweeters. The amps are two five channel with 365 watts per channel at 4 ohms. The drivers are all made by SEAS which were designed with the help of Mr. Linkwitz! He also designed the PASP for a picture perfect crossover points for each driver. XLR from the Rotel RC1590 to the inputs of the XLR of the ASP and XLR outs to each the XLR inputs of the 10 amp channels. 50 years of his research and the incredible sound sold me! For more information look up Linkwitzlabs.Com There is enough information on the website to keep you entertained for years!

Without any specific experience of the bi-amping craze of the 1990s when some speakers were produced with four terminals to that end I would just throw in some general advice. 

The two factors that most affect the performance of a speaker system will be the character of the speaker itself and the character of the room in which they are placed. Speakers generally fall into two distinct types, those which are forward and in the room and the other type which are speakers that seem more neutral and less present. Rooms are either acoustically live or dry. Running extra wires will not produce an improved sound if you are not satisfied with the speakers to start with or have not attended to the issues of placement and room acoustics. It is easier to damp a vibrant room than to add liveliness to a dry room. 

It is worth remembering that no speaker, however good or well adjusted, will be equally satisfactory to your ears in every type of music or material. That's another reason why speakers should be carefully auditioned if possible beforehand across different pairs and brands. 

On the question of bi-amping it was supported by arguments concerning low frequency distortion arising from integrated amplifiers with a low rate of slew. One solution to this problem is a much simpler and effective route adopted by Philips at an earlier stage - the Motional Feedback Loudspeaker system which still has a thriving fan base in Holland. Each box is essentially an active loudspeaker (carrying on from cinema sound systems in which different speakers were driven by separate power amps) but with the added refinement of distortion detection and cancelling servo circuits built into one or more drivers. Apart from producing a noticeably cleaner and more powerful bass (especially from a smaller box) the overall tone of the speaker was improved. 

It may be it is that which you are really looking for so I would suggest you look into MFB speakers! From my experience these systems are not only neat and tidy in terms of design but offer a high quality sound lying somewhere inbetween the two types of characteristic speaker sound mentioned at the start. Stereo separation is also excellent. The only drawback is maintenance - finding a tech who can take them on is very difficult…..unless you live in Holland!

Biwire...good.  Beamping.... no good

I'm using a home built analog crossover with low-noise / high-speed op-amps. It's 24dB/octave, nothing very exotic. I started with TDM. There are many manufactures to choose from for a relatively low price. Many prefer digital crossovers, I'm just not one of those. TDM and DBX on the low end or Marchand and Bryston on the higher$. Even Behringer is decent from what I understand.

Fiesta75 what kind of crossover do you have? What is the price for a decent crossover after the preamp. Thank you.

I have a bi-amp set up, tube preamp,  tube for mid & high and SS for Low. I love it.

Robert

You can bi-amp with the crossovers still connected in the speakers, no jumpers between speaker posts. Even without an electronic crossover at the amplifier inputs you will still hear a noticeable improvement in sound. With an electronic crossover at the inputs, you will see an even greater improvement due to limiting the frequencies each of the amplifiers need to reproduce, this saves power for the specific driver ranges. This savings is most noticeable in the mid and high frequencies produced. Keeping the speaker crossovers in place also adds a layer of protection for the drivers in the speakers. The way I'm doing it, bypassing the internal speaker crossovers, is dangerous for the drivers. However, for me, the reward in sound is worth the risk, but it is not for everyone. If you would like more details, feel free to PM me. What speakers are we talking about here?

Jumper is usually OK,  bi is always better.

The Cable Company sold me bi-amp speaker wires and said this is better than using jumper cables.  They didn't cost that much more.  Who knows if any of this makes any difference. 

This can make a big difference on certain speakers and not make any difference on some speakers. I tried using jumpers and one set of cables on my apogee duetta 2's and it didn't sound near as good as using a set of bi- wire cables.

Ok - so let us assume I have ordered an Octo DAC8.

Do I do the active XO with something like J-river, etc software?

or…

do I use some analogue active XO? 

I think there are countless reasons to bi-amp (or not).

One of my setups uses floor to ceiling line arrays using 30 peerless TC9 drivers per tower. The enclosures are sealed (no ports) and have almost 0 output below about 150Hz.
I use a pair of subs and midwoofers per side to take care of the rest of the frequency response (20-150Hz).
Easier for me to bi-amp in this situation, utilizing class d amps with DSP for crossover duty.

Strangely, this setup sounds better to me than when using any of my tube amps. The reverse is true when using my horn speakers…YMMV…

I have bi-wired and bi-amped three sets of passive speakers with separate posts for bass and treble from different amplifiers. To my ears, I have never been able to notice any difference. In my cases, the amplifiers sent the full range to each.

The Cable Company sold me bi-amp speaker wires and said this is better than using jumper cables.  They didn't cost that much more.  Who knows if any of this makes any difference.   

Bi amping can make a huge difference if you have two amps with different characteristics.  For example, if your primary amp has weak bass, a second amp with good bass powering the woofers would make a difference.

I tried Bi-Wire, Bi-Amping years ago and Bi-Wire only made a small difference, but Bi-Amping with a better crossover (I used an old tube ARC two way) made a wonderful difference.

YRMV.

JD

This will answer your question.
 

Assuming a speaker is set up for proper bi- wiring / amping, & all other things being equal, I would think a speaker would have the potential to sound much more dynamic & clear @ louder volumes with the increase in available power. To move & control & big woofer takes so much more power than a midrange or tweeter. It has a much bigger motor & requires much more current. The distortion levels should remain much lower when the speaker is pushed hard. 

Kraft,

That's a great idea you made. They might consider an amp with a volume control on the upper amp so they can level match the powers.

Active bi-amping is obviously the best eliminating the passive elements in the signal path (big coils mainly, and caps; in some cases resistors). 

But even PASSIVE bi-amping can have significant benefits. 

Example: the 2 coil bass of my Infitiy Quantum 2 dips below 2 ohm impedance and requires very powerful and stable amp. Yet the same amp has to drive the EMIT planar magnetic tweeters through the passive crossover. By 'splitting' the task, a poweful (but not very 'sweet') brute amp (class A/B, maybe even a class D) can be used for the bass (200 Hz crossover), and a better sounding but less powerful (class A? maybe even tube?) amp for the low mids and highs. 

Cheers, I think I was bogged down by the alternatives, which now, I have realised does not apply or answer my ambiguous question. Thank you all for your replies.  

read my initial comments.

My speakers have built in x-overs, so does that rule out the use of electronic x-overs, as I said, maybe this forum is for the tech savvy’s only, I just want to be able to have my system enabled to produce its best performance.

I biamped a set of Maggie 3.3 speakers with a pair of moon W3 amps and a Bryston 10 b active crossover. The Sence of space and being there was impressive for sure. The Sence of ease that you get with a huge amp was there as well. It also had the speed of small amps. I enjoyed that for many years. It cost a bunch extra but you may find that you really enjoy it. Don't forget that it's not just an extra amplifier it is also two more power cords two more high quality interconnects two more stands one for the amp one for the crossover. There is a bunch of extra money involved.

I did a tube biamping on a set of Maggie 3.3 removed the external part of the cross over and used a Bryston 10b. With two 120 watt solid state amps it had that Sence of ease you get with a huge amo but still had the speed of the small Amps. It costs a bunch but I did enjoy it for many years. The Sence of space and the like the singer is right there was in surpassed. 

Passive bi- amping can be achieved before the amps, given the right speakers. Marchant makes a passive line level crossover for this.

Pre 8 is the best way to achieve this.

@393gadget there is a big difference between bi-amping and going active, which is what has been discussed.. Bi-amping involves leaving the crossovers in tact and feeding each leg separately, going active involves removing the crossovers and having that function take place between the preamp and power amps. 

No need for any fancy jumpers! A few inches of copper wire will do just fine. That's what I use on my Snell Type A's.

Yes, just use one set of cables per speaker and a jumper between the positive pair and between the negative pair terminals. No need for a more expensive bi-wire cable. 

Sounds very technical, to an amateur, my speakers each have four terminals, so the amp will be connected to one set of the terminals, is it as simple as that no setting up need?

There is a lot of information on active bi-amping apogee speakers, but quite a few people don't like the sound as much as the passive crossover. 

There’s a huge audio benefit just not for you. Twice the amp twice the cables for some lucky audio manufacturers. I was biamped with Bel Canto REF1000 mk2s for years and when I started selling them off to buy new, I was surprised at the difference. Like no difference. The 1000s sounded good.

@393gadget,

’’Is it discernible,’’ Yes

I agree with @jasonbourne52, @fiesta75, @kingharold

Mike

See the article below on BI-Amplification last page.

http://www.lansingheritage.org/html/jbl/reference/technical/monitoring.htm

Always crossover at amplifier inputs. And, in my opinion get rid of the internal crossover in the speakers too.

@fiesta75 - yes, an active circuit is a completely different animal. Where the signal is truncated before amplification.
There are benefits depending on the drivers used to band pass lower frequencies even to the bass driver.

If you meant actively crossing jasonbourne52 yes, it can be better. Obviously implementation will require sound knowledge of basic principles, often more knowledge than the original designer had at the time. I thought you meant after amplification.

And for that an electronic x-over is necessary.

So your stand, if I understand you correctly @jasonbourne52 an electronic crossover, as in any crossover designed to pass on an alternating electrical current? What? The speakers are designed and sold with electronic crossovers in them. Do you mean a digitally controlled electronic crossover?

________________________________________________________

If the speakers have two sets of terminals, I’m going to assume the designer created a crossover that has separate circuits for each sets of drivers, not always a two way. I am also assuming you presently like the sound produced by the loudspeaker in question 393gadget?

My pair of speakers have one set of terminals, there are capacitors and inductors that block the lower frequencies and remove the higher frequencies, and then another pair that feeds the tweeters that are taken off the top of the same signal in the same circuit. These circuits do a few things simultaneously, which is why often it’s called a dark art to get right. They supply the drivers a frequency range that mask driver breakout (where the driver doesn’t act linearly in response to the energies it sees) and there’s a handover of duties in drivers where the sum of SPL (sound pressure levels) delivered by the drivers throughout the crossover frequencies are supposed to sound as though one driver is playing, and as it’s through a reactive network, and so also cohesive in the time domain. It’s like solving a Rubik’s cube, whereby correcting one side you might get two others wrong. Then there’s shunting capacitors to control the energies the drivers see, to balance out the frequency response, in my particular crossover.

Now, if you’re going to bypass the crossovers the designer used, you’d damned well better know a lot more about the drivers’ frequency response, and impedance characteristics.

In my pair of speakers the power which is alternating current, gets truncated and lower frequencies are sent to the bass driver, the high passed energies are then delivered to the tweeter, sharing both the active and the ground.

A bi-wire crossover can be more complicated to get right, and is distinctly designed to work with a separate ground and active per circuit, instead of sharing the potential offered by the ground between the frequencies that are passed through, as in my pair of speakers. That is, unless they are jumpered.
With all electrical circuits to actually work, potential is needed, and a true bi-wire crossover actually has separate circuits within it to feed duties to drivers.

To bi-wire to a single amplifier, using a star ground to the terminals, where the speaker wires are not sharing the negative potential.
And pesky-wabbit sates correctly the reactance of the crossover with the drivers gets separated and distinct for the two amplifiers. There is certainly potential for better performance this way.

Ultimately, the cost / performance benefits are something to be weighed up, in order to buy two amplifiers, would a superior single (more costly) stereo (or mono block) make the biggest difference? And wiring a star to ground using bi-wire on a single channel amplifier, would the money be better spent on a better quality traditional speaker wire?

Certainly the electrical circuits in bi-amping are different than bi-wiring, using a single amplifier or for a channel with multiple circuits feeding the drivers in a traditional wiring configuration.

https://www.hifipage.com/high-end-hi-fi-jargon-explained-275/

Thanks for the comments, I’ll be shopping for additional speaker cable, and certainly give it a try, all I have to do is obtain advice from my local retailer on the steps forward. 

I am a big fan of multi-amping if done actively.  I tri-amp my DIY horns, and I find that a separate amp for each driver with nothing between the amp and the speaker except wire produces clarity and realism unique to that arrangement.

+1 for both of the above comments. I've been multi-amping for many years. Started in 1976 with just bi-amp and will never go back to passive crossovers again. Good luck!

There are benefits to Bi-amping in that each amplifier only drives one drive unit (or sets of drive units) and therefore restricts the range of frequencies and dips and peaks in the impedance curve it must drive.

Wire companies that claim to sell bi-wire cables are just pulling your leg! For more profit of course!

Only if you use an electronic x-over and bypass the woofer x-over. Simply using a separate wire to the woofer input does nothing because the woofer x-over is still in use. This passive woofer x-over usually has an inductor which compromises amplifier damping. Eliminating the woofer inductor has the benefit of better amplifier control of bass frequencies. And for that an electronic x-over is necessary.