Canuck Audio Mart

By no means a new concept, but I do get a lot of blank expressions when I mention it to people as one of the best ways to set up a system that you can tweak to match your speakers to your room to your ears, without EQ.

If your haven't heard about it before, the concept is pretty simple, you have one stereo amp driving the highs and one stereo amp driving the lows. You need a pre-amp capable of dual outputs, one to each amp. Even some new home theatre amps will let you do this. And finally of course you need speakers that can be bi-amped. Your amps don't need to be matched to enjoy this and it is actually tweakers heaven to try different amps, solid state, tube, integrated or not, doesn't really matter as you have 3 volume controls to match things up.

Today I'm running the GF P-307 (Tube) as the pre-amp with the GF A-534 (300B tube) driving the lows and the GF A-330B (300B tube) driving the highs and the GF RBS-2 (2-way Vifa, 86dB) as the speakers. Don't forget to remove the single amp jumper bars from the speaker connectors.

I turn the amps to 3 o'clock and use the pre-amp to control overall volume, then adjust the individual amp's volume to tailor the sound to what I want, the RBS-2 soundstage best when pointed straight ahead (as do most speakers), but normally I find the top end a bit weak straight ahead, so normally I have them toed in for tonal balance. Now I can point them straight out and give the top end a boost (which I actually do by reducing the low end amp) then bump the up the pre-amp volume.

The difference between a single amp and the horizontal bi-amp is beyond beautiful. The amps perform better with a single speaker load. The speaker's crossover performs better not having to split the load. Again you sit there and go I want a tad more bass for instance and do a simple tweak and have it, you can change speaker positions (WAF for example) and compensate.

If you ever have a chance to hear a bi-amped system go for it and have fun, you may have a hard time listening to single amps again, no matter how good it is, you generally can't tweak it like you can a horizontal bi-amp system. And then there is tri and more horizontal amping

Ian

Nice system. I've been a big fan of horizontal amping for years. The benefits from increased headroom, power bandwidth, and tone control without the ringing caused by an equalizer are apparent for anyone who has gone from a single amp setup.

In my rig I've used solid state for the woofers and tube amplification for the mids and highs. I'm using a Bryston 4bsst to get me the tight bass that you can't get from tubes and a McIntosh mc2102 tube amp for those sweet mids and highs. I control gain and tone using the gain switches on the rear of the Bryston amp and by the bass/treble controls on the McIntosh c220 preamp. Both amps are connected to the preamp.

Years ago I heard a Naim/Linn Isobarik triamp system. It sure was sweet. I also have heard the Waveform/Bryston Mach 17 triamped system and it was probably the best dynamic speaker setup I have ever listened too.

I also heard a few home grown biamp system where the original passive x'overs in the speakers were replaced with an electronic x'over and it was horrid.

Big fan of VERTICAL passive bi amping - especially with with Mid Fi Equipment.

- Vertical bi amping increases the channel separation opens up the sound stage
- bi amping has lower distortion than bi-wiring*



The idea of a Horizontal passive Bi amping makes a lot of sense.
- with a tube amp for the mids and highs
- solid state for the lows

With horizontal bi amping, how important is it to get the phase relationship between the 2 amps right ?





* please lets not get into a debate about the attibutes of bi wiring

Phase is often raised as an issue in biamping especially biamping with different amps. Personally based on my listening I think this is more of a problem when the internal crossovers specifically designed for the drivers are bipassed for active biamping but not in passive biamped setups. It is true however that active biamping has the extra benefit of lessening the load on the amps. However any dual amp setup has headroom to spare compared to using a single amp. So, this is just another of those examples where a theoretically correct configuration doesn't make any difference in practical listening applications.

When using tube and SS amps horizontally the far greater impact comes from the introduction of greater harmonics in the mid/high range, the extra bandwidth available for the woofers and the ability to adjust gain to alter tone. Perhaps its the fact that the 4bsst and mc2102 blend well but phase artifacts if they are there aren't noticeable with that amp combo.

Prior to this setup I had vertically biamped a pair of 4bssts behind each speaker using short cable lengths and was also very pleased. Theoretically that configuration would not have any phase anomolies. Suffice it to say I much prefer the SS/tube horizontal biamping.

Is there a difference between vertical and horizontal bi-amping?

I've tried horizontal and vertical biamping, both passive and active, and didn't find it made enough of a difference to warrant the extra expense.

However, my poor results may be due to my high sensitivity speakers (96-100 dB) benefitting little from two sets of amps driving them. Hard to say.

Having said that, I now use active speakers in one of my systems, and they work very well indeed, noticeably better than the manufacturer's passive version. Of course, I'd expect the manufacturer to optimize driver, crossover and amplifier interaction to a degree I couldn't...

On the other hand, moving up same manufacturer's product line produced as good or better results.

Obviously, different people get very different results.

If you've got the extra gear and cables, or the spare cash to acquire them, it's certainly worth a try.

Joel.

I guess I should have asked "What is vertical bi-amping and what is horizontal bi-amping". Thanks.

I Have found the answer to my question!

I am set up that way with my system.

In my case, my speakers are tri-wired.

I use a single end amp with a High Pass Filter (cut off at 80 and 100 HZ) to the tweeter (or for tweeter and mid).

I have an hybrid amp with adjustable gain control for both channel that I use for the mid and bass ( something bass only).

My linestage has a balanced and a single end output.

My system is all Space Tech Lab including the speakers.

Took me a while to adjust the sound but the sound is great.

But I plan to go with an external active cross over in the future.

I tried tubes on top and solid state on the bottom but found that there are issues with the coherency and feel of the sound. Basically the tonal characteristics I got from the Solid state amp (W5) which had a pretty far back in the soundfield presentation, did not gell well at all with the more intimate and forward presentation of the tubes (granite audio 860.1 mono's) on top. The sounds just didn't mesh.

There's also the issue of their being overlap at the cross-over frequencies between the two amps. I'm surprised people don't find the meshing of the two sounds to be particularly off at the crossover points.

My personal opinion is that the best way to really make sure bi-amping sounds correct with passive crossover speakers is to get two pairs of identical stereo amps.

I believe much depends on how well particular tube and ss amps blend together. Unfortunelty there is no guideline there other than experiment and see for yourself. Meshing of the sounds at the crossover points is less of a problem if one at all if you are relying on the internal speaker crossover which has been optimized for the speaker. It becomes a bigger issue if you are actively biamping with an outboard crossover.

I've had good experiences with identical amps as well and prefer vertical biamping. However if you get the amps right, tubes and SS are amazing.

Wow some nice systems, some pics would be cool, bryston with mac on top, a complete Space Tech Lab system, very nice, you guys must have lots of friends Glad to see that you are enjoying the benefits of bi-amping or are curious.

dr.joe, i can imagine you've got things set up to suit your very high efficiency speakers and at that point probably don't need to consider bi-amping as simple speaker positioning will tailor your sound enough.

Vertical Bi-amping is of course the ultimate (actually a combination would be), especially for serious channel seperation, but getting 4 amps matched is not for faint hearted or light wallet. Our A-88 (KT88s) is a dual mono block on a single integrated chassis, so with 2 of them you can do either horizontal or vertical fairly easy, hmm I'll have a go at vertical with them and report.

I really enjoy the sound of the 300B on the bottom (and top), so for me this works as I can get the sweetness of the 300B on the lower frequencies. The A-534 is a cool design with EL34's driving the 300B to full effieciency so the bass speed is faster than traditional 300B designs and will drive less effiecient speakers.

I have noticed any phase issues with different or matched amps, but in tube land getting perfectly matched amps is highly unlikely and getting your speakers perfectly aligned is almost next to impossible, with equal acoustics on each side another hard one in the real world.

Hi Grant. I PM'd you. Maybe it's another A-88 I should try! Let us all know how the vertical bi-amping compares to the horizontal.

Or maybe I should just get more sensitive speakers and avoid all the wiring hassles!

How can guest post again. I thought we changed this way back???