Horiz/Vert Biamping


I see many references to horizontal vs vertical biamping and the definitions seem to be contrary to how I would define these: I would define them as such:

Vertical: Defined as one amp for the Top freqs and another amp for the Bottom freqs.
Horizontal: Defined as one amp for the Left channel and another for the Right channel.

But these above definitions do not seem to be what anyone else here uses so I am curious as to why they are defined exactly the opposite.

And I can see there would be one major advantage for each situation. When the amps are matched, better channel separation would be expected if an amp is used for each channel. But to have an amp for the top and one for the bottom might bring on more openness in the mids and highs as the amp driving that range is not stressed by the low freq demands on the same power supplies in a stereo amp. I guess true dual-mono stereo amps would alleviate this or is this still not entirely the case? Or is it really a better way to go with a different amp optimal for each of the 2 freq ranges? And if so, what about synergy around the crossover point between the two amps' sonic differences?

Any thoughts or experiences here would be greatly appreciated. This mainly pertains to Magnepan Series 3s but other speaker usage would be interesting.

Thanks.....John
jafox
Think of vertically bi-amping as turning the amp on its' side i.e. so that it standing vertically on the shelf or next to the speaker rather than laying down ( as it normally would ) horizontally. Once you get the picture of the amp standing vertically, it will remind you that you are running one channel for the lower section of the speaker and the other channel for the upper section of the same speaker.

To further imbed this easy to remember idea in your head, think of how your speakers are spread out horizontally ( or side to side ) in the room. Horizontal bi-amping does the same thing i.e. uses one channel for the lows ( or highs ) of one speaker and then spreads the other channel of the amp over to the other ( horizontal ) side of the room for the equivalent section of the other speaker.

There are benefits to each type and which works best will depend on the type of speaker load that you have. If one is running a speaker that has a highly reactive mid / tweeter section ( E-stat's, etc... ) with multiple woofers, my opinion based on personal experimentation is that horizontal bi-amping works best. Since both sections of the speaker are going to pull pretty hard on the amps power supply, which is common to both channels in most designs, both the bass and treble may "suffer" at the same time. Having a dedicated amp for the treble with a separate amp for the bass helps to ease the load on each amp and power supply. Since it is unlikely that both frequency ranges would be "surging" at the same time, effectively narrowing the frequency range that each amplifier / power supply must feed can increase efficiency and minimize the stress on teh system as a whole.

If one has a "normal" speaker with relatively mild loads like cone mids, dome tweeters, and a woofer(s), which woofers always need quite a bit of power and have larger amounts of reactance / reflected EMF to deal with, one is typically better off with vertical bi-amping. This allows the power supply to shift most of the current draw to where it is needed with the woofer on one channel while it pretty much "coasts" with the channel feeding the mid / tweeter section of the speaker.

Obviously, these are generalizations and each situation is different, so you'll have to do some trial and error and see what you think works best. The one advantage to vertical bi-amping is that there is less potential for crosstalk to occur from the left to right channel than if both channels were being used in a normal "stereo" fashion. This is because, in effect, you now have "two channel monoblocks" feeding each speaker.

Having said all of that, i can understand the confusion between the vertical and horizontal nomenclature that we use. I think that this comes from the fact that most systems are installed in some type of rack with the equipment arranged in a vertical array. With this configuration, it is easy to assume that "vertical bi-amping" would make use of the two left channels of the amps that are stacked on top of each other for one speaker and the two right channels of the amplifiers feeding the right channels. This would use the two channels that were "vertical" to each other, making this a logical conclusion. The other method, using the two channels of one amp, which are typically laid out side by side, would be the "horizontal" mode of bi-amping according to this type of logic. Too bad "logic" doesn't always work with audiophilia : ) Sean
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Sean:
It was the designer of my speakers that first brought the equation and recommendation up to me for Vertical amping and then I saw an article in one of the major Mags where the reviewer stated that he would not even consider thinking of a new speaker today unless it gave him the ability to do Vertical amping.

The more I ponderd the idea the more it made sense,but to explain it is a total nightmare.I have been to 3 BB's where people have gotten the explaination screwed up which in turn played with my head trying to explain it and I have been into audio for quite some time now.

The disadvantages are using more Power and more wires,but the benefits outweigh the drawbacks if you want the best you can get.Then again it must all gel right.

My speaker designer is making an outboard XO(3-ways) with my speakers which should be ready by the end of the month.

One thing that is really driving me nuts is trying to find the right amps to use.I have a modified B&K ST-202 and have been waiting to see if the new LeAmpII's are better than the originals which of what I understand have gotten less than stellar exceptance in the audio community.But the new ones are suppose to be a breed apart from them.Mike Barnes of nOrh says they are comparable to SOTA stuff and they only cost $400 per Monoblock set.If it's true I want 3 sets.Then again like the old saying goes if it's to good to be true it usually is.

Thx!
Abex: One can not buy the capacitors, transformer, chassis, heatsinking, output devices, etc... for a truly "SOTA" SS amplifier for $400. Bare in mind that i'm talking wholesale costs and volume purchasing here also. As such, i would not get my hopes up too high in terms of out of the box performance.

Having said that, the new design might make for an excellent platform for upgrading / modifications. One can devise an excellent circuit yet compromise the performance of the unit by building it to a low price point using lesser quality components. As such, replacing the "mass production" low cost parts with higher grade parts can turn some "budget" products into truly "kick ass" performers. Sean
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Yes,I realise this to that is why I have a Modified B&K ST-202.I am waiting for the opinions of the LeAmpII's from some people at the Midwest audio show going on this week.

If worst comes to worst I will try to find some Mark Lev amps in the future to Horizontally amp the speakers.

Thx!