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Who Here is Vertical Bi-Amping?

I recently tried vertical bi-amping and I am very impressed with the results. For the record, I am using “vertical” to refer to using two stereo amplifiers (one amp per speaker) where each amp uses one channel for the midrange/bass driver(s) and the other channel for the tweeter. I am using passive crossovers between the amps and speakers.

My first impression is that there is a noticeable increase in detail and a large reduction in treble harshness at higher listening levels. This makes sense to me because now the tweeter is independent of what the midrange/bass driver is doing. (Technically its “independence” is equal to the channel separation spec of the amplifier.) When the mids call for lots of power which can stress the performance of that channel, the tweeter performance isn’t affected. 

After reading what I could online, I was hesitant to even try vertical bi-amping since I saw lots of mixed reviews on bi-amping in general. I decided I had to try it after reading this post on another forum by Mark Donahue of Sound/mirror Inc. (no affiliation):

“...We have been vertically biamping the speakers here in our mastering studios for 25 years and have yet to find a monoblock that delivers better performance than a pair of stereo amps.
Going back almost 20 years we were looking for a big solid state amp to drive the brand new at the time B&W 801 II. What we found at the time was that the larger monoblock amps from B&W (MPA-810) and Threshold (SA-1000) did not sound nearly as good as the similar stereo amps in a vertical biamp configuration. Every couple of years we would try out the new big monoblock de jour (Krell, Spectral, Cello.....) and every time we found that the stereo sibling of the big monoblock yielded better imaging and lower overall distortion.
Recently we went through the entire routine again. I finally had to retire my five trusty old Threshold S-500 series II due to the need for true balanced inputs. I tried the Classe CAM400 and was underwhelmed with the imaging and clarity. I then replaced them with the (Less Expensive!!) CA-2200 stereo amp and the difference was shocking. Better imaging, better impact and smoother frequency response from my Dunlavy SCV’s.”

I’m very glad I tried it as my system is sounding much better! Does anyone here vertically bi-amp their speakers? If so, what has been your experience and do you find it better/the same/worse than monoblocks, stereo amps, horizontal bi-amping, etc.?
mkgus

Showing 1 response by alymere

alymere
20 posts
 
Check out http://www.linkwitzlab.com/
I have all three of his last systems. Bought the Orion, built the LXmini and the LX521.4. One feature they share is the following equipment architecture: source>pre-amp>(crossover/equalizer)>amplifier channel>driver. The Orion has two tweeters (one forward and one backward facing), one mid-range, and two woofers (one forward and one backward facing) per side. A minimum of 6 channels of amplification are required, 8 channels makes more sense so the woofers can be fed by pairs of bridged channels. To allow flexibility, a 12-channel amplifier (ATI AT6012) is recommended. The LXmini has fewer drivers than the Orion, the LX521.4 has more.

The benefit of the approach is that each driver has the optimal crossover points, roll off and amplitude relative to the other drivers. Analog solutions for the crossover exist as do digital solutions to allow you to dial in the set of curves that works best in your room. I never thought to refer to it as ‘vertical’ or ‘horizontal’; it’s just every driver getting exactly the set of frequencies where it performs optimally.

IF (and this is a big IF) you have the time and inclination to fuss around with your system to make it sound just right in your room and some budget to try a few different solutions, you might find the Linkwitz path fruitful. This is not plug-and-play gear; it takes time and a lot of listening, moving things, and swapping gear to get it right – and every little component and every wire matters. After living with 'oct-amped' (is that even a word?) dipoles I’ll never buy a 2-way speaker in a box again.

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