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 barryaudiophile

My current system is 8 individual amps, one for each speaker group.  That is line of six tweeters (one line for each side), a second line of 4  mids (again a line for each side),  a single fill-in for low mid, and 4 woofers in a bin (again 2 bins).

My point of interest in the design concept was that the audio band is 11 octaves wide,  3-octaves on the tweet (2.5k TO 20k), 3 octaves on the mids (312 TO 2.5k), 1-octave low-mid (160 to 312) and 3-octaves of low-end (20 to 160) so that each individual combination of amplifier and speaker is operated in a relatively limited bandwidth domain, and thus dynamic stress level by asking not a lot from each.

As I have a 50-year history of high-end audio design and fabrication this was just an advanced hobby project, an easy and not expensive  build 10 years ago when I moved into a this new house, and I was able to optimize each amp/speaker combination.

It works quite well.  As I now have a new no-feedback current mode gain cell topology that I am integrating into my new products designs, I guess I will have to rip this all out and update/grade it over the next couple months.

Good to throw it all out and start over again, it has demonstrated that the 4 way system idea yields good results. Such is the fun of audio.