Benchmark AHB2 Amplifier, opinions and competition

FYI I’ve been listening to my system for a couple of weeks after vertically bi-amping rather than horizontal bi-amping. There is defiantly more punch and immediacy! My wife commented on it. :)

Yes, it's easy to understand, bass/upper bass is the most "power sapping" area from an amp in music.
 In vertical bi-amping the whole power supply of one  amp, is dedicated to just one bass driver instead of two, like in normal stereo or in horizontal bi-amping.
And forget about bridging, it just turns "good" amps into higher wattage "average" amps.

Cheers George 

hifidream
Was my thinking totally off?

Yes Steve, the AHB2 has one power supply for both channels.
By having one amp playing one speaker, one channel for highs and the other for lows, then the total power supply’s stored energy (joules) of that amp has all it’s energy available for just one bass driver on big transients. Instead of sharing it for two bass units horizontal bi-amping the way you have it. The highs don’t take much out out the supply. Buy vertically bi-amping these instead of horizontally, you should hear a marked improvement in the lower mids and bass, highs should remain the same.

It would be a different story if the stereo amp was true dual mono construction, with 2 transformers and completely dual mono power supply. Then it would make no difference if it were vertically or horizontally bi-amped.

Cheers George

hifidream
While I don’t have an issue with clipping. Since I bought two at the same time they have consecutive serial numbers and would share the same part lots. They should sound identical. . . As you said it’s free to try, and it makes logical sense.

From Magnepan: "The MG20.1 has optional bi-amplification and bi-wire capability."

Seeing you have Magnepan 20.1 and have enough watts with one amp, I suggest you vertically bi-amp the two amps, one channel on the ribbon tweeter and the other channel on the bass panel, of each speaker, with each amp.
http://www.av2day.com/wp-content/uploads/2014/05/biamp2.jpg
It will sound far better than bridging the amps, and give you the best sound using two identical amps.

Cheers George

One amp for each speaker, one channel running the low frequencies, the other channel running the tops. To my ears, this is always more open, dynamic and detailed.

That's because in vertical bi-amping all the energy stored in the power supply of the one amp is devoted to just one bass driver, and the other amp the other bass driver.
Horizontal is compromised, as the power supply in one amp has to service both channels bass drivers.
And bridging the amp is just wrong, unless you want/need very high wattage, but be prepared to "take a hit" on all the other parameters that make an amp a good one.

Cheers George

Here's something to ponder over.

Subjective shootout, Schiit Vidar $700 v Benchmark AHB2 $3000
Quick read looks like they prefer the sound of the Vidar more than the 4 x!!!!! more expensive AHB2
https://www.superbestaudiofriends.org/index.php?threads/benchmark-ahb2-impressions-vs-vidar.5131/

Cheers George

rvpiano OP


Nice amp, if you want to hear them at their best, don't bridge "if there's no need to", as all you'll gain is watts, everything else takes a hit.

And if you have two of them better to run them in stereo mode and vertically bi-amped, instead of bridging.
http://www.av2day.com/wp-content/uploads/2014/05/biamp2.jpg

Cheers George