Benchmark AHB2 - To 'mono' or not to 'mono'

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After being disappointed with mono-bridge SQ, I have now tried @georgehifi’s suggestion of vertical bi-amping.
I can already see, what @georgehifi was saying, and where I can go with this approach.
With this approach, the sound-stage is just mind blowing, which has +ve impact on overall enjoyment/experience. I am hearing things which I never heard on the familiar tracks and that too on the very low volumes. The overall SQ has improved. Its just more musical (to my ears).
For me (and my ears) bridge-mono is definitely out.

Glad you found that out, as I’ve said many times all you gain from bridging (mono’ing) amps is extra wattage, but every other measured parameter that makes for a good amp take a hit for the negative.
Please let us know once you’ve got vertical bi-amping setup with better cabling that you want to get, how much further the sound quality progresses.

Cheers George

Seems a lot of people are bridging these.  I think I understand why people decide to do this.

The amp excels in micro-detail (or "micro-nuance" if you will).  But it also sounds somewhat constricted and anemic in my system, even with 89 dB efficient speakers which don't have terrible impedance swings.  When I use my class A tube amp or class D hypex they both sound more open and powerful.  In addition they both (especially the class D) have better defined bass than the AHB2 - despite the number of people who extol the AHB2 bass.

So I am guessing that if you want to experience the micro-detail and also want to have macro-control over the speakers, mono bridging may be the way to go.

For those of you who have a really good Class A or Class D amps, the AHB2 in stereo mode may sound a bit wimpy, and therefore may not necessarily provide a better listen experience, largely dependent on the type of music you listen to. YMMV.

YMMV indeed.

Most assuredly, the amp is not the only part of the equation.  I use 2-way Joseph Audio Pulsars and am not trying to power a large woofer, and with the AHB2, they give me every bit of bass that I expect and then some. Other people have commented similarly when they listen to my system. 

And just an update: Since my original post, I have been trying different brands of cables and have settled on some that I think have improved the overall sound and dynamics vs. what I had been using - none of which were cheap cables, by the way. I think my next investment is the Graphene upgrade to the Pulsars.

Thanks to everyone for their input.

I also have a single Benchmark AHB2, driving Fyne F-702 speakers from a Rogue Audio RP-1 preamp.  My previous amp was a Macintosh MC2120 that I bought new 42 years ago and had completely refurbed about 12-15 years ago.  When looking to replace the Mac, I looked at Parasound and the Rogue Audio’s Dragon and Stereo 100.  what prompted me to replace the 2120 was that the speakers did not sound quite as good in my home as in the dealers residential style setting.  My first though pt was more power, but the 702s are fairly efficient at 92 db.  After reading numerous reviews and noting that Benchmark has a 30-day audition period, I ordered the AHB2, receiving it four days later—with it having a production date of a few days before arrival.  After getting everything hooked up and listening for several hours, I have concluded that the audition period is not needed.  Even my wife, who likes music but is not “into” listening thought the difference was astounding.  Incredible clarity, silent background, excellent soundstage and reproduction of individual instruments and what I suspect is the harmonica of individual instruments.  Strings sound fuller, and I hear the full character of, for example, the different brass instruments—French Horn, trumpet, coronet, baritone, trombone.  Finally, bass reproduction is superb, even at lower volume levels.  The improvement was simply astounding.

Our room is not too large, which led me to consider the less powerful amplifier (100 wpc for the Benchmark vs 120 for the McIntosh MC2120).  However, I can achieve fairly realistic listening levels with my Rogue preamp at the 40/42 (of 60) on the preamp volume control, with no signs of clipping from the Benchmark.  Given the other comments about using the Benchmark in the mono mode, if I were to conclude I needed more power, I would use two in the stereo mode, with one amp driving each speaker vertically, voting for clarity over raw power—although 200 watts per channel is a good bit of power.

Mono is almost always better with the AHB2, except with my hard to drive Thiel CS3.7. The stereo amp is actually better suited than the mono since it can go down to 2 Ohm area. I now use the AHB2 with KEF LS50's but once I get a more AHB2 suitable speaker, I will re-buy the second AHB2 that I sold. 

The AHB2 becomes quieter, plays louder, and stronger in mono. I know from prior experience with other speakers.

I also do not buy expensive interconnects to hook up the AHB2 since it is AES48 compliant. I use 15-foot Benchmark XLR's. The AHB2 benefits from good speaker cable. I use Audience FrontRow with SpeakON termination at the amp end. You can also use short cables when you go monos and use the cheaper XLRs for the longer lengths to the AHB2s from the preamp,

The AHB2 is my favorite amp though I have others that cost much more.