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

I own a single Benchmark AHB2 amp and have been considering another in order to run both in bridged mono mode, which will provide significantly more power to my speakers and presumably, greater dynamics. I've read in other threads where other owners (and perhaps others with opinions) had implied both positive and negative impressions concerning this approach. Assuming I'm not considering purchasing other amps at this time, does anyone have experience with both approaches and will you please share your impressions?
wwoodrum
georgehifi's avatar
georgehifi
10,312 posts
 
but since the AHB2 only accepts XLR


Plenty like these around, if you look at all differing prices.

https://www.ebay.com/itm/A15-1-5m-5ft-unbalanced-RCA-to-balanced-XLR-M-Canare-L-4E6S-Audio-Cable-/322492289636

https://onecall.com/audioquest-mackenzie-2m-rca-xlr-analog-interconnects-cable-pair


I am going with the opinions of those who say they’ve done it.

Pitty, no I’ll rephrase that, sad, you’ll never know then, just how much better your system can get, by vertical bi-amping, instead of bridging (mono’ing) your amps.

Cheers George
wwoodrum OP
55 posts
 
@George - I’m not questioning the theory behind what you say. But I believe in empirical observation. Tell me you’ve done it  both ways with this amp and your way is better; I will gladly spend what I have to in order to try it. (That said, TWO pairs of Nordost cables is an investment not for the faint of heart, regardless of length!)
wwoodrum OP
55 posts
 
@douglas_schroeder -I have the Frey 2 on the power side from a Qb8 that is fed by a Valhalla2 20-amp cable. The results are sublime.
georgehifi's avatar
georgehifi
10,312 posts
 
Tell me you’ve done it both ways with this amp and your way is better; I will gladly spend what I have to in order to try it.

Yes with many amps I have, not with this amp. There is no valid reason to believe it won’t be the same as EE engineering principals would prove it to be the same also.

There is no "magic voodoo" circuit in the AHB2 that can turn the EE engineering principals around 180 degrees and make it better spec’d bridged than in non bridged mode.
It will always have better specs in "stereo mode" than in "bridged mode", (save for extra wattage in bridged that all.)
Believe what you want, it sad though.

Cheers George
ssnkssnk
21 posts
 
@@Georgehifi

Thanks for sharing your thoughts on the potential root cause for change in SQ for mono application.

I would like to try ‘vertical passive bi-amping’, as per your suggestion. But since, I will have to spend some more time/effort/$$ to get appropriate speaker cables and other connectors, I guess it will have to wait for some time. Also, it will give me only 200watts per channel, and not 380watts, which I expected to get from the setup. Let me know, what you think.

I waited for the delivery of this second ahb2 for 2.5 months, but now I am truly shocked/surprised/disappointed by the mono performance of this otherwise excellent amplifier, to say the least. There is no return-policy in the country where I am located. So, I am pretty much stuck with this, or I can try selling it. Or, maybe I need to give it a bit more time to ‘settle-in’ (I don’t even know how it will settle-in any more than what it is right now though. I was told there should be no break-in period for his amp).

This new sound reminds me of my short time (except the noise floor) with ‘Cambridge Audio 851W’ (Power Amplifier, 200Watts @8ohms) – costing just 22% of what I spent on two AHB2.

I hope I am doing something wrong with the setup and it will get fixed. I had high hopes from this combo.

@@mijostyn

Thanks for your suggestion. I will try reading-up on ‘Channel D’s Pure Music’, and educate myself on the technology/equipment.


I will spend more time with the system over the weekend and will update again!

Thanks all for your suggestions
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