Running Benchmark AHB2 in bridged mode and 4 Ohm Speaker

Quote from instruction manual:

The AHB2 power amplifier can be run in two modes: 

 STEREO mode - Two output channels 

 MONO mode - One output channel in bridged mono 

The bridged MONO mode will deliver almost 4 times as much power into an 8-Ohm speaker, and will do so without any increase in distortion. The MONO mode is an excellent choice for high-power applications. In MONO mode, two amplifiers will be required for stereo operation. 

kijanki3,

we still don’t get the full Bridged spec picture.
There are no specs accompanying these copy/pasted excerpts you put up, again misleading, if you are referring it back to the other figures on the other page that geek101 put up.

Lets see both distortion graphs THD+N  and THD for both bridged and non bridged into 4ohms or less. This will be the true test of what the OP wants to do.


Cheers George

Here you go: Page 26 "performance plots" fig. 1, 2, 3

https://cdn.shopify.com/s/files/1/0321/7609/files/AHB2_Manual_-_Rev_G.pdf?6581480924542235084

These plots show almost identical THD at 4 ohm, 8 ohm and bridged 8 ohm max power. As for damping factor - it does not make any difference, since it is already very high.

In the application notes on calculating the performance of an amplifer/speaker combination under,  ' AHB2 THD+N and Power into 4 OHM BRIDGED MONO' it shows THD+N is .00083% at 518 W. It reaches 1% at about 590 W. 

@georgehifi This article https://benchmarkmedia.com/blogs/application_notes/ahb2-driving-pmc-mb2s-studio-monitors also talks about second iteration of using ABH2 as mono blocks. 

Seems like outstanding question is just the damping factor everything else looks excellent to me. I will ask this question to Benchmark and see what they say.

Benchmark does seem to perform quite well in bridged mode, in-fact lot of thought went into making it work in that mode. That is why they never made it put out a lot of watts in stereo mode. Even at $6k and putting out 500w per channel at non existent distortion and quite good voltage peak 64.4(beats the requirement I have which is 54) is a deal compared to what is in the market today. Please feel to correct me if I am wrong.

Only Bryston 4B3 comes close at this price range and it suffers from cross over distortion that benchmark does not, if I understand it right.