Running Benchmark AHB2 in bridged mode and 4 Ohm Speaker


Does running this amp in bridge mode mean each channel will see half the impedance i.e 2 Ohm each when connected to a 4 Ohm speaker.  If so will this cause a problem when the speaker dips to 3 or 2 ohms?. 

Anyone running Benchmark AHB2 in bridged mode with low impedance speakers?. 
geek101
The OP has Legacy Aeris loudspeakers (a design that requires bi-amping) which according to at least one Legacy dealer really likes high power amps.  The OP wants to know if the Benchmarks in bridged/mono mode will have trouble driving the Aeris.  The responses from people with actual experience using the Benchmark in mono configuration say that the amp should perform well.  Other people with no experience with the amp beg to differ.  The OP decides to go with the mono Benchmarks.  The outcome really shouldn't come as a surprise being that Audiogon is primarily a subjectivist audio site.  Experience trumps speculation, even when the speculation comes from informed sources.

I hope the OP will let us know of his experience with the bridged Benchmarks.
clio09
You are correct, other than the recommendation by Roger, we haven’t really had any discussion on that. Vertical bi-amping is the way I roll these days and see no reason to go back, regardless of which pair of speakers I am using. I think using two Benchmark amps in that manner will yield very good results.

twoleftears
BTW, am I right in noting that there has been little discussion here, until just now, of vertical or horizontal bi-amping, which are other possibilities, no?

My first post to the OP geek101 at the beginning of page one.

https://forum.audiogon.com/posts/1646450

Trouble is his terminals don't allow it!

Cheers George
Speaker impedance always varies with frequency. Speaker impedance may be much lower than the rated "nominal" impedance at certain frequencies. The over-current fault detection circuits prevent potential damage that can be caused by driving very high signal levels into very low impedances. In STEREO mode, at full output, the current limit can be reached if the load impedance dips below about 1.3 Ohms. In MONO mode, at full output, the current limit can be reached if the load impedance dips below about 2.6 Ohms.

This is from the AHB2 manual... page 18



The OP has Legacy Aeris loudspeakers (a design that requires bi-amping) which according to at least one Legacy dealer really likes high power amps. The OP wants to know if the Benchmarks in bridged/mono mode will have trouble driving the Aeris.  
I looked at the manual and I dont see any requirement for bi-amping. I dont know of any speaker that "requires" bi amping though I am all for it if there is an active crossover before the power amps. 

This is a $21,000 speaker, Why use the Benchmarks on that? There are better choices and bridging the Benchmarks is not a good idea given the low impedance
@ramtubes, Impedance minimum for top section of Aeris is only 3.8 Ohm (this information is from the source). So it seems AHB2 is fine with that.

Which amplifier would you think can be a better option than Benchmark AHB2 given that I have gotten myself one amplifier for $2100?. What do you think in technical terms another amplifier can be better than Benchmark and at what price and size?. I am looking for 150 watts with no distortion per channel easy, which means no crossover distortion or anything else. Just because I have spent some money on a speaker does not mean I am going to weight that and buy an expensive amplifier. If I could find a $2k Legacy Aeris I would have purchased that instead. I want a great amplifier optimized for cost.

Please let me know I have been looking for a while. I just cannot audition 10 amplifiers to compare and select which sounds good in my room and with the speakers I have. I have to look at the specs, build quality, technical innovation and what generally people think. Anything that comes close to this in my opinion is Hypex NC500 based modules which again can be obtained for $2k approximately. I will consider if you can point me few of them.

General rule of thumb is fine but at the end I am constrained by my experience and capacity to audition amps and I like to re-verify past ideas. Technology changes and things change. If someone says X amp sounds good then I have no context, I will go read the specs, read the forums and reviews and move on.