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
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.


geek101
With someone who knows, looking at the access via the back plate amp, it wouldn’t be hard to split the passive xover and add a second pair of speaker terminals for the bass driver.
Then you can purchase the 2nd AHB2 and can vertical by-amp for the best sound, as I said in my first post.

Cheers George