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

I have seen the amp clip at what I thought should have been a reasonable volume, but only on a very demanding recording - Steely Dan's 'Gaslighting Abby' from "Two Against Nature." But just that once and so I'm not too concerned in that respect. 

In general, I'm extremely happy with the performance of the amp and the Pulsars together, and I don't want for the ability to create more loudness in my listening room with most of what I listen to. Maybe I should just leave well enough alone until I'm ready to invest in some nice neutral-sounding mono-block amps with more horsepower. If I had the second amp, I'd go with George's advice and try bridging too, to see what my ears tell me. Since I don't, it seems like the money I'd spend on the second amp would be better spent in other ways.

Thank you all.

A lower damping factor will make the amp sound less tight and it may give you a slight bass bump at the speaker resonance frequency.

For the damping ot the membrane movement - speaker's own impedance is in the series with the amp's output.  Most of this impedance is resistive.  Assuming 6 ohm (for 8ohm speaker)  and 0.05ohm output impedance, we might have 6.1ohm vs 6.05ohm  - not audible IMHO. 

My first question was going to be whether you really need the extra power for your situation. It seems you may not.

JA at Stereophile measured the Pulsar’s sensitivity at 83.5dB(B)/2.83V/m, which is quite low, so certainly some situations/program may benefit from more power than the 100W/ch of a single AHB2.
https://www.stereophile.com/content/joseph-audio-pulsar-loudspeaker-measurements

There would be absolutely no issues running the AHB2 bridged with your Pulsars - their impedance is mostly above 8ohms and only drops as low as 6.5ohms.
The distortion specs of the AHB2 in bridged mode will be just as vanishingly low as in stereo mode (see Audio Precision measurements conducted by JA and elsewhere).

Regardless of the measurements, I can say that in my case (ATC SCM-19 - low sensitivity 8ohm rated speakers like yours) I got an audible improvement from bridged AHB2’s.
The sound was essentially the same (no surprises) but more ease and better sound staging with the bridged amps. I also took the opportunity afforded by mono blocks to change to short speaker cable runs (and longer XLR interconnects). This probably contributed to the improved sound I noted. Certainly, being able to run very short speaker cables is an advantage of monoblocks.

Bottom line.
If you don’t want/need the extra power or the cabling flexibility afforded by mono blocks, just stick with the stereo AHB2 - but rest assured if you decide to go to bridged mono AHB2’s you won’t encounter a sonic penalty with your speakers.

For the damping of the membrane movement - speaker's own impedance is in the series with the amp's output. Most of this impedance is resistive.

A speaker relies both on mechanical damping and electrical damping, its Qms and Qes parameters; Raidho for example expressly recommended high damping factor amplifiers for their speakers as their woofers had high Qms and relied on the electrical damping of the amplifier. There are threads on trying to find a suitable amplifier for them as their bass would sound loose and bloated with low and normal damping factor amplifiers. Just compare a Pass and an Audionet amp and you will see how their bass is very different; the Audionet's bass is much more damped and dry with better transient response, but it can sound dynamically constricted with low Q overdamped speakers

Since the OP's Pulsar Seas woofers have more mechanical damping they may not need too much electrical damping from the amplifier; bridging the amp may offer a more dynamic bass if the stereo amp/speaker pair is overdamped.   

Electrical damping occurs because moving coil generates voltage that produces current in direction that causes motion of the membrane in opposite direction hence stopping the membrane.  This current is equal back EMF (voltage on the speaker) divided by impedance in the circuit that consists of amplifiers output impedance, cable impedance, and the driver itself.  At the end it comes to 6.1ohm vs 6.05ohm difference (about 1%).  Also for the same reason the highest effective damping that can be achieved is equal about 1.5 (nominal speaker's impedance divided by resistive part of this impedance).  It might explain why some tube amps, that have very low DF (as low as 1.5), still sound great.

There might be other reasons why some amplifiers sound worse when bridged. It might be unregulated (in most cases) power supply voltage that is sagging when twice the current is demanded.  AHB2 power supply is line and load regulated and should not sag.   From all the reviews, I've read, AHB2 sounded even better in bridged mode.