Running Benchmark AHB2 in bridged mode and 4 Ohm Speaker

Maximum current won't double.  (It will be still 29A).    Maximum current is an absolute maximum that amplifier can deliver.  This specification shows amplifier's ability to drive difficult low impedance loads.  It says that when 4 ohm speaker's impedance drops to 1 ohm amp can deliver 29V peak.

Also, I'm not sure where specification 480W/4ohm came from.  My manual (version G), as well as their website, shows 480W/6ohm bridged and 130W/6ohm unbridged.  480W is not that far from theoretical 530W for ideal voltage source.

The maximum current that can be delivered into 8 ohms or any other load will double when the voltage doubles.  I obviously wasn't talking about the 29 amp "Maximum Audio Output Current" as specified by the benchmark website.  We were discussing current capability into varying typical speaker loads.  The maximum continuous current capability into 8, 4, whatever loads will increase when an amp is bridged.  

The maximum continuous current capability into 8, 4, whatever loads will increase when an amp is bridged.  

Agreed.  The only confusion is word "capability".  IMHO it should be:

The continuous current into 8, 4, whatever loads will increase when an amp is bridged.  

Using the manufacturers own specs there's no refuting the current sag.

Not bridged
100w into 8ohms
190w into 4ohms =Clearly very close to doubling it’s watts, good current

Bridged:
380w into 8ohm
480w into 4ohms =Nowhere near doubling it’s watts, current diminishing.

Would be even more interesting to see  independent measurements done.

Cheers George

George, there is no current sag.  More watts mean more current.  You are overestimating the importance of doubling into 4 ohms.  It's not important in this case.  What is important is how much power is available and how an amplifier handles various loads.  If you lowered the gain on the amp so that in bridged mode it would only put 240 watts into 8 ohms it would still put 480 watts into 4 ohms.  It would be doubling but would have the exact same current capability it does now.  The issue is just that when you double the voltage you also double the current so the power is multiplied by 4.  You just shouldn't think of the bridged total watts into 8 ohms the same as unbridged.  Think of it as doubling the power.  The bridged Benchmark will deliver 200 watts at 8 ohms and 400 at 4 ohms.  It will actually put out more than that at both 8 and 4 ohms but you still get twice the power at 8 and it doubles that to 4.  What's not to like?