Running Benchmark AHB2 in bridged mode and 4 Ohm Speaker

There's a bit of anti-bridging hysteria on this thread.  I've run bridged, vertical bi-amp and regular and the idea that bridging is necessarily bad is silly.  Current certainly doesn't go down in bridged mode.  Watts are volts times amps and volts = amps times impedance.  An amp that can put 100 watts into 10 ohms, say, means that it is putting 3.33 amps at 33.3 volts into the speaker.  If you bridge it and get 200 watts into the same load the current has gone up.  In this case the formula for current is the square root of the watts divided by ten.  The current for 200 watts is the square root of 20.  For 400 watts it's the square root of 40, etc.  

Keep in mind, too, that the amp is only driving one speaker so it's not working as hard for the same volume.  There is certainly the potential for problems with low impedance loads but I've never experienced it.  I'm running two amps bridged mono into 4 ohm speakers now, have been doing it for 6 years and have never had a problem.  I like the option of being able to buy a second identical amp if the first one is a little underpowered.  

How much power the amp can actually put out will vary.  My point was just that bridging increases the watts an amp can deliver to a speaker and increasing watts means increasing current.  

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?

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.  

An amp that can put 480 watts into 4 ohms can put 240 watts into 8 ohms so it can double from 240 to 480.  You can just think of it as an amp that puts 240 watts into 8 ohms and doubles into 4.  Its ability to put more than 240 watts into 8 ohms isn't that relevant.  Regardless of how you think about it, the amp delivers more current in bridged more.  At any given volume the bridged amp will have better current capability.  At 100 watts into 8 ohms it can double to 200 into 4 and again to 400 into 2 ohms since we know it can deliver at least 480 watts total.  A speaker is a passive component so obviously increasing the power delivered to it increases the current.  How else could it be?  

You can't double voltage without also doubling current.  volts = current times resistance.  29 amps into 8 ohm speakers would be 6,728 watts.  That is instantaneous and not remotely sustainable, obviously.  Actual sustainable current is directly related to watts.  More watts means more voltage and more current flowing.

Max current will double.  If an amp can double the voltage into a load by bridging then the current capability also doubles.  I'm not sure what the max current rating really means.  29 amps into 8 ohms requires 232 volts.  I'm pretty sure that isn't possible.  Maybe it's theoretical short circuit current or something.  

bridged will be as flat or flatter at every volume that unbridged is capable of.  Obviously.  Bridged can put out 100w into 8 ohms, 200 watts into 4 ohms and 400 watts into 2 ohms.  There will come some volume that is much louder than unbridged is capable of where bridged will start having problems keeping up.  That isn't relevant to most people, though.  Most people aren't running bridged because running stereo won't get loud enough.