Originally Posted by craig3972
... to back up to the previous question, I am currently running two JL M6450 amps to the 6 inboats, would you change to two of the JL M600/6?
Should I be running the inboats setup as 4ohm?
The JL Audio M6450 and M600/6 are the same power even though the ratings differ. The reason is that JL Audio used to rate their amplifiers on a more stingent basis. Once everyone adopted the CEA rating method, based on looser standards, and JL Audio soon converted to the industry standard, the power rating increased. They're still under-rated (often by as much as 35%)...and they need to be due to the fact that they must meet power at a 12.6 V supply because of the voltages provided for setting the input gains and most people are going to tune the system at rest.
The differences are going to be a) the M600/6 is fullrange Class D instead of Class AB and is 60% more efficient, and b) the M600/6 has a sophisticated roll-back protection circuit that keeps the amplifier from self destruction and thermal shutdown. So there are real advantages with the newer amplifier but not in power output.