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<blockquote data-quote="Bennett Prescott" data-source="post: 19322" data-attributes="member: 4">Re: PVL and RMS.......Steve,Personally I&#039;d set your RMS limiters at half that, at least. That 3dB isn&#039;t such a big deal to our ears but in terms of driver heating and power compression it means a lot. I would suggest the continuous (whatever the lowest power rating for the driver is) number as a maximum.Your peak numbers are probably best determined experimentally, at least with cone drivers. The problem is whatever you set now with the driver &quot;cold&quot; will be meaningless after half an hour at a gig. As the voice coil heats up the resistance increases and you need to apply more volts to get the same driver movement... this is what power compression is all about. However, if your RMS limiting scheme can keep power compression low, then you can add those volts without overexcursing your driver. You need a reasonably accurate model of VC temp though, or else a good impedance reading, and I&#039;m not sure you can do that kind of thing in the iTech amps (or any non-manufacturer-specific amp).Long story short, I would tend to pick an RMS number that is low, and a peak number that is high. The more you have time to really screw around and see what your box does under duress the better you can set these numbers. For those peak numbers your amp rails are probably your limiting factor, when you take a pro driver and heat it up and lose 2-3dB to power compression... well, who has twice the amp rails to throw at it now? Not I, said the cow.</blockquote>

[QUOTE="Bennett Prescott, post: 19322, member: 4"] Re: PVL and RMS....... Steve, Personally I'd set your RMS limiters at half that, at least. That 3dB isn't such a big deal to our ears but in terms of driver heating and power compression it means a lot. I would suggest the continuous (whatever the lowest power rating for the driver is) number as a maximum. Your peak numbers are probably best determined experimentally, at least with cone drivers. The problem is whatever you set now with the driver "cold" will be meaningless after half an hour at a gig. As the voice coil heats up the resistance increases and you need to apply more volts to get the same driver movement... this is what power compression is all about. However, if your RMS limiting scheme can keep power compression low, then you can add those volts without overexcursing your driver. You need a reasonably accurate model of VC temp though, or else a good impedance reading, and I'm not sure you can do that kind of thing in the iTech amps (or any non-manufacturer-specific amp). Long story short, I would tend to pick an RMS number that is low, and a peak number that is high. The more you have time to really screw around and see what your box does under duress the better you can set these numbers. For those peak numbers your amp rails are probably your limiting factor, when you take a pro driver and heat it up and lose 2-3dB to power compression... well, who has twice the amp rails to throw at it now? Not I, said the cow. [/QUOTE]

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