i dont see how that makes sense...
if i set them both at the same level and the gk is louder... how will the carvin have more head room?
I'm using my ears... i sure if i max both of them out the gk would be louder but instead of risking my speakers.. i set them at the same level and the gk was louder.. im sure the carvin was using more power but more power doesnt mean more volume.
How are you deciding that they are "set at the same level"? Turning the volume up 1/3 of the way does not necessarily mean that you're getting 1/3 of the power or volume available, and putting the volume knobs in the same position on both amps does not mean you're using the same portion of the available output or power on each.
"Headroom" generally means that you can put out more power before the amp starts clipping or compressing--it doesn't necessarily have anything to do with the position the volume/gain knobs are set at. At what settings does the GK start clipping, and at what settings does the Carvin start clipping?
Mike

thanks Bobby