# Headroom question using REW



## logan00 (Feb 10, 2007)

I am confused on this and I hope someone can help me. I have dual HSU HO subs and I have used REW and the 1124p to flatten out my response. If I run REW with only one sub playing at a time, REW says that I have -10db of headroom, no matter which sub I play. When I have them both going, REW says I have -5db of headroom.

How come I seem to have _less_ headroom with both subs playing than when I have only one playing at a time? Also, when the headroom number comes up, it is in red with both playing, but in green when either one is playing alone. 

Thanks


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## Otto (May 18, 2006)

Hi logan,

The "headroom" measurement that REW is providing is that of the input of your PC clipping. So, it makes sense if it gets smaller when two subs are playing, since they are louder and pushing you closer to clipping. 

Have you ever used a mic and set levels based on a needle or meter moving? The louder you yell into that mic, the less headroom you have going into that system from the mic. And the louder you yell, the more you move that needle into the red. Same thing with the colors of the meter in REW.

It's not measuring the headroom available in your stereo system or to your subs.

Have a good night.


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## logan00 (Feb 10, 2007)

Thanks Otto, I got it


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## Chrisbee (Apr 20, 2006)

You can easily adjust the "Sweep Level" in "Settings" under "Soundcard".


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