barometric level change ?

I don't know if this figures into your problem or not, but water is a more efficient carrier of sound than air. That means humid air will carry sound differently than dry air will. I've noticed that there is a good amount, but too little or too much humidity can make music sound worse.

Phild, You're right about the humid air/dry air thing, but since air-conditioning is designed to remove humidity from the air this probably wouldn't be pertinent to listening indoors (this time of the year anyway). As to sound "pressure" levels, you've probably got something else going on. Mwalsdor, do you use a subwoofer in your system? If you do, my bet would be that you have your sub turned up too high. Those low frequencies will increase the sound pressure level dramtically, yet still be inaudible. If you have a sub, turn it down to where it still reinforces the low end but doesn't give you a headache! Tony

Hi Cadman, please post the results of your experiment with respect to running the aircon in your listening room; the issues of +ve pressure & humidity question?? Just curious to know the true causes of your very interesting acoustical problem. Thanks, Phil.