Why do certain areas of my room have feedback?

[CZ Eddie]

I've got the newer Radio Shack digital SPL meter. When I was testing with REW today, I noticed that certain areas of my room gave off gnarly feedback. I think "feedback" is the right word. It sounds like a continuous ~50-80hz tone that gradually gets louder until it's fairly loud. The sound comes through my subwoofer.

If I stand in one area of my room, I get this "feedback". If I move a foot in any other direction, the noise instantly goes away. If I move back into this area, then the sound slowly comes back on until it gets loud again.

There are multiple areas like this in my room. It doesn't seem to be particular to any type of area.

Anyone know what is causing this? Or if it can be used as a tool for figuring out my room response?

[brucek]

Or if it can be used as a tool for figuring out my room response?

REW is your best tool for understanding the response of your room.

The feedback is caused by the line-in being enabled in the playback mixer of windows. It's called monitor mode and should be muted/de-selected when using REW.

brucek

[CZ Eddie]

Thanks, Bruce. I'll check for that the next time I use REW.