Moving the microphone instead of the subwoofer

[olatheguy]

I'm awaiting arrival of my first real subwoofer and I have a question about taking measurements. It is frequently suggested to place the subwoofer in the listening position and crawl around the room and listen to find the best placement location. However, I've not heard anyone suggest taking REW readings at these various positions instead of just listening by ear. Is this a reasonable approach to finding a few good starting locations?

[brucek]

Is this a reasonable approach to finding a few good starting locations?

Yes, it's what we always recommend.

The best REW function to use for this is the RTA, since it's dynamic.

Follow the info below on using the RTA:

To use the RTA feature of REW, you must first setup the levels as if you were about to make a standard response measurement.

This involves running the Check Levels routine for the mic at the listening position to 75dB and the Calibrate routine. You can even run a measure to have a reference.

Then, select the Spectrum tab in REW and setup the controls as shown in the picture below.

Then, select the REW Generator and select Pink PN and start the signal using the play button.

Press the Red record button on the Spectrum page.

You can monitor your Input Level on the Spectrum page in the bottom left hand corner.

If it reads clip at any time (because you're moving the mic around when using the RTA), then simply turn down the REW input level a bit.

Below shows a response measure I took (that gets transferred to the RTA graph), and the black line is the RTA itself. Now I'm ready to move the mic around and watch the black line change.



brucek

[olatheguy]

Thanks brucek for such a clear description of the process. I'll give it a shot when my subwoofer arrives.