[brendans13]

Hey guys,

First time playing around with REW on my computer setup.

Consists of a set of Usher S520's, an SVS SB1000, and a Cambridge Azur 740A.

Noticed that the upper end of my frequency response starts dipping quite rapidly at around 8kHz.

Is there a chance that my tweeters could be damaged?

 

[brendans13]

Looks like there is a bug in REW that makes the image export all grainy when running in fullscreen in 2560x1600 resolution.

Had to reduce the REW window size and export again to get it to show correctly - here's the fixed image.

 

[HifiZine]

Is your mic calibrated? If not, it could be the mic. Also, what distance is the mic from the speakers?

Having said that, the rolloff is pretty steep.

Also, if looking at the response of just the speaker (and trying to remove/ignore the room), measure just one speaker at a time.

 

[brendans13]

Yeah it's a Radioshack 33-4050 SPL meter and I'm using the calibration file from the forums.

Mic distance is only around 0.7m from each speaker (pretty much where I sit in front of the screen) so just occurred to me that maybe it is too far off-axis from the tweeters.

 

[HifiZine]

On the calibration file download page it says "Radio Shack SPL meters are limited to 3KHz" and the cal files stop at 1 kHz. So high frequency measurement isn't really possible with those.

 

[fusseli]

On the calibration file download page it says "Radio Shack SPL meters are limited to 3KHz" and the cal files stop at 1 kHz. So high frequency measurement isn't really possible with those.

This is 100% correct. To measure high frequency with any accuracy you really need a calibrated mic of good quality. I'd recommend a USB mic like the UMM-6, no sound card required and the price is fair.