First, pretty green with REW and slowly working my way through the learning process.
As part of this, I was playing around and just taking some quick speaker measurements. Noticing a couple of spikes, I started getting curious.
I shut off pretty much any sound source in the room and got it down to about -50dB according to the SPL meter.
Then, I placed a heavy cloth over the UMIK-1 and shut off the speaker output (muted).
Took another measurement - which SHOULD then come pretty close to just reading the noise floor.
This is where my question comes in.
I'm seeing two spikes that consistently appear at about 40Hz and 120Hz. (The rest of the measurement happens below my room noise floor (-50dB)
The 40Hz spike is lower than the measured noise floor so not sure if this is something I should be concerned about for future speaker measurements (sub) but the 120Hz spike is about 6dB above.
- and yes, I do have the calibration file applied to the mic in REW (5.20 RC6)
Curious if this is something anyone else has seen or has any ideas of what might be causing it?
This also raised a question in my mind. Shouldn't all measurements start out this way? Wouldn't you want to first see what the room is generating BEFORE any tone sweeps are performed? Any existing peaks like this could have someone chasing their tale trying to adjust their speakers to eliminate them....when they really aren't able to.
As part of this, I was playing around and just taking some quick speaker measurements. Noticing a couple of spikes, I started getting curious.
I shut off pretty much any sound source in the room and got it down to about -50dB according to the SPL meter.
Then, I placed a heavy cloth over the UMIK-1 and shut off the speaker output (muted).
Took another measurement - which SHOULD then come pretty close to just reading the noise floor.
This is where my question comes in.
I'm seeing two spikes that consistently appear at about 40Hz and 120Hz. (The rest of the measurement happens below my room noise floor (-50dB)
The 40Hz spike is lower than the measured noise floor so not sure if this is something I should be concerned about for future speaker measurements (sub) but the 120Hz spike is about 6dB above.
- and yes, I do have the calibration file applied to the mic in REW (5.20 RC6)
Curious if this is something anyone else has seen or has any ideas of what might be causing it?
This also raised a question in my mind. Shouldn't all measurements start out this way? Wouldn't you want to first see what the room is generating BEFORE any tone sweeps are performed? Any existing peaks like this could have someone chasing their tale trying to adjust their speakers to eliminate them....when they really aren't able to.
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