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Discussion Starter · #1 ·
I am using a Dell laptop, Win 7, UCA222 usb soundcard (local calibration) , ECM8000 mic with generic calibration.

I am trying to smooth out my lower end as much as possible. Speakers are IRS Betas with a woofer and upper\mid panel on both channels. The attached shows the results from each panel alone as well as all working. Clearly there are room resonances that I am working through with placement etc. BUT

What I circled is the very low frequencies from the testing of my upper \ mid panels. They are not capable of reproducing the frequencies the system picked up so I am wondering if that is a system issue of some sort and where it might be?
I suspect it is and will buy a UMIK - 1 as soon as I can just to eliminate the extra wires and troubles.

Here is the picture capture and I will also try attach the mdat
 

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This is likely just the signal falling into the measurement noise floor. The noise floor rises at low freqs. This may be a little higher than normal, but not by too much - depending on the conditions. The cause is from the mic noise and room noise (HVAC) and other sources. It can be ignored as it will not impact the measurements of SPL.

You can take measurement without any speaker sound to see if the noise floor measures near this level.
 

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Discussion Starter · #3 ·
This is likely just the signal falling into the measurement noise floor. The noise floor rises at low freqs. This may be a little higher than normal, but not by too much - depending on the conditions. The cause is from the mic noise and room noise (HVAC) and other sources. It can be ignored as it will not impact the measurements of SPL.

You can take measurement without any speaker sound to see if the noise floor measures near this level.
I have mistakenly done the measurement without any speaker output and it shows the same shape from 10 to 30 although at 20dB below what the upper panels show. However, I am not going to worry about it as you suggest.

Now to address the standing waves... They are all at the expected freq for the length, width and height of my room.... I am fighting nature...
 
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