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Did my first measurements - what do they mean?

ricof

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Hi, I got my UMIK-1 today and did a series of measurements at my MLP. Below are some screengrabs from REW. VAR smoothing for the SPL graphs.

I'm in a modest room - 2.5m x 3.5m x 2.5mm (width by length by heigh) and I am sat facing the 2.5m wall. Desk with large monitor and two laptops either side of it. Speakers on stands behind and to the side of the main monitor. I have 4no. 1200x600x55mm acoustic panels looking after the first wall reflections, 2no either side of the MLP.

Any feedback gratefully received and please do let me know if you need any further info or measurements.

spl comparison.jpg


waterfall no eq.jpg

waterfall with eq.jpg
 

alex-z

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Use thicker absorption panels to get smoother mid-bass. Treat your rear wall and ceiling, not just the side walls.

I would fill in that dip from 600-1000Hz, and reduce the 10000Hz peak, assuming those issues are caused by the speakers and not the room. Do near-field measurements of the speakers to verify.

Add at least one subwoofer. Your bass output below 100Hz is lacking, and dies off after 50Hz. Ideally you want smooth bass extension down to 20Hz with a slight rise.
 
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ricof

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Use thicker absorption panels to get smoother mid-bass. Treat your rear wall and ceiling, not just the side walls.

I would fill in that dip from 600-1000Hz, and reduce the 10000Hz peak, assuming those issues are caused by the speakers and not the room. Do near-field measurements of the speakers to verify.

Add at least one subwoofer. Your bass output below 100Hz is lacking, and dies off after 50Hz. Ideally you want smooth bass extension down to 20Hz with a slight rise.
Thank you for your reply. I am considering treating the ceiling but the rear wall is actually mainly a built-in cupboard and the door is next to it.

I can measure nearfield but how close should I position the microphone? Sine sweep or pink noise?
 

alex-z

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Same distance as the baffle height should be sufficient, this isn't for high precision, just verifying which issues are caused by the room, and which are inherent to the speakers. If you really want to be thorough, you can also measure each driver with the mic approximately 1cm away, which will show you the crossover point.

Sine sweep, same as your other measurements.
 

AnalogSteph

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Accuracy at mid/high frequencies should also improve dramatically with a much shorter window, like 2-5 ms tops... a tweeter measurement should be fine with <1 ms.

We don't hear like an omni microphone with a whopping 500 ms window, so I would take existing mid/high-frequency results with a medium-sized salt shaker... probably way too much room on there.
 
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ricof

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Accuracy at mid/high frequencies should also improve dramatically with a much shorter window, like 2-5 ms tops... a tweeter measurement should be fine with <1 ms.

We don't hear like an omni microphone with a whopping 500 ms window, so I would take existing mid/high-frequency results with a medium-sized salt shaker... probably way too much room on there.
Thank you for your reply. What window size would you recommend for general stereo measurement?
 
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