Originally Posted by imureh
Was yours from CSL? Man I have tried really hard to get it open. I am afraid of damaging it now
Ray, I have two UMIKs, one from CSL and the other a stock mic from miniDSP, miniDSP told me they use some adhesive on the thread cap screw ring, why I don't know. My latest one from them was impossible to open with conventional items like tweezers or pics, I finally used a Q tip with a couple drops of penetrating oil sprayed on it and circled the ring on the barrel end around the mini USB port. I let it sit overnight and the next day like magic the ring came right off.
If you change the gain setting on the PCB with the dip switches, stay with the 6dB range, that will get you about 127 dB before clipping, plus any lower and the UMIK becomes too insensitive for any critical measurements other than compression sweeps. The 18dB setting on the PCB board is labeled 011, this translates to off on on with the dip switch, if you want 6dB it's 101 on off on, thinking of the 0 as off simplifies the process when looking at the small board.
Before you change the gain hook up the mic and open REW, open both the Generator and REW's SPL meter, click start on the SPL meter and select a 100 Hz sine wave on the Generator and click start, I use HDMI 3 or center channel for the test, with the mic at the MLP turn up the MV until you get a 80dB reading on the SPL meter, take a notice of the MV used to reach 80dB. Change the gain setting to 6dB inside the mic and then adjust the Sens Factor (Cal File) by 12 dB and do the above procedure again and nothing should change, the same MV used prior to reach 80dB should be the same as before you changed the gain.
Here's an example of my cal file or SENS FACTOR prior to changing the gain setting:
"Sens Factor =-2.020dB, SERNO: 7022539"
"Sens Factor =-14.020dB, SERNO: 7022539"
That's all there is to it..........Hope this helps you and anyone else wanting to measure louder SPLs without mic clipping.