[Eeglablist] firwsord dB question

Russell Toll Russell.Toll at UTSouthwestern.edu
Wed May 1 06:21:08 PDT 2019

Hi Andreas,

In the firwsord.m function on line 78: devdb = -20 * log10(dev);

Should devdb be calculated as 10 * log10 or as is, 20 * log10? The value of dev (.0002 for Kaiser window) describes the desired ripple limit as a ratio of desired to original signal, both in microVolts I think. However, as we don't necessarily want the power, should decibels be calculated as a regular log ratio (10 * log10)?

I frequently get confused with voltages and power so I could very well be, and likely am, wrong. Just wanted to verify the function was correct as written. Thanks very much for your help and teaching!

Very respectfully,

Russell T. Toll, Ph.D.
Assistant Professor
Department of Psychiatry
Center for Depression Research and Clinical Care
UT Southwestern Medical Center
6363 Forest Park Rd, Suite BL 13.206
Dallas, TX 75235-5479


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