[Stephie Bench]

Generally, a true log taper is difficult to implement, so the mfgrs implement it by two piecewise linear segments. The 10/90% allows 20 db change from mid to max, a 30/70% allows a 10 db change mid to max. Note that a linear pot only provides a 6db change mid to max.

Patrick, the files I just emailed you are set up for a linear pot. I included response curves for bass max, mid, min, 400Hz max, mid, min, and treb max, mid and min.

I played wiyh the values a little, so, for instance response with all pots set midscale, the response is:
50 Hz +7
100Hz +6
200Hz +2.5
400Hz 0
1k +3.3
2k +5.2
5k +6
10k +6

Bass at 50Hz Varies from +3.5 to +15
Mid at 400Hz varies from -9 to +9
Treb at 5k varies from +3.5 to +15

-Stephie