My Toshiba WX-1 ** 3-Way Speaker Mod & Yamaha-like 'Natural Sound' Loudness Control

I managed to wrangle another Super Grail unicorn from DecentMan4You. He's different, his prices are over-inflated but a solid deal none the less...It works almost fully but the Auto tape search function doesn't work & causes tape a to click while rewinding but still works completely & all other functions are correct.

The interesting part for me was this 'ESBS Level' control which I gather doesn't stand for Extra-$#!++Y-BASS-System.

Regardless, it sounds alot like the 'loudness' control & Bass you would get from a good late 70's, early 80's Yamaha reciever which had the 'Loudness' knob instead of a button.

Can anyone give more info on this setting and what it does? I'm guessing a loudness contour control that does the same thing for the 50Hz center frequency, as the Bass knob does for the 100Hz center frequency. I'm just wondering if I'm correct as it seems so...

I'm really warming up to this Toshiba & it has more juice than some guys give it credit for. It's not a bone crusher like the M90 or even the M70 but it's got some gas at 8 OHMS & I can see some bounce in the 6.5's...

Thanks,
Cpl

Here is some crops from some schematics. Can't say much, it would help to know what those Q443 and Q444 are. I don't know much about what components tone controls (in general) need.