Pioneer Audiovisual - The Pioneer SG-90 equalizer from 1983 had many control knobs to calibrate frequences in accordance with the room. Our current AV receivers with MCACC already know how to do
CINE HIFI - PIONEER SG-90 Graphic Equalizer (SATILDI)... | Facebook
Pioneer SG-90 34 Band Stereo Equalizer Top of Line, Ex Sound, | Reverb