Bose 901 Series IV Active Equalizer Demo

Bose 901 Series IV Active Equalizer Demo. These units were made between 1978 and 1983. They were designed to be used with the Bose 901 series speakers but can be used on any stereo with the proper connectors. Low filter control. Is −5 dB at 40 Hz. Low frequency slider is +- dB over 100 to 400 Hz. High frequency control is +−8 dB at 10 KHz.

[@fdouglas5172]

If you have a switched outlet on the back of your receiver that is where you would plug this in. It will then be turned on and off automatically with the receiver power. Liked seeing the inside and back of the unit.

[@AudioElectronicsChicago]

cool, it is a must with the 901 speakers