The Elan controls are volume, pan, filter, and Q switch.
The low-pass filter adjusts the cutoff frequency from about 350Hz - 6KHz. Only frequencies below the cutoff frequency are passed. When fully open, all frequencies below 6KHz are passed through; when fully closed, only frequencies below 350 Hz are passed.
The Q switch is on when set to the down position. When the Q switch is on, it boosts the cutoff frequency of the low-pass filter by about 8dB.
Elan Plus controls have, like the Europa controls, the addition of bass and treble boost/cut switches.
