1973 or 1974 rear speaker control

[rudyjrusa]

hi - does anybody know if this item was an option or aftermarket addition.  the picture shows a rear speaker control button.  what is it's function???  have not seen it on many chargers.

[hemihead]

It's factory , my 73 has it too.

[Charger1973]

Its stock.  Both my 73s have them.  It fades the speakers front to rear, usually the knob is broken/missing.

[Nacho-RT74]

Is factory to MONO Radios setups with rear speaker. controls the balance between front and rear speaker, normally installed as far I know on driver's side hole... 5x8 speaker

same setup was available also on 71/72.

also on earliers but with different look and location