Stereophonic electronic piano

Claim 1

An electronic piano including a case, a plurality of keys arranged in a keyboard and supported by said case, said case having upstanding panel means presented toward said keys, tone generator means in said case and controlled by said keys to provide electric oscillations corresponding to the musical tones related to the respective keys, amplifier means in said case electrically connected to said tone generator means for amplifying the electric oscillations therefrom, and loudspeaker means in said case electrically connected to the output of said amplifier means to convert the electric oscillations into audible sound, said loudspeaker means including first and second speakers mounted in said case relatively adjacent the opposite ends of the keyboard, each speaker being connected to the same output of said amplifying means, the first speaker being disposed adjacent to the bass end of the keyboard for reproducing bass tones, and the second speaker being disposed adjacent to the treble end of the keyboard for reproducing treble tones, whereby the tones reproduced by said loudspeaker means appear to be distributed across said keyboard in accordance with tonal frequency, the natural frequency of the first speaker being lower than the natural frequency of the second speaker, the speakers being mounted at openings in said panel means that are presented toward said keys, said first speaker being peripherally sealed to said panel means to isolate substantially the forward and back waves emanating therefrom, and said second speaker being peripherally spaced from said panel means to permit local interference of the back wave and the front wave of the second speaker for partial cancellation of relatively bass tones.