[jimIaleggio]

Hi...I'm a piano rebuilder doing research on destructive resonances at this moment on piano soundboard ribs. Using a Dayton 4ohm 40watt exciter paired to a Fosi 40watt bluetooth amp and frequency app on my phone to drive the piano ribs. Ribs unattached to the soundboard, exciter mounted at the bridge location, ribs ends clamped. Driving the exciter for short amounts of time, heats the thing up big time. So much so that I have to stop after a couple of minutes and cool the exciter with compressed air.

Any clue what I am doing wrong with the setup?  I'm not an audio person...mostly a woodworker learning new tricks

[FullRangeMan]

Welcome to AC 
When the exciter VC overheats thee are overload, a piano board is too big, these exiters were designed to drive a small panel.

[jimIaleggio]

oops...maybe I didn't explain it well. I am not exciting the full assembled soundboard. I am only exciting individual ribs before they are glued onto the sound board. So, they are only approx 24" by 1"x1". Is that still too high a load?

[FullRangeMan]

Seems this not a panel.

[Phil A]

Welcome!