I want to add line out jacks to a digital piano with built-in speakers

Question

I have a Casio Privia PX575r Stereo Piano.

Both the left & right channels have their own onboard [LF]woofer AND [HF]tweeter. On each L & R stereo channel I intend to install an onboard 'line out jack' respectively.

Each Piano L & R channel will be sent to its own 'new' jack and thus to its own [Behringer 1800FX keyboard active speaker] amp.....so that the Piano's instrument tones can be PANNED between the two Behringers.

Let's just consider the Left Stereo Channel.

To maintain the left channel's individual [LF] woofer & individual [HF] tweeter signals into one Left Channel jack....I intend to solder each speaker's [+][-] hot terminals to one TRS guitar Jack...the woofer to the TRS tip..&..the tweeter to the TRS ring. Their common ground wires will be added to the Jack at the same ground point.

This prevents the woofer talking to and 'blowing out' the tweeter. My assumption is the tweeter 'brilliance' frequencies are lost if I do not include it.

The external AMP will have a balanced [mono Line In].

Will this work? What did I miss? Your thoughts please? Thanks a bunch. Richard.

Answer 1

Unfortunately this will not work. Or more specifically, it will not work well. The problem is that the signal sent to the speakers is very different than the line level signal expected by the amps.

There are speaker level to line level converters (most often used in car audio), but the resulting signal often leaves something to be desired.

If you are willing to mod the piano you could tap the line level signals before they are sent to the on-board amp.