If I understand this correctly:
1 You are going to take several audio signals,
2 Amplitude modulate each one on to a discrete carrier frequency in the range 500 to 3000khz,
3 Amplify the resulting set of AM signals to 1000watts
4 Individually demodulate the signals using an envelope detector (a diode)
5 Drive a speaker with the output of the diode detector.
So, after I picked my self up off the floor, where I had collapsed in a gibbering heap paralysed with hysterical laughter...
I can only say that your proposal seems to be seriously flawed in many ways.
Please correct me if my understanding is wrong.
If my understanding is correct, I will reply pointing out the problems with your proposed scheme.
JimB