I am a beginner and i need help with my speaker build

Hello can someone explain to me something.
I had problem with the power suply where when I conected the subwoofer it could go only till 75% volume and then it will go into overvoltage and stop working so I have change the power supply and did test the subwoofer again and it works till 100% volume without any distortion but only on test tracks that are 100% only bass and no highs. Does that mean that the subwoofer works but when given a full spectrum distorts at higher frequency?
 
Problem solved when I connect the subwoofer in series.
I think since the amp board is 6 amp and the subwoofer is a 4+4 Dayton epique it made the amp work extra hard and distord but since I conected both terminals it gone to 8 ohm I think🤔
1000014909.png
1000014910.png
1000014911.png
1000014912.png
 
I thought carefully and I would like to add another amplifier to the system for the subwoofer but I don't know how to connect 2 different amplifiers to a single source (which is from the first amplifier that has aux, bluetooth). Can someone help me?
 
The crossover components have arrived and I made the crossover and tested it and everything seems fine but when I was doing the tests I noticed a few problems that I need to solve. The first problem is that the subwoofer needs 200w rms and 400w peak and the audio board has a maximum of 200w per channel and at maximum volume when I turn the subwoofer on I hear weak bass, distortions and cut outs because the subwoofer requires more power than the audio board can provide. the second problem is that I hear very high distortions in the tweeter and a little in the midrange otherwise everything seems ok. What can I do to solve the problem?
 
I did some more tests and found that a wire was not connected correctly and because of that the tweeter had distortions, however I came to the conclusion that I need to find an integrated amplifier that has bluetooth, aux, etc. to which I can add some power amplifiers for each speaker. But I can't find such an amplifier that works at a voltage of 24-72 v. Your idea seems good, but until I solve the problem with watts I can't progress with the project. Does anyone know where I could find such an amplifier?