Use 2 Computer-Power-Supplies in Series for Plus and Minus 12-Volts.
This is assuming that the Output of both Power-Supplies are isolated from the Mains-Voltage and Ground.
Then there will be no need for Over-Voltage-Protection.

A Boost-Converter is a poor choice for any Audio-Power-Supply application.
.
.
.

 

True.

but can you tell me how it works cause i think i might be able to use this on future projects

 

Most computer power supplies, which have all been switch-mode circuits that I have seen, are not filtered well enough to serve as power supplies for audio amplifiers. The various noise voltages that do not cause any problem in most digital circuits DO cause a bit of noise in audio circuits, where they appear in the output signal. Adding a boost-mode circuit will probably make that noise level even greater.
Certainly it is possible to adequately filter out the noise, but it does take extra components and circuitry, and it is not a small effort.
The higher powered amplifiers that I have seen that are intended for automotive applications appear to use power supplies that are an inverter circuit that often includes a regulation scheme of some variety.

 

I would have said something similar,
but it's evident that PaPiャSly is using what he can get real cheap,
a Computer-Power-Supply is the most "Power-per-Dollar" that's readily available.

I an ideal world,
I'd say to buy a custom, ~10-pound, Toroid-Transformer,
with about ~40 High-Current Caps to go with it.
.
.
.

 

An amplifier designed for 24 volts may work on 12 volts, although at much less power. Also, it may be possible to change the output voltage of the supply. Many times switchers can be adjusted a bit. And as the POWER would be less, probably the parts could handle it. So adjusting the voltage might be the way to go.