Using USB type c power pack to power 12-24v chip amps

I only found few 5 watt class d amps that will power off 5v regular USB. But higher power amplifiers need 9v+. I am looking for around 20w per channel+40-50watt for subwoofer in 2.1 set up

I am building a pair of speakers and ideally want to eliminate all the wiring.

At the moment I have 2 speakers. One speaker will have a Ryobi battery and charger , amplifier and speaker drivers.

Was hoping to make things a little more delicate and integrate battery pack than can be charged with usbc..

Charging is no problem but how do I extract 12-18v put of the power pack. How to facilitate stable 12,18 or 20v DC current out of power pack to power the class d amplifier.
 
The battery pack would need to support USB Power Delivery and your device would need also to support USB PD. E.g. by using IP2721.
However there are portable starters that have 12V or 19V output. E.g. https://www.telwin.com/en/prodotti/index.html?id=829566&lingua=E
I was thinking of using a usbc to 12v DC chip to constantly power that battery pack and use 9v 1a output to power the amp .. but 1a sounds very little.

Can the portable charger be charged with usbc?

Edit: yes I see it has USB charge option.. very interesting
 
You sure USB van supply that much power?

And why step down to 5V first (USB) and then boost to higher levels?

What´s wrong with straight getting, say, 19 to 24V from a laptop brick?
There you can get up to 60W RMS

The amp you show needs MINIMUM 9V so no way.