So long story short, using 50 40w shakers and this nobsound amp with a 90W power supply (19v 4,7A) at high enough volume it started to cut/clip. So i sis a lot of testing and comparing with an old (2001) sony reciever (dad's old electronics)

I tested on the sony reciever, at first i thought it didnt worked, but it needed more volume gain on the reciever, it was strange that i had to go up to 30-35 from 50max since is rated 100W (8ohm) output, the signal through my pc sound car is is a bit weaker than nobsound with usb. Edit: it was weaker too becuse of audio enhancements on windows, before that volume was 40

Just tested chair shaker conected to a front speaker channel on the reciever. Strenght of vibrations could go higher than the nobsound and without any clipping/cut, and overall it felt better.

With my 90w power supply the nobsound should be able to run a 50w shaker just fine, i tested it with the seat shaker, cranked volume to 100% in simhub and amp and clip/cut presented after some sustained strong vibrations, a few times.

Did the same test but now using the 3.5mm plug on the nobsound, volume was a bit weaker than via usb, but problem persist.

Now for the last test, i plugged in the 40w shaker with everything still at max, and oh boy, shakers just cut almost all the time. So its definitively a power issue, im gonna have to get a 100W power supply to do a full test. Else, the nobsound is just not cut for bass shakers use.

Of course the sony reciever could run both at a higher volume without problems.

On another note, since my 50w is mounted on an office chair with an steel L shape angles and wood, when i mount it on a steel plate maybe i will need less power for the same effect.

I have another usb sound card (creative g3) to compare using the reciever as well. So im considering getting another amp, not sure if their ns-04g would be enough or maybe go with another brand.