Bass Shakers won't go louder than 20%

Hi all ! 

So I'm making a Bass shaker setup with 5 BS.

They work fine when the volume is under 20% in simhub but after that, they make a clinking sound and nearly vibrates anymore. 

I checked the output values and it seems to be around 17V at the  Bass Shaker at 20%.

The power supply seems fine, I checked the output and it delivers the 540W.

I don't understand why, does anybody has an idea ?

Here are the components :

https://www.audiophonics.fr/fr/vibreur-exciter/haut-parleur-vibreur-exciter-100w-4-ohm-o88cm-p-2947.html

https://www.audiophonics.fr/fr/modules-amplificateur/wondom-aa-ab34181-module-amplificateur-tda7498-class-d-6-x-100-watts-4-ohm-p-10049.html

https://www.amazon.fr/LEAGY-Haut-parleurs-Enregistrement-simultan%C3%A9s-%C3%89quipement/dp/B07W21PGJQ

Thanks in advance !