On 11 is the knob on the amplifier going past the normal 10 being the loudest. Going past that level. Knob goin to 11.  
The band believes sound is healing almost like ascension. They feel the music  to be  an emotional experience in body and mind. A spiritual connection to earth through the root of sound their music.  Maybe a yoga type graphic?  Sort of like sound meditation.
They are also drawn to tribal /native american style 
Antlers? Bear claw? Arrows? 
A bear claw holding a guitar plugged into an amp that says On 11<
Also a butterfly playing guitar plugged into an amp that says On 11 with a big knob? 
 They are a true hard rock band and all men Maybe pretty things in a more hard rock music way
 They  use music as healing if that makes sense 
This is not new wave- they like vintage 60s//early 70s hippie movement like Led Zeppelin. Graphics Hendrix etc 
**in psychedelic/hippie  vintage style -**
The band does not like skulls but they are also artists and would like something a little more than changing letter fonts. They can do that themselves.
This band is very up and coming and this is an important project