what ^ said.
amp gain setting info, test tones are at the very bottom...
https://jlaudio.zendesk.com/hc/en-us/articles/204374120-Amplifier-Level-Setting-Guide
other good stuff to know...
https://jlaudio.zendesk.com/hc/en-us/categories/200265750-Car-Audio-Support
long read, but good read...