Something's wrong if foam tips are dropping your bass - especially by a level as extreme as -7dB. Disappearing bass is an obvious indicator of an incomplete seal but I don't see how you could get an incomplete seal with comply foams... they're supposed to be huge. Perhaps you have mutant alien ears or the tips were old/somehow defective?
My T400 tips are nice but they can considerably screw up tonal balance since the plastic core doesn't extend to the end of the tips and your ears squash the unsupported opening. As a result, many people recommend cutting off the foam not supported by plastic core or recommend putting the tips on backwards (uncomfortable). I would like to see this problem solved as I think all the comply tips are like this and other foam/foam hybrid tips don't have this problem as much.
Trimming off the foam overhang is standard practice for me. It's easy, quick and remediates any sound issues the Comply's have. Trim them flat to the end of the plastic core.