Leaderboard

You need to specify what's your vehicle, what is the sub model the box specs and some pictures if possible. Looks like a box issue, installing a DSP could help flatten your response but not the other issues, in some situations inverting the phase of the signal to the subs can help some cancellation issues, other times box location / sub, port firing direction etc can help. try what is suggested and if you still not get results then provide the details I asked about above.