I herd my subs popping months ago and I looked all over and everything says it’s my subsonic but ive tried setting it to half and octave below tuning but I still have popping. I’ve tried setting it a little bit higher and I still had popping so I thought maybe it was a voltage issue because I was on my stock 90 amp alt so I got a 300 amp alt. After installing the new alt I tested it and I’m still getting the popping noise and my subs get smelly. The amp is a Skar audio RP.2000.1 the Low pass is at 80hz subsonic is set at 30hz. My head unit is a kdc-x998 everything is set flat for eq, in my crossover settings I have set 24db slope 60hz frequency center. For my sub level I have +15db because I’m using the built in amp on the head unit for my speakers in the doors so my volume limit is 25 and with 15db on the sub level it’s clean. I used a dd1 to make sure it was clean signal from the rca. The box my subs are in is a Atrend 15SPLDV it’s a 6 cubic foot box 3 per chamber, center port tuned at 37.66hz. I really have no clue what’s wrong so if anyone could help that would be awesome.