idk this has never happened just wanted 2 get some ideas of wat might have happened but i was playing some frequencies in my car and when i played a 20 hz. note one of my subs made a weird popping sound like...does neone kno wat this could be thank you

the freq you played was outside the subs ability to repoduce it corectly and clearley

but its weird i have all the same subs and they played it just fine

Your sub may have been bottoming out on the back plate of the motor.

Not all of your subs are responding exactly the same. There are too many variables to make it perfectly in sync.

So, don't do that again.

If the enclosure isn't tuned low enough or if you have too much power or if the enclosure is too big or the sun has worn out spider and surround the subs will pop when playing low frequencies especialy 20hz. That's just a few things that can cause the problem you had