Realistic Minimus 7's static/poping on bass

Hello,

I have some optimus pro 7AV's which are pretty much the same as realistic minimus 7's and I've been getting some good usage out of them the past few days, pushing probably 30 or so watts into them, and today I noticed that on bass notes there is a sort of static or continuous popping coming from them.

Something tells me it's the tweeter and that those old crossover capacitors are the problem but I wanted to ask here to make sure.

Any help is appreciated.

Thanks.