About 14 months ago, I installed a new Polk MM840 in my car on the rear deck, basically an infinite baffle application. It's powered by a Pioneer GM-D7500M amp through my stock head unit connected by a PAC SOEM-T line output converter. It worked great for about a year, until one day the MM840 developed a terrible popping noise.
I replaced the damaged MM840 with another brand new MM840. The day after the new driver was installed, it developed the identical popping sound, making it unusable.
So, my question...what can I do to stop ruining these speakers? I do not believe they were driven too hard. The max volume I would use is about 12/35 max on my head unit. I do not listen to hip hop or bass intensive music. I thought that perhaps my line-out converter had gone bad, but I have checked it and it appears to be fine. Any suggestions would be much appreciated because I want to get another MM840, but I don't want to damage the next one. I'm not looking for warranty service, just advice.