Let me start off by saying I have yet to find a headset that allows for communication via phone while riding. I can hear them somewhat but they can hardly ever hear me. Only if it's a full face helmet. Soap box over.
I went looking to add bass to my newly acquired F3-T. The cost to add 2-8 inch pods, a wiring harness, a box to adapt to the BRP system, and a 2 channel amp, plus installation was 2k, $1900+ ouch! For two speakers! I didn't get what brand names, it didn't matter, I was already walking.
Let's be real, you're only going to get so much bass from an 8 inch speaker anyhow; in addition, mp3's lose some depth anyways. So is there really a point? I rip most of my music in FLAC, so depending on the original source, the quality can suffer. An 8 inch could provide some pop, but for 2k, I'm not Rockefeller! I also think they look tacky (pods, I mean). So the only realistic solution I see is a speaker replacement.
So, what is available? I'd rather not play with OHM swapping. If you know what speakers fit or fit with MILD modifications, please provide a link. I think the stock system is loud enough, it just lacks pop in the bass department, which may be something I have to live with.