My BMW had 61/2” underseat woofers Which didn’t sound too bad and went impressively low when I first got the car. They became an issue when I fitted some old school 4” MB Quart front stage components and 30 watt amplifier for the front stage. 30 watts is a lot of power for the mids and tweeters when high passed at 200-300 Hz and completely overwhelmed the 6.5” midbasses and I blew them running too much clean power into them. I ended up replacing them with 8” focal midbasses and running them on a 100 watt amp. The midbasses in the bmw are mounted in the floor though, which helps enormously in getting a solid mount.
In your case I would do as inphase suggests and pay a lot of attention to beefing up the door and deadening it. Then run as much power as you can, stopping at either the speaker rattle limit.
I had been trying to figure out a place to hide one or hopefully two of the Tang Band W6-2253S, shallow mount 6 1/2” 100w subs. I could almost get one up under the dash in a small box, facing downwards, but I would still need to hide another amp as well. After looking at what I could move around under the dash or behind the center console to make room, I decided to let it be with the decent in door drivers that I already had.
One of the better systems I had used an 8” on each side, hidden up under the dash, would like to try that again sometime, but the newer cars just aren’t cooperating.
One of the better systems I had used an 8” on each side, hidden up under the dash, would like to try that again sometime, but the newer cars just aren’t cooperating.
Thanks, that's the main reason I'm replacing the stock rear "subs" or "midbasses" or whatever they are. I'm afraid I won't be able to run much power through them. My dad's 2 series has underseat woofers as well, but they are 8 inches not 6.5 I believe... did your car have the hk upgrade? Just wondering, how much power did you run thru the stock woofers to blow them? My father wanted help with upgrading his sound system so I was just looking at options.