OK well all know that we love our bmw 5 series very much, and those of us who are not fortunate to have the logic 7 soundsystem all know that bass response in our bmws SUCK.... some of you dudes out there have some complicated ways of getting the subwoofers underneath the seat to pump out more bass, but thats just too.... complicated... can anyone help me get MORE BASS in my bmw cabin.... please feel free to email me at acebmw5@yahoo.com

I'm not 100% sure that the non L7 systems do have the subs.... I thought the three additional speakers with the L7 setup (13 vs 10) were the two underseat subwoofers and the center speaker in the dash. Either way, have you tried experimenting with the bass/treble etc settings to see if improves the response to something closer to your preference?

I just want to correct that the 3 additional speakers are located backdoors (2) and center speaker in dash.
Both L7 and std system has subs underseat.

Non L7 subs produce less bass.

my point exactly, i found these people called BSW....Bavarian Soundwerks, google BSW BMW and u will find their home page. these company specializes in bmw sound and what not, i asked them and they said that upgrading the amp to push more power to the subs would solve the problem... what do you think?

You might blow your underseat subs, if you just add a powerful amp. My suggestion would be, change out the underseat subs and add a new amp. Or get sealed box in your trunk with a new amp. I did it, so its very very easy.

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is it neccessary to put it through the back seats like that? cuz i dont have the folding rear seats...

and also, how would i change the underseat subs? they are so shallow, i dont know of any aftermarket subs would fit down there...... i want to keep my car looking 100% stock, so that huge subwoofer box in the box...not an option.

AFAIK, only SWS-8 will replace subs under seats perfectly. Others are too thick. I replaced on my previous E60 and it works great. Bass is more crisp and clear. I'm thinking about swabbing it for my new E60 without adding an amp, but I found that 70W might not good enough for SWS-8.