Lookin for suggestions ...
 

I am helpin a friend, "upgrade" his stock audio in his car ... I havent owned a car for the past few years (been gettin around on a motorcycle), hence I am a lil out of touch ... He has 2004 BMW 530i and wanted to put in a 12" Type X powered by a MRD-1001 ... I am not a big fan of the type X sub as I belive it to be a fairly inefficient sub (I could be wrong) but a 13W7 is outta his budget ...

so what would be a good way to start the upgrades? I want to suggest a Vented box to him, nothing huge as he wants some useable trunk space, but am lost as to which drivers would provide sufficient clean thump. He wants SQL...

Currently I am "researching"

12" Adire Audio Brahma
12" Kicker L7
12" Image Dynamics IDMAX

Any and all suggestions to a Amp/Driver combo are welcome ... and do you guys think that the factory speakers should be powered off their own dedicated amp or the factory deck in the car is decent enough?

You have tons of choices still. The new RE subs are coming to market now, the Eclipse titanium drivers are great, DD 9500 series, Focal and Boston, lots to choose from. Once the sub is narrowed down, then a amp can be chosen for the task at hand. I would definitely have a amp on the front / rear speakers so that they at least have a hope of trying to keep up with the back end and the copious amounts of bass energy slamming the occupants around the car.

what back seat do it have (ski boot,60/40......)?

thats why I am having "issues"... I can never make up me mind LOL ... I am now also wondering if a sealed box would be good for him ... he doesnt need ridiculous ghetto thump SPL, just something that would be sufficiently loud for the entire cabin ...

have a look
http://bimmer.roadfly.com/bmw/forums/audio/6064195-5.html
http://bimmer.roadfly.com/bmw/forums/audio/6147032-1.html

go ported

Some of the BMW's I have done have worked just fine with a single driver in a small sealed box. Eclipse makes a good sub for this application. Great low bass extension and tonal accuracy as well.