So I just moved my Pioneer sub into my BMW 328i. Same enclosure, same amp. New power/ground wires, new rcas, new speaker wire.

The headunit is BMWs factory and the amp is getting signal from a LOC that is connected to the BMWs factory amplifier.

The subwoofer does NOT sound the same anymore as expected. But the problem is that its not close to as loud as it was on the expedition.

They told me the BMW has a well-sealed trunk, could this be the reason why Im somehow not feeling the bass anymore?

I also had to lower the gains a bit (from what I had it on the expedition) and the sub gets hot faster and my trunk has been getting that burning smell constantly since I installed it at noon. So I know that means lower the volume, but then I lose most of the bass.

My crossovers still the same as when I had my sub in the expedition. Im also using a 300amp fuse for my knukonceptz 0 gauge cable. I had a 100amp fuse on my RF 4 gauge in the expedition.

Can anyone tell me whats going on? shouldnt it be louder since its a smaller car? or at least equivalent?

single sub system right?

your system will sound different in different cars 100% of the time.

Depends on where you have it placed in the trunk, as opposed to where you had it located in the Expedition, settings on each head unit, etc. Sounds like you changed just about everything except the sub, box and sub amp. Subs usually sound cleaner and louder to the ear in an SUV or hatch. Cars are more fun to drive than SUV's generally, but it's more difficult to get good sounding bass from the trunk than from an open hatch area.

There is a steel plate between the trunk and passenger compartment. The Europeans know how to build vehicles well and they don't skimp on shit like the Big 3, although the Big 3 have built some cars in a similar fashion. Your bass is essentially trapped in the trunk. You need a way to vent it into the cabin.

my friend has a 2000 328i with a sundown sa 12 in a box that i built for him. running 0ga, 250amp inline anl fuse, on a 2100 brutus and gets really loud.

he popped out the center metal peice where the arm rest folds down and pulled away all the insulation.

i guess try that and see what happens im not sure how much it will help but its worth a shot, thats if ur ok punching out that metal peice. it is perforated.

Yes single 12 ported

So the interesting part here is the bass trapped in the trunk.

Will check what can be done to somehow let it travel to the cabin. I hope I dont have to mess too much with the car integrity.

Btw this is a 2008 BMW 328i sedan

Edited February 25, 201114 yr by slim142

I am his buddy with the 2000 328i BMW, it is also a sedan and I literally just punched out the sheet metal in the middle, I also didn't want to lower the integrity of the beamer, so I also took out just the foam in the middle and left all the rest of the foam that was behind the seat, and when I the armrest is down, it allows my sa-12 powered by the 2010 model brutus (BRZ2100.1D) and it takes all 2100 watts and loves it, to allow air into the cabin. But when I fold the center armrest up, it becomes just as quiet as before... it took alot if thinking and how I wanted to do it before I actually committed to doing it. I am very pleased and because of where my amplifier is mountd, I get the awesome hifonics blue light in car, subtle but nice if you ask me or anyone who has seen it

I have a 2009 528xi with one ten in a ported box in the trunk and its hella loud. Do you have a separate bass knob or is your sub controlled by bass in the eq along with the rest of the system?

also I dont know exactly what system you have but in a 5series there is a separate amp for the subs that only sends a low signal. If your car is the same way make sure you have the LOC plugged in to a regular speaker wire not one of the sub wires.

I have a 2009 528xi with one ten in a ported box in the trunk and its hella loud. Do you have a separate bass knob or is your sub controlled by bass in the eq along with the rest of the system?

I do, a separate bass knob came with my brutus, and my box is all the way in the back with the port facing the trunk, its in a 2.28 cubed box (.14 speaker displacement) tuned at 37 hz. Me and mkremer90 built it awhile back.

I am his buddy with the 2000 328i BMW, it is also a sedan and I literally just punched out the sheet metal in the middle, I also didn't want to lower the integrity of the beamer, so I also took out just the foam in the middle and left all the rest of the foam that was behind the seat, and when I the armrest is down, it allows my sa-12 powered by the 2010 model brutus (BRZ2100.1D) and it takes all 2100 watts and loves it, to allow air into the cabin. But when I fold the center armrest up, it becomes just as quiet as before... it took alot if thinking and how I wanted to do it before I actually committed to doing it. I am very pleased and because of where my amplifier is mountd, I get the awesome hifonics blue light in car, subtle but nice if you ask me or anyone who has seen it

Ill check my middle arm rest thing tomorrow and that foam that you talking about so if I need any help, ill come back here and ask you

I really want to bring the bass to the front! its annoying to have a sub playing bass and barely heat it lol

I have a 2009 528xi with one ten in a ported box in the trunk and its hella loud. Do you have a separate bass knob or is your sub controlled by bass in the eq along with the rest of the system?

Yes I have a bass remote. I have my bass at 0 (default) on the radio and the bass knob on the amp is currently at 11 o'clock. The bass remote is turned 3 clicks, more than that and it gets into distortion.

also I dont know exactly what system you have but in a 5series there is a separate amp for the subs that only sends a low signal. If your car is the same way make sure you have the LOC plugged in to a regular speaker wire not one of the sub wires.

I doubt there is another amp for the bass. In my trunk, the left side has the amp and the right side has the battery. I dont know where could BMW possibly have put another amp. I know my car doesnt have factory subs, I believe there are 6.5" drivers under the front sits, but they dont go that low.

Sorry jdeuel20 my comments were directed at slim142

In the trunk on the left is where my amps are also. There is a smaller silver amp with a 20 pin harness going into it which is the sub amp and a longer silver amp with a smaller harness which powers the rest of the system.

what year is your car?

Yeah check and go ahead and get back to me, my sub box is in the middle and the amp is behind the box.

I doubt there is another amp for the bass. In my trunk, the left side has the amp and the right side has the battery. I dont know where could BMW possibly have put another amp. I know my car doesnt have factory subs, I believe there are 6.5" drivers under the front sits, but they dont go that low.

Won't be an extra amp, but very well may be pre-processed and knocking the signal out.

Most likely though you are just missing the cabin gain from the SUV and experiencing the loss in the BMW. Firing direction in that car makes a HUGE difference. IE, you probably need to build a box specific for it depending on what yours is doing now. I take it you also don't have the fold down seat option, that was a life saver in my last 3.

I doubt there is another amp for the bass. In my trunk, the left side has the amp and the right side has the battery. I dont know where could BMW possibly have put another amp. I know my car doesnt have factory subs, I believe there are 6.5" drivers under the front sits, but they dont go that low.

Won't be an extra amp, but very well may be pre-processed and knocking the signal out.

Most likely though you are just missing the cabin gain from the SUV and experiencing the loss in the BMW. Firing direction in that car makes a HUGE difference. IE, you probably need to build a box specific for it depending on what yours is doing now. I take it you also don't have the fold down seat option, that was a life saver in my last 3.

I dont have the that option, but I do know that just by removing the foam and sheet metal from the fold down armrest, made the biggest difference in the world.

Mine had the skipass and fold down seats. Helpful. Making your ski pass will help, but NOT as much as correctly aiming it. How are you firing now?

The speakers under your seats are the factory subs/midrange. The are powered by the same amp as the rest of the speakers but the amp has a built in low frequency part you shoud read this

My link

Also might want to get a hold of Technic on that forum. he makes some nice harnesses that eliminate the need to cut anything. There is a lot of info on there about the sound in bmws just look around.

I been playing around with the sub position, gain, bass boost on the headunit and not much luck. I mean, I have definitely increased the bass, but the gain has been minimal.

I have set my gains with +5 bass on the headunit so I can have the 6.5"s help with the bass. I have also moved the sub so that it aims the backseat and not the trunk anymore.

When the trunk is open, the bass is really loud, as soon as its closed, its like it gets cut in half.

No M5, I dont think my car has the fold down option. Is there any lever or switch that would let me figure that out? Cause so far, I tried pushing it and looking around but no look.

Crazy, I went to the backseat and saw the arm rest metal sheet (when arm rest is opened). Its a 1-piece metal sheet that has the arm rest plugged at the bottom. Im affraid of force-pushing it out and braking it. Any tips in here?

I also went to the trunk and on the top, there is a hole, inside that hole there is a foam which seems to be the one you talk about? Im not sure if this is connected to the cabin at all. Didnt want to take it out before asking.

I think Im gonna take pictures and better illustrate my situation and the car.

Edited February 26, 201114 yr by slim142

I been playing around with the sub position, gain, bass boost on the headunit and not much luck. I mean, I have definitely increased the bass, but the gain has been minimal.

I have set my gains with +5 bass on the headunit so I can have the 6.5"s help with the bass. I have also moved the sub so that it aims the backseat and not the trunk anymore.

When the trunk is open, the bass is really loud, as soon as its closed, its like it gets cut in half.

No M5, I dont think my car has the fold down option. Is there any lever or switch that would let me figure that out? Cause so far, I tried pushing it and looking around but no look.

Crazy, I went to the backseat and saw the arm rest metal sheet (when arm rest is opened). Its a 1-piece metal sheet that has the arm rest plugged at the bottom. Im affraid of force-pushing it out and braking it. Any tips in here?

I also went to the trunk and on the top, there is a hole, inside that hole there is a foam which seems to be the one you talk about? Im not sure if this is connected to the cabin at all. Didnt want to take it out before asking.

I think Im gonna take pictures and better illustrate my situation and the car.

I will also take some pictures of mine and post it up here tomorrow, I will take pictures of everything im talking about. Hopefully this will help.

Its a trunk what you exspect! thats why i ditched my trunk and went and got me a wagon!

I prefer sportier cars or sedans, the only sporty wagon I can think of is a volvo gti/r32

Hey guys

Been pretty busy lately, but here are the pics to explain better my situation.

This is the metal/aluminum? plate that seems to sit between the rear row and the trunk. I dont know if it can be taken out.

Now on the following pic, you can see this foam that I have no idea what the purpose is for (keep noises from trunk away from cabin?). I dont know if its a duct to the rear sits. This hole is on the top middle part of the trunk. Inside this hole is this foam which seems to be removable but dont know if I should remove it or not. (Pic taken with camera facing up)

Let me know what you guys think!

Edited March 9, 201114 yr by slim142