Technic

In the other audio thread you just found out that there are woofers under your seat, which got me thinking that may be possible that your installer is not tapping those woofers for your subs, thus the lack of sub bass. Have you checked that out?

inktoxicated

cool thank you chris. the bass slams i know it does. but im only hearing like 35% of it. its going inna few days to get the seat cut. also wiring in the underseat sws-8s. never even knew i had underseat speakers. so thats another reason i have no mid bass at all. because they arent working at all now like they used to do to running aftermaket amps. and the installer never knew anything about them. so im wiring them up to a 5 channel amp they will run off the 5th chanel my highs off the other 4 and ill sell the 4 channel in there now

methodsound

I will point out that your subs have a beauty board semi sealing off the path leading to your interior. See if that has any effect on the bass. For the noise, the filter up front is on the right track. I also noticed you are not using shielded signal cables, and your amps are very close to the alternator cable in the floor of the trunk ( the alternator wire is a major EMI issue, even with a filter ).

I can not speak for other shops out there, but my policy is this: There must be an improvement in sound quality before it leaves the shop. Otherwise what exactly was accomplished by the installation? There has to be a value for the customer. I was not there, and I am sure you can work with your installer to resolve the issues, and get the sound improvement you are looking for. And in fairness your installer might not have had full control of the design and product selection. They have to have the last word if you want to hold them accountable for the results.

PS. the factory wires leading to your front subs are brown and red. The brown is positive, but most assume the opposite. If you use a signal summing devise with the sub input out of phase it would create a huge dip and spike in the bass response curve. That might be part of the issue. I avoid using analog summing devises on those cars, and just use the high for the highs and the low for the lows. You get a cleaner and higher voltage signal that way. If you need to sum I suggest the Audison bit 1 or the JBL MS8. I hope one of these tips helps you out. Good luck.

inktoxicated

well orginally when i took the car there to get the interior speakers replaced and the subs put in i had no clue i had underseat woofers. i just noticed i had them yesterday. i cant beleive i found them this time after already checking 4 times lol. i didnt know u had to push the seat allll the way foward to see them. either way the installer had no idea about the oem subs so im not sure what oem wires he spicled into to get a signal for the low pass. im assuming he just cut into the high speakers. my subs do get low tho thats not the issue the issue is the trunk not letting the bass into the car. either way i got a xmas list of shit for them to figure out and now that theres are new underseat wires to speak of maybe thatll clear some shit up

Technic

Your subs right now are high passed at around 100Hz at perhaps 12dB slope... in other words, they are not subs. Therefore that's the problem of not "feeling" them, not your trunk.

But hey, that's your car. But for anybody else reading this tragedy, please... tap wires 8 and 18 (left woofer) and lines 6 and 16 (right woofer) at the trunk OEM amp (regardless of the OEM system, the woofer lines are exactly the same pins) as inputs to your line output converter and then to your sub amp RCA inputs. Those are the correct wires for any trunk sub.

After doing this it will be very difficult to justify cutting the trunk up...

6spdcoupe

What you are hearing is simply loudness. It is not possible for them to play lower than 90/100 if they were not installed properly. Not in any way, shape or form possible, at all.
The fact that they never knew they were under the seat tells me that they are not hooked up properly. YOU did not need to know they were there, THEY did. It is certainly not new
of BMW to have them there which also makes their install suspect.

inktoxicated

i didnt know i had them. i thought i had a e60 that got gyped some subs. but then i realized i did. so when i went there with all my stereo shit i never mentioned anything about the subs under the seat becaue at that point in time i had no idea they were there. so they didnt even think of wires for the subs/low pass. so now that they know im sure everything will get figured out. im still cutting the ski hole out. im assuming the that mtx req5 summed the inputs for the subs because they do hit low

6spdcoupe

But like I said, as the consumer it is not your responsibility to know. It is great to know about your vehicle, but at the same time you are paying someone else for the 'expertise'.
If they did not know about the under seat drivers, then the likely hood of them hooking up the signal to them is null. You should not have to be doing the work and research for them.
Hats off to you for doing so, but they should have been more prepared. This is not a 'bashing' of them, just the facts.

inktoxicated

oh i agree ive done so much googling on this fuckn stereo shit im loosing sleep. if this is there first e60 then i should get a discount for being a guinea pig and allowing them to learn something during the process. shit i think the labor should be free. i just ripped out my front seat because the curosity was killing me if i had a 6.5 or a 8' under there because the grill type was diffrent from what ive seen in pics. with my rectangluar grill housed a 8 incher and the sws8 poped right in.so imma run those to my pdx 5 amp on the sub channel. so now when i go to have the 10s figured out theyll see the wires from those and make everything proper. because i do beleive those wires were never touched

Victory

I did my own stereo upgrade and I changed the under seat subs out to Earthquakes. It didn't take me too long to learn that Earthquakes absolutely suck. They claim 150RMS...yeah right. Four of them blew in 3 months. Anyway, I got into it again and switched out the Earthquakes for a pair of Pioneer TS-SW841Ds. I had to modify the sub enclosure a bit. I'm no pro installer, so if I was able to do it most people can.

The under seat subs are receiving 150w RMS each and they are low pass crossed over at 250. The two 12's in the trunk are crossed over at 80. The system finally sounds and feels awesome. I am very very happy. In your install I think you may have a sonic hole somewhere between 80-100 (the sub) and 250-500 (midbass). The stock subs aren't really "subs" they are more midbass drivers covering up to around 250 or so. If you added a trunk sub that's cut off at 100 and disconnected or didn't power your underseat woofers them you may have a gap in midbass (100-500 or so) sound. The trunk subs should provide bass you can feel. The underseat subs are going to give you the bass you can hear. One more thing looking at your install. If those trunk woofers are enclosed in a box and pushed back in there then cutting the hole isn't going to give you much of anything IMO to justify the work. I have a similar setup and cutting a hole (unless I turned my woofers around) would give me very little to nothing.

You can read about my install here. I plan to update it with my latest mod, but I wanted to throw this out there now.

Here are a few pics to give you an idea of what I did. Hope this helps.