I saw a posting of a member that installed a JL 12w7 with the factory box in a 740i. Since the search feature is down right now, does anyone know where the post went or have a link to that post. I want to install a sub in my car and want to know how I can obtain a line out from the factory system. Thanks.

http://www.cardomain.com/ride/652272/3

http://www.cardomain.com/ride/652272/4

PM me if you have any questions.

http://www.cardomain.com/ride/652272/3

http://www.cardomain.com/ride/652272/4

PM me if you have any questions.
NTB,

i think people are intimidated with hacking up the car like that, but it's actually not that difficult at all. i now i wouldn't it any other way at this point...i love having a full trunk and seat-shaking bass:D

do you still have your components sitting around?

i used easier the method of tapping into the rear deck subwoofer speaker line and using a line-level to rca converter to feed a sub amp.
Although this method is much easier (and reversible) , it doesnt sound nearly as good, because the you only receive a limited freq response thanks to the dsp crossover.

But does it sound "ok"? The stock audio in my 2001 F150 has better bass than my 750iL.
I'm not an audio geek, so it seemed the easiest way to go. Especially since the batteries are right in the trunk for power. Do they have a sub with a powered amp built in?

NTB,

i think people are intimidated with hacking up the car like that, but it's actually not that difficult at all. i now i wouldn't it any other way at this point...i love having a full trunk and seat-shaking bass:D

do you still have your components sitting around?

Still have all the other parts sitting around, not sure what i am going to do with them yet.

And I agree, it is hard to explain to people how easy this is to accomplish and it is reversible.

But does it sound "ok"? The stock audio in my 2001 F150 has better bass than my 750iL.
I'm not an audio geek, so it seemed the easiest way to go. Especially since the batteries are right in the trunk for power. Do they have a sub with a powered amp built in?

If you are going to upgrade your audio system, why not do it the correct way. Sure it will cost a little more and take a little longer, but it will be done correctly.

I'm really not interested in upgrading the whole system. It actually sounds quite fine for my needs, except for a "slight" lack of bass.

BTW, can anyone direct me to some idiot proof directions on how to set the settings on the DSP amplifier?

PM me if you have any questions.

For some reason I do not have the privilege to send PMs yet. So, will the re-wiring render the existing amp useless? All I want to do is add an amp to power a sub with the best sound quality possible. I want to leave the other speakers stock and operational using the DSP amp. Thanks.

If you are going to upgrade your audio system, why not do it the correct way. Sure it will cost a little more and take a little longer, but it will be done correctly.

The "correct" way is almost impossible with an E38 that has Nav. The audio/DSP system is integrated into the entire Nav and OBC display, and the DSP system does not provide discrete channel outputs... only specific-speaker outputs - all 12 of them.

You can't remove just the audio part of the Nav/DSP/OBC unit, unless you wanted the car to have a stand-alone audio system. Where you'd install it so that it's clean and doesn't look like somebody's kid brother is training himself to be an installer is a mystery.

The DSP system is quite a neat bit of kit, and can be markedly enhanced simply by upgrading the speakers themselves. Using the sub speaker-level outputs to a good amp will give great results - the amplified bass signal, cut down to line-level and them re-amplified, is still fine. Bass signals do not require the crystal-clarity of the higher frequencies.

http://www.robertlevinson.com/seven/take_a_look/images/audio_front_speakers.jpg

http://www.robertlevinson.com/seven/take_a_look/images/audio_sub4.jpg

http://www.robertlevinson.com/seven/take_a_look/images/audio_sub_and_amp_boxes.jpg

- Rob

i have to say, i still like the look of this trunk space (NTB, i jacked your picture man, but it looks more like my trunk than your current trunk;)) with bass and the flexibility to do whatever i want with the audio/video system while still retaining ALL functions. imho, it sounds 100% better than the dsp sound with factory speakers...just imagine when i upgrade with a good amp, passive eq, and components.

http://memimage.cardomain.net/member_images/4/web/652000-652999/652272_4_full.jpg

i have to say, i still like the look of this trunk space

Quite frankly, my trunk could have been laid out more efficiently, and that amp box could have been hidden elsewhere... but when my car's audio was installed at the Polk main facility, they were installing the components for "show" display... and as Alpine was a sponsor, they wanted the amp to be easily visible.

- Rob

Quite frankly, my trunk could have been laid out more efficiently, and that amp box could have been hidden elsewhere... but when my car's audio was installed at the Polk main facility, they were installing the components for "show" display... and as Alpine was a sponsor, they wanted the amp to be easily visible.

- Rob
that's makes more sense then, for sponsors sake to have the equipment's brand easily visible...but for more stealth "factory" look, you can't beat the 5" subs along the rear deck. i'm actually trying to find a way to hide the amp as well so nothing is visible...maybe where the dsp used to be...

The "correct" way is almost impossible with an E38 that has Nav. The audio/DSP system is integrated into the entire Nav and OBC display, and the DSP system does not provide discrete channel outputs... only specific-speaker outputs - all 12 of them.

You can't remove just the audio part of the Nav/DSP/OBC unit, unless you wanted the car to have a stand-alone audio system. Where you'd install it so that it's clean and doesn't look like somebody's kid brother is training himself to be an installer is a mystery.

The DSP system is quite a neat bit of kit, and can be markedly enhanced simply by upgrading the speakers themselves. Using the sub speaker-level outputs to a good amp will give great results - the amplified bass signal, cut down to line-level and them re-amplified, is still fine. Bass signals do not require the crystal-clarity of the higher frequencies.
- Rob

The correct way to do the audio system in a E38 is very easy to do once you understand how the audio system works in the car.

The DSP amp has nothing to do with the NAV or OBC display. Both of these are controlled by the turner/preamp. All E38's with or without DSP have the same turner/preamp, this unit senses if the DSP amp is connected in the car thru the i-bus. When it is not connected in the car the tuner/preamp controls your volume and sends it out as a 4 channel RCA output. When the DSP amp is connected in the car the tuner/preamp changes the output to a balanced output and hands over volume control to the DSP amp.

The problem with using LOC's off the DSP amp to a aftermarket amp is the crossover points.

Here is some reading on the DSP amp.
http://www.geocities.com/jyl087/dsp-analyzed.htm

The correct way to do the audio system in a E38 is very easy to do once you understand how the audio system works in the car.

http://www.geocities.com/jyl087/dsp-analyzed.htm


Excellent write-up and solution.

However, the line between "very easy" and "not many I would trust to do take apart and re-solder my OE pre-amp" is a bit further north for most people.

That write-up is not necessarily the sort of thing you would trust to "Joe's Slap Together Stereo Shop". It would require a serious professional.

- Rob

Excellent write-up and solution.

However, the line between "very easy" and "not many I would trust to do take apart and re-solder my OE pre-amp" is a bit further north for most people.

That write-up is not necessarily the sort of thing you would trust to "Joe's Slap Together Stereo Shop". It would require a serious professional.

- Rob
i disagree, i read it and did it myself...actually it was my first time soldering anything (but i am very good with my hands...so i was fairly confident that i could handle it). it does seems pretty intimidating, but i'm a very hands-on common sense type of person so i read the write up and began to open everything up...once in there it all became obvious

Excellent write-up and solution.

However, the line between "very easy" and "not many I would trust to do take apart and re-solder my OE pre-amp" is a bit further north for most people.

That write-up is not necessarily the sort of thing you would trust to "Joe's Slap Together Stereo Shop". It would require a serious professional.

- Rob

You do not have to take the preamp apart and do any soldering, you can add the missing plugs on the wireing harness at the preamp. You do not even have to buy them, you can remove them from the DSP amp wireing harness.

Seeing that you had Polk install your system you would think they would of done it correctly. They should be some serious professionals.

It takes longer to get to the parts you need to work on then the time it takes to do the work, it is very simple once you see what needs to be done.

i disagree, i read it and did it myself...actually it was my first time soldering anything (but i am very good with my hands...so i was fairly confident that i could handle it). it does seems pretty intimidating, but i'm a very hands-on common sense type of person so i read the write up and began to open everything up...once in there it all became obvious

Md750, did you even get my PM reply?

Good to hear you got it done.

Md750, did you even get my PM reply?

Good to hear you got it done.
i thought i replied to you...i'll do it now