US I4 (400hp) has fake engine noise pumped through speakers

[ShootingSight]

Another, probably stupid, question - but if that additional frequency is being pumped into the amp, does that mean our music isn't getting all the boost it could be getting from the amp? Additionally, snipping the wire could mean we would get a better volume control with the music? (i.e. we wouldn't have to get to half volume on the knob to have a decent level on the music)

Based on the wiring diagram posted further up, I don’t think that wire generates the sound. I think that wire communicates engine RPM to the amp, so the amp knows what frequency to inject. By disconnecting the wire, the amp thinks the engine is stopped.

Unfortunately, this means you cannot use the wire to inject fart noises, though you might spoof it by injecting a false rpm signal, which would create an interesting pulsing as the injected noise goes in and out of phase with the real noise.

 

[Kaz]

Thank you, this is great news. I know you had a couple of other threads on the sound deadening, etc., but the pics there didn't make it obvious. At your leisure, can you post a pic that shows the general location of the amp and this harness (if you even have one handy)? Trying to figure out if I'm brave enough to start disassembly.

If you look in the electronics sub forum there are incredibly detailed photos of amp/dsp installation from a couple authors, the area is the rear passenger side behind the passenger seat. The stock sub and electronics are all back there. You don't have to but, taking the passenger seat out will save you boatloads of backaches and there are multiple layers of things you take off to expose everything. Easily done in a day. If I were you I would just drop it off at FS Audio, have them soundsskins pro the car while they are at it -

 

[Kaz]

Another, probably stupid, question - but if that additional frequency is being pumped into the amp, does that mean our music isn't getting all the boost it could be getting from the amp? Additionally, snipping the wire could mean we would get a better volume control with the music? (i.e. we wouldn't have to get to half volume on the knob to have a decent level on the music)

I am really eager to hear what kind of benefit the stock system has without the need to create the exhaust and engine noise especially in Sport/Track mode. The wire is simply sending RPM data and luckily we don't have microphones and noise cancelling to deal with on top of that.

 

[675430VME]

Thank you, this is great news. I know you had a couple of other threads on the sound deadening, etc., but the pics there didn't make it obvious. At your leisure, can you post a pic that shows the general location of the amp and this harness (if you even have one handy)? Trying to figure out if I'm brave enough to start disassembly.

Ditto that!

 

[Rapture]

Thank you, this is great news. I know you had a couple of other threads on the sound deadening, etc., but the pics there didn't make it obvious. At your leisure, can you post a pic that shows the general location of the amp and this harness (if you even have one handy)? Trying to figure out if I'm brave enough to start disassembly.

You should be able to just pop off the trim piece in the lower section of that rear quarter trim panel to access the amp wiring. I don't have a picture of how it attaches but it has 2 push in connectors toward the seat area and then pulls out forward once you pop out the front section. That is the only piece you should need to remove to access the amp wiring.

 

[Kaz]

Same view just with more stuff...stock sub and speakers are all removed, Audison amp and JL Audio FIX eventually mounted where sub was -

 

[Medic518]

Based on the wiring diagram posted further up, I don’t think that wire generates the sound. I think that wire communicates engine RPM to the amp, so the amp knows what frequency to inject. By disconnecting the wire, the amp thinks the engine is stopped.

Wasn't me asking about the fart noises - but my question still stands, if the frequency is not being injected could the music signal have more power available, and hopefully better volume control?

 

[Kaz]

oh also, in case any of you go cave diving into this, this weekend...there are three wire terminals that go into the stock black amp. Two of them are power, they send signal to the speakers and you'll see a bunch of bare wires converging into the terminal. The third one has two black wire looms and carry signal into the amp...the green wire is in that one, it's the only terminal with those two wire loom bundles covered in black. @docron

 

[675430VME]

oh also, in case any of you go cave diving into this, this weekend...there are three wire terminals that go into the stock black amp. Two of them are power, they send signal to the speakers and you'll see a bunch of bare wires converging into the terminal. The third one has two black wire looms and carry signal into the amp...the green wire is in that one, it's the only terminal with those two wire loom bundles covered in black. @docron

I did it, now it feels way better, even the oem stereo sounds better. However I think there are still some fake noise coming from other speakers, I wonder if there is another green wire from another amp that I could unplug.

 

[F1 SML8R]

As @Kaz suggested, I poked around in the electronics sub-forum and found the interior disassembly PDFs that someone else posted. I hope they don't mind me posting here for everyone's easy ref. Thanks again to all of you for "cracking the code" on this one. This is what car forums are about.

Cheers!