Help: Stock Bose: added DSP amps, Impendance?

[jjcuff1]

I have a M35 2007 with Navigation and Bose 8 speaker setup.
I replaced all speakers with infinity 2ohm compnents in front and shallow mounts in back
I added a alpine amp a while back and line-out to a kicker box. Great sounding but the bass overpowered the HU and the infinity and sounded like mud.
Then added alpine 4ch with audio control LC8i DSP for the lineout and signal leveling and powered the infinities. Sounded great like a new aftermarket headunit and bass kicks but I thought I was crazy, but kept hearing phasing.

as days went on I confirmed that random speakers would drop out, at low volume espcially or over bumps, then pop back on. I thought I had blown channels on the stock amp feeding the audio so I bypassed them. Long story short I had, at one point, run my whole stereo afrom just one channel (left front and split with rca) to all 4 and randomly any speaker could drop out then pop back on. They didnot sound blown either they would just drop out then sound fine.

So I determined that the amp can not be blown (at least) not all the channels. Since if I run one channel to all 4 and still only 1 speaker drops out WTF. So I figured it was the speaker connections. all 4 though really loose? Anyway. the Audio control has a iphone rca input. So it bypass the amp input. I plug my iphone and the system rocks! all 4 speakers bumps turns whatever never cut off randomly. Back to the head unit and it happens. Although the headunit sounds better when all 4 are playing. cleaner and more stereo effect.

One last piece to the puzzle. When the speakers drop out (any or all) If I turn the volume up to say 30-50% the speakers turn back on.

I am thinking I have an impendance problem. Does the factory amp sense impedance on the output and cut signal to protect the hardware? Since it is going to a DSP now maybe, based on the music level and the bumps cause speakers to randomly ground & discharged what little capacitance they have in the amp&wires that they drop out. Little bump in volume and they output again?

[svard75]

Were you using the speaker out from the stock amp? I would subscribe to alldata just the have a look at the stock amp schematics. Using high level outs for input is no good. Since you still want to use the factory amp for things such as nav and telephone and since it only uses one speaker leave the factory amp connected to that one speaker (drivers midbass). Then find the low level ins from the hu to the amp and tap RCA into that for your new system. The only thing is you may need to have a diode connected to the factory speaker just in case if something feeds both so you don't create a loop with two amps.

[jjcuff1]

I had a shop do it. I think he used the stock amp putputs. Just like we did for the sub. There are 6 channels out from the stock amp.

sub 1
midbass 1
fronts 2
rears. 2

I think from the headunit there are only 3 leads. The stock amp does its own DSP and splitting?

[svard75]

Shops don't always know what their doing. Try alldata to figure out the low level outs from the hu.

[svard75]

Don't know if this will help but on the 06 m35 the leads from the audio control unit is 4 wires. On the amp side it's pins 9,10,29 and 30. Try and tap into these wires and see if you get line level.

[jjcuff1]

Thanks nice thing with lc8i it can take 2 channels and make it 8 seperte.


So where are these pins/leads? Under the driver trunk goong to amp or behind head unit in dash?

[svard75]

Been thinking about something I read where a guy with an m37 was attempting to do the same as you and he tried to use the line out from the head unit. Issue is there are two different line inputs depending on your system. If you have the entertainment with a DVD in the armrest then there's A four channel for the main audio unit and a separate 5.1 from the DVD. He also mentioned that he found an issue where the signal from any of these two sources was the same regardless of the volume adjustments which means the amplifier also contains a sort of bus that tells the amp to increase volume when the head units knob is turned.

This poses an issue and unfortunately the only way to accommodate it is with a line level converter for each channel or buy a booster amp for each speaker as this one http://www.qualitycaraudio.com/store/vi ... duct=21191

[svard75]

What you have there is a good unit a d should do the job. Did you line level match this unit?


Level matching is a breeze
AudioControl couldn't make it much easier to set up your system. Just set your factory stereo to about 3/4 of its maximum volume, and turn the output level controls of the LC8i until the "Maximized" light begins to flicker. Adjust the gain controls on your amps and you're done. You've just matched your levels, so you can count on getting maximum performance and minimum noise from your amp setup.

[svard75]

Sorry to post so many times but I also thought about what you said where speakers would cut out while going over bumps. There is a setting in the oem hu that increases the bass when exterior noise increases. This is based on a microphone mounted to the steering column. I think it's noise cancelation or something like that. Turn that junk off so the Bose amp doesn't overload your line driver.

[midnightclub619]

Been thinking about something I read where a guy with an m37 was attempting to do the same as you and he tried to use the line out from the head unit. Issue is there are two different line inputs depending on your system. If you have the entertainment with a DVD in the armrest then there's A four channel for the main audio unit and a separate 5.1 from the DVD. He also mentioned that he found an issue where the signal from any of these two sources was the same regardless of the volume adjustments which means the amplifier also contains a sort of bus that tells the amp to increase volume when the head units knob is turned.

This poses an issue and unfortunately the only way to accommodate it is with a line level converter for each channel or buy a booster amp for each speaker as this one http://www.qualitycaraudio.com/store/vi ... duct=21191

Question on this - I have a Audio Control LC7i and I hooked up the input coming from the radio to the LC7i and completely bypassing the factory Bose amp, but now I can't turn the volume up or down. The volume stays at a specific level and can't be changed. I have this going to an after market amp. Would the LC7i correct this? Thanks for your help

[TDot]

Sounds like you have shorts going from the head unit/oem amp to the after market stuff. Or the lc8i component is bad on the input line. Check if the connections are twisted and taped or soldered going to the input. If they are, you can test the lc8i by plugging your iPod in the speaker level input by stripping the RCA wires you have and see what happens.

[jjcuff1]

Hi

Still have the problem. All 4 speakers randomly cut out or about 99% volume drop. the rear ones also crackle a little like distort sound blown. but if I go over a bump or turn hard they pop back on like nothing was wrong. So annoying.
I also notice my bluetooth is horrible now for users on other end of the call. they get so much echo. But in past I have fixed the cut outs by moving the wires going from the HU to the stock amp.

Now if I plug directly into the LC8i with my iphone. The stereo rocks all 4 speakers play loud and clear bumps or not.

[psyopper]

By plugging your iPhone directly into the LC8i you've completely bypassed the head unit - this effectively tests all of the wiring and connections from the LC8i to your speakers (which work fine) and isolates the problem to something *before* the LC8i. I'll bet you have a loose wire/connection somewhere between the head unit and the LC8i, or a loose ground off of the head unit. When you hit a bump it jiggles and looses the connection, and a different bump reconnects it. I'd work backwards from the DSP, my money is on something connected directly to the back of the head unit.

[jjcuff1]

I am starting to suspect the HU itself. I removed the wire harness and traced back to the LC* and all seems fine did trace and remove and reinstall still same issues. has to be HU to Stock Amp. Also the Bluetooth is a tell. Once I jiggled things and got it to work, people reported that my Bluetooth sound perfect, then wham it went away again and the middle bose speaker sounds horrible with iPhone calls. crackles and requires 90% volume.
the Middle speaker is 100% stock. the wires were not cut bypasssed or ampped. it just goes through the stock amp then to the speaker. so it is either a short inside the amp that is getting bumped or crazy ground that is shorting.

[midnightclub619]

What I haven't done is connect the Mic or the Voice Guidance yet to the LC7i yet. I've been researching and looks like this might remedy the problem. I will try this tonight. If there is a bus connection that is controlled by the stock Bose amp, would anyone know how to redirect that, if even possible?

[jjcuff1]

I didn't know I can input the mic into the lc8i?

My concern with Bluetooth. I wonder if I am part of the TSB I heard people say that infinti will repair? I have the mic above my head and I think there is one under the wheel. I suspect one or both are blown or because of my ground issue, the reverb/noise cancelling gets housed to the other caller. Now the sound to me sounds perfect. it goes thru the stock center channel untouched by lc8i. Sounds great when it is doesn't short and sound volume is very low.

I thought that the center channel can not be ammped or bypassed unlike the other speakers.

[midnightclub619]

True. I haven't touched the center channel. That is still hooked up to the stock Bose amp. But since I completely diverted the audio signal to the LC7i there is no audio going to the center channel anymore. The sound is going to my door speakers via LC7i and after market amp. This is where I'm running into my problem. The volume is at a certain level which I can control thru the gains of the 4 channel amp I have but thats it. I can't control the volume from the oem radio anymore, which is frustrating.

[jjcuff1]

OK I hear you similar situation:

I use the line level remote for the lc8i to control the line level of the subwoofer amp and it allows me to select either the stock HU as the signal or the iphone. Which I then need to have plugged in via headphone jack, annoying and ugly. Thensound and music requires using the iphone. Which is unsafe and difficult. I do have to turn the HU off though because the center channel still is active and will play what is on.

I was thinking maybe that is not bad if:

I use just the stock center channel for voice and phone calls (when it works and not sound like crap)
then wire in a bluetooth dongle in teh trunk to the lc8 rca inputs.

3 mount my iphone or table convenient spot near dash or even in front of the HU screen and us that to control volume and switch while I drive, then if phone calls come in switch to HU


These OEM HU are so integrated all this technology is coming to a head. pretty soon they have to separate the HU from the car and allow upgrades otherwise it is ridiculous. I love my m but have to sell it if I want my phone to work and use the OEM controls for hvac. The m35 stereo is so bad, worse ever I have heard but didn't think it would be this unreliable just having the stock amp in line. It is so bad! the noise canceling and sound quality.

It would be great if all future touch HU from the OEM had HDMI/USB aux inputs or something. SO if you decide to run aftermarket head unit it will not have a display, just be a black box with compatible protocols and it will input into the stock screen HU like a home tv. then you switch inputs and whatever your black box stereo outputs is displayed on the screen to control it for stereo outputs to your amps.

I know there is a companythat sells an overlay for our screens thats converts it to a touch screen and video input. So we can input our iphone or tablet signal with touch screen to the LCD display then you can control volume/songs from teh touch screen like it was your phone.

Still need to have iphone output to amps.

My phone output is very low. it is clean but I have to keep it at 8-10 clicks to hear it clean there is no low setting just loud and loudest

[midnightclub619]

Yeah, I see your situation. I'm going to try to hook up the rest tonight to see what happens. I will post results tonight

[midnightclub619]

So it looks like there is a a bus connection within the amp. I had to redo all the wiring from the stock Bose amp that I originally had. From the amp speaker connections (2 brown harnesses) I had to tap into the outgoing speaker leads. You still have to tap into the remote wire (solid brown on white harness). Other than that, all the leads for the speakers go to your LC7i, including the sub (if you have aftermarket or stock to use) then to your after market amp.

So the order is as follows:

stock Bose amp > LC7i > after market amp.

I'm going to write a review on my install for those that could use it. Hope this helps

[jjcuff1]

I didnt realize you were talking about how to hook up the lc7i. Sorry I thought you had it installed,like mine, and was having issues with using the line aux.

The install is straight forward, mine sites on the drivers side fender liner to the left of the trunk. I spliced into the 2 brown harness located right above the deck on the drivers side. the stock amps speaker outs. they feed into the lc8i and then to the amp. Typical line level setup.

The issue I have is the outputs form the stock amp. even after I adjusted the lc8 I have shorts cli[p outs etc I suspect it is the impedance of the stock system and the new install. it only got very bad after I amped the speakers. I had an amp on the sub before and it was no problem.


one thing that is very weird: the bass signal only comes from the back speakers. Even though I was hoping the lc8i would as they told me would normalize all the signals into full range so I can have a true balance it doesnt work.

the rear speakers clip out and distort bad when I listen to the HU. I am happy just using the front channels, but when I fade to the front all the bass is gone.

another weird thing. When I do the infiniti oem audio test for all the speakers. The bass signal only comes out of the front drivers mid. Shouldn't it come from the rear sub?

Again, I wish I could completely rip out the stock amp but that has the speaker outs, nav and phone functionality not the stock radio correct? is there a way to take the bus from the stock HU and convert direct into a LC8i?

[midnightclub619]

Yeah, I was talking about hooking up the LC7i. I was trying to bypass the Bose amp completely but that was a failure. If it wasn't for that bus connection everything would've been perfect. That would've been the cleanest signal from the stock HU. So had to revert back to the bose amp for the audio signal. I haven't tuned up the speakers yet bc it got really late, I'll be doing that tonight so I don't know if I'm having that problem yet. I'll find out tonight. I'll do the oem audio test also see what kind of results I get.

Ripping out the stock amp is almost possible bc I was able to bypass it but the bus connection was the brick wall. I tapped the audio signals that was being sent to the amp. They are practically RCA's from the HU. But when I turned everything on, I had no control over the volume bc of the bus connection on the amp. So had to revert back to the normal line level install. I followed the FSM and was able to determine the audio signal, Mic & Voice Guidance lines but if I can't control the volume from the stock HU then there was no point. I didn't know if its even possible to bypass the bus connection any other way outside of the bose amp.

[jjcuff1]

Back to my earlier point. Between the broken bluetooth, unreplacable amp and aging interface I love the car but not dropping any more into just buy a newer car to get what I want.

The line level lc81 setup is relay nice and clean but compared to my other aftermarkets it is doesn't compare nothing seems powerful or super crips when at normal volumes like a real aftermarket HU where you just listen and go wow that sounds awesome.

add to that the you cannot hook up any iphone wire or bluetooth that has any sound volume or any sort of legal controls to use the HU.

[midnightclub619]

Yeah, I totally agree. Once I'm done with this install I won't need anything else for a while. That is until its time for me to get a new car. but that won't be for a while.

What are you using for your iPhone & Bluetooth?

[midnightclub619]

So I was able to complete the install and I am having the same issues as you are. Once I begin to turn the volume, only the front speakers clip out and only the rear speakers and sub are working. I didn't get a chance to line level match as mentioned above. I'll try that tomorrow. Other than that I haven't noticed the rear speakers clip out. I hope this is the extent of my issues.

[jjcuff1]

The line level didn't do much for me other then set gain for the amps. Maybe your gain is off then it will clip the signal. Mine are clipping per see but not in pairs. I pulled the bus and checked wires to lc8 and back to speakers and like I mentioned earlier with ipod the speakers work but so weird that with HU the rear speaker sounds and acts blow

I think in general, lc8i or not, the impedance to the stock amp is key. Without the right speaker load the stock hu compensates its output which in turn effects and vary the quality to the amps. If I crank the volume up I can get all the speakers to pop back on and it works till the next bump.

i think the stock HU is building capacitance. If I crank the volume up it builds it faster, thereby changing the impedance it sees and then outputs the line level signal until I hit a bump, then the capacitance discharges and it repeats. The question is wher ein the amp can this occur?

I am wondering if it is the volume control signal, maybe that board is fried and then shorts out for each speaker. I assume the volume control isnt a true fade/balance from the HU but some A/D output for each channel. maybe one of the modules is fried.

I have seen replacement amps online but so much money. Wonder if local shop can repair properly or test.

What about your audio test do all speakers get the right signal? the bass?

I removed my stock sub.

[midnightclub619]

Ok.

I did the speaker test and sound was only coming out of the left speakers so I started from the LC7i and found the problem.

So I solved it. Apparently, I had some speaker wires exposed on the LC7i that were touching each other. Once I fixed that problem, full sound out of all my speakers! Finally! All door speakers and my sub sound great now. I hope it stays this way.

I also removed my stock sub.

Next project is to get my Parrot bluetooth kit to work

[jjcuff1]

Interesting. I listened some more this weekend and the Sub signal plays thru the front left. i wonder if I have a cross/short somewhere and could be a cause of all the clipping.

The rear driver speaker I suspect is not only clipping but is also blown as it distorts and cracks now 100% of the time.

I have a isimple iphone hook that goes into the sat link, and my sub at first was hooked up to the rear sub with a line converted. I wonder if any of those connection are shorting? I will double check those and probably remove the isimple since I never use it anymore

[midnightclub619]

I did the speaker test and all sound is working properly as it should.

for the clipping issue, I would check all the wiring from the amp to the LOC you have. Did you go by the FSM for the wiring diagram/colors?

The sub has its own wires from the amp. I used the sub out from the stock amp for the sub channel. I was going to use the rear outs for the sub channel but changed my mind at the last minute and just one for one with the wiring and speakers leads.

Like you mentioned there could possibly be a short somewhere between the stock amp and the LOC. Or possibly from the LOC to your after market amp. Hard to say tho. A short was my problem and once I pinpointed the short and corrected it, I didn't have anymore issues with that.

[jjcuff1]

OK I spent all day Saturday going through my system. I had several issues that combined for many problems:
I basically had front passenger and rear drivere speaking cutting on/off uslaly over bumps but occasoinally even the other speakers would drop to 5% volume. very frustrating and annoying harmonics when speakers randomly cutting on/off. Sub seem to always work BUT the sub signal strictly only works when I have the rear speakers on. If I try to fade out the rears I have no sub signal. I had horrible echo on bluetooth to the other users when on phone. It would go away when all speakers eem to work but if they were cutting on off, the center channel would also clip on/off

so
1: the battery terminal was very loose
2: The Ohms to ground between the audiocontrol and the alpine amps and stock amp was over 20ohms!
3: The front passenger crossover terminal blocks were stripped all wire leads were falling out
4: The driver rear speaker I tested with 3 speakers and dindt seem blow but I replaced both rears with kickers
5: the RCA jacks for the front and rear drivers side at the alpine were loose and worn.


so after all that the system worked great, sounded loud and hit and the bluetooth phone had no problems sounded goo to other end. All for about 3 days. Then some bumps and drives and rear left speaker cut out again and the blue tooth got worse.

Good News. It seems the other 3 speakers/channels all appear to work and no longer are cutting on off because of I fixed other issues. But I narrowed the main culprit to the rear left channel. So as a test I split the rear right channel to both left and right. The stereo sound very clear and all 4 speakers but the bluetooth was bad and I had no bass.

So now I am wondering WTF? It seems without the rear left channel plug in I have no bass signal yet that appears to be the blown channel. I am wondering if the sub installer ran the sub off the rear left speaker? BUT odd thing is I have the sub amp hooked up to the sub outputs and its own RCA and without those hooked up I get no sub signal at all I do not understand why both signals need ot be hooked up to get a signal. Otehr thing is maybe that channel has a ground short since when I leave the RCA unplugged is when all bass and phone messes up. that is ground issue for sure.

I will trace the rear left to the sub and stock amp make sure sub has its own signal
possibly run new speaker lead to that channel from stock amp to lc8
I do not think it is in the wiring to the door speaker but at the stock amp. I will bypass stock ammp to check the speaker
worse case: I will resistor shunt out the left channel at the lc8i output. maybe with no load it is getting goofy. and see if base comes back and I can still bypass it with the right channel

Anyone have there stock amp repaired or replaced?