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In my Q7 2015, I have a MMI 3G system without Navigation. The amp in the right rear hatch is a 38 pin unit. It is not Bose and it does not have a Bose subwoofer in the tire compartment. I placed a JBL Bass Pro sub there. In the right side of the hatch, near the bottom of the fuse box array, I have a receiver module with a Quad Lock 40 pin connector. It is true that the MMI controller in the front center of the Q7 has no copper low level outputs.
I believe the receiver radio in the hatch does have low level outputs for the Q7, but not in the D4 Audi A8.
Academically this may be irrelevant as the Q7 does not have a switched 12V line so there is no remote wire to use. I used hi level outputs from the factory amp to the Mille amp, which senses hi level input and auto turns on.
For the 3G era, the navigation systems are pretty straight-forward. MMI navigation was MMI 3G Basic (BNav...) and MMI navigation plus was MMI 3G High (HNav). Then MM navigation plus moved to the Internet connected update, MMI 3G+ (HN+). These are all MOST (optical ring) based systems.
The non-navigation systems are more of a mixed bag. The B8 used Chorus/Concert/Symphony head units; these used copper low level lines if an external amp was present. The C7 used RMC MOST (RMC) under the term MMI radio and MMI radio plus, and even for MMI navigation. Only MMI navigation plus used actual HN+. There was also RMC CAN (not optical), but that was only used in the VW clones it seems. I suspect the 4L Q7, at least for facelift, also used RMC MOST for the non-navigation tier. But other information implies 4L used MMI 3G Basic pre-facelift and then MMI 3G Basic plus (?) for facelift. Would need to see the software revision string to guess more specifically.
But of all the systems, the only one with intended copper low level signal lines is the B8 Concert head unit (Chorus not used in the US; Symphony only for MY09).
The nature of the output signal from the Bose amp would probably need to be better understood to determine how to better match it to the aftermarket system. It's likely the input converter on the Pioneer is not very good. More likely, all the "auto-sense" aspects just always bug me. Is it kicking back and forth between on and off (it doesn't need the remote turn-on lead in high input mode), is it kicking back and forth between low and high input mode, etc. I prefer hard set things.
You did try moving the gain control up to see if it produced a matched output level at some point? Starting it at min was just that, a starting point so nothing too undesired boomed on initial start.
That Pioneer amp has a low pass crossover as well; the output from the Bose amp is already crossed over, so you'd want to disable/bypass any crossover on the amp or set it as high as possible.
The D4.0 Bose sub was originally 4H0 035 481 A. Starting Feb 20 '12, the PR-EP1 option (ANC Active Noise Cancellation) was introduced. For EP0, the original sub was still used. For EP1 ANC installations, new sub 4H1 035 481 was introduced. This is the one with the additional ground line to the chassis. I find images of both subs with a Bose sticker on them, specifying: 10", 160W, 3.2Ω. 160W into 3.2Ω should be 22.6Vac. But audio signals are complicated constructs, and speakers are far from pure resistive DC loads. And who plays continuously at the edge of overload.
I didn't find any posts offhand re D4 or C7 Bose sub modifications that seemed to imply and particular hardship running the speaker level connections into an external LOC or amp, but didn't look extensively.
In my Q7 2015, I have a MMI 3G system without Navigation. The amp in the right rear hatch is a 38 pin unit. It is not Bose and it does not have a Bose subwoofer in the tire compartment. I placed a JBL Bass Pro sub there. In the right side of the hatch, near the bottom of the fuse box array, I have a receiver module with a Quad Lock 40 pin connector. It is true that the MMI controller in the front center of the Q7 has no copper low level outputs.
I believe the receiver radio in the hatch does have low level outputs for the Q7, but not in the D4 Audi A8.
Academically this may be irrelevant as the Q7 does not have a switched 12V line so there is no remote wire to use. I used hi level outputs from the factory amp to the Mille amp, which senses hi level input and auto turns on.
Originally Posted by SMac770
For the 3G era, the navigation systems are pretty straight-forward. MMI navigation was MMI 3G Basic (BNav...) and MMI navigation plus was MMI 3G High (HNav). Then MM navigation plus moved to the Internet connected update, MMI 3G+ (HN+). These are all MOST (optical ring) based systems.
The non-navigation systems are more of a mixed bag. The B8 used Chorus/Concert/Symphony head units; these used copper low level lines if an external amp was present. The C7 used RMC MOST (RMC) under the term MMI radio and MMI radio plus, and even for MMI navigation. Only MMI navigation plus used actual HN+. There was also RMC CAN (not optical), but that was only used in the VW clones it seems. I suspect the 4L Q7, at least for facelift, also used RMC MOST for the non-navigation tier. But other information implies 4L used MMI 3G Basic pre-facelift and then MMI 3G Basic plus (?) for facelift. Would need to see the software revision string to guess more specifically.
But of all the systems, the only one with intended copper low level signal lines is the B8 Concert head unit (Chorus not used in the US; Symphony only for MY09).
The nature of the output signal from the Bose amp would probably need to be better understood to determine how to better match it to the aftermarket system. It's likely the input converter on the Pioneer is not very good. More likely, all the "auto-sense" aspects just always bug me. Is it kicking back and forth between on and off (it doesn't need the remote turn-on lead in high input mode), is it kicking back and forth between low and high input mode, etc. I prefer hard set things.
You did try moving the gain control up to see if it produced a matched output level at some point? Starting it at min was just that, a starting point so nothing too undesired boomed on initial start.
That Pioneer amp has a low pass crossover as well; the output from the Bose amp is already crossed over, so you'd want to disable/bypass any crossover on the amp or set it as high as possible.
The D4.0 Bose sub was originally 4H0 035 481 A. Starting Feb 20 '12, the PR-EP1 option (ANC Active Noise Cancellation) was introduced. For EP0, the original sub was still used. For EP1 ANC installations, new sub 4H1 035 481 was introduced. This is the one with the additional ground line to the chassis. I find images of both subs with a Bose sticker on them, specifying: 10", 160W, 3.2Ω. 160W into 3.2Ω should be 22.6Vac. But audio signals are complicated constructs, and speakers are far from pure resistive DC loads. And who plays continuously at the edge of overload.
I didn't find any posts offhand re D4 or C7 Bose sub modifications that seemed to imply and particular hardship running the speaker level connections into an external LOC or amp, but didn't look extensively.
Sorry for replying sooner, I have been very busy with car off road for nearly a week due to changing my bushes and work.
The sub only produces anything worthwhile listening to when it is connected via the LOC, the bass is deep and strong but once the volume level is turned up to 17 or higher with any music that has long and deep bass (max is 35) the amp cannot handle it and cuts out until either the bass has passed or the volume is turned down, I'm not sure if this is what is called 'clipping' or if it's just that the amp cannot handle the increased input from the LOC, I don't think it would be the sub as the rated performance I expect is way higher than the amp...
Matching these kinds of electronic signals is always a trial and error. Just the way of things when there's not hard set standards. So appears simply the high-input mechanism on the Pioneer amp is not a good match to the Bose amp output. Ok, so a LOC in between. It's all about level matching. I don't have those units in hand to experiment with to see what level settings on the amp gain and the LOC gain would be optimal. They just have to be played with.
As to why the amp is cutting out, that would require actually throwing tools on the situation to diagnose what's actually going on. Is the amp going into thermal protection, or some other kind of protection. Is the signal from the LOC actually clipped or a fine sine wave, or maybe the LOC is cutting out. Maybe the amp is having an internal issue. It's too random to speculate without "hands on playing with it to see where the observations go". Is how I wing that kind of work. :-)
Matching these kinds of electronic signals is always a trial and error. Just the way of things when there's not hard set standards. So appears simply the high-input mechanism on the Pioneer amp is not a good match to the Bose amp output. Ok, so a LOC in between. It's all about level matching. I don't have those units in hand to experiment with to see what level settings on the amp gain and the LOC gain would be optimal. They just have to be played with.
As to why the amp is cutting out, that would require actually throwing tools on the situation to diagnose what's actually going on. Is the amp going into thermal protection, or some other kind of protection. Is the signal from the LOC actually clipped or a fine sine wave, or maybe the LOC is cutting out. Maybe the amp is having an internal issue. It's too random to speculate without "hands on playing with it to see where the observations go". Is how I wing that kind of work. :-)
Looks like I will have to play around and see if I can spot what is actually happening, I'm assuming I might be able to see the protection light come on or off if its going into protection mode but thinking about it it think if it was protecting itself it should take longer or more of an intervention than just turning the volume or bass down for it to kick back in though?
So, not much to update other than what Hermes has said on another thread about the Bose amp 'Rolling back' the bass as the volume is increased in order to protect the system, solution appears to be to install a new LOC like this one
Well Christmas is just around the corner...
Hopefully this will solve at least One of my problems, If I am lucky it will solve both.
Just been looking into how the wiring for the LC2i goes and it seems they bridge the input signals as below, think I might give this a go on my LOC and see if I anything improves.
I have looked into the LOC I am suing and looked at the specs which state it can only handle 30w per channel input only, I'm pretty sure the Bose output would be way more than that given I think the sub is rated to around 300w?
Looking at the above I would say it is way out of its depth connected to the Bose system, can anyone advise?
"W/ch" seems like a bad way to rate the input spec. The LOC should have very high input resistance, minimizing current and therefore power. What it should care about more is the AC voltage levels. You can't know voltage from a wattage number without an impedance value. But yes, I'm not particularly impressed. www.inphaseaudio.co.uk, site isn't even working. And they call them frequency converters instead of voltage converters, haha. The 6-ch one at least is a little better documented, https://www.caraudiocentre.co.uk/pro...c6_p-27541.htm , "Max Speaker input 60 watts @ 4 Ohm". So assuming the SRCA Pro and SRCR Bass would be similarly spec'd if fully qualified, yes, definitely too much power on that Bose sub channel for them.
10-24-2022, 03:15 PM
Not Necessarily
