cocadave

That’s a fantastic write up of what you have done so far, really looking forward to getting my setup started soon and will learn from what you are doing.

great read

h3rmes

Looking forward to your project! This SUV can really sound great! Wanted the Audi World community to realize some great sound quality potential of this gracefully aging 4L platform.

cocadave

at the moment I’ve just added a sub but having issues with it, my plan is upgrade the speakers and possibly the amp to get some proper good quality sounds but at the moment I’m struggling to get the sub performing.

it may be the amp not able to dish it out but I m not sure, I need to do some tests and found out exactly what’s going on first.

h3rmes

I am curious, did you tap high level speaker outs for the amplifier? For the Q7 4L you have a few choices. There is the subwoofer pin outs from the Bose amp and there is the front woofer pin outs from the Bose amp that could be used. Aside from the crazy wiring overall on the Audi Q7 4L, you should be able to get a lo frequency speaker signal.

Another option is to get an Audio Control Line Output Converter (LOC). Something like the LC2i. The logic of the Bose amplifier dictates that at a certain volume level, there is low frequency roll off to prevent the amplifier from overloading. The Audio Control LOC will deconstruct the low frequency signal and add bass when roll off is detected. They call this Accubass. There have been good results with Accubass in situations where there is a bass roll off initiated by the amplifier through the DSP programming.



Cheers!

cocadave

I tapped the rear sub wires to get a hi level feed into a cheapo LOC, can’t remember the name but only cost a few £’s so nothing special about it.

I first stumbled when I couldn’t figure out what the amp needed to use the feed, the LOC has both left and right inputs as well as left and right outputs so I was thinking for the sub to create a bridged output (L+/R-) to give out max available power both inputs needed to be used but with only one source I first tried a single channel which didn’t work but this was due to the sub being wired incorrectly, the sub is an older version Alpine type R dual voice coil, think it’s the 1243d but might be mistaken, anyways the sun has been removed from the enclosure for a couple of years and moved about and just had the jumper inserted into the wrong connection so didn’t produce anything at all, I’m discovered this and corrected the wiring which then produced bass, I’m the mean time I had tried splicing the left and right inputs to the LOC thinking this might help but I never noticed any change whatsoever in using a single feed in or both.

I then tried to use the feed from the rear shelf loudspeakers, both left and right to try achieve a 2 channel source but this was absolutely terrible with almost zero bass coming from the sub.

So going from what you state above, there will only be bass available if you tap from a sub feed which makes perfect sense as to why tapping off the rear shelf didn’t give good results?

I can’t remember how I left it configured, single or both channels being used, I suspect it’s both.

my issue is that as you crank up the volume the bass decreases, you mention above about bass roll off, I believe this is what I am experiencing?

I thought I was going crazy when I realised what was going on, I googled it and found nothing, probably would have if I had used the correct name for it so thank you very much for mentioning it.

Have another issue too but unsure 🫤 f it’s to do with the LOC I am using or just overloading the amp until it cuts out, I don’t think so as the bass seems much deeper when on low volumes than high and of the above I’d rolling back the output then the input should be less too? Basically when I have it past 21 on the volume scale with any bass musivf the amp/sub cuts out until the bass/beat has passed then cuts back in, if it’s a solid bass song then it cuts out for longer durations, if it’s just the odd beat then it’s normally a couple of seconds before it kicks back in again.

I think I’ll try an LCi2 and go from there.

Thanks for sharing your experience, I’m sure there’s lots of people out there in similar situations.

h3rmes

Folks,

I wanted to update the community on this installation. AudioControl LC-4.800 is was spectacular success. The front Hertz Cento Coaxials were able to manage a bridged amplifier output of over 400 watts RMS. Mind you they are only rated for 210 watt peaks. Thankfully AudioControl kicked in a safety circuit to prevent me from doing other stupid things.

The Coaxials work fine with the factory mid and tweeter. The factory head unit is only powering the front mids, center, and tweeters. With a 30 amp fuse, this is plenty of factory power for the speakers. The AudioControl controls the front lower door panel Coaxial speakers and the rear door panel speakers. The high pass crossovers are set at 80Hz.

On another note, the factory head unit is actually in the rear hatch on the right side. I also discovered that I do not have a Bose amplifier. Although, I had to look up a new wiring diagram, this is considered Audi Standard audio and is far simpler to work with than the Bose amplifier. I had my wires spliced in no time.

The JBL Basspro is really a charming addition to the the setup. It is good subwoofer that goes down to 30Hz. I have it set to the low pass crossover to the THX standard of 80Hz.

Overall, at low volumes, the musicality of this configuration is outstanding. Excellent musical separation of acoustic instruments such as guitar, piano, trumpet, and vocals.

Overall, at high volumes, the setup gives you a endorphin rush in your head, and isn't deafening. This is loud without harshness.

Mind you my volume **** is never passed 1/3 when I say high volume. I am sure I can got 2/3 without any fear of clipping. There is an enormous amount of power in reserve and these Centos love gobbling up all that power!

Let us now perform an economics discussion of this upgrade:

$600 4 Cento Coaxial Speakers

$700 1 AudioControl Amplifer

$500 1 JBL BassPro Subwoofer

$200 Various wiring such as positaps and longer wire and speaker leads etc.

Total=$2000

Current price Bang & Olufsen Audi Q7 Option $5000.

It is clear that it is unwise to choose a factory radio upgrade option vs. aftermarket. Lesson learned = simplicity in the options list saves money and sounds better.

Cheers!

Audio Control

Factory Head Unit

Subwoofer

cocadave

Hey Hermes, great write-up and glad you're happy with your efforts.

Can I ask what you have the line outputs going to?

Also, how many speakers did your system have as standard?

h3rmes

The line output converter (LOC) which is built into the LC 4.800 is providing a low level output to the RCA audio cables to the JBL Bass Pro subwoofer. The source of this signal is the factory radio. The factory radio sends a single (-) and (+) single to the front kick panel speakers located at the bottom of the Audi Q7 front doors left and right. The speakers are wired at the factory to take the single signal and divide it between two speakers located on the left and right. I believe it is wired in parallel.

The Audi Standard audio system consist of:

3 - 2 3/4" midrange speakers across the front dash.

2 - tweeters in each door sail panel

2 - 7 3/4" woofer in the front bottom of each door

2 - tweeters one located on the rear door

2 - 6.5" full range speaker on each rear door

A total of 11 speakers.

I may upgrade the 2 3/4 inch speakers with AudioFrog GS25:

cocadave

so you have speaker output wires used as hi-level input into the lc4-800 and then rca cables going to a secondary amp and sub? (the jbl in the wheel well)

If this is the case then you don’t use to the factory sub for signal to the added sub?

h3rmes

Yes. Hi Level Speaker Level inputs were used for the lc4800.

I changed the configuration of the jbl bass pro to hi level.speaker inputs as well.

The RCA low level signal from the lc 4800 was perhaps too low level. I had to turn up the gain and bass boost almost halfway (12tpm) to hear the sub from the front driver's seat.

Also the sub amp presented.a parasitic drain on my battery since it requires a remote wire with the RCAs.

Splicing into the hi level signals for the front kick panel woofers yielded a significant bump up of the JBL Bass Pro bass response. I have the gain at 9pm instead of 12pm. No bass boost is necessary.

Also the parasitic drain on the battery is now gone.

I would have preferred to use the LOC on the LC 4800, however, since my Q7 is an everyday driver, I did not have time to adjust the settings to the way I would have liked since it caused the parasitic battery drain.

There has got to be a way to wire a remote relay on the Audi Q7, but thus far, I have been unsuccessful.

Cheers!