A4 B7 Cab Audio Upgrade...

I'm planning to upgrade the speakers in my 2007 A4 cab, I haven't got BOSE and I'm wanting to keep the stock HU as I prefer the OEM look in the dash.

Want to upgrade front door speakers and the rear panel speakers, plus hopefully a sub in the ski pass space between the rear seats. I'm trying to avoid using additional amps for the speakers, as a result I am looking at some alpine speakers which are relatively low power (25watt RMS) also shallow mount so should fit in the standard spaces and also be ok running off the factory HU. I'm not sure how to remove the front door cards but I'm pretty sure I'll be able to find a guide somewhere online, but if anyone has a link (have searched already but no joy so far), that'd be a great help! Once I've got them off I can confirm what size the speakers are (8" or 6.5"), as I haven't been able to find a conclusive answer about the cab speakers despite lots of searching.

Found out how to removed the rear panels so when I've got them off I can do the same with the rear speaker sizes and looks for a decent upgrade.

Next thing is the sub... having the sub itself exposed and facing into the cabin would be ideal (aesthetics and sound wise), so I'm looking at the Vibe Blackdeath square 6x9 'marine' sub. Already got a 700watt alpine d class amp so power isn't a problem. If I can remove the blackest I'm hoping to have it mounted on baffle board and use it as a free air sub. Spoken to the guys at vibe and as its basically the bass driver from their high power 6x9s that should work fine. Also means I will lose no space in the boot (small enough as it is) and will mount the amp behind/under the sub again in the ski pass space.

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Things I'm not sure on are:

1. If the rear speaker high level inputs will be sufficient for the amp (either straight in or VIA a high level converter)
2. Where to tap a remote turn on feed from to activate the amp, any help on this would be greatly appreciated.
3. How bad in reality are the stock speakers? I've heard far worse car stereos in my time and it sounds acceptable if its not too loud. Am I going to notice much of a difference if I'm JUST upgrading the speakers and not amping them?
4. Seemingly there are (in addition to the dash centre speaker) what I can only assume to be mid-range drivers in either side of the dash. Does anyone know how to remove/replace them and what size they are?
5. The impedance of the facotry speakers (again, NON-Bose). I think they are 4ohms but can anyone confirm that?

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When I get the required info and some free time I'll keep you posted on any progress.

Any input/thoughts/advice/suggestions/help is greatly appreciated!

Bump, especially for the front door cards...

Removed the rear door cards today and am now looking at the Infinity Kappa 50.9i components. 2ohms (factory are 3ohms), 2nd best low freq response I can find for the money and pretty low RMS power requirements... thinking of mounting the tweeters on the rear panels somewhere.

Had great results with infinity speakers in the past and will almost definitely be able to get the same range to match in the front.

Thanks AndyMac.

I found a guide (some kind of technical self teaching Audi guide) for the HU which I have but in an 07 TT, which said it used an external amp of 20watts x 2. Having been able to find NO info about it I'm guessing the a4 would be a 4 x 20watt amp somewhere.

The Headunit is an rns 5.0. If anyone knows the HU/amp specs and also where the amp is (if there is one)...

Also, no opinions etc on the proposed upgrade??

Thanks again Andy. Audi near enough confirmed it when I popped in today (based on their apparent lack of knowledge about their systems?)

Can't seem to find any answer relating to upgrading to the Infinity speakers alone - some say you will lose mid-bass and speakers will be underpowered, others say they have had a great improvement over stock even without an aditional amp. Also cannot decide (if to replace the speakers) if it would be worth the effort to mount the separate tweeters in a component set in the rear rather than coaxials (coax have lower power req which is good if keeping stock HU etc).

As there is no pre-out from the HU, if I were to replace the 2-ch amp in the boot (assuming wiring is in place to just swap it with a new one) with a 4-ch amp to power all the speakers rather than 50/50 from the HU, how would I get the power from the new amp to the front speakers and by-pass the output from the HU??

So either way, if I'm going to amp all 4 speakers, I need to run wires to the front or to the rear and either tap into or replace the original wiring... this is turning out to be more work that I'd hoped. Unless I ran 2 2-channel amps...

I shall plan for the summer and get a 4 channel amp to replace the one in the boot, run the appropriate wiring from the stock HU and take a feed from the Quadlock connector. Replace the amp in the boot and run wires to the front speakers from there.

Thanks for your help Andy, if I ever get round to doing this I will start a thread lol

Still no further with speaker sizes. Until I physically hold it in my hand, I don't think I will know for sure. I'm hoping for 8" (20cm) in the front and 5 1/4" (13cm) in the rear.

Thanks to Gaz RE the front door panels, I'll whip one off when I get a free day and some consistent good weather!

With regards to the proposed build, had a few changes of approach, mainly due to wanting more functionality from the HU. Thinking of a Pioneer double-din touchscreen unit now, between £300-£400 so cheaper than the RNS-E (even with £70 wiring adaptors), much better connectivity and better functionality. This gives proper pre-outs and a 4 channel amp (50w) in the HU itself. This would mean I could run new speaker cable from the HU to the rear channels & upgrade the front & rear speakers, whilst using the Subwoofer pre-out to feed my mono amp in the boot (situated in place of the x2 20w amp previously used for the rear speakers... when I find it), to power the square 6x9 subwoofer in a custom box though the ski-pass!

The custom box will be made to have the 6x9 Vibe sub facing into the cabin:



You might notice the larger 'face' of the box (where the woofer will be mounted), the idea being this is the last piece to be installed and will make the enclosure fixed (unless face removed). This could either be an additional 'face' layer JUST to hold it in place, (in which case would provide a recess for the driver), or it could actually be the front of the box (driver attached directly to it). Probably trim the main body of the box in grey carpet, and the face in black so it blends with the interior (sub face is white for contrast).

Any thoughts on if this will/won't work??

I'm 99% sure the stock boot amp will not have the required gauge wiring for a 700w amp, so new power wires and RCA leads (unless I can utilise the feed from the quadlock connector to feed the mono amp...?).

Nice job! Have you done much fiberglass work before? I'm weary of using it to be honest, even though I've heard it's simple if you take your time and do it right.

The sub I have from a previous car is a 12", so I don't think I'd be able to get the enclosure size required (and possibly the driver) to fit into the space you've used. Also what I found really annoying about previous subwoofers is that it makes your boot lid rattle. Unlike chavs with corsas who think vibrating the the rear windscreen wiper off is cool, I didn't buy an Audi to be obnoxious! Dynamat may well solve this...

I thought having the driver facing into the cabin would give better sound and also look the dog's dandies... Would love to see/hear your install when finished! What amp are you planning to use? How are you going to connect it etc??

Does anyone know if the stock Audi rear amp has a normal +12v ignition switched feed I can tap to turn on my amp with the ignition?? Or is it all coded using the VAGCOM system like the headunit??

Right, well overdue on an update on this... but the good news is the subwoofer install is finished and working excellently

Box:

The original concept as above was changed slightly when I found that the height of the lip between the boot and the ski-pass hole was slightly less than the thickness of one sheet of MDF (15mm I think I used?). So instead of angling the ski pass section of the box upwards I used the base of the box in the boot as a mounting for the bottom of the ski pass section (glued and screwed down). Also managed to use the whole height of the ski pass section and make the box to fit the space.

Rough measurements are:

Boot Width = 89cm
Boot height (max under movable top) = 26cm
Depth of boot section to give approx 0.5cuft volume (internal) = 11.5cm
Front face height (approx) = 35cm
Ski pass section width = 23cm

When I first fitted a sheet of MDF cut to the boot width, it became apparent that there was a curvature in both corners, so rather than try to cut the side panels in the boot, I angles both the front corners of the box, cutting half of a 4cm x 4cm square from each corner. As the base was 100% flat, all other sections were fixed to this.

When it came to the front of the boot section (which sits next to the boot bulkhead), instead of having two pieces and a hole in the middle I decided to keep a strip at the top in the centre for strength (and practicality when lining things up). Again angling the corners, this time for strength as there would potentially be a lot of stress on that join. This meant that when I was making the sides of the ski-pass section the tops needed to be cut at a 45deg angle, which meant using a circular saw (as it’s the only thing I had which would cut at an angle). In the end this gave a really strong joint and the bigger surface area was good for sealing with glue.

The rest of the box was pretty straight forward. Measure twice, cut once was the theory, but attempt the pieces in situ after each attempt to check I was still on the right track. A few corrections here and there but nothing major. Braced the box with some cheap soft wood which came in a long strip, not being cut by me I knew it would be at a right angle

The whole box was made using a jigsaw, circular saw for the 45deg cuts, hacksaw for those awkward to reach places, drill (for pre-drilling the screw holes), counter sunk screws and a substantial amount of PVA wood glue!

Amp:

The OEM headunit (Audi Navigation 5.0) doesn’t have a pre-out, which meant using a hi-low converter and tapping directly into the speaker wires. For those who don't know, the converter takes the high powered signal from the speaker wires and converts it to a low power signal in the form of RCA connections. The converter I got (importantly) also had an automatic remote turn on connection, which activates a low current 12v output to turn on the amp when an output to the speakers is detected. So far I have noticed no lag in the stereo turning on and the sub kicking in which is a big plus!

Wiring was reasonably straight forward, standard battery lead through the bulkhead via a spare grommet and under the dash and tucked under the side trim. Same with the RCA & remote lead (opposite side of the car to avoid interference). One thing I decided to add was some red LEDs behind the driver (hence why you will see a double terminal post o the rear of the box). I hooked them up to the cigarette light feed because it was easy to get to, so that when the interior illumination is on (sidelights on) the subwoofer emits a subtle red glow. Some people may not like this but for the same reason I wanted a white sub not a black one is I want it to be noticeable as well as look neat and tidy.

When the wires reached the rear seat bench I fed them under and then behind the back rests, and carefully fed them around the side of the roll-over bars and into the boot.

Finishing Touches:

To make the box looks as discrete as possible, I wanted to keep a rear grey carpet, and the front face black leather. Leather is pretty expensive however, and I was able to get hold of an 'off-cut' of leather effect material for £5! I could do another 3 boxes with the amount I have left though... I didn’t see any point in spending time in covering the sides no one will ever see, plus the box was made to fit exactly in the space available, so putting a few mm of carpet on a few surfaces might have made it a tricky fit. Carpet & leather both attached using spray glue and a few staples on the edges to stop it peeling.

I secured the box in place using two 'L' shaped brackets which I cut down to size, and attached them to two of the bolts which were at the top of the ski pass tunnel. The middle of these three bolts was used as an earthing point for the amp.

For anyone who has removed the rear armrest in an A4 cab, you will know that there is a relatively unpleasant hole where the seat belts go. Originally I thought about gluing foam to the face of the box and fixing the leather over it, but when it came to it I got a polystyrene block from work, trimmed it down and covered it in the same leather material. I them wedged it under the front face of the box as a sort of 'elbow-rest'. It’s not perfect, but it looks 100% better than having a hole! Perhaps a better solution to come in the future...

Mounted the amp directly over the binding posts so it looks as neat as possible. Still need to create some sleeves from the same carpet to slide over the wires so they are less noticeable but haven’t got around to it yet.

Well, below are the pics. Any questions or comments are welcomed! (Some pics are lower quality as these were taken using my phone)











Top of ski-pass section:





























Driver tested for fit one final time:









Fitted in the boot:







Cable:




The finished product!





And at night...

Apologies for the delayed reply, haven't checked this thread for a while! I never did find out for definate what size the speakers are. I had one of the rear quarters off when installing my smarttop controller, but stupidly I didn't measure the speakers whilst I was there.

The rear speakers are either 10cm or 13.5cm, and the fronts are either 6.5" or 8". In the saloon/avant the door speakers are all 6.5", but because (this has never been confirmed but is highly likely) the cab doesn't have a subwoofer, the front door speaker could have been made larger to compensate, hence possibly 8".

If you're putting aftermarket components in you will definately need to mount the crossovers, but this can be done behind the dash for the fronts, and in the rear quarters for the rear speakers. That way you'll only take the bass/mid cable through the door gromet and can run the tweeter cable behind the dash. Having gotten a little extra bass I haven't had enough inclination to start taking the doors/dash apart to upgrade the speakers... yet.

If you do any upgrade be sure to post some pics and details of your findings!

The trouble is fitting a 'normal' sub into the space available and also not losing most of the sound when the roof is off...

If you don't have drawers under your seats you could look into under-seat subs, although I've never heard one in person. I used a hi-lo converter as my HU has no pre-outs, works well, although now I've found the amp in the boot (which powers the rear speakers, there is no sub as standard I believe), for the sub I would probably tab into these high level outputs and save soldering (crimping would've been sufficient but I like to know nothing is going to come adrift!) behind the dash.

If I was a little less specific with the dimensions and didn't angle the corners (you'd lose a bit more boot space), I could make the enclosures to order! But taking into account the material costs and amount of time it would take me it just wouldn't be worth the effort.

If you can find some cheap MDF, why not give it a try...

Replaced the subwoofer today, after being repaired once and broken beyond reasonable repair by some passengers (kids) at the weekend, it was time to replace it. The marine version is discontinued so I ordered a pair of the standard black 6x9s instead. As they are the only square 6x9's on the market they were my only option! I also fitted the grille to avoid any future damage... even though I now have a spare

Plus point is the pair were about the same price as the single previously, downside is the LEDs are not visible through the cone. The LEDs would have needed re-gluing to the basket anyway so I just removed them and left the feed disconnected inside the enclosure. I actually quite like the black, it doesn't stand out as much as the white and nowhere near as much without the LEDs, but it's more 'stealth'. Before and after pics below:

The replacement is part of a component 6x9 set, however the original was a 'subwoofer' as classed by the manufacturer. They were beefy for 6x9s and small for a sub, so I guess you could argue either way. It takes the strain off the door speakers in my cab though so it does the job and allows the stereo to go louder overall.

Marine Subwoofer

Sold the a4 can this weekend and will be selling the subwoofer installation in the classifieds shortly. If anyone is interested PM me, will be collection only due to size and weight!