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.
Things I'm not sure on are:
- If the rear speaker high level inputs will be sufficient for the amp (either straight in or VIA a high level converter)
- Where to tap a remote turn on feed from to activate the amp, any help on this would be greatly appreciated.
- 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?
- 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?
- The impedance of the facotry speakers (again, NON-Bose). I think they are 4ohms but can anyone confirm that?
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!
Subwoofer Finally Finished!
Right, well overdue on an update on this... but the good news is the subwoofer install is finished and working excellently :)
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!
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.
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:
The finished product!
And at night...