ERPGURU

Hiya everyone, Prestige '09 owner here - and I wanted to know if anyone has replaced/upgraded/supplemented the factory sub in the car? I had a S5 prior and was able to just remove the old sub and replace it with another higher-efficiency one. I know the factory one is located under the cargo tray in the boot, but have not looked at it yet, is it a standard dimension/size? Anyone know what the impedance or wattage of it is?

Love the B&O but as in the S5, the low end is a bit lacking for my taste...

John

GolfGL

It's located inside the spare wheel and actually felt kind of cheap... maybe because it was quite light and plastic. AFAIK, it only has an Audi PN on it (mine is B&O too), no impedance/wattage marked. But the connection to it clips off easily (you have to unclip it before removing spare), so the amplified signal is easy to tap.

ERPGURU

Thanks - I think I will use that connection and snake it out to the right side - would like to place a powered sub in the niche by the 12v adapter..circuit should be able to hand a sub since it is connected to the lighter/adapter there. Let everyone know what I end up doing..

ERPGURU

Just a note - took out the speaker, it is 6.5", measured it with my ohm meter, it is 6 ohms. I bought a JL 6W3V3-4, should be a direct replacement. It is 4 ohms so it should hit a little harder and pull more current. The other stock B&O amp in the S5 handled the drop in resistance fine so though should be ok.

I receive the sub later this week, let everyone know if it does improve the bottom end better...

John

GolfGL

Thanks for the info... does the B&O look physically inferior to the JL? Also do you have the 4-3/16" depth clearance (I am assuming you are going to use the same enclosure)?

ERPGURU

Yes, the B&O (if it is really one) is pretty crummy, it has a little weight, but the driver is paper, looks like a generic driver. There is more than enough depth for the JL to be mounted in the same location.

supahan

Hopefully the amp is fused correctly in the unlikely even of a overload causing a fire or damaging the amplifier.

GolfGL

Awesome... would love to hear how this works out!

A couple of challenges you may encounter - 1) no adjustment for subwoofer level in MMI which may make it difficult to blend in the sub, and 2) although the JL will draw more current since its lower impedance, the sensitivity will determine if you get more SPL out of this compared to stock.

I am copying a post from another forum below detailing the B&O setup. If everything works out your upgrade should better esp. with the 150W class-D subwoofer amp driving the JL!

Sedan Technical specifications

Front door & Front/Centre loudspeaker:
Two 25 mm tweeters
70mm full-range (centre)
80mm mid-range +200mm woofers

Rear Door & Parcel shelf:
25mm tweeters + 168mm woofers
Two 80mm full-range + 200mm "free-air" subwoofer that uses the parcel shelf as a baffle (like the A5)


Avant Technical specifications

Front door & Front/Centre loudspeaker:
Two 25 mm tweeters
70mm full-range (centre)
80mm mid-range +200mm woofers

Rear door and "D" pillar:
25mm tweeters + 165mm woofers
Two 80mm full-range

Luggage compartment:
A 165 mm subwoofer in an 11L bass reflex ported cabinet placed within the excess space of the spare tyre.


Amplifiers (for both Sedan and Avant):
Five 25 watt Class-A/B amplifiers for tweeters, mid-range and centre driver
Two 40 watt Class A/B amplifiers for rear woofers
Two 75 watt Class D amplifiers for front bass drivers
One 150 watt Class D amplifier for the subwoofer



Specifically regarding the subwoofer differences:


The Limo (sedan) has a 'free-air' subwoofer that uses the parcel shelf as a baffle. The A5 uses the same principle.

The Avant does not have a parcel shelf so we opted for a subwoofer in a ported cabinet. The only difference in performance is below 30Hz where the subwoofer port starts to roll off. This will make little difference to the listening experience for 2 reasons : 1. Most music contains very little information below 30 Hz. 2. This frequency area is masked by background noise while driving. The Q5 uses the same principle.

Of course it is possible to put a subwoofer in a sealed cabinet but the loudspeaker itself needs to be very large (as in the A8 / Q7). A ported cabinet can achieve good SPL at low frequency with a relatively smaller loudspeaker.


Furthermore, B&O also told me that:


Both cars are tuned individually as each car is unique. Further there are usually two tunings per car as a car with fabric seats and no sunroof will differ from one with leather and sunroof.

supahan

Great information. Is there a way you can find how many ohms the amplifier is rated at? The sub he is proposing is drawing 50% more current than the stock sub. I would like to do this mod too, if it is viable.

GolfGL

Sorry, no details about the amp. I am guessing it's an ICEpower IceCar1 Class-D, maybe a 4-channel 300W unit. They probably used 2-channels (2X75W) for the front woofers and bridged remaining 2-channels for the sub. Or it might be a standalone 150W unit since it wouldn't make much sense to run a digital link all the way to the back and then send the analog sound back to the front. For sure, it isn't a conventional amp with heatsinks, so I have no idea how it would handle the decreased impedance. Since they are pretty efficient and don't product a lot of heat, I would venture it shouldn't mind the additional current draw especially since it wouldn't be driving a full-load all the time - unless ERPGURU has other ideas! :-)