Factory B&O Sub specs...

[GWS42013]

Hi guys, do any of you gentlemen perhaps know what the specs are on the factory B&O Subs in our cars, my B8.5's sub is a slacking a bit and Im looking to do a OEM+ upgrade. Any suggestions?

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[Gunnark100]

You should find here some info and ideas:
http://www.audizine.com/forum/showthread.php/620737-Bang-amp-Olufsen-Subwoofer-Upgrade-B-amp-O

prefacelift and facelift share the same b&o sub part nr: 8T0 035 412 D

[mcoomer]

Don't have any specs but the B&O system is such an overrated thing. Better than the base system? Yeah, a bit, but nothing that Audi should be hanging their hats on. I'd gladly pay more for a killer factory installed system but that wasn't an option. If you do upgrade, let us know how it turns out.

Mike

[cspcrx]

^ so true. The JBL system in my wife's Tacoma sounds so much better than my B&O.

[onlyaudis]

my old Bose system in my B6 A4 had better bass. I did a 500 watt alpine amp and and 10 in Pioneer sub in a custom made enclosure that hides in the left rear corner of the trunk. removed the factory so called sub and used the hole as a port to bring cleaner bass from the trunk into the cabin. sound deadened the crap out of that entire rear area. system truly sounds amazing now. cost me under $400 to do everything myself.

[Drunktank]

There's been a lot of different threads on this, but I'll try to some it up for you in a short reply.

You have about 4 options for replacing the sub.

1. Take out the B&O/stock sub and replace with a free air/infinite baffle version - http://www.audizine.com/forum/showthread.php/620737-Bang-amp-Olufsen-Subwoofer-Upgrade-B-amp-O

2. Someone is Europe makes an MDF version where you relocate equipment in the left trunk pocket and cut the pocket out. http://www.ebay.com/itm/Audi-A4-B8-Saloon-Sedan-Custom-Fit-MDF-10-Sub-Box-Subwoofer-Enclosure-Bass-/400448411995?hash=item5d3c95d95b:g:zRYAAOSwUV9Wn-tR

3. A forum member make some carpeted fiberglass models where you cut out the left or right trunk pocket http://www.audizine.com/forum/showthread.php/631708-Fiberglass-10-quot-Subwoofer-Cubby-Box?highlight=subwoofer

4. Custom boxes are starting to be made on Etsy that utilize the pocket space but don't require any cutting. https://www.etsy.com/shop/CustomSubwooferShop?ref=search_shop_redirect

Depending on the amp model you use, you may or may not be able get away with using the built-in high level inputs. Some have said the B&O sub speaker wires have worked and some have said the power was too much for their amp to handle. AudioControl line out converters are the favorite to use for this purpose.

The signals used between the sub and mid bass door speakers are crossed over pretty hard, and you may find it annoying that your bass line completely disappears once the signal moves from your new sub to your doors. I highly recommend giving your amp the sub and mid-bass signals and then using the rolling crossover on your amp to customize to your liking. You can easily tap into the door signal at the amp. The wiring diagram is in this thread. http://www.audizine.com/forum/showthread.php/520666-B8-8-5-B-amp-O-Speaker-layout-and-Wiring-Diagram?highlight=B%26amp%3Bo+wiring+diagram

[cspcrx]

Those are some fancy speaker boxes!