So I just purchased my car last week and I'm planning on redoing my speakers, i have 4" for the front door, 5 1/4" for the rear doors and I'm planning on doing two 8" woofers in the rear deck to retain stock looks, but also have a slight more bump than stock. My question is does anyone know if 8" woofers will fit in the rear 6.5" holes without modification? I don't mind modifying, I just wanted to see if it was possible.

 

I have the BOSE Symphony system and everyone/everything told me that the rear doors were 5.525" and the rear deck were 6.5", but both of those figures are wrong (at least in my case).

I had to make modifications to the rear doors to make 5.25s fit and also modify the rear deck for the 6.5s.....and those barely fit.

G/L with everything. Let me know if I can help further.

 

I fit 5 1/4" in the front and 6.5" in the rear without any modification. Just using adapters made to fit standard sized speakers in the Audi holes. I'm not sure if 8" woofers would fit in the rear deck. Maybe if you measured the width from corner to corner of the square in the rear deck from the trunk, you might be able to get a better idea if they would fit.

Also, did B5's come with speaker's in the rear doors?

 

Mine is an s4 and it has rear door speakers but my 2000 a4 i had did not have rear door speakers and both had symphony oem headunit with the bose amps.

 

You could mount the subs from underneath. You may want to purchase free air speakers or dual purpose ones as the characteristics of an enclosed speaker are going to be different than free air i.e. stiffer spring ect. You will get major rattle due to it being attached to sheet metal if you leave it bare but if you want to conserve on trunk space then seal up the deck as much as possible with sound deadening material like Dynamat. It will do dual purpose of sealing one compartment from the other and deaden the sheet metal from rattling. Make sure that the mating surface to the speaker is flat. You can use 3/4" MDF to mount the speaker to then mount the MDF ring to the deck with foam sealant and screws to try and keep it somewhat air tight. If I was going to go free air on the rear deck, this is what I would do. Otherwise build a small box and be done with it. Good luck.

Doug