As loud as possible subwoofer system recommendations (Audi A4 B5 Sedan)

[Firewalker]

Everyone must learn somehow just that one is usually enough for everyone to see it around here. Glws

 

[Jonnyswboy]

I have a crazy trunk build and might be able to give you some advice. Check out the trunk build only Facebook group.

Rough cost breakdown (You could make some more sacrifices but this is best price to performance):
Used American Bass HD 12 or similar subs - $700-800
Used Taramps 8k (go full bridge at this budget or look into CAB-45 at half ohm) - $450
HO Alt + 64AH Headway bank - ~$800
Box - ~$350
Wire and misc - $350
Total: $2750

You're going to have to choose between hair tricks (windy/lower tune) and being loud (high tune) to an extent.

I'd personally go with one of two options (both enclosures on the smaller side tuned ~32hz):
With your budget you will want to tune a bit higher to get loud, probably 32-36hz.
Option 1:
Side aero port

Option 2:
Forward aeroport (I would go with this tuned to 32hz at about ~4ft3 depending on woofers)

You will want the most power your budget can allow. If you can get good priced or used equipment it will allow you to spend more on batteries and alternator which will help you a lot. Check out DIY headway lithium banks.

This is my build which I spent ~$7k and I get decent hairtricks at a select few frequencies (specs in signature). Probably clamping ~5-6kw. I have a big enclosure with a forward slot port which I regret somewhat. It's not as loud as a side or forward aero and I do have some loading issues with certain windows down. 5ft3 is a big large to put a lot of power to and the woofers do start to lose control near rated power. I did seal since this pic.