Adding a subwoofer is really, really easy. The only "hard" part is running that 4 or 8 gauge wire through the engine bay, under the carpet, and to the trunk without making it look like you used a chainsaw to do it.
As for your question, though, your sub is only going to drown out the rest of the music if you tune it like an idiot who just wants his car to sound like a bass drum when you drive through the suburbs. Go for the sub to get that touch of low bass, and if you start to lose mids/treble, then look into getting a nice set of components up front to give you a good sound stage.
The setup in my car is as follows:
- Alpine CDA9856 Deck
- Alpine Type-R 5.25" Components up front
- Alpine Type-S 10" DVC sub in the trunk
- Infinity Ref 310a class D monoblock for the sub
- 4 feet of 8 gauge power wire to the amp (my battery is in the trunk)
- 2 feet of 8 gauge ground wire off the amp
It was really inexpensive and sounds awesome.
