inputs.text: good size price - bmw z3 roadster factory sub 5 14\\ 2 voice coils 2 ohm came apart back factory sub custom box seats no replacehement subs would fit original box could custom fitted available space sub sws earthquake could find reasonably priced went kicker 6 12\\ 1 voice coil 2 ohm built box mdf ended mounting speaker firing downward could not make fit firing rearward like original sub forward upward would pushing air right snapin cover roll hoops anyway still using original 5 channel amp new kenwood head unit little sub seehems job not real thump really high volume levels get distortion though may fault amp rather speaker course need really high volume 80 mph top tell much distortion much ambient noise moderate high volume levels sub performs well everything could expect size speaker limits custom box speaker positioning