Questionhey i drive a 2007 mazda 3 and i want to add a 12inch sub in the back. i want to do this without having to add a new face plate because i think it would look horrible and might not even work. is there a way to do it and have a nob or something installed that you cant see that controls the sub level? or what can i do to install a sub without having to install a whole new stereo?
AnswerYou have to research to know what type of audio system you have now. Some cars have premium sound systems and usually have a factory amp somewhere in the car, some don't.
If you don't have a factory amp, the job is easier.
A LOC(Line-Out-Converter) will allow the connection of an amp IF the amp doesn't already have high level inputs. You can look specifically for this type of amp.
This allows the amp to be directly tapped from the rear speaker wires (no LOC required). The only tricky part is running the properly fused power wire to the trunk through the car in any case.
Look for an amp that also has remote bass control as well as an LPF setting. LPF(Low pass filter) allows you to adjust what frequencies are passed to the sub. You want below ~250Hz for subs.
If done right, you can even control the amp via an on/off switch under the dash if you want.
Run a fused (1 amp, 14 AWG) wire from a fuse in the fuse panel that only has power when the car is on to a switch. Then from the other side of the switch run the same sized wire to the REM (remote) connection on the amp. This allows for full control and you never have to worry about forgetting to turn off the amp. The switch is so you can turn off the amp at will so as not to give grandma a heart attack in the car.
Use a fuse tap that you can get from most any autoparts store.
