Here is my professional advice since I use to be a stereo installer. The stock radio has no Pre outs so you will need a converter. Not just any converter will do. I actually installed a small system in my 3 when i first got it. I kept the stock unit and used a PAC SNi-15 converter. I hooked that converter to the rear speaker outputs of the stock radio. The adapter feed the subwoofer amp the music and I added 4 bass blockers to each stock speaker so they wouldnt bottom when the bass hit hard and deep. So the factory radio was powering the 4 factory speakers which was loud enough for me and still sounded pretty good. I had an amp with a low pass crossover with at least an 18db cutoff but I recommend 24db so you wont get any midbass in your subs. I used 1 twelve incher made by MB Quart. It sounded reall good and the box was small and unobtrusive. You will have to face the speaker back toward the trunk lid or better yet upward toward the rear dash. I played around with teh sub enough to know where to point it to get the best bass performance i could possibly get. Expect the car to rattle mainly in the trunk area. If you dont want rattling get some Dynamat but it cost alot and is a pain to install it. I recommend you install a small digital Mono amp under the passenger seat. The trunk has no room for amps. Get at least 500 watts and get a good name brand amp. Not legacy or the Pyramid crap that will get loud but sound horrible. I actually had 4 boxes made for the trunk. I am using 2 of them. they hold 10 inch subs. They fit perfect!. I can send you a few pics of the boxes and speakers I use. And if you want the 2 other boxes I dont use I will sell them!

 

Cap, I for one would like to see your set-up. Thanks to for the post you penned some great info. I've got to pay some more bills before I upgrade the sound system. If I can keep from getting rear-ended by unisinsured drivers (sore subject[:@])

 

i think putting in systems are a waste of money. why not save it for performance parts. or a pearlescent paint job.

 

[][:-][X(]its gonna be too loud man trust me,.... i got an 04 sedan and i just put in a 10 inch MOMO sub and its freaking wayyy to loud,, the trunk and the whole car ratlles, i had to turn my amp allllll the way down so it doesnt bump like that but its ok i suggest u save ur money for more performance as the mazda stock stereo already sounds really niceeee laaate [:'(][X(][&:][8D][:@][&:]

 

wait so i could wire my sub's and my amp right to the stock deck? Is that a hard task or should I have someone install it for me or i saw some guy had this thing that came off his amp where he just turned a *** and the bass went up or down. If u could help me that would be great. W/e is cheapest please haha