Hello all, first time poster here.

I have been given an MTX Terminator sound package for Christmas.

It includes a single 12" subwoofer, a monoblock amp and an enclosure.

http://www.sonicelectronix.com/item_...X-TNP112D.html

Specs are:

Single 12" Terminator Series Subwoofer
Power Handling:
Peak: 600 watts
RMS: 200 watts
Single 4 ohms

Terminator Series Class D Monoblock Car Amplifier
RMS Power Rating:
4 ohms: 120 watts x 1 chan.
2 ohms: 200 watts x 1 chan.
Max power output: 400 watts x 1 chan.

I have a 2008 Mazda 3 GS Sedan and I am using the stock HU with a LOC tapped into the rear speakers and an 8 gauge wiring kit.

I've had a home recording studio for over 10 years with some pretty nice gear so I've got pretty high standards for sound and the setup in my car (which again was a gift) sounds like crap. The sound is poorly balanced, the sub responds great at 40hz-50hz but barely responds at all to anything above or below that and the overall output is pretty weak (trunk doesn't rattle, mirrors don't shake). My biggest beef is the poor response outside 40hz-50hz, some songs sound great, others sound like I don't even have a subwoofer. Hard kicks at 80-100hz don't exist with this setup.

Given this setup, what would you upgrade first? My guess is probably the HU, then the amp, but I'm not that familiar with the car audio world. Any suggestions?

 

your main beef seems to be with poor bass response below 40 and above 50, your sub\enclosure would be the first thing to look at imo, it will make the biggest difference

a move towards a 2 ohm sub might be a good idea with that amp

at a second glance, there's a bass boost @ 40hz on that amp, if you have it cranked that could explain your poor frequency response (same thing with bass settings on the deck) i would use the bassboost for eq'ing reasons not as a second gain ****)

 

Where in the trunk is your enclosure and which direction is it facing?

If right behind the seat, make sure the sub is firing towards the taillights.

 

First thing I would do is cover all the free angles like positioning the sub and tuning the amp. The sub should be as far back as possible, try it in the rear most passenger corner of the trunk. Doesn't really matter which way it faces back there but I would consider front facing and driver side facing. Tuning the amp means setting the gain to reach maximum output and setting any filters to avoid any cancellation with existing speakers. Integration is key.

If that doesn't do it for you then I would consider building a custom box for that woofer. Unfortunately it needs a largish enclosure to go low. For max-flat SQ response it's best suited for sealed enclosures around 6 cubic feet (but thanks to cabin gain you can get away with smaller). Just how small depends how much you are willing to compromise on low end extension.

Beyond that there are other options like equalization, crossovers (to help with integration), and finally replacing the sub. Try the free stuff and let us know what you find.

 

do you use your trunk ?
the reason i asked is that i would ditch the sealed box and build a 1/4 wave transmission line box tuned it to around 40 hz, dont use your boost on the amp and the box will end being around 7 cuft ( took one 4x8 sheet of 3/4 inch mdf when i did it)

i know i was impressed
mine was hooked up to a old school sony 4 channel amp