Quote Originally Posted by jhnkvn View Post
If you plan on powering your stock speakers on the head unit, you won't go far. Expect that your back will overpower your front.

Never a fan of coaxials. Get separate components -- midbass at the doors and use 3M double tape to mount the tweeters on your dash. Easiest way on how to "position" them is 30 degrees off-axis -- in normal language this means your left tweet should be aimed to your passenger and your right tweeter to the driver.

I'll also throw my vote with the JBL GT-5. If you think it isn't enough, get two. And no, don't get the pre-fabricated GT5-1204BR version, the bump in price is ridiculous. Just get the GT5-12 driver and ask your installer to fabricate a box on it. Is space a premium and you simply want to enhance the bass? If then so, 1 cu.ft sealed would do it.

Take markgy's advice. 4-channel amplifier -- 2 channels for the front speakers, and 2 channels bridged for the subwoofer. This is usually your typical "step 1" setup for most people.
Thanks for the advice sir, I went to our local shop here and i decided to get 2 sets of coaxials, and got the new 2013 kicker comp d 12" dual voice coil powered by the sound magus dk600 wired at 2ohms. the coaxials were powered by the hu, which is a toyota oem (panasonic), i asked the installer to make me a box, i think based on the measurements and rockford fosgate box wizard, its a 1.0 cu ft ported box. I was thinking of adding an amp for the speakers and upgrade the front to separates and leave the back speakers as a "filler". Still have to save some money though, but for what i currently have, im very happy with it.

Ask lang din ako regarding sa box. according to the manufacturer's minimum volume for ported box design is 1.75 cu ft, my current box is around 1.0 cu ft, how would it affect the sound of my bass or would it improve the sq or spl or anything, if i had a bigger box. My initial plan was to have 2.5 cu ft ported box based on manufacturer's maximum recommended volume, however the installer made otherwise. Im really new to this car audio thing, i had only researched as much as i could and this is my first hand experience with this.