Here's the deal: I have an MP3 player, a 150Wx4 amp, and 6.5"s up front and 6x9"s in the back. I want to put subs in place of the 6x9"s since I only use them for low mids and bass. However it was brought up that the subs will rattle the car so I figure I could just make a box for my trunk. My plan is to build a box that is completely hidden and sits flush ontop of the ledges on the side of the deep part of our trunk. Sound like a good idea or will the sound field be screwed up from lack of speakers directly behind me?

 

It will be better (arguably, some like rear fill) then with the 6x9s. Do you like the rear fill? If so, keep it.

 

I'm not sure if I do or not, I'll borrow my brother's sub and find out.

 

What do you think of this. Custom built by my dad and I, and if you wanted you could put two 10's on both sides of the 12.

 

that looks pretty clean install nice

 

Yeah, it looks awesome, but doesn't help me at all!!!

 

i wouldn't mix sub sizes......clean install though!!

 

Well, myself I like rear fill. Since you asked about if the sound field would be screwed up by lack of rear speakers, IN MY OPINION, yes. I happen to like having rear speakers. You can't hear them really, or you shouldn't be able to noticeably, but the lack really bugs me. For an example, get in a car, turn the fade all the way forward. If that doesn't bother you at all, you don't need 6 x 9s. For me, I dislike it...


mj14sports --------> Rockford P4004, right? I love how that amp looks.. I had some issues with its performance and whatnot, but it looks good...

 

I know I won't like just the front speakers, but I'm trying to find out if having a sub for the low-mids and bass might fill it out without sounding strange.

 

In mine, even with the sub, only front sounds weird. Mind you, I do like having most of the full range behind me as well.

 

My fourth-gen setup (I love whoring this pic, so what)

 

Ok, right answer to the wrong question. In that case I think the biggest problem would be getting them EQ just right. You would need to do something like have the fronts handle 200/300Hz and up. Then the 8s in the snails take 80/100Hz up to the 200/300Hz. Then subs in the back handle 80/100 down. Effectively a 4-way x-over. Don’t go by my numbers, but that should give you the idea. The other thing is the 8s would not need much power at all, or they’ll over power the rest or the speakers. The problem is, you putting a lot in (equipment, wires, money, time..) And you can get close to the same result for less then all that. The Pioneers FIE, is close to what you’re talking about. Just adding the sub. If you like that, I would just run it. A sub can only help, and the 6x9s aren’t going all that low to start with.
Did I get the question right that time?

 

I agree with Needaz - put a sub in the hatch. Your soundstage will be good if you can run the 6x9's in the realm of midbass/midrange (80-500 or so) since you won't get deep bass out of them but you also don't want their tweeters pulling the image back. I like rear fill, too, since it rounds out the sound if you turn your head - a common driving occurance. A system with just front speakers and subs sounds too weird if you turn around to back up or make a turn because all the highs are in the front and all the bass is in the back. I crossed my front speakers around 200Hz and my sub around 75-80 Hz. All at 12db/octave.

Note: The crossover point on my amp for the little speakers doesn't tell me where I'm at precisely, so there's no way of telling exactly where the crossover is set. Also, my front speakers are in kick panels, so a combination of cabin gain and enclosure size may improve the frequency response below the crossover. For example if the crossover is set at 200Hz, theoretically, I will be at -12db at 100Hz (one octave lower), but if I get a +12db cabin gain at 100Hz, the crossover will seem like is set closer to 100Hz than 200Hz.

That's what worked for me - your ears will be the real test.