Okay....I've decided to get a new fiberglass box for my subs. The one I had before, cracked right down the middle. So now I just have basic truck boxes in the hatch, and I hate them! What I need to know is this....I hear so many different things that you should have subs facing the back, and you should have subs facing upwards. Which is better? The box I have now, and when I had the Fiberglass box, my subs were always facing back. By having them fire upwards, will there be less bass? I heard that by having them face towards the back of the car, it's louder because there's more area to have the bass bounce off of to get to the front of the car. So I don't know what to do, and I need to get as much info as possible before I start designing my new box. Thanx for all the help!

 

Have them face the back... it is true what they say about having them face back... I know from experience. I had a flat rectangular box with 2 10's in it and before I had it bolted down it would fall on its back when I hit the brakes hard enough and the bass would decrease in intensity. I'm not sure of the physics of it, but I do know that facing the back is better!

 

I've had the best luck with my subs being both louder and better sounding in a 2k tiburon, when facing the center of the rear glass instead of back towards the rear.

 

By the way how did you build the fiberglass box before, how many layers of mat did you use and what kind of resin.

 

Well hear is what all my years of MECP training and installing have taught me and now I will pass my knowledge on to you Daneilson. Subs in all cars especially hatchback should face to the back of the car and here is why. Subs produce a low frequency and their audio waves are longer and not distributed as closely as highs there for it takes a low frequency wave longer to produce it's peak sound( to put a visual of the wave in your mind a low wave is like a double d cup and a high is like an a cup). So by pointing the subs to the back it gives the wave more time to develope to produce it's peak sound because it will go backwards bounce of the back and continue forward producing the lows right production of sound. Also a good trick to use if you compete (DB Drags) with your car before you go to the line turn the air on high and make it freezing in your car it will make the air denser giving you about a 1/2 db more it might not sound like much but some guys tear there cars apart just to gain that much. Now thats a 5 star answer if I ever gave one lol rolleyes.gif Also you might want to consider the material to build your box fiberglass is stong yes but it will flex from the pressure inside the box and you will loose some db's (reason being subs are specific to internal dimensions especially sealed boxes and if your off by an inch due to construction or flex they won't produce properly) don't get me wrong it's a great idea but if you were to build the box out 1/4 inch ply wood caulk the joints and then dynomat the inside of the box you would be much more pleased with the sound (just my opinion) and the cost would be cheaper and then you could fiberglass the outside to the form you want in you trunk.

 

Vin...the box I had was just a regular box made out of MDF, with a single coat of bondo over it. It was then smoothed, primed, and painted. It wasn't the actual box itself that cracked...just the bondo/fiberglass part. Since it was just a single layer, I think with the new box that I make, I'm going to make sure there's multiple layers of it to prevent cracking.


Jaws99....Thanx man on the info. I figured having the subs facing back was the way to go, but I've heard so many things...I just wanted to make sure before I started to get the specs together for the box and get it made up. I'm actually having a friend make the box. I, myself am the one that's doing the fiberglass and paint work since I have alot of experience with it. My first box was done by someone else, so I now only rely on myself for doing the major things. I never actually thought about dynomating the inside of a box. Does it really help? Should I use regular sheets, or is the spray okay? Also, is Polyfill good? I have a ton of that crap in my truck boxes right now. From what I've learned, Polyfill makes the sub act like it's in a bigger box, correct? Anyway, thanx again for the 411, and I'll let ya know how it comes out. wink.gif

L8TR.......

 

Well using the sheet dyno would be better because more of it would insulate the box the spray is good also, but you would need more, for one if the box is going to be wood some of it will be absorbed into the wood because it is wet when it first comes out, second it will not make a complete seal unless you at least put 3 coats on where the sheets are already bonded and third you will spend about $30 for three cans mor if other cans are needed as apposed to about $20 to do it in sheets. As far as the poly fill is concerned you are right it makes the sub feel it has more internal volume than it really does, but your box should be built to the specs of the sub and if this guy can't do that go somewhere else if you want it done right, just for example if you are going to use JL subs they are a sub that is meant for a sealed inclosure and one that is made to be right on the money with specific internal volume if the box is made correctly and you throw in some poly fil you will throw the specs off thus hindering the performance of the sub. There is really no reason why someone should use poly fill unless there trying to make a box that was bought just to fit say any 12 inch sub match the specs of the 12's they are putting in the box. Hope all goes well and I hope all of this helped.

 

Jaws99, I too am MECP certified, kind of cool for me to know of someone else that is.
Lo&sho, If the fiberglass is thick enough it won't flex and is lighter weight than using MDF, however Facing subs back does do what Jaws99 said however in some instances there are different ways of creating the same effect with slighlty different results, I was simply pointing out that in my experience with my 2000 tib that I have had the best results firing them at the center of the glass. Anyhoo, peace out.

 

Thanks tunez I screwed up on the wood thickness rolleyes.gif Sorry I said what I didn't mean with that thick off wood you would have to install leaf springs.