# Subwoofer Boxes (box vs fiberglass)



## MrLister (Feb 17, 2006)

As far as SQ goes is there a difference in a wooden box say built to 1.2 ft^2 opposed to a fiberglass enclosure also built to ~1.3 ft^2? (both sealed)

Any tips for making a fiberglass enclosure as good or closer to as good as the wooden box? (thicker walls, poly filling, subwoofer aiming?)

With a fiberglass enclosure, I guess it would be easier to aim the woofers in any direction. Does this make a difference? i've heard the term stereo bass before but I don't know how much weight that carries atm.


----------



## MrLister (Feb 17, 2006)

anyone?


----------



## camflan (Jun 18, 2006)

would also be interested in knowing


----------



## chuyler1 (Apr 10, 2006)

You can achieve any angle you need with MDF, within reason. I don't think you'd benefit from the precise angling you can get from a FG encloser. 

You would have to make the FG pretty thick to equal the acoustical properties of MDF but I'm sure you can get close enough to the same sound.

I would add polyfill to just about every enclosure so that point is moot.

I have built a few FG enclosures. None have sounded as good as the MDF ones I have built. They sound fine once you get used to it, but for some reason I can always tell that it is fiberglass. Or maybe it's all in my head.


----------



## Jet (Jan 5, 2006)

chuyler...can you describe the differences you have heard betwwen the FG box and the MDF box? I am very curious about this. Interesting topic indeed.


----------



## newtitan (Mar 7, 2005)

think of a drum, which sounds better a fiberglass standard kit from your local shop, or a drum built from a hollow tree?

I know thats pushing it

but there is a reason the best taiko ,and various Djembe, bongo, conga drums are real wood


fiberglass will work, but it does change the sound a tad IMO. if you do fiberglass take the time to deaden the interior walls with some liquid deadener (like 2-3 lauyers)

its makes a big difference IMO


----------



## chuyler1 (Apr 10, 2006)

I've never used liquid deadener but that is a good idea.

At low listening levels they sound the same....but at high listening levels with FG, the sound easily gets pulled to the rear of my car due to some sort of resonant frequency of the box. With MDF all you get is pure bass.

Now again, all my FG boxes have been in hatchbacks so this may be moot if you are installing subs in a trunk where high frequencies will never reach the cabin.

I'm sure there must be someone else here who has had more experience than me so don't take my opinions as fact. They are far from a A/B comparison between the two.


----------



## B&K (Sep 20, 2005)

If the FG box colors the sound, IMO it is because you didn't use enough glass to make it stiff enough. It should be easy to strengthen an enclosure beyond the strength of MDF with glass, it just takes layers. I would argue that if you made a FG enclosure and an MDF enclosure that had exactly (obviously only theoretical here) the same resonances and shape they would sound identical. However, where I can I'd use MDF for the ease; for me FG isn't for looks or show but to fit a driver where it would be hard to otherwise.


----------



## MrLister (Feb 17, 2006)

chuyler1 said:


> I've never used liquid deadener but that is a good idea.
> 
> At low listening levels they sound the same....but at high listening levels with FG, the sound easily gets pulled to the rear of my car due to some sort of resonant frequency of the box. With MDF all you get is pure bass.
> 
> ...


One interesting thing I learned recently is that a subwoofer, when playing without any distrotion in a perfect box should not give away it's location. When it's playing you can't feel or tell that it's behind you. When there's distortion only then will a subwoofer sound like it's coming from the back, so that's why you felt the bass go to the back of the car with a FG enclosure.

There was a demonstration done with this a while ago where a guy was playing the sub and you'd close your eyes and you wouldn't be able to tell where it's coming from, he'd then turn up his little knob and it would distort it the amount he turned it up and all of a sudden the noise would shoot from an exact point of where the subwoofer is.

So if you can ever hear and pinpoint where the subwoofer is coming from, that most likely means there's distortion there.


----------



## chuyler1 (Apr 10, 2006)

Distortion, motor noise, and other objects rattling will all lead to subwoofer localization. If you were in a field with a perfect box and someone spun you around I'm sure that the test would work perfectly. But in a car, the entire car is going to shake and vibrate...no matter how much deadening material you use. At moderate listening levels you can definitely make the subs dissapear, but at loud listening levels something will grab your ear eventually. 

The sounds I was hearing were not the normal vibrations or distortion...it was something in addition to the sounds I was hearing with my previous MDF box.

Anyway, It takes a alot of resin and matte to equal the thickness and rigidness of MDF. I think that is the primary reason most FG boxes don't sound as good. I'm not going to spend a fortune and weeks on end adding layers to the box.

I'd say my official opinion would be to use MDF whenever possible and for as much of your install as you can. Its cheaper and will yield the best results for your money spent. If you want to build a FG box that is 3/4" to 1" thick then go ahead...but be ready to spend lots of money on the resin.


----------

