http://www.caraudioforum.com/vbb3/sh...d.php?t=297123

 

Looks like MDF with carbon fiber veneer...

 

im no expert on acoustics, but im pretty sure this equation stands...


Strong + Light != Good Sound Quality

 

If you're talking about wheels, sure, But in audio you're better off with strong and heavy. Remember Newton's third law :

For every action there is an equal and opposite reaction.

A box that's light, will be more prone to vibrations caused by the movement of th espeaker placed in it.

Anyway, if it's MDF + veneer, then it's a not quite light yet very nice looking box

 

carbon wrapped build material is birch and an aerospace composite foam. Weight has noting to do with sound quality. The key factor is ridged and this material is about 4 tims as stiff as 1" MDF. The total weight of this enclosure is about 5 pounds. If anyone is interested to learn more I have the number of the guy who builds them.

 

interesting to say the least. always looking for a way to have good bass and not gain too much weight

 

A 1" MDF box of the same size weights over 30 lbs

 

Mass is equally important as stiffness in cabinet construction. Your main concern is cabinet resonance. You want a resonant frequency that's as high as possible. This frequency is directly proportional to the sq root of the stiffness, and inversely proportional to the sq root of the weight.
Take a read at this one:
http://hyperphysics.phy-astr.gsu.edu/hbase/shm2.html#c2

Basically, Stiff & Heavy = good, Soft & Light = Bad.

If you cut the weight in half, you must double the stiffness. The thing that will make or break that enclosure is the thickness of the carbon fiber.
If it's made thick enough, it will still be lightweight, but should be so stiff that it will compensate.

In all truth, I made a statement without seeing the specs, and I apologize...

Care to post the specs so I can do the proper math?

 

what specs? The box is not made of carbon, just covered in it. Why would you want a resnat frequency as high as possible, that going to effect the tuning of the enclosure. I am not trying to tune it for 110 Hz. Physics are not the same in a car as they are outside of one. Basicly in a cabin of a car all bets are off. I have been doing this for a long time and thats the one thing I can say is a fact.

 

you want the resonance out of hearing range...............

 

Sorry, I didn't clarify... In this case I'm not referring to the tuning frequency of the port. I meant the resonant frequency of the cabinet itself, which you want to be as high as possible (>20Khz like dexmix says).

The specs I was asking for, were the build materials and their thickness.

MDF has a stiffnes of about 3.4 GPa. I wanted to see how it stacks up with what you're building.


By the way, the laws of physics apply all over the known universe, including car cabins


(I know what you meant, I'm just being a D!ck now... )

 

Just because something is light doesn't mean the resonance frequency is neccasarily lower. Also, the key is that the encloser is difficult to resonate period.
Dan

 

I am not building it, a guy in califonia is. It's birch and an aerospace composite. I have his number though if you want to call him. When I called the owner of Digital Designs this is what he reccomended to me.