chrislee8

I have a eclipse 88100.4. it is 10" aluminum sub.

Here is some spec:

Vas: 2.94 Ft2.

Enclosure Volume Example:
1 Ft2(Cubic Foot) = 12" x 12" x 12" = 1728"
1.5 Ft2 box = 12" x 12" x 18" = 2592"/1728 = 1.5 Ft2

Woofer Internal Volume Table: 10" is 0.09Ft2

According to the above spec, I am confused.

What does the Vas mean? Does it mean it is the box volume supposed to be?
What does the Woofer Internal volume mean?

Does all the spec mean: 2.94 Ft2 is the box volumn supposed to be? then
2.94 = 12x12xA/1728 ->
144A = 1728x2.94 ->
A = 35.28"

so assume H=12" W=12" then the D is supposed to be 35.28"
then how the internal volume number come into play?
Did I calculate that in a proper way? If not, please advise.

Thanks in advanced.

chrislee8

com'on guy, please help me out. Shouldn't be hard for u, right?

2 Da Max

iTrader: (2)

www.bcae1.com

go to building box, and type in the specs, it should help you out

Robert_J

Vas represents the volume of air that when compressed to one cubic meter exerts the same force as the compliance (Cms) of the suspension in a particular speaker. Vas is one of the trickiest parameters to measure because air pressure changes relative to humidity and temperature — a precisely controlled lab environment is essential. Cms is measured in meters per Newton. Cms is the force exerted by the mechanical suspension of the speaker. It is simply a measurement of its stiffness. Considering stiffness (Cms), in conjunction with the Q parameters gives rise to the kind of subjective decisions made by car manufacturers when tuning cars between comfort to carry the president and precision to go racing. Think of the peaks and valleys of audio signals like a road surface then consider that the ideal speaker suspension is like car suspension that can traverse the rockiest terrain with race-car precision and sensitivity at the speed of a fighter plane. It’s quite a challenge because focusing on any one discipline tends to have a detrimental effect on the others.
Taken from Eminence

Your sub will take up .09 cubic feet of space when mounted in the box. You have to make your box .09 cubic feet larger to account for this. If you add any internal bracing you need to factor in that as well.

To find the correct box size go to the Eclipse web site or put all of the Thiel/Small paramenters into a sub simulation program and let it tell you the proper enclosure size.

Finally, all of your measurements are correct IF you are using internal measurements.

-Robert

chrislee8

Thanks for your explaination, I m clear on the definition now.

So my box's depth could really take up 35-36", wow, that is 3 feet long box.

Does it seem right? One seal box for 10" sub need a 12"x12"x36"(roughly speaking) in size?

Damn, I m only using roughly a 1 Cu. ft box.

Can anyone verify the size? Do u suspect any problem on my calculation?

all the specs I have taken from my sub's manual, they are all right.

That doesn't seem right to me. hmmm.....

MacAlert

iTrader: (1)

The internal volume for the box should be in ft3.

Robert_J

A 12x12x36 inch box made out of 3/4" material give you a gross volume of 3803.625 cubic inches or 2.201171875 cubic feet or 62.2931640625L. (I just cut can pasted out of the calculator program. You don't need this many decimals.) Subtract .09 cubic feet for the displacement of the sub. I'd also subtract about 10% for bracing (if you use any). If you stuff it with polyfil, add 10% to 15% depending on how much you use.

-Robert