View Full Version : Sealed box vs. RMS of sub. differences?

02-22-2008, 10:52 AM
I did some search, and reading and did not find my answer.

So the question is the difference in sealed enclosure compared to the power of the sub.

I'm looking into Alpine subs, currently have a Type S, RMS 300W, alpine recommends a 1.25 cu/ft. sealed box.
And I want to upgrade to the Type R, RMS 500W, and alpine recommends a 0.85 cu/ft. sealed box.

What I don't understand is how the box play a role here, because what I though would be that if there is more power, then there should be a bigger box, so theres more air to flex.

But from recommendation, more power, smaller volume :wow:

Can someone explain this concept to me?
Thank you!

02-22-2008, 11:05 AM
I can't give a very technical explaination but more of a basic, hopefully someone can back me up with some more theory.

Basically in a sealed application the air inside the box acts as a spring or a shock absorber controlling the travel of the cone. The smaller the volume inside the box the stiffer the spring or shock absorber becomes thus actually requiring more power to maintain the same amount of movement. With a bigger box the spring is "weaker" and so it takes less power to push the cone out of control.

02-23-2008, 12:15 PM
Well if you put a lot of power into a bigger box, wouldnt that make the "spring" force flex more? and that causing to have a louder pound to it?

02-23-2008, 12:26 PM
The simple answer here is that you are comparing two different subs, with two different designs and two different enclosure requirements. When cross-comparing models like this, there's really no correlation or connection between RMS power handling and enclosure size.

When comparing a single subwoofer in different alignments yes, there is going to be a connection between mechanical power handling and enclosure size (larger box, lower mechanical power handling).

But you are trying to make connections to variables where there are none to be made.