sub design determines ported or sealed enclosure?

[bjmsdrum00]

i was wondering what properties of a sub make it better suited for a sealed or ported enclosure? x max, vas??

 

[Sheep]

Just guessing, but I's say it would not really matter. A ported sub and a sealed sub have different response curves.

Ported going lower before dropping off severely, while a sealed sub has a more gradual decent higher up.

SheepStar

 

[j_garcia]

It does matter. I would say when you look at specs, various Q parameters are going to play a role in which type of box a driver is better suited for. VAS definitely is a factor.

 

[zildjian]

Vas / compliance of the driver is a big factor; sealed enclosures work best for drivers with high compliance; ported enclosures for drivers with low compliance (stiffer surrounds).
I use large subs in sealed enclosures for tighter defined bass; but you can get more boom for your buck with a ported enclosure, but if you're building it yourself be careful as the ported enclosure is harder to tune 'perfectly' to your driver than a sealed enclosure...
Brad

 

[j_garcia]

but if you're building it yourself be careful as the ported enclosure is harder to tune 'perfectly' to your driver than a sealed enclosure...
Brad

That's interesting - I've read the opposite, that sealed designs are a bit tougher to implement perfectly while vented are a bit easier as long as you have all the parameters.

I like the sound of a sealed sub and my car subs were all sealed, but in the house I like the output and extension of a vented design.

 

[zildjian]

Just did a quick search on 'ported vs sealed subwoofer enclosure' and this is one of the first links that comes up.

http://diyaudiocorner.tripod.com/dilemma.htm

It does a pretty good job going through the pro's & con's with enough technical aspects/math to give anybody a good basic understanding of what factors you have to work with & consider.
Brad

 

[bjmsdrum00]

zildjian, that link is awesome, exactly what i was looking for!!! i really did search, i promise, and couldn't find anything like that.

"Look at Driver A's Xmax of 0.15". With such a short linear throw, it is not well suited for sealed box duty. Speakers specially designed for sealed boxes will generally have a greater Xmax than others."

"Conversely, If you try and use a driver designed for very small sealed enclosures (higher Qts and Xmax, low Fs) in a ported enclosure, you will often find that the port length must be very long to tune the box to Fb with a port diameter large enough to avoid vent noise"

thats exactly the stuff i was needing.