Box Building
Thread Starter
50 Watt CAFz'r
Joined: Jun 2006
Posts: 69
Box Building
Hey, I was just wondering if any of you know of any good sites to give me tips and instructions on box building. Im lookin for such things as building your port size and tuning and what not
thanks
thanks
Thread Starter
50 Watt CAFz'r
Joined: Jun 2006
Posts: 69
1. what is the resonant freq. ? Im not really all to clear on this subject and I realize I need to understand this in order to understand the qts. And also when the dealer website, say orion for example, says that their sub is best built for a ported box does that mena that they themselves have measured the Qts and that the sub is best suited for a ported enclosure or they are they just saying the sub will perform better as in power handling, lower distortion and all that good stuff?
2.What does it mean for the sub to become unloaded after the cutoff freq. ?
2.What does it mean for the sub to become unloaded after the cutoff freq. ?
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Joined: Feb 2006
Posts: 16,860
Originally Posted by kyle_nelner4
1. what is the resonant freq. ? Im not really all to clear on this subject and I realize I need to understand this in order to understand the qts. And also when the dealer website, say orion for example, says that their sub is best built for a ported box does that mena that they themselves have measured the Qts and that the sub is best suited for a ported enclosure or they are they just saying the sub will perform better as in power handling, lower distortion and all that good stuff?
2.What does it mean for the sub to become unloaded after the cutoff freq. ?
2.What does it mean for the sub to become unloaded after the cutoff freq. ?
1) Everything has a resonant frequency. Pluck a string on a guitar, strike a tuning fork, clink a glass. They all will make the same tone every time - at the frequency they resonate at. For a speaker, the mass of the cone assembly combined with the compliance (or how soft/stiff) of the suspension determine a specific frequency that the driver will move the most with the least power input. This is the resonant frequency. Never tune a vent at or below it.
Speakers can be designed to work well in a sealed box, vented box, or some other enclosure style, or to try to work well in many box designs. It all depends on the goals of the designer.
2) Lets say you tune an enclosure to 35hz. As you play frequencies below 35hz, the box has less and less control on the driver. Usually by an octave below tuning your driver is on it's own for trying to control motion. It is like there is no box at all. Fortunately there isn't a whole lot of musical information down this low and if one is concerned about it, the addition of an infrasonic or "subsonic" filter will ensure that things don't get out of control down low.
The resonant frequency or Fs of the sub should be listed in the T/S or Thiele Small paramaters which sould have come with the subs, or on the box, or somewhere online.
Paul did a really good job explaining what the resonant frequency is in the above post, hard to make it anymore clear than that....
Paul did a really good job explaining what the resonant frequency is in the above post, hard to make it anymore clear than that....
Last edited by StickyFingaz; Aug 31, 2006 at 04:31 PM.
