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need help building a box
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<blockquote data-quote="vasyachkin" data-source="post: 56983" data-attributes="member: 544250"><p>sealed box is a second order system meaning it has 2 * 6 = 12 decibels per octave bass rolloff below "corner frequency."</p><p></p><p>ported box is a fourth order system meaning it has 4 * 6 = 24 decibels per octave rolloff below corner frequency.</p><p></p><p>corner frequency is the resonance frequency by the way.</p><p></p><p>a cabin with windows closed is also a sealed box in itself and has a 12 decibels per octave BOOST below a certain frequency determined mostly by the largest dimension of the cabin. approximately where the largest dimension of cabin is half the wavelenght of a certain frequency - that frequency is the corner frequency for cabin's boost. by matching the corner frequency of a sealed box to that of the cabin you can cancel the box's bass loss with cabin's bass gain and achieve near-flat response to almost zero hetz. on the other hand you can NOT do that with ported box because 24db per octave does not equal 12db per octave.</p></blockquote><p></p>
[QUOTE="vasyachkin, post: 56983, member: 544250"] sealed box is a second order system meaning it has 2 * 6 = 12 decibels per octave bass rolloff below "corner frequency." ported box is a fourth order system meaning it has 4 * 6 = 24 decibels per octave rolloff below corner frequency. corner frequency is the resonance frequency by the way. a cabin with windows closed is also a sealed box in itself and has a 12 decibels per octave BOOST below a certain frequency determined mostly by the largest dimension of the cabin. approximately where the largest dimension of cabin is half the wavelenght of a certain frequency - that frequency is the corner frequency for cabin's boost. by matching the corner frequency of a sealed box to that of the cabin you can cancel the box's bass loss with cabin's bass gain and achieve near-flat response to almost zero hetz. on the other hand you can NOT do that with ported box because 24db per octave does not equal 12db per octave. [/QUOTE]
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