Quote:
Originally Posted by rlacoste
You are rewriting the book on loudspeaker design… 
Sealed box has 2nd order high pass behavior while vented box ( front or rear) has, at best, 3rd, but usually 4th order high pass behavior.
The group delay is a measure of the slope of the phase response at any given frequency. In any passive loudspeaker which is a minimum phase device, there is a unique relationship between amplitude and phase which allows for determination of phase from amplitude. Therefore phase response can be calculated from frequency response.
A group delay of a 3rd or 4th order system ( i.e. vented) is always larger then a 2nd order system ( i.e. sealed).
Read Dickason's "Loudspeaker Cookbook 7th edition" for a reference :
Page 31 –sealed box group delay simulation - max GD 7.5ms
Page 64 –vented box group delay simulation - max GD 40 ms (no less than 24) |
Is that your reference book .....
You do realize you are mixing up what i have said, research linear phase and then look into the understanding and the relationship of port location on a BR, next look up the importance of what you propose factoring listening distance and port location , its not to mean it does not exist , its of little to zero importance to the differences you purpose ...
Its like this
Horn speaker fan boys ....... Sensitivity is everything
Panel speaker fanboys ........ Mass and no box is everything
BR fanboys ......... Vents produce real bass
Seal box fan boys ...... group delay is everything
Sounds familiar ....
You can harp and spin the science anyway you want , in the end there is no one key to this lock, if there was there would only be one type of speaker selling , there is no best speaker in the world regardless of who writes it or how many times it has been spoken or how the marketing department spin the science ...
Charles experience mimics mine ....
Sometimes its as simply as ,
A man should look for what is, and not for what he thinks should be.
-Albert Einstein
Regards ....