4th order, 5th orde,r 6th order Filters, What does it Mean ? ?

[LE15-Thumper]

4th order, 5th order, 6th order Filters, What does it Mean ? ?
Slope per octave ?

And Giskard talks a lot about group delay. Is this just phase shift within a certain band of frequencies ? If you have a lot of group delay for instance from a bass filter/booster such as the BX63. How does this anomily show up in the sound, What do you hear that is undesireable ? What does group delay sound like ?

[aust-ted]

My understanding of the filter order relates to the # of effective elements in the filter. A simple cap filter is regarded as a first order and is 6dB/ octave. If you add a inductor you have a second order filter (ie two active elements) and you get 12dB/ octave. Can get more complex than this but that is how I think of it, so a sixth order would have 6 active elements and would be 36dB/ octave.

Group delay relates to phase distortion. I find the terminology confusing. The following webpage has a detailed explanation of it -http://www.trueaudio.com/post_010.htm

Regards
Ted

[rek50]

http://www.the12volt.com/caraudio/crosscalc.asp Some explanations here and calcs to boot.

[Dougie]

Here is a great link with great graphics that explain crossover slopes and what they mean.

http://www.bcae1.com/xoorder.htm

Doug

[4313B]

Gotta love the net!

YEAH BABY! :nutz:

Remember having to actually walk to the Library 20 miles one way in hip high snow uphill both ways to get any information at all? :banghead:

[Mr. Widget]

And Giskard talks a lot about group delay. Is this just phase shift within a certain band of frequencies ? If you have a lot of group delay for instance from a bass filter/booster such as the BX63. How does this anomily show up in the sound, What do you hear that is undesireable ? What does group delay sound like ?

What does group delay sound like? That is a good question. I have never done an experiment to isolate group delay and make a comparison, and in fact doubt that it would have been possible to do prior to the digital age. With a DEQX unit it would be possible to listen to a low frequency system both with and without group delay correction... it would be an interesting comparison and I might give that a shot when time permits.

Without having done the above comparison I can only report on the subjective listening quality of systems with more or less group delay. Since other variables have also been changed I am not certain that this is the correct representation, but to me systems with excessive group delay tend to have less control, sound boomier, exhibit poor transient response etc.

Widget