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!

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?

[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