We can not hear group-delay under 100Hz?

[SY]

Originally Posted by Pano

Obviously not. It's being discussed right here, isn't it?

Indeed. Perhaps some nice fellow who is quick with Goldwave could prepare a couple of files like I suggested above to isolate the effect of group delay, and let people answer the question from experience rather than proclamation?

[Pano]

Yeah, Helmuth - that's one way of looking at it. But I have no idea if the audibility stays at a constant product over the frequency range.
Someone here should know.

[Pano]

Originally Posted by SY

Indeed. Perhaps some nice fellow who is quick with Goldwave could prepare a couple of files....

How did you do GD in Goldwave? I've never tried. Game to try it, tho.

[planet10]

Originally Posted by system7

High inductance on the woofer produces a slow deep bass which is almost like built-in bafflestep compensation. Low Inductance woofers produce fast lighter bass.

To be able to produce "fast" bass a woofer needs to have good HF response, typically one of the benefits of a low inductance woofer. Moot once you add a LP filter.

dave

[Helmuth]

Originally Posted by Pano

Yeah, Helmuth - that's one way of looking at it. But I have no idea if the audibility stays at a constant product over the frequency range.
Someone here should know.

If it was half cycle the product would be 500 and there for full cycle 1000.

It makes a quick look at GD effect easy when it works this way.

[system7]

It's all about the steepness of the slopes, isn't it?

Group Delay gets worse with steep slopes. This applies to bass rolloff too, and if you can't hear that big closed boxes (2nd Order, 12dB per octave) are faster than reflex (4th Order, 24dB per octave) you must be deaf!

I'd reckon you can alleviate crossover midrange group delay issues with some time alignment between drivers and low order slopes.

[sreten]

Originally Posted by system7

It's all about the steepness of the slopes, isn't it?

Hi,

Of course it is, which determines phase response. They
are all related, choose your position of the same thing.

rgds, sreten.

[Pano]

If you want to test this by listening, I've made some files for you. You'll recognize the song. It has good content below 100Hz
The audio file was split into 2 parts, one was 4th order low pass filtered at 100Hz, the other high pass filtered at 125Hz. The spread is because the filter is butterworth and combines flatter with the slight spread. The file was then recombined. Phase is rotated 180 degs at 110Hz (because of the spread) and continues down to 360 degs at DC. Or vice-versa, depending on how you look at it.

The files are here, you can download them. About 1 min long, each 2.2meg in 320KBS mp3 format. Can you tell which was manipulated, and which was not? Or at least if there is a difference or not between the 3?

[Pano]

To find the download:
Click on the cloud beside the file/track. It will take you to the track.
Look for the Down Arrow to download

[SY]

Well done, Pano! I'd suggest people use the ABX plug in for foobar to determine whether or not they can actually hear the difference.