What frequency interval for ETC measurement?

[Raptor25]

I'm doing a couple of measurments to read the ETC. Which frequency interval should i use to view the ETC chart? Because i cannot choose which frequency interval to view in REW in the ETC mode (i think fuzz can do this?). Or am i completely lost?

Should it be the upper part of the Schroeder frequency?

[ciro]

Are you talking about time (ms)? Press left and right mouse buttons while moving it left and right (if is not you´re asking for sorry I misunderstood)

[Raptor25]

Originally Posted by ciro

Are you talking about time (ms)? Press left and right mouse buttons while moving it left and right (if is not you´re asking for sorry I misunderstood)

No mate. When i'm about to do a measurement i can specify a frequency interval (say from 500 hz to 20khz). I need to know which interval is most appropriate for a ETC measurement with one speaker. Surely the lower frequency doesn't have any effect on the ETC?

[ciro]

From REW help:

"An important property of an impulse, not intuitively obvious, is that it if you break it up into individual sine waves you find that it contains all frequencies at the same amplitude. Strange but true.

Ciro

[JohnPM]

Make a full range measurement, 0 to sample rate/2 (22.05 or 24kHz depending on the soundcard sample rate). If you want to see the result within a particular octave or 1/3 octave band use the "Filtered IR" graph to select the band.

[Raptor25]

Originally Posted by JohnPM

Make a full range measurement, 0 to sample rate/2 (22.05 or 24kHz depending on the soundcard sample rate). If you want to see the result within a particular octave or 1/3 octave band use the "Filtered IR" graph to select the band.

Thanks all.
But does anyone know why my ETC curves always gets bad?

This is with loopback timing correction and right speaker only.

Is it even possible that i get the majority of the reflections as fast as a couple of ms (around 3,42 ms as shown on pics)?