Tweeter measurement

[sm52]

Hello John. I really liked the latest version of REW. Looks like everyone's wish came true! Thanks to.
I have a question about measuring the tweeter. The tweeter is AMT, a Hale emitter, I'm not sure what it's called properly. I measured it in the finished case in its place where it should be. I don't understand the GD graph of this driver. It shows a delay of 22ms from 20kHz to 2kHz. How can one driver have such a delay?

 

[John Mulcahy]

I don't know the source of the group delay, sorry. The measurement is pretty noisy, probably better to start it at about 500 Hz to remove the noise where there is no response, measure near field to reduce the room effects, and probably worth measuring at 96 kHz to allow a higher end frequency and get a better view of the overall response.

 

[sm52]

Thanks. I will try these options.

 

[sm52]

I have reviewed the measurements of other drivers and found similar behavior on the GD graph - around 19ms. The measurements of other tweeters involved other amplifiers and other wires to them. The microphone, microphone preamp, soundcard and laptop were the same. What do you think could be the reason?

The measurement is pretty noisy

There is noise, but up to 50 Hertz. Could this affect the 20 kHz range?

 

[John Mulcahy]

As I said, I don't know the source of the group delay, but you are wrong to make a claim about it being 19 ms or 20 ms or anything else. There is so much noise and room content in your measurement that it is difficult to say anything much about it, smoothing it to 1 octave is just smearing all of that into something you cannot meaningfully comment on.