Best way to measure phase at each end of a transmission line??

[DeeLuxx]

Hi All,

Working on a TL design - that thread is here: https://www.diyaudio.com/forums/mul...s-duevel-planets-clone-transmission-line.html

Wondering what the best way would be to accurately measure the phase at different points of the transmission line?

My idea so far, is to get a focusrite sapphire, two measurement mics, and then to have one at the speaker cone, and another at the TL port exit. Also thinking of drilling holes in the side of the speaker cabinet to insert the mic at different lengths along the TL, and then plug the holes that aren't being used.

No idea about software either, i assume REW might be of use? but again no idea, never done this before.

For reference, I work usually with RF, and i'm used to tuning antennas with a vector network analyzer, so i'm not sure what the acoustic equivalent would be.

Thanks in advance for any suggestions!

 

[plasnu]

About software, I record the signal and see the actual waveform with audio editor. Reference signal is recorded on the left channel, and measured signal on the right.

 

[DeeLuxx]

That makes sense.

Does the audio interface sample the channels at the same time? or is there a slight phase delay in the sampling which you have to remove later?

Guess it wouldnt be so bad at the lower frequencies.

Thanks!

 

[plasnu]

That makes sense.

Does the audio interface sample the channels at the same time? or is there a slight phase delay in the sampling which you have to remove later?

Guess it wouldnt be so bad at the lower frequencies.

Thanks!

1. Yes.
2. If the mic is close enough to the speaker, you will not see phase shift, especially at low frequency. (180 phase shift?, then the connection is wrong. LOL)

Good luck!