Recent content by ReDRuM

Thank you :)

Hello, I'm wondering what influences the "not reliable" parameter for RT60 measurements. I'm testing some panels, and am noticing that while testing the empty room, RT60 measurements are rarely labeled as "not reliable", but with panels added, many more values are flagged. The sweep is fairly...

It's neither really! The spectrogram is the same as a waterfall graph, but viewed from above. So in other words, the "hole" you are mentioning simply denotes that the frequency in question has decayed completely by that time. That's it. Ha, no worries, your comments regarding alignment have...

I think we (at least I have) might be reading too much into the spectrogram. From your first spectrogram message: The blue area you have marked is not a "null"... It is simply the point in time where that particular frequency has decayed completely. The spectrogram is basically just a...

The measurements labeled as "R" and "L" are the mains, full range, no cutoff. Adams S3A

EDIT: Ignore, wrong! Obviously, the measurement for my R speaker shows otherwise... It clearly shows the reflection happening at 5 ms, when, by the logic above, everything under one period should be at 0 ms. In this case, for 100 Hz, one period is 10 ms. But in all my other measurements the...

EDIT: Ignore, wrong! :) I think my sentence came out more complicated than necessary :) My point is simply this: If the offending reflection happens too soon, it is impossible for the algorithm to place it *exactly* where it should be on the time axis. In your SBIR example - 5.5 ms. So it...

EDIT: Ignore this, completely wrong :D If I had to guess, I'd guess this: On the spectogram, if a frequency range shows close to zero level at t=0, this probably means that the reflection causing the dip happens sooner than the "lower bound" necessary for extremely precise interpretation...

Thanks, that worked. But now I'm super confused :greengrin: If setup that way, the R speaker measurement makes sense I guess (the one you posted). It shows maximum level at t=0, and then it shows "dips" occurring later on. But the L speaker looks like this: I would read this as: Close to...

I think I understand what you mean, but I'm having a hard time replicating your spectrogram. Could you please share the settings, so I can explore?

Understood, thanks. Is my understanding above correct? With the right side window set to 11 ms, the 90 Hz dip already starts appearing, so it is impossible to know if it actually appears sooner?

And if what you wrote above is correct -> That the 90 Hz null starts appearing right at the window size where 90 Hz starts "showing up" at all (1/T), then it is possible that the offending reflection actually arrives even sooner? Say 5,6 ms (this would be 1/2 λ extra path = 100 Hz dip SBIR)...

Firstly, thank you jtalden and Matthew for the help, much appreciated! I should have chosen my words more carefully, sorry about that. I understand everything you wrote... I wasn't trying to read the source from the data "literally"... What I meant was, if I can be certain that the offending...

Hello, I’m trying to figure out which surface is the source of a nasty reflection that’s causing me headaches, I hope someone can help. Questions are numbered, for easier navigation :) But feel free to refer to whatever :) The dip is around 90 Hz or so: Engaging the sub fixes it (the sub...

Thank you!