Recent content by dcibel

I have this very device, compared against other calibrated devices and found levels within 0.3dB so the specifications are accurate. Good enough for me, and results in measurements in REW that are SPL accurate at any frequency to that level of accuracy. I use it with a few different mics, with...

Clock adjustment is a check for difference in clock rate between the playback and recording devices. It will only be truly and reliably zero if the playback and recording device is the same, not possible with a USB mic. Typical values <100ppm are normal. If you want to check accuracy and...

Hi John, Just a thought for future development of the RTA window. It would be great to be able to see a live spectrogram here to display the history of the signal being measured. For an example, here's a screenshot from some antique software that I used to love, I just can't get it to run on my...

Thank you John, it's much faster now, maybe 5x.

So it is, never mind then ;)

I've highlighted in red the part I was referring to, which is the THD trace.Reading through the AudioXpress article, the focus is on a modified THD calculation, which I don't believe REW is doing, although all other aspects are covered.

For what it's worth @John Mulcahy , the THD figure on the distortion chart is still shown in the "traditional" way even when "plot harmonics at the harmonic frequency" and "use harmonic freq as ref" are checked. It's not bothered me in the past as I usually disregard THD as I'm more interested...

John beat me to the punch.

https://www.listeninc.com/wp/media/2026/02/Article_Frequency_normalized_distortion_AX_March-2026.pdf From a quick scan, these features are already in REW via the "use harmonic frequency as ref" and "plot harmonics at the harmonic frequency" options. Use dbr Y-axis scale to view a normalized...

I opened overlay window, placed side by side with the main window, and watched adjusting SPL offset affecting both main window and overlay, without needing to add the offset to the original data. Same result if the offset it applied in the overlay window. Likely overlay window was set to...

thanks John. As a feature request, it would be nice to be able to show the noise floor result on the SPL tab in addition to the distortion tab.

Ah, I see it now. It's shown whether the phase trace is enabled or not, so it looks a bit out of place when phase isn't shown, since there's no phase axis units on the chart.

Hi John, I was measuring some capacitors today, and noticed that when the "overlay model traces" is selected for the component model, there's an additional horizontal dashed line near the bottom of the chart. Also, set graph limits for impedance is having some trouble with very small values...

ETC, or an impulse response for that matter cannot be determined with constant stimulus signal measured via RTA. So, you can use RTA for many aspects of real-time response analysis, for ETC, RT60 decay, etc. you need to run a sweep measurement.

Use File -> Import -> Impedance instead of drag and drop, it will be imported properly.