Troubles with spectrogram frequency Y-scale

[Rinkode]

Hello Spectrum Viewer team,

I'm a PhD student using the Open Ephys GUI (v0.6.7 (Plugin API v8)) to record LFP signals, and I’ve encountered a potential issue with the Spectrum viewer plugin's frequency scaling on my two Windows 10 laptops. (version 0.2.0-API8, 2023-04-11)

Since I'm in France, the power line frequency is 50 Hz, with harmonics expected at 100 Hz, etc. However, in real-time analysis with the Spectrum viewer in spectrogram mode, changing the Y-axis frequency scale doesn’t seem to impact the displayed power as expected. I’ve attached sample data where I've alligned 3 different timescale displays, first alligned in full screen, then with frequency alligned (with noise bands in orange).

You can observe that:

• The noise bands appear misaligned with 50 Hz when adjusting the frequency scale.
• These noise bands sometimes align inconsistently with various frequencies, depending on the scale.

I would expect the Spectrum viewer to display frequency bands consistently, reflecting the 50 Hz power line noise and harmonics, even when the Y-axis frequency scale is adjusted.

Additional Feedback:
If you’re considering feature updates, it would be incredibly useful to have options to adjust the power colorscale and timescale in the Spectrum viewer to better assess signal stability over time.

Thanks for your help and any insights you may have!

Best regards,
Rinkode

[anjaldoshi]

Hi @Rinkode,

Thanks for the detailed report. We'll take a closer look at it and update you as soon as we have figured out what's going on.