MP3 320kbs fake or not ?

[ebon gull]

Hi guys, I hope you're doing well. I've been dealing with a problem for several weeks now. I download music from a DJ pool, and the sound quality varies considerably. All the tracks are supposed to be 320 kbps MP3s, but I get the impression that some of them are actually 128 kbps tracks disguised as 320 kbps. Some tracks have a consistent spectrum up to 20 kbps, but others have a noticeable drop at 16 kbps and then rise back up to 20 kbps. Do you think I should ban all music that has a spectrum similar to image 2? Can I still mix with it in clubs?

[nocturne sluice]

You're misreading the spectrograph.

Image 2 looks perfectly fine.

Not all sounds have every frequency within them, hence you won't always have songs that fill every frequency range in the spectrum.

[ebon gull]

OK, so I see that it's only a problem if there's a clear cut-off at 16 kHz? It seemed to me that image 2 could mean poorly transcoded music.

[nocturne sluice]

Again, you're misinterpreting the spectrograph

Or maybe not, I dunno. I can't hear the track

If the track has the tell-tale watery high end, then yeah it's a transcode

It's pretty easy to tell with your ears if it's a 128Kbps MP3