Re: Trying to learn to understand spectral analysis of mp3s Reply #25 – 2016-05-13 08:41:57 Quote from: deathcoreRULES on 2016-05-13 01:07:21Quote from: bennetng on 2016-05-12 18:54:59M4A file, Bitrate 61 kbps. Cut-off at 20.5 kHz.[EDIT]Didn't notice I am in the mp3 forum, so it may be off topic? mp3PRO can make the spectrum looks full in low bitrate as well although it requires a compatible decoder.But M4A/AAC is suppose to preserve more frequencies than MP3What if I transcode this 61kbps aac to a 320k mp3? Looks like someone (I am not talking about you) will really believe that it is a direct 320k encoding from a lossless source without even listening.I don't understand why some people (I am not talking about you again) in 2016 still believe that more HF in spectrum = high quality or high bitrate. Lossless codecs can generally reduce a 1411kbps audio file to somewhere about 500-1000kbps, then how can a lossy codec really preserve something up to 20khz at 61kbps? Of course a lot of audio information are generated or synthesized by clever psychoacoustics and DSP experts. Nowadays a lot of people (not you again) pretend they are real experts in these area by merely looking at a spectrogram, how hilarious.