If you are bored of downloading music having a crap or uncertified quality, this tool is made for you!
Spek
https://spek.cc/
This tool is a sound spectrum analyzer. I'm gonna show you how to interpretate the analysis's results:
WAV Format
This the best commercial sound format that you can find. Here's a screenshot of how it looks when it gets analyzed by Spek:
Usually, a .wav sound takes between 30mb and 80mb depending the song's length.
Authentic MP3 320Kbps
This is the cheapest and most common sound format that you can find and buy on the internet. However its quality is not always certified. If you right click on the sound file and check the properties, you can find the bitrate.. But this is not a reliable information! That's the point of using Spek to check the real track's quality. Here's the same song as the one above, as MP3 320Kbps:
The frequences might go under or sometimes even above the 20kHz limit but must NOT go under 15kHz. An authentic MP3 320Kbps usually takes between 9mb and 13mb, depending the song's length. Less, it's transcoded or fake.
To make sure you've got an authentic MP3 320Kbps, you should buy/download your music from official sources such Google Play; Beatport or official artists and labels's soundcloud/facebook pages for free downloads.
Now let's check how to bust a fake or transcoded MP3 320:
Transcoded / Fake MP3 320Kbps
Supposed to be a 320Kbps, but the song doesn't sound good and the spectrum is stuck to 15KHz. This only means it has been recorded from youtube who doesn't even support 320kbps.
Usually, all those sites such "mp3plate" or "skullmp3" etc etc.. provides very low quality rips from youtube.
If the sound spectrum reachs the lower frequences, it means it is 192Kbps*, 128Kbps* or less.
* The mp3 format is declined under several compression levels, lower the value is (128kbps) lower the quality is. Higher the value is (320kbps) better the quality is. It also affects the file's size.
Unlike the FLAC (Free Lossless Audio Codec) which can be converted back to WAV without any loss on the sound quality, a compression into mp3 format is irreversible. You might convert the tune back into any format you want, you will never recover the original quality.
Now you can enjoy your music