How to check the quality of tracks

I always challenge audiophiles to put their ears where their mouth is and do a blind trial of sit in a room and listen to 10 various iterations of a track then tell me what they think the format of it is(eg mp3, wav) and that if they are 100% successful, I will STFU. They can even pick the amp and speaker system. Never had one take me up on the offer. 🙂
Honestly, I reckon that 128k mp3 is even good enough to gig with.

We actually did a 10-person blind test like that a few years ago. 4 DJs, 1 live sound guy, 2 musicians and 3 “random” people. The test took place in a club that we had access too. I used a laptop with a high quality 24-bit sound card and optimized drivers. We ran a 5m balanced XLR into the house PA.

I was the instigator and I had 5 tracks. From each I had a wav rip, a 128, 192, 256, 320 and a lossless (FLAC) 30 second clip. I had score sheets made up. I played each of the 6 clips in random order per track. The “audience” had to indicate which clip number had which quality.

At the end I collected all the sheets, ran it through a spreadsheet with some weighing factors. The outcome was not totally unsuspected by me, but did surprise a few ardent anti-MP3 peeps in the room.

Even without the weighing factor, the answer was VERY clear. Lots of people got 128kbps right most of the time. Two people got 192kbps right most of the time, some others some of the time. NOBODY had any significant statistical succes determining the difference between 256, 320, FLAC and WAV.

Since then I will accept 256 kbps as bottom quality. 320kbps is truly fine with me. The one thing I a not too sure about yet (and which might make for a nice follow-up research sometime) is how the quality of MP3 holds up when heavy processing is done to it, like all kinds of FX and/or pitch control. Does an MP3 deteriorate faster or more than a WAV when run through DSP (digital sound processing)?

Greetinx.

Some great advice from the guys above.

I agree that these days you can practically ignore the file type and size. I’ve heard some great 192kps MP3’s and some shockingly bad AIFF/WAV files. A lot of this (in my experience at least) seems to be down to a fairly recent trend of over-compressing and/or excessive boosting of the track volume*.

*This is based on my observations – am more than happy for someone more technical to correct me!

The result of this is a very ‘loud’ but muddy sound that can be quite hard to deal with. Obviously listening to the track is your first port of call, but I’ve also found that when buying online, you can examine the waveform of the track preview. If the waveform has very few peaks/troughs (is more like a square than a bunch of lines), it’s often an indicator that the file may sound awful regardless of what quality you buy (genre dependent obviously).

As I say, this has been my experience but hopefully this may help you avoid buying poorly mastered tracks.

GP

Depending on the length of a track let’s say around 5 to 8 minutes the file size wil be around 12 to 19 MB for a 320 Kbps mp3.
I would recommend getting everything of 320 kbps or better quality. Just to have a good standard. If you for example use a lower quality in a mixtape and you then want to compress that mix because of the file size you may hear differences in volume.
But like everyone has already said, listen good. Have a few benchmark tracks that you know sound good and compare.
Sometimes the High freq sounds glitchy or warped and sometimes the Low freq is muddy. Trust your ears!