FLAC vs. MP3: Can You Really Hear The Difference?

Being a casual listener for most of my life, I was content with the MP3 format. 

Back in the day, a new phone would come pre-loaded with songs. A phone would have a built-in music player app and a sizeable album of popular songs, which was awesome. I didn’t have to go and download the songs myself. 

A few years in, I started streaming my songs instead. Spotify streams its songs in MP3 with a bit rate of 160 to 320 kbps. At the time, I thought this was fine – great, even. After turning over to the “dark side” a.k.a. becoming an audiophile, I switched over to using FLAC (Free Lossless Audio Codec) files. 

Now, as much as I’d like to save you some time by telling you that it’s way better and that you should make the switch as well, I can’t. Why? It isn’t as simple as saying that lossy always loses out to lossless audio files. And truth be told, some people can’t hear the difference at all. 

So is lossless just a hoax then? Or is it a case of the untrained ear? I doubt that people having difficulty hearing any difference would have anything to do with this. 

First, lossless isn’t a hoax, and second, there’s no such thing as a golden ear. Lossless files do provide better sound and you can hear it just as well. An absence of proper listening gear like a decent source and a set of cans might be the reason why it’s harder to discern though.  

A Little Look-See

Everyone keeps saying there’s compression going on with MP3 files but the gravity of what it means doesn’t strike you until you see what it actually looks like. I want you to look at this spectrogram right here. 

On the waveform, you can clearly see that the frequencies cut right off at 15 KHz. Now on its own, this really doesn’t make much sense but take a look at the second image. 

The waveform now cuts off at 20KHz. What does this mean? The first image shows the lowest bit rate that MP3 can go, which is 128 kbps. The second is probably what you’re using when you stream music, which is 320 kbps. 

On paper, this is a numbers game but I can more than argue that 320 kbps sounds a heck of a lot better than 128kbps – and I mean, A LOT. Guilty as charged, I used to download 128 kilobit MP3 files on my old phone and that was mainly for storage reasons. 128 kilobits uses about 5MBs less and for what it was worth back then, I really needed the extra storage. 

I still use 128 kilobit MP3 files to date but only when I need to remind myself how bad it sounds. If you must use MP3, make sure to always stick to 320 kbps. But wait, there’s more. Now take a look at the next image.

There are more frequencies past 20 KHz now. Even though it’s not a lot since it’s an old recording of Engelbert Humperdinck, those extra bits of waveform are pieces of information, such as texture, airiness, and what have you. On other tracks that are relatively newer, the same comparisons yield a waveform that goes all the way up to 22 KHz. 

Suffice it to say that there’s a real difference in quality here, both in the spectrogram analyses and playing it by ear. The spectrogram did a good job of showing us what the waveform looks like based on file type but seeing isn’t believing – hearing is. To that end, we’ll be doing a little test.

FLAC vs. MP3: The Test

In this test, we’ll be using FLAC files and MP3 files back-to-back and testing them with an array of headphones and IEMs. We’ll be testing out three songs in total. 

Some cans and IEMs I’ll be using are the Harmonicdyne Athena, Hifiman HE400SE, Raptgo Bridge, Tangzu Zetian Wu, and Whizzer Kylin HE03D. For sources, I’ll be using the Shanling M3X Ltd., iBasso DC03 Pro, and the Venture Electronics Megatron. 

If you want to compare notes, feel free to do some on your own and read my insights afterward.

1. Be The One by Bree Runway ft. Khalid (FLAC 16-bit vs. MP3, 320 kbps)

Okay, this one was really hard as it was a real prefrontal cortex stress test. I did hear some differences, mainly with the bass and the transients but for the most part, the MP3 sounded just as good as FLAC. 

The bass sounded a little diffused and wooly in some parts of the song on MP3, while FLAC showed a tad more presence. The transients were about the same, getting a bit faint on MP3 while FLAC presented them with a little more snap. 

All else, performance-wise, I can’t complain about MP3 as it’s only roughly 8MB. FLAC on the other hand is 23.3MB, which is twice as much space. The differences are small and yet personally, I’d still pick FLAC over MP3 since I have the files on my laptop and I don’t mind the extra storage tax.  

2. Billy Toppy by Men I Trust (FLAC 16-bit vs. MP3, 320 kbps)

I’ll say this now. There isn’t that definitive line where you go “Oh, this one’s the MP3”. In a blind test, I’m at least a hundred percent sure you won’t be able to tell the difference. Again, these impressions have been made after hours of constant critical listening. After a series of brain torture, I came up with the following. 

On this specific track, the projection of the bass was noticeably stronger on FLAC, whereas the MP3 sounded a little flatter. The voices, especially the little whispers near the end were a little more resolute and audible on FLAC as well. The MP3 version performed pretty well here but the point still goes to FLAC. 

At first, I wasn’t sure if there was any difference at all given that MP3 had more of the same texture and presentation as FLAC. The devil is in the details though and when it comes to having even just a little bit of more detail, I think FLAC wins here. 

3. Orb by Ichika Nito (FLAC 16-bit vs. MP3, 320 kbps)

I picked a pure instrumental track to see how the transients without any of the distractions would sound and although I deliberated whether I’d pick Polyphia or Ichika Nito, I ultimately ended up with Orb since its recording is cleaner.

With most FLAC files, I always see good improvements in the bass and the transient response, so I thought “Hey, why not a track with lots of it”. 

On this track, FLAC easily takes the win. The staging was audibly better and the strings lingered more naturally than its MP3 counterpart. There was a sense of power behind the strings when listening to the FLAC version that almost lets me think I can see how much pressure Ichika Nito is putting on a note before he switches scales. There was a level of dynamics that was lacking in MP3 that was just so apparent on FLAC. 

The details were also better on FLAC despite having the same clean layering as MP3. These kinds of tracks are the ones I love having in FLAC as they’re well-recorded and the level of information and nuance in them are easily perceptible. 

FLAC vs. MP3: Which Should You Go For?

Ultimately, FLAC does sound better than MP3 but not by a huge mark. Still, a little goes a long way and I do think that small details matter.  

At the end of the day, MP3 isn’t the devil. It’s convenient and it uses less storage space, plus it’s more accessible than FLAC. On the other hand, FLAC presents ultimately better playback and is ideal if you plan on converting your files to other formats like WAV or MP3. 

The differences I picked up on my tests were conceived with much effort and as much as you may attribute half, if not most of it, to placebo, I’m sure that FLAC definitely edges out MP3 at 128 kbps. Yes, I tested that out too. So for all intents and purposes, if you must use MP3, stick with 320 kbps. It’s not entirely there but it gets quite close. 

Final Thoughts

In conclusion, the FLAC vs. MP3 debate ultimately comes down to your personal preferences and priorities. 

While FLAC undoubtedly offers superior sound quality when compared to MP3, the differences may not be enough to have everyone make the switch. For audiophiles who prioritize sound quality above all, FLAC remains to be the optimal choice. Other considerations like equipment and the fact that you may or may not hear the differences yourself still apply though. 

In the end, whether you lean towards FLAC or stick with a well-encoded MP3 depends on what you want. I know that I probably wouldn’t be using FLAC if I was just cruising my beats in a cafe, but hey, that’s just me. I prefer to leave my intense listening sessions at home, where I can access my bulky headphones and sources with all their matching wires to boot.

MP3 and FLAC have their own merits, and the choice should align with your specific needs, listening environment, and your personal rig.