Does A Higher Bitrate Mean Better Quality?

If you have an audiophile friend, then you’ve probably made the mistake of playing them a song at 123kbps and barely lived to tell the tale.  As they sprawled around on the floor like a supervillain subjected to the worst noise imaginable, you had to wonder if they were just pretentious or does higher bitrates really mean higher quality. 

Higher bitrates mean that more audio data is being transferred per second.  So, provided that the song was recorded in a high-quality format, a higher bit rate should offer better audio quality.  However, at very bitrates, the increase in audio quality can only be noticed on high-end speakers.

Using the bitrate to judge audio quality is a decent rule of thumb.  However, bitrate is just one link in the chain from the recording studio to your ears, meaning that there are cases where even high bitrates will matter less.

How Does Bitrate Impact Audio Quality?

To best understand how bitrate affects the audio quality of the song you are listening to, you need to understand the journey that the song takes from when it is recorded in a studio to when you eventually hear it.

One of the most straightforward analogies explaining this process is to think of a song like a river leading to a dam and flowing through the sluice at the dam wall.  Let’s explain.

Capturing The Rivers:  Sample Rate And Bit Depth Explained

Most of us have some sort of idea of how a recording studio works.  First, analog instruments are played, and their sounds are captured and recorded in a digital format.  This process is like collecting water from various rivers and streams into a dam. 

The amount and quality of the water you can collect are determined by the size and quality of the streams.  In music terms, this is called the sample rate and bit depth.

Sample Rate Explained

Sound samples or “audio pictures” are taken and stored as an instrument is played.  If you don’t take enough samples, there could be gaps in the song in pieces of data missing.   Typically, music is recorded at 44.1Khz for CD quality.  This means that samples are taken at a rate of 44100 per second.

The sample rate is much like the flow rate of a stream or river leading into a dam.  A constant flow rate will obviously give you a much better result than a stream that trickles intermittently. 

Any gap in the sample rate will result in a hole in the music, meaning that in that instant, no audio data is transferred, so having a high sample rate at the point of recording is crucial.

Bit Depth Explained

Let’s assume you have a constant flowing stream, but that stream is very shallow.  In this case, while there is indeed a constant flow of water, the actual amount of water isn’t all that great.

This is where bit depth comes into play.  Bit depth refers to the actual amount of audio data that can be captured inside each sample.  Bit depth is much like image resolution, where higher resolutions equal more data captured inside each image.

The typical recording bit depth is either 16- or 24-bit.  Like photos, the difference in quality isn’t necessarily immediately evident to the naked eye, especially from a distance.  But the lower resolution will quickly become problematic if you start cropping, zooming, and editing the image. 

The same applies to audio.  It’s doubtful that your human ear will hear the difference between 16 and 24-bit depths, but as soon as you start compression and processing, the end result could vary quite a bit.

Accessing The Dam Waters: Bitrate Explained

So, you’ve captured the audio track into a complete and mastered data file.  This file is the dammed-up river waters.  Obviously, it’s not possible to move the whole damn of data downriver at the same time.  So, the data needs to be compressed in some form to be practically accessible. 

This compression happens in various ways depending on the chosen audio format, which includes MP3, CD, Vorbis, AAC, etc.

Think of these formats like the sluices on a dam wall, which also come in various shapes, sizes, and mechanics.  And some are objectively just better than others. 

Bitrate is basically the amount of water that can flow through these sluices.  In other words, bitrate determines the amount of audio data retained after compression.  During the compression phase, bits of audio data are discarded, just like not all of the water in the dam makes it through the compressed sluice. 

Most formats are pretty intelligent with how they discard this data, starting with data that your typical human ear cannot hear and then moving further into the audible range with increased compression.

A Higher Bitrate Means More Audio Data

So how does this dam analogy explain whether or not higher bitrates mean better quality?  Well, higher bitrates simply mean higher data flow rates or more water passing through the sluice. 

However, if the initial data capturing process was low quality, then a higher bit rate won’t help.  If you just dammed up a whole bunch of murky water, or if your dam is nearly empty, then having a big sluice isn’t going to improve the quality of water sent to the farmlands below.

This can also be thought of as writing a summary for a book.  If it is a badly written book, then it doesn’t matter how long you make the summary because it won’t improve the book’s quality.  But if it was a great book, you could lose some important details if you make the summary shorter.

In the same way, if high-quality audio data was collected, then the bitrate would absolutely impact the quality because the lower the bitrate is, the more data will be lost, and the worse the song will sound. 

Higher Bitrates Don’t Matter If You Can’t Hear It

Let’s assume that audio was captured on a high-resolution sample rate and bit depth, leaving you with an audiophile’s dream track.  In this case, a higher bit rate means that the song’s audio quality will be higher, but this may not matter as much as you think.

Let’s take one last look at our analogy.  Even if we have a perfect dam and a massive sluice, that water will go to waste if the farmers downstream don’t have big enough pumps to utilize the increased flow.

In the same way, the last bottleneck in your audio journey is the hardware that you use to listen to your music.  And, if we’re being honest, most people don’t have the high-end audio systems or headphones to ultimately benefit from ultra-high bit rates. 

So, unless you’re rocking a digital-analog converter (DAC) and an expensive high-fidelity sound system or headphones, then you likely won’t notice too much difference between Spotify’s high (160Kbps) and very high (320Kbps) options. 

That being said, once you drop below 96kbps, you don’t need expensive gear or an audiophile’s ear to notice that your music doesn’t sound great.  192Kbps is the optimum point between data usage and audio quality for most people. 

Here is an example of how bitrates affect the audio quality of an MP3: https://www.youtube.com/watch?v=0O8MclLD1d0.  First, see if you can tell the difference between the song’s 320- and 192Kbps versions.  And then notice the evident decline in quality below 96Kbps.

Conclusion

Higher bitrates allow for high flow rates of audio data, meaning that less audio data is discarded during the compression process.  However, higher bit rates cannot improve the audio quality of recorded samples, so if the sample is low quality, the song will just be bad. 

References

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