Bluetooth audio; it’s just like wired audio but without the wires… right? That’s what most people think, but you’re not like most people. You’ve heard about audiophiles’ gripe with the technology, but why is that? What makes Bluetooth technology so different from wired technology? What are the benefits and drawbacks? If you have these questions and others, then you’ve come to the right place. Here’s your ultimate guide to Bluetooth audio.
In this piece, we’re going to dive into how Bluetooth audio works, what makes it better/worse than wired audio, what you should consider when purchasing Bluetooth audio equipment, and more. It’s for burgeoning audiophiles and people who are just curious about the technology. So, let’s dive in.
How Bluetooth works/Codecs
So, let’s start off with one of the core aspects of Bluetooth technology. Obviously, one of the defining features of Bluetooth technology is the fact that it’s wireless. This makes it extremely convenient to use, especially if you find yourself moving around a lot.
While Bluetooth and wired connections are different forms of communication, they’re actually more similar than you might think. In fact, a Bluetooth connection is pretty much the same as a wired connection only with a few extra steps. For a wired connection, the digital signal (your audio file) flows to your device’s DAC (Digital to Analog Converter). This chip will convert those 1s and 0s to actual electrical signals. Those signals are then converted into sound by your audio drivers. It’s pretty straightforward, though this is a simplification of the process.
Bluetooth also involves converting a digital signal into an electrical signal. The only thing is that the signal needs to be sent over the air, and that’s where the codec comes in.
What are codecs?
To explain what a codec is, let’s use an analogy. Let’s say you’re using a pair of Bluetooth headphones with your smartphone. Well, think of your phone as your current house and your headphones as the house you’re moving to. Now, think of the codec as the team of movers transporting your belongings from your old house to your new house.
The codec is responsible for performing several tasks, and one of them is compressing the signal. Your audio file may not be gigantic, but it’s too large to be sent over the air smoothly due to Bluetooth’s limited bandwidth. So, before the signal can be set over the air, it needs to be compressed. The codec will squeeze out the data it feels is not necessary. For instance, it will squeeze out frequencies in the audio that are above what a human being can hear. However, the codec will make sure to keep the fundamental data to make sure you have a complete song.
Going back to our movers analogy, compressing the signal is like the movers packing up all of your belongings neatly and stuffing them into the truck, making sure not to pack too much stuff in one go.
Then, that compressed signal is sent over the air to the headphones. At this point, it’s still a digital signal. Once the signal makes it to your headphones, their onboard codec decompresses that signal, converts the signal to an analog signal, and sends it to the drivers to be converted into audio waves. So, think of the codec in your headphones as family members who unpack the items and place them in the new house.
So, the codec is responsible for compressing and decompressing the audio signal. In fact, that’s where the name “Codec” comes from. It COmpresses and DECompresses data (CO-DEC).
Digging deeper into the codec
Explaining codecs can get a little complicated once you find out that a codec isn’t just one thing. There are hardware-based codecs and software-based codecs. Starting off with hardware-based codecs, these are the physical chips that compress and decompress the data. Think of the hardware-based codec as the actual movers who physically pack up the items.
A hardware-based codec is actually an SoC (System On a Chip). Just like the chip on your smartphone, a codec is composed of several different chips integrated into one chip. Depending on the maker, a codec can contain chips like DACs, ADCs (Analog to Digital Converters), amps, and other chips.
Hardware-based codecs can have several of these chips integrated. In fact, some codecs can have up to six DACs in them.
What about software-based codecs?
If you’ve been in the audio space, then you’ve probably heard of codecs like aptX or LDAC. These are codec algorithms developed by Qualcomm and Sony, respectively.
If the hardware-based codec is the team of physical movers, then the software-based codec is the knowledge of how to pack the items efficiently. These algorithms dictate how the data is compressed. Different algorithms can compress the audio more than others and allow for different bit-depths and sample rates. A lower-quality codec will mean that you’ll hear lower-quality audio and a higher-quality codec means the opposite.
For example, Qualcomm’s aptX codec can send a signal of up to 16-bit/44.1kHz to your headphones. So, your music, no matter how high-quality the track is, will be compressed into a 16-bit/44.1kHz file.
However, aptX HD can transmit data at up to 24-bit/48kHz. So, depending on how high-quality your audio file is, you’ll hear clearer audio using this codec.
There are other codecs that offer different specs, like aptX Adaptive, SBC, AAC, and others. More basic codecs will compress your data even more while premium offerings will try their best to send a lossless file over the air. However, it’s not possible for true lossless Bluetooth audio transfer yet.
Do hardware and software-based codecs have to be compatible?
Yes. The device decompressing the signal needs to be compatible with the device compressing it. If you buy a pair of headphones that are compatible with Sony’s LDAC codec, your phone will need to support that compression algorithm in order to decompress the signal. If not, then it will only use the codec that it’s compatible with.
The same thing goes for your headphones. If your phone uses LDAC, but your headphones don’t support it, then your phone won’t use the codec.
Why do audiophiles dislike Bluetooth audio?
You’ve probably heard about audiophiles’ disdain for Bluetooth audio. Most music lovers won’t really care, but there are those who wouldn’t touch a pair of Sony WH-1000MX headphones with a 29.5ft pole. Why?
The reason was mentioned in the sections above. The thing is that the audio has to be compressed before it makes it to your headphones. No matter how fancy or expensive your Bluetooth cans are, you’re still listening to a compressed audio signal. This is one of the reasons why many people were upset when smartphone makers removed the headphone jack from their phones and tablets.
That’s not a reason to disregard Bluetooth headphones altogether, however. There are companies like Sony that make some of the best Bluetooth headphones on the consumer market, and they represent the audio amazingly. So, if you drop $349 on a pair of expensive headphones, you’re still likely to hear some amazing audio, especially if they’re compatible with a high-quality codec.
However, the true audiophile will be able to hear the difference between a pair of Bluetooth headphones and a pair of wired headphones. With wired headphones, the digital signal is directly converted into an analog signal and sent right through your wire, uncompressed, to your drivers.
What is Bluetooth latency?
So, if you’ve used Bluetooth headphones or a Bluetooth speaker, you’ve probably noticed a little delay in the audio when you do things on your device. Say you’re playing a game, and you’re hearing everything happen a split-second after it happens on your screen. This is called the latency, and it’s an unavoidable part of Bluetooth technology.
At the moment, there’s no such thing as a no-latency Bluetooth device; there’s always some sort of latency. Why does it exist? Remember, your device has to compress the audio before sending it to your headphones. Then, your headphones need to decompress the audio data before converting it to an analog signal and sending it to your drivers. This multi-stage process slows everything down.
The latency varies depending on the software codec you’re using. Going back to the movers analogy, if the codec delivers a higher-quality signal, it means that it’s sending more data over the air. The mover needs to pack more furniture per trip, which takes more time. As you can imagine, packing up an entire living room takes more time than transporting a few boxes.
So, there’s a converse relationship between audio quality and speed. If you want a lower latency, you’ll need to use a lower-quality codec. It’s just the sacrifice you have to make in these days, as there’s no best of both worlds.
But wait, there’s no delay when I’m watching YouTube!
This is true. Most popular video players will secretly offset the video; they’ll play the video just a bit later so that it plays in sync with the delayed audio. Not all video players do this, however. You could hear the audio in sync on YouTube but hear it out of sync on your phone’s media library. It all depends on the app you use. You can expect services like Netflix, Disney+, Hulu, Paramount+, and most other popular streaming services to have this technology.
Why do I hear the latency when watching YouTube on my computer?
Well, it all depends on the application you’re using. 9 times out of 10, you use the YouTube app when watching videos on your phone. The YouTube app offsets the video.
However, when you switch to your computer, you’re using your computer’s browser. The computer’s browser most likely doesn’t offset the video and audio, so you’ll hear the latency. Even if you put on YouTube, your browser still dictates what you hear.
What are Bluetooth versions?
Bluetooth is a technology just like a line of phones or computers. There’s an entity that oversees and develops different versions of Bluetooth called the Bluetooth SIG (Special Interest Group). This massive partnership of thousands of companies helps develop Bluetooth much like how a company develops its devices.
As time goes on, we see different versions of Bluetooth launch. When that happens, device makers will need to make their devices compatible with that version if they want to enjoy the features. So, if a new device boasts a new Bluetooth functionality, this is most likely because the Bluetooth SIG developed a new standard.
The most recent Bluetooth version
Right now, we’re on Bluetooth version 5.4. Arriving in 2023, Bluetooth 5.4 brought some pretty big innovations, but the major upgrades don’t pertain specifically to audio.
How far can Bluetooth reach?
That can be a pretty tricky answer. Back in the day, Bluetooth signals could only reach about 33 feet. However, with recent advancements, the range skyrocketed. With Bluetooth 5.0, released in 2016, the range sits at about 800 feet at the very farthest. That may sound impressive, but this is only under ideal conditions. So, don’t expect to hear your music clearly from two football fields away.
There are certain factors that affect the Bluetooth range. For instance, if any obstacles stand in the way between your devices, they can impact the range. Also, the weather can actually reduce your range. The water in the air during a rainstorm can cause interference between your device and headphones. Another factor is the number of other Bluetooth devices in the area. They can also bring additional interference which can impact the range.
So, just know that, if your device is compatible with at least Bluetooth 5.0, you’ll be able to listen to your device from pretty far away.
Benefits of Bluetooth audio
So, the question is whether you should put your money towards Bluetooth headphones or speakers. There are benefits to using Bluetooth audio devices and some of them are pretty straightforward.
Convenience
Firstly, you can’t argue with the convenience of using a pair of wireless headphones. You’re not tethered by a cord, so you can freely walk around with your headphones or earbuds on your head. As for speakers, you’re free to place them anywhere in your house without worrying about wires.
Control
Next, Bluetooth headphones give you more control over your media. A good pair of wired headphones will likely have a volume control wheel or a little controller on the wire. This controller allows you to adjust the volume, play/pause the music, and skip tracks.
Bluetooth headphones can do all of those things as well, but they can offer a much more customizable experience. Depending on the headphones you get, there will be an app associated. These apps typically allow you to customize what happens when you do certain gestures on your phone. For example, many apps allow you to pick up/reject phone calls, enable noise cancelation/transparency mode, summon the voice assistant on your phone, etc.
It’s important to know that this doesn’t apply to ALL Bluetooth devices. Different companies offer different features and capabilities. However, Bluetooth headphones have much more potential than wired headphones when it comes to control.
Bluetooth speakers don’t typically come with robust controls, as you’re not likely to take phone calls, use noise cancelation, or summon your voice assistant on it. Still, you’re able to control your media playback.
Compatibility
This is a pretty sad thing to say, but the majority of mobile devices that hit the market just aren’t compatible with typical 3.5mm headphones. You’ll need a USB-C dongle to listen to your device using wired headphones. That’s an extra bit of hardware to carry around and keep track of.
However, most mobile devices like phones, tablets, and computers come with Bluetooth connectivity. If you buy a new phone today, it most likely won’t come with a headphone jack. All you have to do is connect your Bluetooth device and start listening to music.
Cons of using Bluetooth audio
Of course, nothing is perfect. Bluetooth audio has its cons as well as its benefits. We already touched on the issue with audio quality. If you care about the sound coming into your ears, then you’ll want to pass on Bluetooth headphones.
Power
Wired devices typically get their power from the audio source. Bluetooth devices, on the other hand, require their own power supply. This can be frustrating, as your audio device can run out of battery power. It’s always a bummer when your headphones die on you when you’re not around a power source.
Connection issues
When you use any sort of wireless device, you do so under the assumption that the connection stays consistent. However, connection issues can happen with any connected devices. There are instances when audio devices fail to connect or lose connection. As for earbuds, it’s possible for the left and right buds to fall perpetually out of sync, and this actually happened to an Android Headlines writer. You just don’t get this with wired connections.
Switching devices
Next, switching devices can be pretty frustrating. If you’re using a wired audio device, switching to another device usually consists of just plugging the cord into the new device. In the case of Bluetooth, you have to go through the process of unpairing the headphones or speaker from the old device and pairing them with the new device. This usually involves digging into the Bluetooth settings. There’s no plug-and-play with Bluetooth.
What to consider when buying Bluetooth devices
With all that said, what should you think about when picking up a new Bluetooth device? If you care about audio quality, see what codec the device is compatible with. Look for the LDAC or aptX HD label on the box or website. Companies usually proudly boast compatibility with these codecs, as these are some of the best on the market.
Next, check out the battery life on it. Many companies tell you their devices’ battery life based on clinical laboratory tests, so you’ll have a good idea of how much listening time you’ll have. You don’t want a pair of headphones that constantly die on you before the day is out.
Don’t overpay for “audiophile-grade” Bluetooth tech. There are premium companies out there selling Bluetooth headphones that cost far more than they should! Just remember that, no matter how good the hardware is, you’ll still be hearing a compressed signal. As such, there’s a limit to how good the music will actually sound.
At the time of writing this, Sony’s best Bluetooth headphones are the WH-1000XM5. They retail for $349, and that’s around the price for great consumer-grade audio hardware. You’ll more than likely be perfectly fine with those headphones. So, if a company tries to sell you headphones for twice that price or more, just know that you’re not going to get a much better experience. The same thing goes for TWS earbuds and speakers. It’s always important to know what you’re getting into before buying expensive audio gear.
And there you have it! The more you know, the more you grow! Hopefully, this guide was able to shed a bit of light on one of the most popular audio technologies.
