Andrew Heinzman
Bluetooth has matured into a high-quality, reliable listening standard. But hardcore Netflix fans, gamers, and musicians may find the lag associated with Bluetooth headphones intolerable. Here’s where that lag comes from and a few solutions to keep you from going back to a pair of wired headphones.
Update, 9/9/22: Checked content for accuracy, product availability, and dead links. Updated buy links for Creative Outlier and Apple wireless earbuds. Added clarification for Bluetooth versions 5.1-5.3.
Just to Be Clear, Latency Is Unavoidable
Bluetooth 5.0 Should Resolve Most Audio-Video Issues
For Minimal Latency, Focus on Audio Codecs
Just to Be Clear, Latency Is Unavoidable
We’re going to spend the bulk of this article looking at Bluetooth standards and audio codecs. Newer standards and codecs reduce or compensate for audio latency, so they’re the first thing to look at if you’re interested in reducing your audio setup’s lag.
But before we get into that messy, confusing world, let’s take a moment to evaluate why audio latency exists in the first place.
Audio latency is, essentially, the time it takes for audio data to move from your phone or computer to your headphones. Wired headphones produce an imperceptible amount of lag—about 5-10ms worth. Within this 5-10ms window, your phone or computer processes digital audio data, converts said data to an analog audio signal, and streams the signal through your headphones or speakers.
Bluetooth devices spend a lot more time in that initial “processing” stage. First, digital audio is processed by your audio source (phone or computer). Then, it’s passed to your Bluetooth headphones over a wireless signal, where it’s converted into analog audio and blasted into your earholes. Additionally, a pair of true wireless earbuds may introduce extra lag to ensure that the left and right buds stay in sync.
In the end, Bluetooth headphones and earbuds experience at least 32ms of audio latency. But that’s only in ideal circumstances. You’re more likely to run into a 100-300ms delay, especially while using true wireless earbuds. Thankfully, that 100-500ms delay time isn’t a death-blow for watching video, so long as your headphones and phone (or computer) support the Bluetooth 5.0 audio standard.
Creative Outlier Air TWS True Wireless Sweatproof Earphones, Bluetooth 5.0, aptX/AAC, Long Battery Life 30hrs Total, 10hrs Per Charge, Graphene Driver, Dual-Voice Calls, Siri/Google Assistant (Black)
The Creative Outlier Air wireless earbuds conform to the Bluetooth 5.0 standard and support aptX HD and AAC codecs. They have a massive (total) battery life of 30 hours, and come at a reasonable mid-range price.
Bluetooth 5.0 Should Resolve Most Audio-Video Issues
Bluetooth 5.0 is the current standard for wireless audio transmission. (However, some newer devices utilize advances found in versions 5.1, 5.2, and 5.3.) It processes data faster than previous iterations of Bluetooth—effectively generating higher quality audio with shorter delay times. But Bluetooth 5.0 doesn’t totally mask the latency of wireless audio. Instead, it compensates for lag through a technique called audio-video sync (or A/V sync).
A/V sync is an interesting solution to audio lag. With this technology, your phone estimates the audio latency of your setup and adds that same latency to whatever video’s playing on-screen. In the end, your video and audio information are aligned and appear to work without a shred of lag.
The easiest way to check for A/V sync is to connect your Bluetooth headphones to a phone or computer and fool around on YouTube. If your device is under the throes of A/V sync, pausing a video should generate a short on-screen delay. As in, the video itself (not just the audio) might take nearly half a second to actually pause.
And just to be clear, Bluetooth A/V sync isn’t a new thing. Manufacturers and software designers are simply implementing A/V sync more than they used to. A set of Bluetooth 5.0 devices are almost guaranteed to work with A/V sync, while outdated tech isn’t. It’s also worth noting that A/V sync is useless for gaming or music production, as these applications are interactive and happen in real-time.
Audio-Technica ATHM50XBT Wireless Bluetooth Over-Ear Headphones, Black
Audio-Technica's wireless over-ear headphones support the Bluetooth 5.0 standard, along with aptX, AAC, and SBC codecs. It's a fantastic all-around solution for fans of cans.
For Minimal Latency, Focus on Audio Codecs
Bluetooth 5.0 and A/V sync will solve the average person’s Bluetooth latency issues. But if you’re an audio nerd or a gamer, then you may want to take steps to dramatically decrease the latency of your Bluetooth devices. In this case, we suggest shopping for headphones based on their supported codecs.
Codecs are responsible for how digital audio is encoded and decoded for wireless transfer. The universal Bluetooth codec, called SBC, is probably the codec that you’ve used the most. SBC doesn’t use up a lot of system resources, but its 100-200ms latency and 16-bit audio make it a poor option for people who are obsessed with lag or sound quality.
Currently, the most popular alternative to SBC is aptX HD. It’s a 24-bit solution with lag times that average between 40 and 100ms. In other words, it sounds better and works with less latency than SBC. Gamers can take things a step further by honing in on headphones that support the uncommon 16-bit aptX LL codec, which operates with just 32 to 40ms of lag, or the aptX Adaptive codec, which flip-flops between bit rates and delay times depending on your current task.
aptX codecs are available on Android devices, Macs, and some Windows machines. But aptX is not supported by iOS devices. This creates an interesting dilemma, as iOS users are stuck using the universal SBC codec and a format called AAC. This AAC codec, which is the brains behind AirPods and PowerBeats earbuds, generates lossless audio (a good thing) but works with 140 to 200ms of latency (a bad thing). It’s a near-universal, high-quality codec for iOS, Mac, Windows, or even Android users, but it’s also a little laggy, and it limits the ability for iOS gamers or musicians to fine-tune their audio latency.
If a codec is supported by both your audio source and your Bluetooth headphones or speakers, then that codec will be selected for use automatically. Just keep in mind that codec performance varies slightly from device to device.
Apple AirPods Pro (1st Generation)
The AirPods Pro earbuds support Bluetooth 5.0 and operate on the AAC and SBC codecs. These earbuds work flawlessly with iOS devices, and feature the best ANC and transparency tech on the market..
Bluetooth technology is advancing rapidly. We’ve reached the point where Bluetooth headphones, earbuds, and speakers are a more comfortable listening solution than their wired alternatives—at least for most people.
The only major sticking point, it seems, is latency. While most issues are resolved with Bluetooth 5.0 and A/V syncing, gamers and musicians should pay close attention to the codecs that are supported by their devices.
Sources: RTINGS, SoundGuys, Guiding Tech
