At this point of time, we’ve reviewed a number of wireless audio products. Be it speakers, headphones, earphones, or even true wireless earphones – we covered them all. While we did mention audio delay is a thing, we didn’t measure and compare audio delay between multiple different connectivity methods.
So our job here today is simple – we compare the audio delay between 4 different mediums by utilizing two different flagship smartphones of 2019.
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DISCLAIMER: This is not a direct comparison of the audio delay between the two smartphones featured in this experiment. There are too many other variables like audio delay from the microphone that is not taken into account.
Every phone’s test here is meant to be comparing its relative audio delay between its different audio connection methods, eg. loudspeaker, audio jack, and Bluetooth with & without aptX.
UPDATE: The wireless audio delay saga has expanded!
Over the course of the few months since we first did the tests, we have done many other tests covering more audio codecs, devices, and even some over true wireless earphones that claim to have “ultra-low latency” or have “gaming mode”.
Our tools for today – the Xiaomi Mi 9, UGREEN Bluetooth audio adapter, UGREEN Type-C to 3.5mm audio jack dongle, and the Samsung Galaxy S10+.We first need to decide a test setup. By using PUBG Mobile, we equipped our character with an 8x zoom scope and used AWM sniper rifle in the training grounds to aim at a tree beside the bridge.
Then, we used these two smartphones to film each other shooting a tree in PUBG Mobile. We did that for 5 times on each audio connection medium.
We then counted the number of frames taken from the shooting animation started until the sound is heard, did some math and we got the audio delay in seconds. Since we shot the tree 5 times, we were able to calculate an average.
In the Android operating system, you can actually select what Bluetooth audio codec you want to choose under the developer options menu. Knowing this, we were able to compare the wireless audio delay with and without Qualcomm aptX.
In this experiment, we tried a total of 4 different audio connection methods:
- Direct loudspeaker
- Audio jack/dongle to PC’s line-in audio port
- Bluetooth 5.0 with aptX to PC’s line-in audio port
- Bluetooth 5.0 with SBC to PC’s line-in audio port
Experiments 3 and 4 are done by utilizing the UGREEN Bluetooth receiver that converts any wired speakers, headphones, or earphones to become wireless. Learn more about these UGREEN audio accessories here.
Once all the data were gathered, we found out some interesting results.
By calculating the frames, we were able to deduce these numbers by a simple formula. We also took the audio delay for loudspeaker (the speakers on the phone itself) as the reference since it is the “fastest” audio path possible. From there, we were able to calculate just how much more delay is added when we used other audio connection methods.
The Mi 9 is pretty straightforward. There were no audio post-postprocessing technologies built into MIUI 10. We just started recording and got all our data in one shot. From here, we realized that the Mi 9 is actually pretty good for gaming out of the box. For our full review of the Mi 9, click here.
Xiaomi Mi 9
|Average time taken
|Compared to loudspeaker
Remember that the Mi 9 is already using the Snapdragon 855 chipset. Qualcomm is now the owner of aptX technology – and it is just unplayable via Bluetooth, with or without aptX codec. With over a second of delay, it is very noticeable in both playing games and watching videos.
Samsung Galaxy S10+
We had lots of fun with the Samsung Galaxy S10+ even when we reviewed it initially. When I first tested the audio delay, I was reviewing the Galaxy Buds (review here). In that review, I mentioned that Samsung smartphone users can tune it to however they like. What I forgot was that I left Dolby Atmos turned on for my first test.
That is why in the video, you see the future-me interjecting a segment in, explaining what happened.
Samsung Galaxy S10+
Dolby Atmos enabled
Dolby Atmos disabled
Average time taken
Compared to loudspeaker
Average time taken
Compared to loudspeaker
By general consensus, turning off Dolby Atmos will remove some delay caused by audio post-processing for enhancements. In our result table, we are able to confirm that theory. It’s a surprise to see that the Galaxy S10+ with Dolby Atmos turned off managed to deliver the audio within a second. For wireless audio, this is actually very good.
When Atmos is turned on, there are some extra post-processing added to the mix. Sure, you get better audio quality – but extra audio delay is introduced into the mix. All of these happens before the audio is sent out to your audio device. In our table of result, Dolby Atmos enhancements do add quite a significant amount of delay, especially for wireless audio.
This tells us that the Atmos feature is only best to be used with wireless audio devices for music only. And no, we’re not comparing the audio quality differences here since we are focusing on just the delay.
Why aptX still experiences extreme audio delay
It’s no surprise that aptX is not some magical protocol that will eliminate all delay. It is a codec. As explained in the video, codec comes from two words – compression and decompression. We talked about this circa 2 years ago when aptX was still an obscure feature!
In this case of wireless audio, the audio stream itself is most efficiently sent by first compressing it, then send through whatever protocol you choose. In this case, it’s Bluetooth. Compressing and sending the file through will result in loss of fidelity, just that different protocols will result in different levels of loss.
On the receiving side, the smaller file is decompressed. Whatever is obtained from the decompressed file is what you hear on your speaker, headphone, or earphone.
Qualcomm says that aptX achieves this by “reducing the size of the audio files” and “without affecting the sound quality” – though its fidelity is not the point of this article today. It does not magically enhance your audio quality, but merely tries to retain most of it. If your audio source is in low fidelity then aptX will not help either. In the case of high bitrate music files like FLAC, then aptX will be able to retain most of that audio quality.
aptX Low Latency?
There are multiple variants of aptX. We have the basic aptX, aptX HD, and also aptX Low Latency. There is another aptX Adaptive that adjusts itself between audio delay and bitrate.
In Qualcomm’s very own website, it states that “your brain can’t tell the difference between a delay of 0 and 100ms”. From our audio delay test here, we can confirm that since we play games like PUBG Mobile using earphones and headphones all the time.
While our UGREEN Bluetooth audio device is said to be “low latency”, we still experienced wireless audio delay. That is because both the Mi 9 and the Samsung Galaxy S10+ that we have here, do not support Qualcomm aptX Low Latency. We are unable to test that but we can confirm that “low latency” does not mean “no latency”.
Will wireless audio be a viable option for gaming soon?
I don’t think so. With our situation here, you need a phone and a headphone or earphone that supports Qualcomm aptX Low Latency. The headphone/earphone part is simple since the UGREEN Bluetooth adapter does support aptX Low Latency (review here) but none of our 2019 flagship smartphones support it. Maybe the Samsung Galaxy Note 10 will support that.
As of now, all wireless audio transmission method will have added delay despite whatever codec you use. Wireless audio is suitable for music since there is no synchronization to worry about. For movies and games, you might want to stick with a wired headphone or earphone. Or buy UGREEN’s USB-C to 3.5mm audio jack dongle.