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Bluetooth Jul 25, 2024
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Speaker measuring and reporting - Spinorama Mar 19, 2024
Bluetooth
vs Bluetooth
In today's era of streaming, using Bluetooth for audio playback is a necessity rather than an option. However, not all Bluetooth connections are created equal. By default, phones use energy-efficient and stable connections but often with low-quality codecs. Currently, the only high-quality codec* available on Android phones is LDAC (Lossless Digital Audio Codec). Developed and owned by Sony, the exact computational logic of LDAC is not public. Allegedly, it allows for lossless music playback. Independent tests have concluded that close toCD-quality transmission is possible, but HD is borderline and open to interpretation. Strictly speaking, HD is not yet achievable, but equally strict tests have shown that even professional ears can't distinguish between CD and HD quality in blind tests.
Your audio receiver supports the LDAC profile. The first step is simple: connect your phone to the receiver. Open the list of Bluetooth devices on your phone and click the gear icon next to your device. This will open the device menu, where you need to activate the LDAC codec. If your receiver doesn't support this codec, the option will not appear. Done? Far from it. For some reason, Android and phone manufacturers have decided to hide quality settings behind several more steps.
Next, you need to activate Developer Options on your phone. For Samsung, navigate to: Settings -> About Phone -> Software Information. Then, tap on "Build Number" seven times. On other phones, the process might differ slightly.
Now we can start setting the audio quality, but only if the relevant Bluetooth connection is active. Select Developer Options, which should be marked as "On." Scroll about halfway through the options to find:
HD Audio - Activate this option.
Bluetooth Audio Codec - Select LDAC.
Bluetooth Audio Sample Rate - Choose 96.0 kHz.
Bluetooth Audio Bits Per Sample - Select 24 bits/sample or 32 bits/sample (currently 24 is in use, but for future purposes, you can choose 32).
Bluetooth LDAC Audio Codec: Playback Quality - Select Optimized for Audio Quality (990/909 kbit/s).
Now you have the best possible codec and connection speed. It's worth checking these settings occasionally, as Android tends to adjust options for optimization rather than quality.
Is the difference in audio quality audible after making these changes? Yes, very much so. Even if you think you have a tin ear, the difference is noticeable. The original audio stream should also be of good quality. For instance, for Radio Paradise, choose either Ultra or, if the connection speed can't handle it, High. In any regular streaming environment, select the maximum possible quality.
If your audio receiver is older and doesn't support LDAC, I strongly recommend considering the purchase of a separate Bluetooth receiver. I made this change with my Yamaha home theater system, and the difference in audio quality is remarkable. At the time of writing, the price range is 50-200 EUR. If you use a digital output, there's no difference. The signal goes directly from the chip to the output, so choose the receiver with the best price. There likely isn't much difference even with the analog version, as the DAC part of the Bluetooth microchip is the same across the chip series. The latest Bluetooth version at the time of writing is 5.4; if possible, choose the latest available version. Later versions offer more high speed connection stability.
Is the audio quality better when using a cable? It depends on the source, the receiver's DAC solution, and the capabilities of the rest of your audio system. Such a noticeable jump in audio quality is no longer possible. Further steps with cables and FLAC, etc., can improve quality for specific situations. Very dynamic music, a keen interest, and the ability to listen to the finest details of the audio. If the sound is half background and half for listening, there's little point in striving for an even higher quality solution unless it becomes a hobby in itself.
Notes:
Some phones and Android versions change the playback quality to optimal every time they reconnect. This cannot be bypassed with Android settings. Since it is extremely tedious to reapply the audio quality optimization every time (it does not simply apply by selecting but requires reconnecting), there is help from a paid application. Bluetooth Codec Changer (https://play.google.com/store/apps/details?id=com.amrg.bluetooth_codec_converter) allows you to set the default LDAC profile optimized for audio quality at a reasonable price in the paid version. This way, you don't have to chase the quality in developer options every time.
Be prepared that higher quality will drain the battery faster than usual, produce more heat than usual and is stable at close distance only.
* An even better codec is available: Qualcomm aptX Lossless. Boasting a maximum bit rate of 1200 kbps, it surpasses LDAC's 990 kbps and is said to transmit CD-quality audio with no loss. This codec is relatively new and not yet widely adopted.
Note (11.09.24)
If the selected 990 kbps transmission quality causes intermittent sound, the following settings might help: WiFi - off (or alternatively, only 5 GHz WiFi), Location - Location services - Wi-Fi scanning - option Off, and Bluetooth scanning - option Off, as well as turning off the device's screen while listening to music. Naturally, the distance from the receiver and other 2.4 GHz WiFi networks may also affect the signal transmission quality. If these settings cannot be used or are ineffective, alternatively, it may be worth setting the LDAC audio quality to 660 kbps. This level is more stable in terms of connection and still offers reasonable sound quality. Below this speed, another codec might be a better choice.