Why iPhone does not have AptX17 codecs
Exit iPhone 7, from which Apple removed "outdated" Mini-Jack, caused a heated discussion on sites audiophile themes. This fraternity has not favored Apple smartphones as a music player before because of the very mediocre DAC. Bluetooth at that time was not taken seriously at all, because the iPhone never had support for codecs with CD-quality. And still no. Why? Let’s figure it out.
Apple Ecosystem offers us to listen to music through small headphones or HomePod
What is the difference between Bluetooth audio codecs
As usual, I’ll start from afar.
When transmitting audio via Bluetooth from the source to the headphones or speakers, audio codecs are used. These are special programs that are “wired” into the transmitter and receiver, with the help of which data is encoded and decoded for better transmission wirelessly.
There are 5 basic Bluetooth audio codecs: SBC, AAC, aptX, aptX HD and LDAC.
Sbc – The most common codec, as it is the default algorithm for transmitting sound via Bluetooth. The sound quality when using this codec is very mediocre, but enough for many. Actually, this codec was originally designed for voice transmission in Bluetooth headsets.
SBC is a codec, thanks to which any headphones will work with any smartphone. But here the sound quality is not the best
It was because of this codec that for a long time, wireless sound was considered terrible and unworthy of the attention of self-respecting music lovers. But he also became a pioneer in introducing Bluetooth music transfer.
- Supported by all wireless audio transmitters;
- The most reliable connection.
- Poor sound quality
- High noise and distortion.
AirPods – some of the best wireless headphones with AAC support
- Good sound quality on iPhone;
- Reliable connection.
- Sound quality is lower than most codecs;
- Relatively low prevalence outside the Apple ecosystem.
AptX is the second most common codec. Thanks to its presence, the iPhone could produce the best sound with most headphones
The compression algorithm used in AptX was developed back in the 1980s. Qualcomm, the current copyright holder of the codec, claims that the codec provides quality comparable to a CD. A controversial statement, it seems to me.
- Reliable connection;
- Wide frequency range;
- Low background noise
- High prevalence.
- Sound quality in some cases is almost no different from SBC;
- With a large number of Bluetooth devices around, the reliability of the connection is greatly reduced.
Read on: How iPad has impacted the music industry
Aptx hd – The most optimal codec at the moment, which allows you to transmit sound in quality close to CD. In terms of the totality of parameters, this codec gives the optimal ratio of sound quality and communication stability. It significantly downloads the Bluetooth channel, but at the same time gives a very decent sound.
Qualcomm said that with this codec, a sound close to Hi-Res is achieved, but tests do not confirm this. Although it sounds really worthy.
- High bitrate when transmitting sound;
- Wide frequency and dynamic range;
- The lowest level of background noise;
- Sound quality in most cases is good.
- Reliability of connection is below average;
- Does not transmit Hi-Res audio in appropriate quality;
- Relatively low prevalence. Headphones supporting aptX HD are not among the most numerous.
In addition, LDAC has three modes of operation, and in only one it gives quality that is really superior to all other codecs. But in this mode, your devices are unlikely to connect by default, priority is given to a more stable and less quality option.
- High sound quality;
- Maximum bitrate among Bluetooth codecs;
- Wide frequency and dynamic range;
- For most parameters, it corresponds to 16-bit sound.
- The default connection is 330 kbps or 660 kbps with poor sound quality;
- Unstable communication in 660 kbit / s and 990 kbit / s modes;
- Weak prevalence. Headphones that support LDAC are not very common. Basically, they are released by Sony, of course.
Why Apple only uses AAC
With AAC, sound is encoded not only during transmission, but also during storage. AAC stands for Advanced Audio Coding. At one time, this audio encoding algorithm was positioned as the successor to MP3. AAC usually has better sound quality than MP3, with the same “file size” or even less.
Many people think that AAC is Apple’s proprietary format, but it is not. AAC was developed by a group of companies that included, for example, AT&T, Bell Labs, Dolby, Nokia and Sony. Public release took place in 1997. Apple only uses the AAC format to store music in iTunes and Apple Music.
Like MP3, AAC is a compressed file format. Both coding algorithms cut off the highest and lowest frequencies, and also actively use the features of human hearing to remove information about sounds that a person does not distinguish when listening to music. As a result, AAC files sound worse than CDs, but in general, algorithms compress music quite efficiently, so most people do not see the difference in blind tests.
In Apple Music, all files are in AAC format 256 kbps
Like MP3s, AAC file quality is measured based on its bit rate. Typical AAC bitrates include 128 kbps, 192 kbps and 256 kbps.
Without going into technical details, we list the reasons that make AAC sound better than MP3:
- When encoding in AAC, samples with a frequency span of 8 to 96 kHz are used, and when encoding in mp3, samples with a span of 16 to 48 kHz are used, which provides a richer sound;
- Higher algorithm performance;
- Greater accuracy when encoding AAC sound is ensured by using a smaller sample size (128 or 120 units versus 192 in MP3). Smaller sample size is better because it allows you to more accurately describe the analog sound wave in digital form;
- Sound frequencies above 16 kHz are processed more efficiently. Let me remind you that in the mp3 format, these frequencies are simply deleted.
Thus, higher sound quality while saving space allowed AAC to win a place in the hearts of Apple engineers. In addition, Apple does not plan to enable Tidal and other Hi-Res services to deploy on its territory. So, in their opinion, there is no need to implement other, better, codecs in their devices. Therefore, for wireless sound transmission in their devices, the Cupertinians chose only AAC. Also, it seems to me that Apple for some reason does not want to pay Qualcomm for the license for AptX. It is unlikely that money matters here.
Read on: Apple will predict who will be the next music star
Why AptX on iPhone
You can compare the sound quality of two codecs ad infinitum. Graphs with comparisons of the frequency range, impressions of the AptX and AAC collision head-to-head, subjective and objective opinions – all this is in abundance on specialized resources. I want to say something else.
Your expensive headphones do not play 100% due to the lack of AptX HD codec in iPhone
The absence of other codecs severely limits the choice of wireless headphones for my iPhone. Of course, they will work, but communication will occur using the SBC codec with the worst sound quality. And what’s the point of buying some Marshall if you don’t get their signature sound? If you want AAC support, buy Beyerdynamic Aventho Wireless, but that’s a completely different amount of money. And for them you cannot get the highest quality possible paired with your iPhone (also not the most budget smartphone), since it does not support AptX HD. I’m not talking about connecting the iPhone to a home stereo system. Not all receivers have AAC or AirPlay support. It turns out some kind of vicious circle. In addition, cheaper Android smartphones (like the LG G7) are becoming more universal in this regard than the iPhone. I hope in the new, “revolutionary” iPhone of 2020, Apple will turn to face the market and music lovers. After all, sometimes you want something more interesting than AirPods.