The iPhone 6 does not yet have high-resolution audio

After having invested in Beats, increasing the storage capacity to 128 GB and working on its music streaming system, current devices are not capable of reproducing this high quality sound. In fact, Tim Cook made no mention of Hi-Res audio support when it introduced the iPhone 6 and iPhone 6 Plus.

High-resolution audio (HD audio) is commonly known as the sound that goes beyond CD quality, and it is not something we expected as an innovation, but Neil Young's campaign on Kickstarter has swept his project PonoPlayer, which is essentially an iPod that plays high-resolution music.

In numbers

High definition audio is lossless audio, without any compression. There are two numbers that give us an idea of ​​this capacity, they are:

• Frequency and sampling rate, frequency is a representation of what the human ear can hear, it is estimated that we hear up to about 20 kilohertz and above this figure it is considered inaudible to humans (called ultrasounds). Usually the sampling rate of a digital audio recording must be twice the maximum frequency to be played, the audio CD uses a sample rate of 44,1 kilohertz, which covers sound up to approximately 22 kilohertz frequencies.
• Decision, is the number of bits used to store each sample of the analog signal, digital audio will have more quality the higher its resolution. The CD works with 16 bits.

La high resolution works with a sampling frequency of 192 kilohertz, capable of reproducing sound of up to 96 kilohertz and with a resolution of 24 bits.

Reality

There is much debate as to whether this improvement in audio quality is actually perceptible by the humanNor does increasing this resolution create conflict with current listening equipment.

I believe that the improvement in quality is overshadowed by the drawbacks, which would be roughly; new listening devices such as speakers and headphones, greater need for space for the storage of music and specific requirements of the formats that would change the landscape of the playback software figure.

The studio

To test the high-resolution audio capabilities of the iPhone 6, Mashable worked with several test tones, generated by the audio-testing expert, David Ranada, and with a sample rate of 96 kHz and 24 bits per sample in Wav format, these were taken directly from the iPhone headphone jack and registered at the exit in a Hi-Res Audio Recorder which operates with a sample rate of 96 kilohertz and with 24 bits per sample.

These recordings were then put on Adobe Audition to compare with the original signals, which cannot be played with iTunes (gives an error) so applications for HD audio were used,  Onkyo's HF music player and OraStream's app.

When the test tone was played through the iPhone on both OraStream and Onkyo, the output level dropped rapidly when the frequency rose above 18 kilohertz, until it reaches 22 kilohertz, where the signal is zeroed out directly.

With regards to resolution, the difference between the noise coming from the jack of the iPhone is remarkable compared to Onkyo.

Conclusions

IPhone 6 does not play Hi-Res Audio, most likely the limitation has to do more with the software than with the hardware. The digital to analog converter (DAC) or what is the same, the piece of hardware that converts digital bits into music, is the Cirrus Logic 338S1201 chip, according to recent teardowns.

This chip is made to measure for Apple, then the specifications are not in the public domain, but being part of itto CD42L range of the company, it is very likely that be able to reproduce high-quality audio (24 bits and 96 kilohertz).

Which leaves us with the fact that Apple's limitation of reproducing audio up to CD quality is determined by the search for higher battery performance, which is quantified in a maximum of 50 hours for the iPhone 6 and 80 hours for the iPhone 6 Plus.