Launched in fanfare in early September 2016, the LG V20 (read our complete LG V20 Review) has the most powerful audio hardware in the smartphone space today. Smartphones are starting to push further into high-end audio features and this is not something that most people are familiar with. There were previous “premium audio” handsets such as the HTC 10 or ZTE Axon 7 which featured improved digital to analog converters (DACs).
DAC stands for Digital to Analog Converter, and it’s the electronic block/component/module/device that will take the digital audio signal (your digital music file/stream) and convert it into an analog signal that goes to an Amp, then a speaker for listening.
Integrating a high-quality DAC in a phone is a relatively new concept, and there are scores of external DAC “boxes” on the market, that could look the one below. It’s a fairly heavy and convoluted way to use a “mobile DAC” (see this $499 “portable” DAC connected to an iPhone)… but the miracles of electronic integration make it possible to embed this kind of capability in a modern handset.
Digital to Analog Overview
Your digital music files are either encoded with standard audio precision or in HiFi (High-Fidelity) precision. “Precision” or “Fidelity” is mostly defined by three factors at recording and encoding time: the compression scheme, the bits per samples (16/24/32) and the sampling frequency, which defines the resolution of the sound. The bits per sample represents the maximum amplitude of the recorded signal, or the dynamic range, depending on how the signal is treated. Some high-quality services like Tidal stream audio in
Obviously, it is better to have HiFi audio files or audio-source, but even regular audio files can benefit from a better audio system because of noise reduction and up-sampling techniques – to a point.
When we met with the audio team of LG Korea, they pointed out some key differences between them and the closest competitor. It wasn’t named, but it looks like the HTC 10 phone’s specs. In any case, there are a few things worth nothing:
The Signal to Noise Ratio (SNR) is 125dB (LG), versus 110 dB (competitor) which is a large difference between decibels (dB) are on a logarithmic scale. If we were to convert dB to a linear scale, 110 dB would be 316,227 and 125 dB would be 1,778,279 – that’s the kind of difference we’re talking about. You can play with online converters if you are curious.
A larger SNR value means that the good signal (music) is much more prominent than the noise. Audio in general and DACs always some noise going on. During recording, it could be anything going from background noise to recording instruments. During the conversion to analog, it’s mostly about electronic noise. That’s why high-performance DACs have very complex designs.
Why Quad DAC?
"THE QUAD DAC OF THE LG V20 PUSHES SNR DOWN TO UNPRECEDENTED LEVELS FOR A SMARTPHONE"Why is Quad DAC better than Single DAC you may ask? The initial instinct is to think “well, more is better” – it’s not always true, but in this case, it is, and here’s why: Each DAC will process the audio signal (source) and reduce noise, outputting an analog signal (outcome).
The output signal of each DAC is then added together to increase the source signal. As this is done in analog, the level of noise goes down relative to the overall audio signal. The Quad DAC of the LG V20 pushes SNR down to unprecedented levels for a smartphone.
That’s also why the Quad DAC volume control in the LG V20 is done in the analog space. If you control the volume in digital space, the amount of noise can rise because you are reducing the (good signal) while the noise remains constant (because induced by electronic components).
Why not Octo-DAC (or more)?
You may external DAC designs that boast having more than 4 DACs. They are interesting, and in theory, you could reduce the noise even further, but I don’t think that there is such an option for a tight mobile integration now. Also, the cost/benefits ratio may not prove to be a smart choice. Without further data, it’s just hard to tell.
DAC Audio Controls
Because this functionality is new on smartphones, there is no built-in mechanism to control it in the default OS sound settings. LG has added an interface to enable/disable Quad DAC. Why would you disable it? To save power.
It’s not like it is using a lot of power, and I could listen to HiFi DAC music for more than 15 hours in the plane with a reasonable impact on the battery (maybe it went down by 30-35%?), but it wasn’t enough to have me worry about it as the depletion rate was not alarming for this kind of trip. Still, this is a mobile environment, so every milliamp is worth saving.
Once ON (you need to connect a device to the 3.5mm jack port), you can tweak the volume and the balance. As the LG Specs showed earlier, the volume control is more fine-grained than competitors’.
The LG V20 can also detect and adapt the power output to all audio devices connected to it. Most of the time, you will use headphones, but not all are created equal. High-end headphones can accept a more powerful signal, and high-end amps take an even stronger one.
How does it sound?
The audio outcome is surprisingly good and perceptible. I’ve tried the LG V20 with the Bang & Olufsen earbuds that are shipping with the Korean version (not in the USA, unfortunately) and the audio quality with either normal MP3 files I own, or HiFi files, is drastic.
The sound is cleaner, crisper, and sounds noticeably “better” in general. Of course, this is somewhat subjective, but every media people in the room agreed that there is a big difference when compared to other high-end phones, including iPhones and Galaxy phones, and phones with a single DAC."I COMPARED THE LG V20 WITH A $3400 PLAYER: NO PERCEPTIBLE DIFFERENCE IN QUALITY"
Finally, I went “high-end” and borrowed a pair of Sennheiser HD 800 (~$1,400) and an Astell & Kern AK240 SS HiFi music player (~3,000). With the HD 800 headphones, I compared the LG V20 with that $3400 player: no perceptible difference in quality. If you take away one thing about this article, that should be it.
Keep in mind that “audio specs” can be a lot like “megapixels” sometimes. The big numbers don’t always lead to a big outcome. That’s why the real-world testing phase with quality files and headphones/speaker is more important than technical. I just wished that you could all hear this for yourself and decide for yourself, but I hope this will help.