Greetings everyone,
For the past while I have been looking to improve my music listening experience, and wanted to share my journey in looking for Smartphones which also are excellent as portable music players. During this journey such questions came up as: are the DACs in current phones as good as anything else? Are 32 bit DACs worth it? Do stand alone amp + DAC combo units make this a moot point? Does 24 bit or 96khz add any distinguishable quality.
(for those who don't feel like reading a long post I have included heading to make it easier to skip over parts)
Some details filling in the story
First an introduction:
I have been using my Samsung Galaxy S3 as a portable music player for the past 3 years or so. In all, I have been happy with it, especially when I got the RBH HP-2 headphones earlier this year. I use Neutron Music Player, and ultimately I was left unsatisfied seeing the 16bit and 44.1khz hardware output. I felt I was missing out on the potential of my 24bit, 96khz .flac files.
Some will be thinking already that I am already misguided by chasing after 24 bit and 96khz, and it seems they are correct (
https://xiph.org/~xiphmont/demo/neil-young.html ). Luckily it did launch me into researching what is the best out there.
What is out there:
What are top end phones such as the Samsung Galaxy S7 offering in terms of audio hardware? According to Samsung, not a damn thing apparantly:
http://www.samsung.com/ca/consumer/mobile-devices/smartphones/galaxy-s/galaxy-s7/hardware/?search-form-input=s7+specs Nothing is listed on this product page. Not even a spec sheet (that I could find anyway).
Most manufacturers however will list marketing chaff in the audio sections of their specification sheets (instead of, you know, actual technical SPECIFICATIONS) Take Sony for example:
http://www.sonymobile.com/ca-en/products/phones/xperia-xa-ultra/specifications/
It seems these larger manufacturers know that their audio hardware is an afterthought so the actual specifications are swept under the rug. However there are some companies out there who have made it a point to get a high quality chip set into their phones to appeal to fans of good audio. On that note, a good website to look up full phone specifications is:
http://www.gsmarena.com/
Where to find actual info on what is out there?:
Well after doing some digging, I found this thread over at Head-fi which is as comprehensive a collection of phone audio specs as there is out there:
http://www.head-fi.org/t/662095/best-smartphone-for-audiophile
The thread started in 2013, and has kept current up until the present day. It is a long thread, but ultimately gave me some much needed perspective to form a foundation to research from. Essentially, the top best sounding phones out there currently are the LG v10, LG G5 with B&O audiophile module (not available in North America), ZTE Axon 7, and soon the LG V20. There are a few more out there, but these are the main stream ones.
ALAS, the LG V20 will ship to North America with the Uber DAC, but it will not carry the B&O Certification in that market, if that means anything. I have read rumor that it ships with a pair of B&O earbuds ($149.00 retail), so not sure if that will happen the US either.
In the thread, there are several members who have owned a multitude of phones and have done side by side comparisons. Many claimed that phones such as the Galaxy S7 were of passable quality, but any of the phones with the ESS Sabre DACs were phenomenal. There is praise for the AKM implementations, but those implementations seem to not be as common as phones with a sabre dac on board.
Big thanks to the head-fi community for the collection of info in that thread.
My findings:
The DACs made specifically for a great audio experience seem to indeed bring a difference in quality over the 'generic' ones found in most devices today. The features of being compatible with 24 bit, or sample rates higher than 48khz may not bring much to the table, but it seems that the quality and implementation of these specialty chips makes a big difference.
It the past, the two chips to beat were the 'burr-brown' and Wolfson DACs. Now ESS has come out with its Sabre line of DACs (
http://www.esstech.com/index.php/en/products/sabre-digital-analog-converters/sabre-hifi-mobile-dacs/ ) featured in the top LG phones , and AKM in direct competition (
http://www.akm.com/akm/en/product/datasheet1/?partno=AK4490EN ) featured in the ZTE Axon 7.
I originally had my eyes on the Galaxy S7, since it was rumoured to have an ESS SABRE DAC, but on launch it shipped with what appeared to be a in-house implementation by Samsung. The specs were not available, and in this case "no specs, no money" was applicable. Later on I took a look at the LG phones, but alas, the v10 is not available in Canada, and the G5 audio module is not available in North America, and won't work on North American phones if special ordered. I decided to go with the Axon 7, since it was available in Canada.
Comparison between the Axon 7's AKM, and the Galaxy S3 Qualcomm WCD9310 DACs:
First off, I am not going to go into things that I 'think' or 'feel' were different. Those are best left to a double blind test to sort out. I will only mention what was definitely noticeable.
After looking for months for a good phone for audio, I have learned that the 32bit feature of the DAC on the Axon 7 won't make much difference. Even playing my 24bit, 96khz files shouldn't be too noticeable. However the question here is what difference does a chip designed for a good audio experience have over one which is there to do a reasonably good enough job? The answer seems to be: a lot!
I used Neutron Music Player, and my HP-2 headphones on both devices. I transferred my music library to both via SD card. I listened to the albums "Endless Forms Most Beautiful" and "Imaginaerum" by Nightwish, "The Phantom Agony" by Epica, and "Solar Echoes" by Nigel Stanford. All are 16bit 44.1khz .flac files. With Nightwish and Epica being Symphonic metal bands, they cover a wide range of sounds which cover a lot of musical ground to test against.
With the AKM DAC on the Axon 7, I can hear every sound in detail. On the Galaxy S3, some sounds seem to blend/fade into the buzz of the electric guitar. Essentially finer or quieter details are fuzzy, and are hard to pick out. On the Axon 7, I could hear details I never noticed before, and could make out lyrics that may have been drowned out by the rest of the music, or were otherwise unclear. Again, this isn't me 'thinking' I hear a difference, it is definitely a noticeable difference. To really put it in perspective: As I listened in bed, and my mind wondered off, I would have my attention snapped back to my music now and then as I heard a detail or made out lyrics I hadn't noticed before.
It is definitely worth looking for a device with a good DAC implementation on it. The sound difference is pretty big. However, people with high impedance headphones will still need a separate amp, and many will probably already have an amp/DAC combo which makes my discovery moot. Also I don't own my own dedicated headphone amp or amp/DAC combo to test against, since I don't want to carry around extra devices (which is the main reason I have been looking for the solution built into a phone). However I feel it is worth exploring, since in this day and age it is fairly silly to need to carry around more than one device.