A simple guide to digital and streaming(hopefully), from my experience
I thought some readers might be interested in a simplified view of digital streaming be it from a web provider/service, music data files on a networked and/or storage device or a CD. So at risk of being shot down by existing and longer in the tooth users of the digital music world here are my thoughts on the subject. Possibly naive but most taken from a considered view and having read various articles and having taken inputs and feedback from others on this forum. I have formed these views whilst at home trying to cope with poor health, and have taken my time looking into this and hope it will be of some benefit to others who may be confused by it all.
I would emphasise prior to reading this that at there are many, many ways and solutions available to get digital music of a reasonable quality into your home, but for the first timer this can be a confusing and daunting topic. I am not suggesting that high end products delivering digital solutions do not do a good job or are not worth having, but as with most things the law of diminishing returns for money spent comes quickly into play, and also not everyone is an audiophile seeking the holy grail of musicality(whatever that may be).
I recently have purchased some equipment to enable me to primarily stream digital music from a service provider, TIDAL in my case but there are many others available, and to access my digitised CD's on a NAS (Networked Access Server) from one simple piece of software (I actually use Volumio and Audvrana for different reasons). Also to use my CD player as a transport only, and get the benefit of a better DAC(digital to analogue converter). My solution does this simply and in my opinion and listening experience is very good sonically and it also has been very good value for money. I know digital music has been around for at least 34 years to the end-consumer but there is and has been a lot of rubbish and hearsay talked about it, which is misleading and confusing for most layman. I have worked in the IT industry for over 35 years and I sometimes consider this to be a smoke and mirrors approach by those with serious commercial interests in the industry to make money out of the end consumer. So if you are interested in enhancing or improving your digital music experience below is some possibly important and interesting information to assist you making a considered judgement on what to buy and how much to spend to get a good result. Of course if you want a simple one box pretty solution that a magazine or hifi shop tells you is the bees b****cks then you can spend thousands, but don't think that it will necessarily get you the best sound or actually anything better than what you could have purchased for a few hundred pounds. Remember computer processing power is relatively very cheap compared to what it was 35 years ago, and it is also quite easy to implement nowadays, although many would like to tell you to get a good result you need to spend a lot to make sure its all good, anyway that’s another can of worms discussion. Also remember if your amplifier and speakers are not that great then consider whether it really is worth spending a fortune on a digital input. Also consider that getting an expensive digital box and then streaming it around a house to loads of wifi enabled UPnP (you plug n play) speakers, of whatever make, is not necessarily going to give you a great musical result, it will give you a sound but thats about it, not necessarily high fidelity, if that what you want to do then fine. However you could purchase a digital radio and connect an iPod/MP3 player or mobile phone and play music through it in a room, and there is nothing wrong with doing that if that is all you want or need.
The link to the article below was posted on an Art of Sound forum thread that was discussing issues with digital music per-se and public misconceptions and beliefs about its quality, good or bad dependant on the bit rate and sample rate and how the end result was affected by the original recording/mix. I think it is quite an interesting and informative read.
See https://people.xiph.org/~xiphmont/demo/neil-young.html
The thread mentioned was quite a heated debate at times which continues. Taking a simplistic view there are those that effectively say digital is digital and the different bits/sampling rates are just a marketing ploy to sell the same music many times, and in the other camp at the other extreme there are those who say they can tell the difference between lossy data files mp3/AAC and lossless(CD/FLAC 16bit/44.1kHz) and hi-res 24bit/96kHz and above.
So lets try and put this into context:-
Lossy, to most people is MP3/AAC, or similar formats sold/accessible on iTunes, Spotify or other sites. Basically this is low-res digital which has elements of the digital information removed, and this can vary depending on the codec (codec is a device or computer program for encoding or decoding a digital data stream or signal) used when originally converted to it. A lot of digital music sold is 128kbps(kila bits per Second) as being good quality, to be honest in my view it is pretty poor, it is used by companies because it saves on physical space and download/streaming requirements. In my opinion it is only worth listening to in a car or when out and about (even then I would avoid it), but lots and lots of people in the world only listen to Lossy music files and are quite happy. MP3/AAC at the top end of lossy capability is 320kbps and to be honest if it has been converted to this using a modern codec implemented within the last 10 years then it becomes very difficult for us mere human beings to tell this apart from CD quality (one caveat here is that both have been taken from the same master and not remixed prior to the process of transfer), i.e. compare apple with apples. Also there are several studies that back this view up).
Personally I sit in the middle here, I know that I can sometimes hear the difference between a 320kbps Lossy music file and a Hi-res lossless file of the same music, but not all the time, so by default I opt for at least CD level quality the majority of the time when at home.
A final thing to bear in mind with lossy music data-files is that if it is new or modern music it is very likely to have been deliberately compressed when mixed before converting to lossy, this effectively raises selected musical contents volume across audible frequency ranges, making a wall of sound, so highs and lows are lost (dynamic range). This is done deliberately for mass market usage for on the go in cars, on headphones and cheap speaker systems, it’s partially why it sounds boomy and bassy. If this has been done there is nothing you can do other than buy or stream a hi-res version and hope it has not had the same done to it, which unfortunately can be the case.
Lossless digital music is basically CD quality as we know it, and FLAC which take less space up (there are other equivalent file formats), the article mentioned above explains why 16bit/44.1kHz is all that we mortals need to hear music as it was recorded/mixed at a high quality when replayed. Effectively the 16 bits gives sufficient headroom for all types of music, our listening range from silence(around 20dB) goes up by +96dB, which enters the pain threshold. 16bit actually adds more than 96dB I believe. The sampling rate is more than adequate to capture the musical signal and render it accurately without loss of tone or change being able to be heard. So what is the hi-res digital stuff about, well it is used in recording studios as it allows a much lower sound floor and a higher top, this means a recording engineer when mixing can raise and lower an instruments perceived volume without introducing noise and effects can be added to a track without noise becoming an issue. The end result can then be transcribed to 16/44.1 without loss or introduction of noise.
So here is the contentious part some say they can hear the difference between say 16/44.1 and 24/96 or higher, is this possible; well for most no it is not, and many articles back this up. However it is estimated that about 1 in a thousand at a reasonably young age can hear up to 22kHz and that very very few can hear beyond that. To be able to tell the difference between 16/44.1 or 16/48, 16/96 and 24/192 all of the same original recording you would need to have continuous hi level content above 18kHz, probably for a few seconds, and at a discernible sound level of say at least 70db, it would also need to be the dominant sound in the overall piece of music for the time it was present (or it would probably get lost in the mix). Add to this that the equipment used needs to be able to reproduce music above 18kHz, and this is not just the speakers but everything in the chain of reproduction, DAC, pre-amp , amplifier and speakers. Yes there are speakers nowadays that will produce up to 40kHz and more. So if the system is capable of it, the music has the content and the human has capable ears then it is possible that they can tell the difference between CD and hi-res, but it is likely to be limited and extremely hard to be accurate I suspect.
Just as an aside, early CD’s and digital music files from the 80’s and 90’s can be poor in sound quality due to the inadequacies of the digital transfer process and/or the care taken by the engineer at the time, and obviously the quality of the original master used, but not all are poor.
So to sum up in my opinion you are wasting your time and money worrying about digital music quality of anything above 16bit/44.1mHz unless you have had your ears tested and know you can easily hear above 18kHz, and your equipment can easily and accurately reproduce up to 22kHz of high quality sound.
So from a practical point of view how do we approach getting the best from digital music reproduction, be it streamed from a web service provider or from a music data-file or CD. I think the answer for most people is that you need a reasonably high quality DAC(digital to analogue converter) in the reproduction chain that is powered by a clean PSU(power Supply Unit) which does not introduce noise to the circuitry (a rechargeable battery pack can do this more than adequately or a more expensive linear power supply). Surprisingly a very good result is relatively easy to achieve nowadays without spending a fortune. Although there are manufacturers who would like you to think otherwise, especially if you fall into the geeky audiophile category. To be able to stream music a simple set up with a RaspberryPi 2 or 3(Small Card Computer) and either a DAC card connected to it which processes in pure I2S (protocol a computer/chip uses to process sound) and then out to RCA(stereo analogue output) to go to your amplifier (cost currently for a good one £100-150), or a Raspberry Pi with a S/PDIF(coax and optical, typical cost £80-120) to go to a DAC in a box. The second option enables you to connect other digital equipment to get get the benefit of a better hi-end DAC. However in the second solution the digital signal will be converted from I2S to SPDIF (probably at 24/48kHz) and then back to I2S for the external DAC to process the digital signal and convert to analog and then to RCA analog output. Is this an issue, probably not, the key thing is for the external DAC to be able to perform re-clocking to synchronise accurately, if it cannot do this accurately then jitter is likely to be introduced(noise), however most external DAC’s are built to do so very well nowadays. I use a very good external DAC which was around £250 and it performs extremely well, but I could have easily spent many thousands on an external DAC, would it have got me a better end result, maybe and maybe not.
I hope you the reader found this helpful and informative, and hopefully not too boring. Personally I believe CDs will die over the next few years and streaming of music will move forward at a high pace, so if you move into the digital streaming realm understanding what you are getting and at what cost may well be important to you if you like your music.
(Apologies for spelling or grammatical errors in advance, written English was never my best subject)
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Originally Posted by AJSki2fly
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