AJSki2fly
17-09-2012, 16:51
Recently on another Forum a post was complaining about the quality of reproduction of his computer compared with the same music played on a CD player. There were a number of posts about changing this and that, most valid and some not.
Anyway I put the following up and I would be interested on any thoughts, clarification or views that would help my understanding further:- :)
"The variables when playing music from a computer be it PC or a MAC are quite substantial. Windows does its own EQ. which you need to bypass, not something I have bothered trying as a load of hassle. I did some work around recording and mixing some years ago at a very low level whilst on a music course, and with a PC the best thing to do was to migrate the music processing off the sound processor of the MLB (logic board) and onto a dedicated external processor that is set up for the job. This gives best results.
With respect to digital music it is important to understand its limitations in relation to what you are listening to.
Lets start at the top, a FLAC file of an Album is about as close you can get to the original digital master recording, remember that if this has been created from an analogue tape there may already be some loss or introduction of change from the original. So replay of a FLAC file through the right set up will give the best result. Ignoring amplification and speakers etc.
The next step down is a CD, this is 16 bit and is compressed from the original FLAC and is somewhere between a quarter and a fifth the amount of digital data compared to FLAC.
CD's have there own issues, jitter being well known and the ability of the Laser to retrieve the information from the disc, and the DAC to be able to accurately convert to Analogue. Meridian over the years have extensively developed CD players that extract as much as possible and get the best out from a CD, as others have done. There are trade offs on the conversion process, where something that is very accurate and fast can sound too sharp or clinical, whereas a slightly different approach can sound softer and more musical (dare I say it more akin to vinyl), the reason for so many CD players and DACs out there.
The next step down is AAC lossless or MP3 hi-res, now you only have to look at the actual file size and compare with a CD to wonder what is going on. Lets say a average CD is about 600 megabytes, the same in lossless will be about 100mB a factor of 5 yet again. My understanding of the compression that is going on here is that it is actually removing aspects of the musical content, to gain the size, and obviously that lower the size the worse it is. I was told that the compression of MP3 and AAC and its reproduction actually relies one your brain filling in the holes that are missing using your musical experience, a bit of trickery the brain does.
So this for me this raises several issues. I in fact went through a process of digitising all my CD's a few years ago to my computer and creating a digital music library, putting it on a drive and hooking up to various media players and finally ending up with an Apple TV (not streaming). Then one day a friend recommended some music for me to try out, so I downloaded and started listening, and I was shocked. It sounded weird and horrid. I thought I had a download issue and repeated it, still the same. Then I checked my system and listened to some other music, all OK there. So initially I thought rubbish recording/music, then I was lent the CD and listened again and hey it was good, not muddled, and quite good. So what was going on?
Well here we come back to the brain trickery bit, the music I was recommended and downloaded was outside my previous musical experience and my brain had no terms off reference to fill in the missing gaps, new instruments and style and so on, so it sounded weird. I investigated this further, by listening to MP3 albums of artists I had not listened to for a long time and once again I sometimes felt it was lacking somehow. But when I played the CD it was as I remembered.
So have stopped playing CD's, I decided to stop the rot and go back to playing CD's and brought a secondhand Meridian 508. I have even thought of going one step further a back to vinyl, but there are issues when you already have a large CD collection and Vinyl is not without it's own compression issues, but not the same as CD.
So the answer is not simple, in fact I fear for current generations who are probably completely unaware of the impact on reproduction quality, and hear music not as it originally recorded or intended to be heard, and just believe that what comes out of a computer, MP3 or iPod is right.
I know this explanation is not technical, I do not intend it to be, more an insight and a thought provoker, and I am sure that it will raise or sorts of arguments. But I will say this, the less information you have to input into a processor(CPU) from the original then the less likely you are to be able to re-construct the original, no matter how good the algorithms and programming is."
Anyway I put the following up and I would be interested on any thoughts, clarification or views that would help my understanding further:- :)
"The variables when playing music from a computer be it PC or a MAC are quite substantial. Windows does its own EQ. which you need to bypass, not something I have bothered trying as a load of hassle. I did some work around recording and mixing some years ago at a very low level whilst on a music course, and with a PC the best thing to do was to migrate the music processing off the sound processor of the MLB (logic board) and onto a dedicated external processor that is set up for the job. This gives best results.
With respect to digital music it is important to understand its limitations in relation to what you are listening to.
Lets start at the top, a FLAC file of an Album is about as close you can get to the original digital master recording, remember that if this has been created from an analogue tape there may already be some loss or introduction of change from the original. So replay of a FLAC file through the right set up will give the best result. Ignoring amplification and speakers etc.
The next step down is a CD, this is 16 bit and is compressed from the original FLAC and is somewhere between a quarter and a fifth the amount of digital data compared to FLAC.
CD's have there own issues, jitter being well known and the ability of the Laser to retrieve the information from the disc, and the DAC to be able to accurately convert to Analogue. Meridian over the years have extensively developed CD players that extract as much as possible and get the best out from a CD, as others have done. There are trade offs on the conversion process, where something that is very accurate and fast can sound too sharp or clinical, whereas a slightly different approach can sound softer and more musical (dare I say it more akin to vinyl), the reason for so many CD players and DACs out there.
The next step down is AAC lossless or MP3 hi-res, now you only have to look at the actual file size and compare with a CD to wonder what is going on. Lets say a average CD is about 600 megabytes, the same in lossless will be about 100mB a factor of 5 yet again. My understanding of the compression that is going on here is that it is actually removing aspects of the musical content, to gain the size, and obviously that lower the size the worse it is. I was told that the compression of MP3 and AAC and its reproduction actually relies one your brain filling in the holes that are missing using your musical experience, a bit of trickery the brain does.
So this for me this raises several issues. I in fact went through a process of digitising all my CD's a few years ago to my computer and creating a digital music library, putting it on a drive and hooking up to various media players and finally ending up with an Apple TV (not streaming). Then one day a friend recommended some music for me to try out, so I downloaded and started listening, and I was shocked. It sounded weird and horrid. I thought I had a download issue and repeated it, still the same. Then I checked my system and listened to some other music, all OK there. So initially I thought rubbish recording/music, then I was lent the CD and listened again and hey it was good, not muddled, and quite good. So what was going on?
Well here we come back to the brain trickery bit, the music I was recommended and downloaded was outside my previous musical experience and my brain had no terms off reference to fill in the missing gaps, new instruments and style and so on, so it sounded weird. I investigated this further, by listening to MP3 albums of artists I had not listened to for a long time and once again I sometimes felt it was lacking somehow. But when I played the CD it was as I remembered.
So have stopped playing CD's, I decided to stop the rot and go back to playing CD's and brought a secondhand Meridian 508. I have even thought of going one step further a back to vinyl, but there are issues when you already have a large CD collection and Vinyl is not without it's own compression issues, but not the same as CD.
So the answer is not simple, in fact I fear for current generations who are probably completely unaware of the impact on reproduction quality, and hear music not as it originally recorded or intended to be heard, and just believe that what comes out of a computer, MP3 or iPod is right.
I know this explanation is not technical, I do not intend it to be, more an insight and a thought provoker, and I am sure that it will raise or sorts of arguments. But I will say this, the less information you have to input into a processor(CPU) from the original then the less likely you are to be able to re-construct the original, no matter how good the algorithms and programming is."