|
You are reading the older HTML site Positive Feedback ISSUE 41january/february 2009
Ten Questions about Computer Audio with Pete Davey of Positive Feedback
Computer Audio has become the new rage in audio and for good reason: one has an easy and instant access to all their music as well the ability to search out countless other titles via the internet. The issue is simply where to start, though the answer is quite obvious: get a computer, rip and store the files, and then play them back to some DAC. Of course being audiophiles …err the nuts we are… the questions start to pile up rather quickly. Mac or PC, and then once you got that settled, there is all the minutiae related to just setting-up that computer's OS and configuration. Then comes how best to rip and how best to save the files, and then to where? Okay, so now that I have my files, how best to play them back and how best to get the files out of the computer and to what DAC? Yadda, yadda, yadda… each question leads to further questions to clarify the previous that then lead to other questions that suggests another question and …a downward spiral down into the rabbit hole we go. So I went to the 2009 CES and found not only a wealth of information, but a wealth of confusion or at the very least, a wealth of disagreement among those that are either in the recording/software side, the hardware-side, and/or the "expert" sides of computer audio. Now CES is not the best place to get all the answers… time is an issue as is finding all the people to ask, so I came up with 10 ‘key" questions (these are my 10, you may have others or perhaps might not find these of any benefit to you, but I chose them because they are of interest to me and besides they reflect the most common or important areas that seem to pop-up whenever one talks about computer-based audio, so go pound silicon if they don't work for you.) and emailed them to 12 people in the industry to answer. Their responses are here...
1. Let's start with interfaces; the obvious choices are USB, Firewire, Optical, and S/PDIF. What is your opinion on any of these interfaces? What if any, are the advantages or disadvantages of one over the others in terms of resolution, jitter, etc.? I believe the interface itself doesn't really matter as long as the transport is done correctly. There are rumors that one offers slightly less higher or lower rates of jitter but that all depends on implementation. USB has become popular because everyone has a USB port. Most USB DACs out there are really just external sound cards with a simplified output. Personally I've chosen an optical output so that I can decouple the PC from the DAC circuit altogether. 2. With regards to software there are also strong opinions as to some being vastly superior (or for that matter, inferior) to others; people clearly hear differences in how files are being played back and therefore prefer one over the others. There is also a growing opinion that Pro software is the only way to go and that using iTunes, WMP, MAX, or other free software playback programs (FooBar, JRiver, MAX, etc.) is not the way to go. That is, these are sonically and musically inferior to the Pro software because the Pro software (say for example Amarra, Izotpe, etc.) is simply "better" at playing back music files. What is your opinion on what is going on here? That is, why would any of these programs be superior—or for that matter, inferior—to another with respect to say a .wav file in any resolution: 16/44.1, 24/96, or 24/192? Is it a matter of timing and jitter? Issues with the operating software and processing? The fact that some software runs "cleaner" than others—that there is nothing running in the background to muck things up? Or as some suggest that the "math" is simply better in some software than in others? Let's keep in mind here, that computer audio is new to a lot of "audiophiles." Everyone talks about one software player being better than the other, when it really doesn't matter. The "better" software players will allow the user to choose what type of output they want to use. Some consumer grade software doesn't allow this and will output it using the system driver which could be altering the sound (allowing volume control, albeit implemented correctly causing dither issues.) Some of them have built in sound enhancers and equalizers. As long as the software allows bit for bit output then it really doesn't matter. I hear a lot of people talk about loading music into RAM first, which by design ALL computers do and have been doing for a long time. Everything is loaded into RAM before processing! Ignorance is bliss.
3. Let's move on to ripping. As with the above, there are proponents that claim only certain software, and optical drives for that matter, can "accurately" rip a CD. That they can clearly hear differences between rips via different means; even though the rips are bit for bit perfect. Any thoughts on what is going on here? Is there an advantage to using specific ripping software or drives over another? Say iTunes, WMP, Max or whatever when compared to say EAC? Bits are bits. As long as you get a perfect representation of the original then you have it. It's not rocket science. People prefer EAC mainly because of how verbose it is with its error checking. If it has a scratched up disc, it will get a bit wrong and the checksum will be incorrect. It will then re-calculate what that bit was supposed to be using parity and fix it. Done. I personally use iTunes these days; I'm in this for simplicity.
4. File formats. Any reason why a .wav, AIFF, or FLAC file is better than say Apple Lossless? Again people suggest a strong preference for one over the others, so something must be going on here? A file format is simply a container. FLAC caught on because it's free! It compresses audio like how WinZip compresses data by removing empty space but with checksums to put it back during playback. This means it's lossless. Apple Lossless and FLAC are bit by bit perfect and this has been proven by engineers with the correct equipment. People still aren't satisfied with this answer so they choose to find another thing to bitch about, now it's that the processor isn't powerful enough to re-inflate the compressed file fast enough for jitter free playback! Give me a break, if your made in China iPod can do it, your $2000 Mac Book Pro can do it while calculating Pi to the nth place and re-encoding a 30gb Blu-Ray disc to h.264. Ridiculous to think otherwise. 5. There is also a movement towards Pro DACs. Naturally there are DACs of varying quality and performance, but is there any reason why a PRO DAC would be better than a DAC made by a manufacturer from the audio community? Say ones of comparable quality and build? A DAC is a personal choice, as all of them have their unique sonic signature. Some people even prefer Tube DACs to give it the "analog fuzzy" feeling. Who am I to differ? As long as it knows how to handle the minute jitter and to reproduce the audio the same way it was created then I don't care. Obviously most pro DACS have a less-noisy power supply and are more neutral sounding because that's what they are for. Another plus with pro DACS is that you usually get a word clock in so that you can slave its clock to a master clock along with all of the other equipment in the chain. This is great for producing music for a master, playback it's not that important.
6. Along those same lines, what makes one DAC a better choice for computer-based audio than another? Jitter reduction, chip sets, power supply, etc? Again I think the most important part here is that it can cancel out any interference from the PC itself. I've chosen an optical transmission path just for this alone. Jitter is a problem of the past; sure it is still there if you pick it apart with a scope but can you hear it? Just buy the DAC that you prefer best. This is like discussing the preference of solid state or tube preamplifiers. Power supply is very important when dealing with high speed digital. 7. What do you see as being the most important factor in getting the best sound in computer-based audio? That is what should the consumer address with the greatest concern when setting up a computer-based audio system? The basics (just like everything else) room treatment, speaker placement and a DAC that sounds good to the consumer. 8. Along with that, what do you see as being the most important factor in NOT getting the best sound in computer-based audio? That is, what can have the greatest potential to adversely affect the sound in computer-based audio? Noisy power; get your power cleaned up somehow and you will notice quite a difference. I can't stress how important it is to have clean power for digital front ends, especially a computer running at 3GHz.
9. Some suggest that they computer must be audio dedicated. That is it must be "built" or configured for the specific purpose of only playing music and that any and all non-audio related programs and such must be eliminated. Your feelings on this? Is it important or not, and why so? Absolutely ludicrous: People that make this statement obviously don't understand how modern computers work. If they think that a computer isn't powerful enough to multitask (what they're designed for) then they are in the wrong business and should stick with hanging trinkets on the wall for better sound enhancement. 10. Where do you see the greatest impact to come in computer-based audio for the future? Software and hardware designers that understand how to output the file without any change made. Right now we are still battling with nice consumer based playback software but with a poor transport mechanism. Pro audio software is for making music, chopping it up and producing! If I have to get off my ass every time I want to change CD's and songs then I think the entire point has been missed for PC based audio playback. Give me a remote control, a sexy interface, and bit perfect sound to my DAC and we'll call it a win.
Pete Davey is a regular contributor to Positive Feedback Online. Peter has built and worked with computers and audio components since the age of 15. Peter has extensive experience in the computer/technology industries where he has held various positions. Use the links below to read other responses to these questions Larry Moore and Eric Hider of Ultra Fi Audio Designs Andreas Koch of Playback Designs Steve Nugent of Empirical Audio Gordon Rankin of Wavelength Audio Jon Reichbach of Sonic Studio/Amarra Vinnie Rossi of Red Wine Audio John Stronczer of Bel Canto Designs Daniel Weiss of Weiss Digital Audio Vincent Sanders and John Hughes of VRS Audio Solutions Charles Hansen of Ayre Acoustics Pete Davey of Positive Feedback Online
|
