|
|
|
|
May 2012
Audiolics Anonymous Chapter 150
More Computer Audio Talk
Article By Bill Gaw
Welcome to my 150th article written for this rag. That's over 12 years slaving over this hot computer trying to write something intelligible that will enlighten the 1 percent of the population who feel that spending $1000 on an interconnect isn't sufficient reason for the white coated gentlemen to "take you away to the funny farm".
As you'll know if you've read my previous tomes,
I feel that a well-built media centered computer can replace many of the source
components in your system. With its ability to connect to the internet, record,
store and play any sort of digital information, act as a room and speaker
correction system for anything from mono to 11.1 channels, if built to high end
standards, it can be the centerpiece of your audio and video system.
In previous articles dating as far back as 2002 in Chapter 29, Chapter36, Chapter84, Chapter101, Chapter105, Chapter106, Chapter119, Chapter 122, Chapter 140 and Chapter 147, I've chronicled my path towards an audio-video music server which would compete with the best high end products out there and for a price that won't break the Monaco bank.
Unhappily there have been a few missteps, not wholly due to my
ignorance, but mostly to the lack of sufficient information out there on how
best to build a high end audio-video playback system. Unlike with Apple, where
you get a complete system with all of the bells and whistles playing nice with
each other, with PC's, each component has its own rules to follow which
hopefully will integrate with both the other components and the programs.
This is especially true with audio. Why? Because Windows, the
main PC operating system is a kludge of many generations of updates and
improvements based on a program that was originally developed for computers from
30 years ago which had 20 meg hard drives, 640 kb of ram and a cpu with less
semiconductors than the least expensive cell phone today. Each new iteration of
the program had to be able to be used on older computers, and thus had to
include fixes that allowed this. As computers have improved, these remnants from
the old days have been kept and added on to with improved methods of processing.
For instance, with our most important processing system,
audio, there are now 6 different methods of transmitting the digits to the
playback equipment from the original direct sound to kernel streaming or....
Each has its pluses and minuses, with various programs and hardware being able
to handle some or possibly all. What has been my bugaboo
lately has been my inability to transmit bit perfect digits from the music files
through the playback program through the RAM to the operating system, stored on
the CPU, then through the motherboard audio chip, thence to the audio or video
output board through its digital output, be it S/PDIF, USB, or HDMI, to the
preamp-processor.
So what have been my stumbling blocks:
1. Motherboard unknowns.
In order for the bits not to have been changed through the above steps, each
component, both soft and hardware have to be able to transmit the bits without
processing. The problem is that most of the components in the chain either don't
have the proper software or processing setup to allow this. For instance, most
of the motherboard audio chips have had processors that only allow bit perfect
transfer of multiples of 48 kHz. Therefore all 44 kHz bits and their multiples
must be translated to 48 kHz before transmission.
Unhappily no motherboard manufacturers explain this anywhere
in their literature, "as the average person cannot hear the difference so it is
inconsequential" according to the powers that be. For instance, ATI makes
two types of motherboards, type P and type H. Type P which I bought previously
as it appeared to have all that I wanted in processing, requires a video card to
transmit HDMI signals and its audio chip only does 48 kHz in direct multiples.
Type H, which also has an HDMI output on the mother board can process and
transmit both 44 and 48 multiples bit correctly, but that also isn't mentioned
in the motherboard description. Unhappily, most will only transmit 16 bit 88 or
172 kHz. signals in two channel through their S/PDIF, USB and HDMI outputs. So
if one has 24 bit or multi-channel files, they will be degraded in the
transmission, unless the music software can in some way over-ride this.
2. Video Cards: Buy ATI
Radeon
If one is only listening to two channel files, one can use the S/PDIF or USB
outputs of the motherboard to transmit the signal to the pre-pro, but if one
wishes to transmit multi-channel signals one needs an HDMI output either on an
audio or video card, or an audio card which will do the D/A decoding. Then one
needs a semi or pro card for quality sound which will cost several hundred
dollars, or a video card with HDMI output that will transmit the digital signal.
While all manufacturers will spend hundreds of words
describing the card's excellent video features, not one will give you any idea
as to what they do with the audio signal. Most just state that they can transmit
"up to 96 or 192 kHz signals" but not whether they'll do any of the intermediate
values. Worse, all NVIDIA Geforce video cards
will not transmit any 88 or 176 kHz signals, at any bit or channel
rate. As most high end audio files are either 88 or 176 as compared to most
video oriented audio files which are 48 or 96 kHz, audiophiles are screwed.
So, for us audiophiles, one needs to make sure that both the
motherboard and the sound or video card will do bit perfect transmission of
their files or have a superior audio card that will do excellent D/A conversion.
As there is little information from the manufacturers as to which ones are
capable, and there's very little information on the various web sites and blogs
which will disseminate this information as most are run by gamers who don't care
about the sound, what's an audiophile to do.
Well, you could be like me and scour the web for information,
buy parts to try them out, find the ones that don't work and discard them, or
one could go with an Apple computer, or one could be happy with bit "unperfect"
playback. Finally one could copy my final parts setup:
1: Video Card: Any Radeon card from the 6000 or 7000 series
should do. Don't go for a super-expensive one unless you plan on playing video
games as even some of the lower priced ones will do superb multi-channel audio
and play blu-ray discs back without problems.
2: Any motherboard with an Intel or AMD series chip with an
HDMI output and a Realtek ALC 889 chip set.
For my computer, after purchasing and switching out multiple audio and video cards, motherboards, and USB inputting to S/PDIF outputting or D/A converters, I've chosen the following:
Motherboard: MSI
H57M-ED65. This unit was chosen as it has HDMI output that allows 88 and
176, 16 bit multi channel output with the ability to transmit 24 bit 88 and 176
through a video or audio card.
S/PDIF: As I prefer direct S/PDIF rather than USB to S/PDIF
output, a optical and RCA S/PDF card was added.
Video Card: Radeon 6800 from AMD hit the sweet spot of
reasonable cost, with the ability to do both 88 and 176 output with excellent
video playback for my Blu-ray concert discs, and the ability to play 3D discs
when my setup allows.
After months of experimentation, this setup gives me bit
perfect playback with best sound obtained for two channel with S/PDIF RCA output
from the motherboard, and multi-channel output through the video card rather
than the motherboard's HDMI output as that output will only allow 16 bit 88 and
176 kHz playback. Using this system, I'd put my sound through my Classe CT-SSP
pre-pro at least at the level of most of the best digital units when using
Windows' using WASAPI event style output.
Next problem; which software program should I use to play back
my audio files? While Windows Media Center and Media player are free and do a
pretty good job, and included with Windows, and Foobar and Winamp are free and
allow playback of cue files, and JPlay gives the cleanest playback by storing
the files in RAM, my favorite all around program is…
J.
River Media Center 17
I've been using this program for about 10 years since its 8th
iteration, and each improved version has amazed me with its musical quality. It
is the Swiss Army knife of audio recording and playback, giving much better
sound than any other program I've played with except for possibly JPlay, which
is only a playback program, but has the ability to store the audio digits in RAM
for decreased jitter. Plus, it now has a dll which can be added to Media Center
17 which will allow RAM playback, but which I haven't tried as yet. But if you
use JPlay, with some anti-virus programs, the computer will lock up so be
careful.
In addition to bit perfect playback, it will do digital signal
processing for upsampling, room and speaker volume and frequency correction,
equalization, and has the best surround sound program I've heard being far
superior to Dolby and DTS. It will rip, and burn CDs, DVD's and with an add-on
program Blu-ray discs, and does a great job of A/D recording. It acts as a
library system keeping track of all of the audio-visual files including those on
network servers, and allows playback of several digital audio web programs
allowing pickup of just about any radio station in the world with signal
processing of all including Google video and YouTube, Sky, Shoutcast, etc. and
direct connection to Amazon and HD Tracks for direct download of high bit rate
music files.
For Blu-ray playback, I recommend WINDVD
for its ease of use and quality of playback. PowerDVD
is also very good but somewhat more expensive.
In conclusion, one needs to be very careful, at least with Windows based computers to get both hard and software that plays nice with each other and has the ability to play back and record all sample rates that our high definition audio files come in. Stay away from all motherboards that don't have HDMI outputs, and all NVIDIA video cards that don't transmit 88 and 176 kHz. sampling rates.
|
