CD ROM Jukebox…
Dedicated PC For Storing and Serving Up Music Media

This is an assessment of an effort which I call The Music Server.

The goal was to make sharable on a private network my 700 CD collection. Originally, I looked into purchasing a CD ROM library jukebox, but the cost was prohibitive; $7,000 being the average cost.

I then asked various "computer experts" and the prescribed method was to build a file server that could serve up stored virtual CD images upon request.

On the advice of a comrade who was supposedly knowledgeable about music servers and was an engineer at a local FM radio station, I could build a fairly inexpensive virtual CD ROM jukebox for under $1,500. This PC could also serve as my primary PC since serving up audio files would require very little processing power.

The following is the hardware and software list.

Hardware:

  • Pentium 4 3.0g LGA 775 socket with hyper threading
  • 800Mhz Front Side Buss Gigabyte 915p Motherboard
  • 1 G 533MHz DDR-II Dual Channel ECC Memory
  • 800g RAID-0 IDE (4 200g drives - 7200 rpm 9ms Seek)
  • 80g 7200 rpm IDE OS drive
  • 54x CD-DVD RW drive

Software:

  • Windows XP Professional
  • Virtual CD v6 (now replaced by WinAmp and WAV files)

Why So Much Disk Space

The answer is, “Not MP3s!”  Most audiophiles are aware of the myth surrounding MP3, WMA, and other compression methodologies.


It is well a known fact that there is at least a 5% or more loss of music quality with these compression techniques.

The only way not to loose any of the data stored on a CD is converting it directly to a straight WAV file format (lossless audio).

When a CD is played in a standard high quality CD player, the Redbook audio tracks are normally converted to 16 bit wave format at a sampling rate of 44.1 kHz.  Then over sampling is applied to correct for any loss caused by the 44.1 kHz sampling.  (Sampling rate is done at 44,100 times per second per channel or 88,200 total two channel stereo per second.  Since there is 2 8 bit bytes per 16 bit word, his constitutes 88,200 x 2 or 176,400 bytes per second.  For 60 minutes of music, this is a little over 630 million Bytes. 

By the way, this gives the listener the polyphony of 65,536 levels of sound from full quieting to full loudness or about 95db.  This indicates a sign wave of +32,767 to -32,768.

Anyway, MP3 compression has a different kind of sampling methodology and dynamic range. It assumes if a continuous sign wave is within 5 to 15% the same (depending upon the compression the user desires) It merely counts the cycles and stores the most prevalent wave form and the number of times it occurred.  Then upon playback, it reconstructs the pattern giving the listener the illusion of sound.  For the average hard-rocker, this loss is probably indistinguishable.  But upon hearing a violin concerto, the 5 to 10% loss is very noticeable. Among other things, the ambiance is totally missing.

Let's Get CDs On Computer

So, I had to get the CD images on the computer.  I tried a variety of CD copying software packages to store the images. I even tried the LINUX Journal’s method of creating and storing ISO Audio CD Images. But I had a lot of trouble mounding and sharing the CD files under Samba. That’s when I decided to go with Microsoft Windows.

What a RIP

One of the biggest headaches was the fact that most media software packages refuse to copy or “rip” a CD into WAV file format.  After a bunch of trials with various software packages such as Window's Media Player, WinAmp and others, I finally settled on a piece of software called Virtual CD, which does create individual WAV files.

However, after loading about 50 CDs, I realized I was in trouble. The following were the difficulties I encountered:

  • The cloning process took an average of 12 minutes to load one CD.
  • Missing Tracks: Normally when a CD is playing and a bad byte of information is encountered, the CD player just ignores this byte and continues. Often times the listener is unaware of the glitch. But, when the same CD is being read by a CD ROM drive in data sector read mode and a bad byte is encountered, after several retries, the whole sector is determined to be bad and depending upon the parameter set in the software, the process is either stopped or the whole sector is skipped. 
  • The music database track title service is often slow and the CD copy program sometimes cannot get the CDs track information.
  • Another disheartening problem is when the track markers fall in the middle of a song. The audio playback software cannot seamlessly concatenate the ending and beginnings of tracks. As a result, there are brief gaps in the recordings where the track markers are on the CD.

The conclusion: there are a lot of problems with making CD images that play just like CDs.  Hence the music server was an expensive and bad idea.

Let's not give up yet.

WinAmp solved three of the four problems. 

  • The ripping process now takes an average of 5 minutes to load each CD.
  • Missing Tracks: Now when the WAV file is copied and a bad byte of information is encountered, the WAV ripper just ignores this byte and continues...in about the same way as does the CD player.  In fact, it sounds the same.
  • Music Match database track title lookup service is very fast and seems to have all of the titles and tracks.
  • But, what is still a problem is when the track markers fall in the middle of a song. The audio playback software cannot seamlessly concatenate the ending and beginnings of tracks. This is very apparent in classical music.  I am looking into concatenating the split tracks of critical files into one file.  Also, WinAmp has a cross fader which helps. I turned it on and set it to 1 (one). Most of the time you can't tell the difference between the original CD and the concatenated WAV file playbacks.  If I am going to do random play, I turn off the cross fader.

Well, it seems to be working, thanks to WinAmp.