CDs are Great

by Martin Brennan September 6, 2023

CDs are indestructible
CD music quality is unsurpassed
CD’s 40+ year reign exceeds any other medium in the electronic era.

I know it’s a cliche but CDs are the “tracks of my years”.

They are often works of genius - performed by some of the most gifted people to walk the planet. But my CDs are also my personal history.

I remember talking to a Brennan owner who described himself as “ten a week” - that's how many he bought. And I know of many Brennan owners who own 3000+ CDs. Imagine the money tied up in that.

My collection of about 200 CDs seems modest - or should that be sensible - by comparison

CDs are an astonishing technological feat - especially for the 1980s. And Philips and Sony did everybody a favour by agreeing to a common medium so we didn’t get a Betamax v VHS format war.

I didn’t know just how clever CDs were until the 90’s when as an engineer I got to design a CD controller chip. Let me give you just a glimpse into the technology.

When I first saw a CD on “Tomorrow’s World” on BBC, I seem to recall the presenter saying that you could drill a hole in the CD and it would still play perfectly because it had error correction.

But how exactly can you correct an error? I mean if there is a hole in the disk how can you make up the music that was in the hole?

Imagine you want to record three bytes of data. (Digital music is stored as binary data - which means ones and zeros and eight bits are called a byte)

The CD recording process adds what is called ECC - error correction codes - to the data - the blue bits.

In this example the blue bits are called parity bits and they are calculated so that the number of ones in any row or column is always even

If there is an error in playback so the red bit is wrong

Then the parity bits for that row and column will no longer be right and that tells you that there is an error on that row and column. You correct the error simply by changing the bit at that row and column.

This simple example can correct single bit errors. CDs extend this basic approach to detect and correct bursts of errors. It’s a bit too technical for here but I was left in awe of the inventors when I’d mastered it.

The Audio CD proved to be such a good way to store data that it was adopted by the computer industry and for a couple of decades most computers had CD Drives and most software was sold on CDROM.

Metadata means things like track names and album art.

Unfortunately music publishers never adopted a standard way to put metadata on a music CD. So CD players don’t know what they are playing, that information just isn’t on the disc. The CD player just knows the track number and how long it is.

In 1994 Ti Kan and Steve Scherf created CDDB - an online database of CD metadata that uses a digital fingerprint of the CD to lookup metadata in a database compiled by us - the listening public.

CDDB evolved and forked along the way but it meant that services like iTunes could play and rip CDs with proper track names as opposed to just the track number.

We currently use the Musicbrainz database - which has data on around 30 million recordings.

Metadata means Brennan players let you search for Artists, Albums and Tracks and display album art - so you get more out of your CD collection.

CDs use 16 bit samples at a rate of 44.1kHz. That might not mean much to you but when Philips and Sony settled on that they didn’t just make an incremental improvement in sound quality - It was game over. The sound quality race was over.

Tape hiss and scratched vinyl were history.

You may have heard about higher sample rates like 192k or 24bit but there is no benefit to these formats outside computers at a studio.

It's quite technical but this Youtube explains why CD quality is as good as it gets.

Because CD quality is so good all Brennan jukeboxes have the option to store an exact copy of the CD music data - either as a wav file or using FLAC lossless compression.

Downloads and streaming services tend to use lossy compression like MP3 to keep costs down. Lossy compression like the name implies throws away information.

I’ve heard from Brennan owners who tell me that after buying a Brennan they started collecting music again.

I checked on Ebay yesterday and couldn’t resist buying Peter Gabriel’s Greatest Hits. A double CD for just £2.92. His recording of “Don’t Give Up” with Kate Bush gives me goosebumps.

And £2.92 for a double album. I remember buying his double album “Lamb Lies Down on Broadway” as a student - I could barely afford it.

Because CDs are indestructible and don’t suffer from scratches like vinyl there’s no problem buying second hand.

Internet technology doesn’t just allow us to play CDs with album art and search by name.

Brennan players use the net to work with Sonos speakers so you are not restricted to listening to music in one room. Put a speaker in the kitchen or bedroom. Listen to different music in different rooms or play through all the speakers at once.

I found my interest in music really picked up after adopting my first Sonos speaker. (I now have six).

So if you have CDs in the attic or on a shelf - dust them off and give yourself a treat.