CD And DVD Audio Difference

I recently wrote about DVD’s and how they work. But before DVD’s, we had CD’s, which I also mentioned a little bit in the article. The thing is that CD’s are actually still very much used. And it doesn’t matter that most devices come with DVD readers, they can read both.

Another thing that I touched was that CD’s aren’t big enough for storing videos and movies. Thus in this article, I’m going to touch the audio differences between CD and DVD discs!

Sampling

The first thing you need to understand is how music is stored on discs. Both the CD’s and DVD’s store music as digital samples. Now the difference comes from the storage size.

With CD’s, the sampling rate is 44,100 per second. The analog signal is also converted to 16 bit for each sample. And it’s done on two channels to enable stereo sound.

Since DVD’s are a lot bigger and contain more data, the music quality can also be higher. To put things into perspective, a standard DVD has 4.7 GB of space. A CD on the other hand has 650 MB. And having a two layer DVD can double that.

So now that we know that, we can understand how DVD’s can also store higher quality music. Typical audio is saved onto DVD’s at a sampling rate of 96,000 per second. And each sample is 24 bits. Simply put, a DVD audio has twice as many samples as a CD.

Another difference is the amount of channels. DVD’s save music as 6 channels instead of 2. Which is also known as surround sound, superior to stereo!

Why CD’s Are Still Used

There’s a very simple reason why CD’s are still used, and that’s because DVD audio as such is still fairly new. The older DVD readers don’t have a built in encoder that would use the higher sampling rate. Instead it would encode at the exact same speed as DVD’s. And replacing them is a financial lost for consumers.

Another reason is that the sound quality is not that noticeably different. Which again from a consumer point of view, spending a lot of money for a new DVD reader while not getting a much better audio quality is pointless.

And that’s not all, Sony and Philips recently announced a new standard that competes with DVD’s. It’s called the Super Audio CD. According to them, the new standard has an EVEN BETTER audio quality than DVD’s. Which might actually bring back CD’s. Especially if you are just planning to use them for music, as DVD’s have far too much storage for that in my opinion.