This article exists to solidly state the truth about optical cables and audio limitations. It can be very confusing for people to set up new electronics that have come out in recent years (I know, I sold for a major electronics retailer for years).
I have seen a wealth of both information and misinformation about audio specifically around the internet, so I will discuss what you can and can’t do with different cables and show you what you need to enjoy your PS3 or Blu Ray audio. .
Solid Statement: You cannot get 7.1 channel audio or HD audio from optical cables or digital coaxial cables.
Limits of optical cables
Optical cables, also known as TOSLINK, are capable of 125 Megabits of data per second. Bandwidth is not a limiting factor for optical cables. This is a common piece of misinformation. The same applies for digital coax cable. Both cables can carry more than enough bandwidth for high definition sound formats.
People still think of fiber optic cords as the king of the hill. After all, what is faster than the speed of light? Why go with a regular cord that can experience electrical interference? However, neither optical nor coaxial will transfer high definition audio. If you were hoping to use an optical cable with your PS3 to get HD audio, you won’t be able to do it.
Both optical and coax cables adhere to the Sony Philips digital interconnect format, or S/PDIF, specification. The S/PDIF spec was made to standardize consumer electronics, but now acts as a bottleneck for new formats.
The spec is limited to around 1.5 Mbit and can transfer 5.1 channel Dolby Digital, 6.1 channel Dolby Digital EX, 5.1 channel DTS, 6.1 channel DTS-ES (matrixed or discrete), and 2 channel uncompressed PCM.
Optical cords will not give you 7.1 channel audio or any of the high definition audio formats (listed below).
What are the high definition audio formats?
- Dolby Digital Plus (lossy)
- Dolby TrueHD (lossless)
- DTS HD (lossy)
- DTS HD MA (lossless)
- Multi-channel PCM (lossless)
What cable do I need for HD Audio?
Only an HDMI cable will carry these newer formats. Additionally, you need a surround sound receiver that can handle HDMI audio and decode these signals. You can usually tell at a glance by the TrueHD or DTS HD logos on the front of receivers.
Note that HDMI 1.1, the original consumer release, did not include HD audio formats. The highly-touted HDMI 1.3 release added these.
This scenario applies to both Playstation 3 and Blu-Ray player owners who are looking to get high definition audio. Many will be happy with their existing home theatre setups and 5.1 DTS sound. For those who have heard the siren’s sound of lossless audio, its time to go shopping for a receiver.
If you are an audiophile, you may already have a brand preference and I won’t suggest any to you. If you don’t know what to look for, though, a great newer option is the Onkyo TX-SR608. It’s a great price point with all the features you need from a respected name in sound.