Home Theater Connection Types

If you are going to build a home theater or make some additional purchases for your already available equipment, then you have to know what kind of cables and connections you'll need to hook up your components. Some connections carry analog signals and some carry digital signals. (For a bit of science, analog signals follow a sinusoidal curve and digital signals use only 1s and 0s.)

Modern LCD, plasma, and the new OLED screens process digital signals where older TV sets like CRT and rear-projection TVs process analog signals. If you connect a digital output (say a Blu-ray player) to an analog TV, then the digital output signal will be converted to an analog signal to enable the TV to show the content, but the results will be lossy because you have converted a good signal to an inferior one. Therefore you have to know how to connect the right equipment with the right connection.

Throughout the article I will go through the connection types one by one and in the section headings I will use the following notation to indicate what signals can be carried by the connection:

• (A) Audio signal only
• (V) Video signal only
• (AV) Both audio and video signals

The High Definition Multimedia Interface, abbreviated as HDMI, can carry both audio and video signals. The HDMI connection is the standard connection for carrying high definition (HD) content. If you have a device that has an HDMI connection, such as a PlayStation 3, and a TV with an HDMI connection, it is the best practice to connect the two with an HDMI cable.

With the HDMI connection, we have the High Definition Copy Protection (HDCP) issue. HDCP is brought to us by Intel to enforce the "fair use" of high definition content - in other words to avoid piracy. It is a proprietary protocol (and thus should be licensed) which encodes the HD contents before it reaches the video playing equipment and decodes it in the display equipment. So, if you cut the line between your Blu-ray player and LCD TV and try to record the contents, you will be only able to see standard definition (SD) content at best. The encoded audio and video data will be decoded at your display device (TV or monitor) to deliver you the content “right.”

If you will be making a purchase for a device that has an HDMI port, then insist on seeing that it is compliant with HDCP.

TOSLINK, or optical fiber connection, is a connection type that only carries audio signals over a fiber optic cable. TOSLINK is the best way to carry audio signals both for its digital nature and the fairly lossless physical structure. Most probably your AV receiver will have one TOSLINK connection and it is the best practice to use this connection with the devices that are able to deliver multichannel audio, such as 5.1 or 7.1.

TOSLINK was created by Toshiba in 1983 and therefore can be found in many AV receivers, CD players, Mini Disc players and DAT recorders.

S/PDIF is an abbreviation of Sony Philips Digital InterFace and, as you have guessed, was jointly developed by Sony and Philips. The connection handles the audio data in digital format and is mainly used to connect DVD players to AV receivers which are capable of processing Dolby Digital or DTS sound. However, the connection is also widely used to carry audio from a CD player to a receiver.

But there is one thing to consider here. Although there are conflicting opinions on whether it is safe or not to connect S/PDIF output to an older amplifier or AV receiver, I suggest that you avoid using this type of connection unless you are certain that your gear was made for it. S/PDIF is a digital output, and you can damage your analog audio equipment with a digital signal.

Image courtesy of Tigerdirect.

Please see the “Component Video and Digital Component Video” section under “Analog Connection Types” on the next page. Digital Component Video is, as the name implies, a digital connection, however there is also an analog connection with the same name that seemingly uses the same connection cables.

This is a connection type that is very rare and for the time being used only in digital photography. It can transmit video signals but there are not many devices in the market that have YCbCr connections. (Almost all the products carry the analog version, the YPbPr connection.)

Next: Analog Connection Types