Audio output via SPDIF or HDMI: which sounds better?

If you want to transmit sound, you have to choose between several types of transmission. In this practical tip, we will explain whether HDMI or SPDIF is more suitable for audio output.

HDMI or SPDIF - what you should use

You can transmit sound in many different ways - optical or electrical, analog or digital:

• With SPDIF and HDMI, the classification is easy. Both types of transmission work digitally.
• The transmission of HDMI works purely electrically. SPDIF, on the other hand, can be electrical or optical (see TOSLINK).
• Although SPDIF is the older format, it is extremely robust when it comes to external interference. If you transmit via fiber optic cable, you are protected as much as possible against electromagnetic influences.
• However, SPDIF has a growing disadvantage: Initially, the transmission standard was only intended for PCM stereo transmissions. The signals from new multi-channel formats such as DTS have an enormously wide range. Because of this, the data rate increases enormously.
• You can no longer transfer the data rates of the new formats via SPDIF. A downmix of the formats is possible, but the data rate has to be severely limited, which leads to quality losses. HDMI, on the other hand, works lossless and is therefore the better choice.
• HDMI has yet another advantage: Both video and audio data run over a connection, saving you a cable.
• There are also other features such as HDMI-CEC. Conclusion: With HDMI you save cable clutter and are well prepared for the future. SPDIF, on the other hand, has now had its day.

In the next practical tip, we will show you how you can easily extend your HDMI connections.