HDMI provides the highest quality as it enables the full, lossless audio data of Dolby TrueHD to be transferred digitally to the AV receiver, and enables the A/V receiver to apply its full digital audio processing capabilities (such as bass management, or sound field processing effects) to further enhance the audio quality. S/PDIF does not have the ability to support the data rates required by Dolby TrueHD, and thus will not support it. Analog will be lower quality than HDMI due to two reasons: 1) the nature of analog transmission is lossy and will degrade while transported over the cables, 2) many A/V receivers will not apply any digital audio processing to the analog inputs, and in such cases analog signals will be sent directly to the amplifier without the benefit of such processing.