Benchmark's Guide for Audio Playback using Mac
A Simple Guide to Configure Your Mac for Optimal Audio Quality

Overview

iTunes uses the audio engine built into QuickTime to play its audio (and video) files. In other words, iTunes is a sort of media file manager that plays its media using QuickTime, just like a website might play its media with QuickTime. Therefore, the information in this section will apply to both players, and we will address both players simultaneously.

Certain information within this article is very specific to the version of the software being used. Please check your software before acting on this information.

Recommended Player Settings

Set word length and sample rate to the highest settings of the audio interface

Word length should be set to the highest that the audio interface is capable, regardless of the word-length of the audio file being played.

Sample rate can be set to match the sample rate of the media or to the highest that the audio interface is capable, since the upsampling in iTunes is harmless

The sample-rate conversion in iTunes 7.X or 8.X will not add significant distortion to the audio. The user should not be discouraged from setting the sample-rate to 96 kHz as a permanent setting, even when the audio is less then 96 kHz.

QuickTime->Edit->Preferences->QuickTime Preferences->Audio->Sound Out

For more information about why this is important, read more about sample-rate and word-length.

Set iTunes volume to "Full"

Volume attenuation may cause severe distortion, depending on which version of iTunes you are using.

The volume controls in iTunes versions 7.X or 8.X will not cause significant distortion. The user should not hesitate to use the volume control in iTunes v7.x or 8.X

This does not refer to the track-specific "Volume Adjustment" settings found in the "Get Info" menu. The "Volume Adjustment" setting should always be set to "None" for all tracks.

Read more about how digital volume controls affects audio

Benchmark's Guide for Audio Playback using Mac
A Simple Guide to Configure Your Mac for Optimal Audio Quality

Overview

Set the correct sample-rate and set word-length to 24 bit

These are set in the ’Audio MIDI Setup' control interface, which is in the 'Utilities' folder:

(Applications -> Utilities -> Audio MIDI Setup).

In the drop-down menu titled "Properties for:", select the output device which you are using

Under "Audio Output", the "Format" should be set to the appropriate sample rate and '2ch - 24 bit’.

For iTunes versions earlier then 7, we recommend setting the sample rate to match the sample rate of the media (music) being played

For iTunes versions later then 7, we recommend setting the sample rate to the highest sample rate that your device is capable of

For iTunes versions later then 7, iTunes must be launched after the sample rate is set in AudioMIDI. Any sample rate changes made in AudioMIDI while iTunes is open will not change the sample rate of iTunes until iTunes is re-launched. Consequently, it will cause CoreAudio to sample-rate convert the audio coming from iTunes. The result of CoreAudio sample-rate conversion is significant distortion.

Set iTunes volume to "Full"

Volume settings below "full" may cause severe distortion, especially on version 6 and earlier.

The volume controls in iTunes versions 7.X and 8.X will not cause significant distortion. The user should not hesitate to use the volume control in iTunes v7.x and 8.X

This does not refer to the track-specific "Volume Adjustment" settings found in the "Get Info" menu. The "Volume Adjustment" setting should always be set to "None" for all tracks.

Read more about how digital volume controls affects audio

Bypass all audio DSP and plug-ins (EQ and any other audio 'enhancer')

For iTunes, disable 'Sound Enhancer' and 'Sound Check'

These settings can be found in iTunes by going to:

iTunes->Preferences->Playback

How to play FLAC files in iTunes

Benchmark's guide for configuring Windows-based media players General strategies for setting up your computer for high quality audio playback

Overview

Windows Media Player (WMP) has extremely inconsistent behavior. Several issues have arisen among users, several of which remain unresolved. There is very little information available from Microsoft about the operation of this software. The information in this article is accurate to the best of our knowledge at the time of this printing. When further information is confirmed, this article will be updated appropriately.

Operation

If Windows Media Player does not stream audio to the appropriate output device, try restarting Windows Media Player. If this does not resolve the problem, open the following menu:

Tools -> Options -> Devices -> Speakers -> Properties -> Sound Playback

Choose the appropriate output device in this menu.

New info on Windows Media Player 12

Windows Media Player 12 (WMP12), which is only available on Windows 7 at the time of this writing, has the interesting quality of playing 24-bit audio files

New info on Windows Media Player 11

Recent tests with Windows Media Player 11 (WMP11) have brought to light some interesting qualities:

• WMP11's volume control outputs (un-dithered) 16-bits with 'Library' playback
• WMP11's volume control outputs 24-bits with HDCD playback
• WMP11's volume control outputs 24-bits with playback of 24-bit audio files

This means that the volume control will cause distortion with 16-bit playback. It is recommended to keep the volume control at 100% for 16-bit audio playback.

Recommended Player Settings

SET VOLUME TO 100%

This volume control can be used in moderation without seriously affecting the quality of the audio. We recommend using an analog volume control (post D-to-A conversion) instead, as it will result in the best signal-to-noise ratio.

Read more about digital volume control, and how it affects the quality of your audio.

BYPASS ALL AUDIO PLUG-IN'S AND AUDIO 'ENHANCEMENTS'

Plug-in's should be bypassed by default, but to make sure, go to the plug-in menu uncheck any active plug-in's. Also, in this menu, choose 'Other' and make sure no Plug-In's are checked. The menu can be found by going to:

Windows Media Player -> View -> Plug-ins -> Options -> Plug-ins -> Audio DSP

Audio enhancements should be bypassed. Open the "Enhancements" window and scroll through to make sure each one is turned off. The menu can be found by going to:

View -> Enhancements -> Show Enhancements  

Read more about how DSP and plug-ins affect your audio

Known Problems

Will not play 24-bit audio

As mentioned above, older versions of Windows Media Player was not able to play 24-bit audio files without a third-party plug-in/codec.