Solving Sound Problems After a Windows 10 Build 2004 Upgrade
Doug Lee

This document presents some tips on how to handle various sound processing issues that have arisen during Windows 10 build 2004 upgrades, acording to this author's observations. The document is organized by symptom, to make finding a potentially useful remedy easier.

Document revision history:

August 10, 2020

Initial publication.

Table of Contents

• Stereo Sound For Monaural Signals, Inter-Channel Echo, Etc.
• Extreme Audio Stuttering
• Hollow or Tubular-Sounding Audio

Stereo Sound For Monaural Signals, Inter-Channel Echo, Etc.

For any device exhibiting any of the following symptoms after the Windows upgrade, make sure audio enhancements for the device are disabled:

• A monaural signal sounds like it is a stereo signal, where the two channels are not equal. This can manifest as an echo, an open-space sound, the sense that the sound is bouncing off of a wall, etc.
• The equalization of the sound is unusual - less bass, more midrange, etc.
• Sound is excessively loud, distorted, prone to abrupt volume changes or initially outlandish volume level, etc.

1. Type Windows+R to open the Windows "Run" box, then type mmsys.cpl and press Enter. This will open a dialog consisting of a list of sound output devices and other controls.
2. Select the device you want to update by clicking or arrowing to its name.
3. Click or press Space on the Properties button.
4. In the resulting dialog, select the Enhancements tab. If there is no Enhancements tab, search the available tabs to find the checkbox mentioned in the next step.
5. Find a checkbox with a name like "Disable all enhancements." If it is not checked, check it with a click or by focusing it and pressing Space. Note: This or the following step may cause any actively running assistive technology (AT) screen reader to stop speaking and will likely terminate any other active use of the audio device. If this happens, shut down and restart the screen reader and/or any other software that was using the device.
6. Click or press Space on the Ok button.
7. Press or click the Ok button in the original dialog to close the audio configuration application.

Extreme Audio Stuttering

If you are using Virtual Audio Cable (VAC) 4.62 or older and experience any of the following symptoms, upgrade to at least VAC 4.64:

• Audio, possibly including default system audio, that plays slowly yet without sounding abnormally low in pitch.
• Extremely stuttery audio sound (rapidly repeating segments of audio, very fuzzy or broken sound for what should be a pure tone, etc.).
• Speech that sounds seriously intoxicated.
• Appearance and disappearance of these symptoms throughout the use of the computer For example, symptoms may appear when an audio application is first opened and suddenly affect all audio and audio applications until all are closed.

See the VAC user manual for instructions on upgrading VAC; but the basic process recommended by this author is as follows:

1. Download your VAC 4.64 copy.
2. Unpack the downloaded Zip into a folder of your choice. Do not try to run the VAC installer from inside the Zip file directly.
3. Stop absolutely all access to VAC lines:
   • Make sure the Windows default input and output devices are not VAC cables.
   • Shut down all audio applications that may be accessing cables. This includes VAC audio repeaters, the VAC Control Panel if open, media players, Skype and other telecommunication programs, etc.
   • Make sure to shut down even Windows applications for configuring audio, such as mmsys.cpl.
4. Remove your current VAC installation via Apps and Features. If you did the previous step correctly, this should usually result in successful VAC removal with no need for a system restart.
5. Install the new VAC version by running the Setup utility from its unpacked file folder. Warning: If you are using an assistive technology screen reader, it may stop speaking during the VAC installation. If this happens, stop and restart the screen reader.
6. Reset your Windows default input and output audio devices as you prefer.

Hollow or Tubular-Sounding Audio

If any of the following seem to apply to your sound and you are running Virtual Audio Cable, try a different device access method as described below:

• Audio sounds like it is emanating from a tube or barrel or perhaps from a strange telephone or small radio speaker.
• Audio is monaural when it should be stereo.
• Audio is missing one of its two channels.
• There is no bass in the audio.

If the above symptoms apply, try the following:

1. Make sure your problem is not covered already by the "Extreme Audio Stutter" section above before trying the items below in this list.
2. Stop absolutely all access to VAC lines, except for the VAC Control Panel if it is open:
   • Make sure the Windows default input and output devices are not VAC cables.
   • Shut down all audio applications that may be accessing cables. This includes VAC audio repeaters, media players, Skype and other telecommunication programs, etc.
   • Make sure to shut down even Windows applications for configuring audio, such as mmsys.cpl.
3. Open the VAC Control Panel application. This application must be run as a Windows administrator to be fully effective. If it is already open but not as an administrator, relaunch it as an administrator.
4. Select all VAC cables in the list of cables at once.
5. Change each of the two dropdown (combo) boxes that say "WaveRT" to "WavePCI."
6. Click or press Space on the "Set" button that has the tooltip "Set specified parameters for all selected cables." Warning: If you are using an assistive technology screen reader, it may stop speaking at this point. If this happens, stop and restart the screen reader.
7. Test your audio to see if the problem is fixed. If you have further problems that can not be fixed by increasing repeater buffer sizes, repeat the above steps but change WavePCI to WaveCyclic where the above directions say to change WaveRT to WavePCI. In this author's experience, this should not be necessary and may result in slower system performance.
8. Once audio is working, reset your Windows default input and output audio devices as you prefer.