Dropouts and other audio problems

If your SONAR application suddenly stops producing audio while in the midst of recording or playback, you've very likely experienced a “dropout.” Sometimes instead of a dropout, you may experience a “stutter” during playback (a small section of audio repeats itself once or twice before normal playback resumes). Or, you may occasionally experience a “glitch” or “pop” during audio playback (a brief interruption or clicking noise is heard, but audio playback then continues normally from that point). It is possible to experience a dropout while working exclusively with MIDI (i.e., no audio data in the project), but this is a different matter and is not covered here.

All of these audio problems are the result of audio information not being sent to or received from your sound card fast enough or reliably enough. During recording, the sound card sends incoming audio data to the sound card driver, which in turn sends audio data to SONAR to store on hard disk. When playing back, SONAR reads audio data from the hard disk and feeds it to the sound card driver, which in turn passes it to the sound card for audible output. If these activities can't be completed fast enough, or if the communication between SONAR and the sound card driver is broken in some way, recording and/or playback will be disturbed.

Causes and cures

The exact cause of your audio problem will vary depending on the configuration of your computer and/or the content of the project file you're working with. The majority of audio problems are caused by one of the factors listed here. Read each of the following topics, in the order shown, and follow the recommendations provided:

The CPU is being interrupted by “background” activities having nothing to do with audio

SONAR doesn't properly “recognize” your sound card

The “I/O Buffer Size” may not be well matched to your hard disk

Mixing latency may be set too low

Your hard disk may be excessively fragmented

Your project file may be excessively fragmented

Your sound card's driver may be obsolete

There may be a conflict with your video card or other multimedia streaming card

Your sound card may have a conflict with another device in your computer

Your project may simply be too “complex” for your computer

Upgrade your computer hardware: more RAM, a faster CPU, and a faster disk drive

The CPU is being interrupted by “background” activities having nothing to do with audio

Turn off these other activities, so your CPU can process audio without interruption:

Turn off the Microsoft Office FastFind option if present on your system.

Don't use any scheduled background tasks (e.g., tasks which are part of the Windows Plus package, or which you have scheduled yourself using the Windows Task Scheduler utility).

Discontinue use of any networking or communications applications on your computer. For example, don't run email programs (like Microsoft Outlook), Web browsers, or AOL client software while you are running SONAR. These programs send and receive chunks of information over a modem or a network connection; when one of these data chunks is sent or received, your CPU may be unexpectedly interrupted from SONAR audio processing to deal with the modem or network data. That interruption can disrupt the smooth processing of audio data, causing a dropout or glitch. If possible, you should disconnect your computer from a local area network, and/or disconnect from any dial-up telecommunications while recording or playing back audio in SONAR.

Turn off your screen saver (if present).

Turn off the Auto-Notification option for your CD-ROM drive. If it is turned on, the insertion of a CD-ROM can interrupt audio processing.

To disable it, open the System applet in the Control panel, click on the Device Manager tab, expand the CD-ROM list entry, double-click on the listed CD-ROM device, click on the Settings tab, and clear the Auto Insert Notification check box.

Disable any kind of virus scanning program that might be running in the background. To find out what programs are currently running, press the CTRL-ALT-DELETE keys simultaneously to display the Windows Task Manager; if you see an anti-Virus program shown on the list of currently running tasks, select that program and click End Task.

If SONAR's Auto Save feature is enabled, disable it.

Remove all programs from the Windows Start Up folder (\Windows\Start Menu\Programs\Start Up).

SONAR doesn't properly “recognize” your sound card

Re-run the SONAR Wave Profiler, which will attempt to analyze your sound card and establish proper settings for it:

Go to Edit > Preferences > Audio - Driver Settings and click the Wave Profiler button.

If Wave Profiler offers you the chance to use “default settings” for your sound card, accept the defaults, close the Preferences dialog box, and check audio playback/recording.

If problem(s) continue, re-run the Wave Profiler, but this time do not accept any default settings.

If you decline to use default settings (or if Wave Profiler can't find any for your sound card), Wave Profiler will analyze your sound card's capabilities by running some tests and automatically establish appropriate settings based on the test results.

If your sound card is listed at www.cakewalk.com/Support/Knowledge-Base/Audio-Hardware-Setup-Guide, read and follow any special card-specific operating instructions listed there.

Re-test audio recording/playback. If problem(s) persist, go to the Next Step.

The “I/O Buffer Size” may not be well matched to your hard disk

SONAR may be reading and writing audio data to/from your hard disk in chunks that are either too large or too small for your particular hard disk's characteristics.

Go to Edit > Preferences > Audio - Sync and Caching and try different values for Playback I/O Buffer Size and Record I/O Buffer Size until you find values that works well for your particular hard disk:

The default value is 64. Try reducing this value, to 32, then 16. After each change, close the dialog box (click OK) and re-test your project's recording/playback behavior.

If problem(s) persist, try increasing this value, to 128, then 256, then 512. Again, close the dialog box and re-try your project after each change.

If you have an older, slower computer or an older, slower hard disk, you should try increasing the buffer size; decreasing is not advised on slower hardware. However, increasing this setting uses more of your computer's RAM. If you have a smaller amount of RAM in your computer, increasing the buffer size may not help.

If problem(s) persist, restore this value to its default and continue with the next step.

Mixing latency may be set too low

SONAR tries to send and receive audio data to/from your sound card with very a minimal delay (so that any real-time adjustments you make to a track's volume, pan, or other settings will take effect rapidly). If the latency setting is set too low, the sound card driver may not be able to keep up with the SONAR, and audio will be disrupted.

Try higher latency settings:

Go to Edit > Preferences > Audio - Driver Settings. Move the Mixing Latency Buffer Size slider control to the right in small increments until you see the value to the right of the slider increase; close the dialog box (click OK) and re-test your project after each increment.

If problem(s) continue, move the slider control back to its original position, and try increasing the number in the Buffers in Playback Queue text box. (This value starts out at 4; try increasing it to 5, 6, 7, or 8). Close the dialog box (click OK) and re-test your project after each such change.

The total effective latency is displayed below the slider; it is determined by multiplying the per-buffer latency time (in msec) by the number of buffers in the playback queue.

Your hard disk may be excessively fragmented

Audio data can be processed most efficiently if it is arranged in consecutive physical locations on your hard drive. Over time, the chunks become distributed at various discontiguous locations on your disk, which makes it more time consuming for SONAR to access the chunks. This extra access time can interfere with smooth audio recording and/or playback.

Try defragmenting the hard disk:

Make sure SONAR, and the Wave data directory are not installed on a compressed hard disk.

Defragment your hard disk. If you have more than one hard disk in your computer, identify the disk which contains the SONAR Data directory (this is where your projects’ audio clips are stored.) To defragment the hard disk, exit SONAR first. Then, select Start > Programs > System Tools > Accessories > Disk Defragmenter. We recommend that you backup your hard disk before defragmenting it.

Your project file may be excessively fragmented

Audio data can be processed most efficiently if it is arranged in consecutive physical locations on your hard drive. During normal SONAR usage, a project's audio data can become fragmented into chunks stored at discontiguous locations on your disk. Accessing these discontiguous chunks can consume extra processing time, which can lead to dropouts.

Try defragmenting your project file:

1.	Open the project file that has audio problems.

2.	Save it as a Cakewalk Bundle (.cwb) file by selecting Save As from the File menu and selecting Cakewalk Bundle from the Save As Type drop-down list and clicking the Save button.

3.	Close the project.

4.	Open the Cakewalk Bundle you just closed

Saving then re-opening the bundle file automatically defragments the audio data used by the project, reducing the chances of a dropout or other audio problem.

When you are ready to save the file again, you may want to save it as a normal (.cwp) file. Saving and opening .cwp files takes less time than saving and opening bundle files.

Your sound card's driver may be obsolete

Obtain and install a new sound card driver (if available):

Consult your sound card manufacturer's website (or contact their Customer Service department) to check for the availability of a later driver version. If one exists, obtain it and install it on your computer according to their instructions. With the new driver installed, restart the computer, then delete the file cw9auddx.ini from your SONAR folder. Launch SONAR and let it re-profile your audio hardware. When it's done, re-test your audio recording/playback.

If problem(s) persist, continue with the next step.

There may be a conflict with your video card or other multimedia streaming card

Some video drivers contain bugs which can interfere with SONAR's operation. Or, the driver may be “stealing” excessive CPU time away from SONAR (some video card vendors, in an attempt to make their cards operate faster, supply drivers that tie up the computer's bus for relatively long intervals (so-called “PCI bus contention”). This can interrupt the smooth flow of audio data between SONAR and the sound card's driver.)

Try to remove the video card conflict as follows:

Try turning off “hardware acceleration” on your video card (if available). This may cause more sluggish screen drawing, but may improve the flow of audio data to your sound card, thereby reducing the possibility of dropouts.

To disable the hardware acceleration on your graphics card: Launch Control panel (Start > Settings > Control panel). Double-click the Display icon. Select the Settings tab. Click on the Advanced Properties button. Select the Performance tab. Move the slider for Hardware Acceleration one notch at a time toward ‘none’ and re-test your recording/playback after each such adjustment. If problem(s) persist, leave the slider at ‘none’ and proceed with the next step.

Try Using the Windows driver for your specific sound card (instead of the manufacturer's driver).

Try using the standard VGA/SVGA drivers provided with Windows (instead of the drivers provided by the manufacturer).

Check your video card manufacturer's website for a later driver version. If a newer driver is available, download it and install it on your computer following the manufacturer's instructions.

If you have an STB Velocity 128 card, and your graphics card was configured and shipped with a new computer, you may want to check the computer vendor’s website (instead of STB’s site) to see if they offer a driver update for the STB card. Computer vendors often will customize drivers to their specific needs and you should use their driver updates.

Try reducing the number of colors used by your video card. 16-, 24-, or 32-bit true color display settings can severely hamper real-time audio performance on some computers; using fewer colors allows your computer to spend more of its processing time on audio and MIDI.

You can adjust color depth by right-clicking on your Windows desktop, clicking Properties, clicking on the Settings tab, and selecting a suitable entry in the Colors list. Also, try reducing the display resolution. Re-test your audio playback/recording with these changes.

If you have one of the following specific video cards, applying the following card-specific .ini file settings can reduce PCI bus contention problems.

If you have a Hercules Dynamite 128 card:

Open the System.ini file in Notepad (or any text editor). In the section called [Hercules], check to ensure that this line is present:

Optimization=1

(The default is 0; if necessary, edit the value to 1 and save the file. Restart Windows.

If you have a Matrox Millenium card:

Open the System.ini file in Notepad (or any text editor). In the section called [mga.drv], add the following line:

Pcichipset=1

Edit the file as necessary, and save the file. Restart Windows.

If you have an early Matrox video card, Disable Use PowerGDI acceleration:

(Start > Settings > Control panel > Display > MGA Settings > Advanced > Performance)

If you have a later Matrox video card, enable Use Bus Mastering and Disable use Automatic PCI Busd Retries:

(Start > Settings > Control panel > Display > Settings > PowerDesk button)

If you have a card based on the S3 chipset (S3, Inc. provides graphics chips for other manufacturers; consult your card manufacturer’s website to see if that card is S3-based):

Open the System.ini file in Notepad (or any text editor). In the section called [display], make sure the following line is present:

BusThrottle=1

Edit as necessary, and save the file. Restart Windows.

If problem(s) persist, continue with the next step.

Your sound card may have a conflict with another device in your computer

Try resolving this device conflict as follows:

Ensure that your sound card is not sharing IRQs with any other device. Although some sound cards claim that they work properly on a shared IRQ, this is usually not the case and it is advisable to avoid such sharing. To do this, right click on My Computer and select Properties from the pop-up menu. In the System Properties dialog box, click on the Device Manager tab, then double-click on the Computer icon at the top of the list. This allows you to look at all the devices on your system and which IRQs they are using. Scroll through the list until you see your sound card. Check the IRQ setting to the left of the icon. If there are other devices (such as a video card) that are assigned to the same IRQ, you should try moving your sound card to a different slot in your computer. Note that entries which say something like “IRQ Holder for PCI Steering” do not indicate conflicting devices, and can be ignored.

Go to Edit > Preferences > Audio - Devices and make sure that only your sound card's input and output drivers are highlighted in both menus. (If you have more than one sound card installed in your system, try using only a single sound card and deselecting the other(s). If you can get audio to record/playback properly on a single sound card, but you encounter problems using two sound cards simultaneously, there may be a conflict between the two sound cards. Contact Cakewalk Technical Support for assistance in this event.)

If problem(s) continue, another multimedia audio device on your system (like a built-in sound card or voice modem) could be interfering with your sound card's functionality. To see if this is the cause of your problem(s), you'll have to temporarily disable these other devices. Note that this may cause other programs which rely on these other devices to no longer work correctly.

To disable these other device(s), in Windows go to the Control Panel, and double-click the Multimedia icon. Click the Advanced tab, and click the plus sign next to Audio Devices. Double-click any audio devices listed there that AREN'T the sound card, and choose Do Not Use Audio Features on This Device. Click OK, and repeat this step for any non-sound card device, including voice modems, 'virtual audio devices' or 'game-compatible devices'. Once the sound card is the only device left, click OK, and restart the computer. After restarting, delete the file cw9auddx.ini from your Cakewalk folder. Once you've deleted those files, launch SONAR, and let it profile your audio hardware. When it's done, try playing your audio again.

If problem(s) continue, try deselecting any MIDI devices which you might be using. In SONAR, go to Edit > Preferences > MIDI - Devices and deselect every MIDI device in both Inputs and Outputs, then when SONAR asks, select Continue with no MIDI input and Continue with no MIDI output, and try re-test your audio recording/playback.

If problem(s) persist, reselect your audio and MIDI devices, and continue with the next step.

Your project may simply be too “complex” for your computer

Your computer may not have enough processing power to deal with all of the tracks, clips, and real-time effects used in your project. You can upgrade your computer hardware (see Upgrade your computer hardware: more RAM, a faster CPU, and a faster disk drive) or you can simplify your project’s content so it demands less processing power.

If possible, try reducing the complexity of your project in any of the following ways:

Reduce the number of real-time effects used in your project. Instead of generating the effects in real-time (nondestructively) during playback, consider applying the effects offline (destructively), before beginning playback.

Reduce the number of distinct tracks being played back simultaneously. Consider “sub-mixing” several of your audio tracks into one track (using the Track view Tracks > Bounce to Track command), and then archiving the individual tracks which were combined in the sub-mix. (Archived tracks don’t use up any CPU resources during playback, leaving more CPU resources available to properly play the non-archived tracks.)

Where possible, record audio using a mono source, rather than a stereo source. Mono clips require less processing power than stereo clips.

Avoid using overlapping audio clips. Where possible, combine/blend overlapping clips into a single clip, which uses less processing power.

Thin the amount of MIDI controller data and the number of SysEx messages in your tracks.

If you can't reduce your project's complexity, or if problems persist even after the complexity has been reduced, proceed to the next step.

Upgrade your computer hardware: more RAM, a faster CPU, and a faster disk drive

If your project makes extensive use of real-time effects (plug-ins), you should consider upgrading to a faster CPU. If your primary concern is playing or recording a large number of tracks, a faster CPU will help, but you may find that adding more RAM, a faster hard disk, and/or an improved hard disk controller may help even more.

The following are some tips on upgrading your hardware:

Audio problems are often caused by a hard disk which is transferring data too slowly. The disk could simply be physically incapable of reading and writing data fast enough, or the disk controller could be causing too much CPU time to be consumed when transferring audio data to/from the disk.

Consider upgrading your equipment as follows:

Ensure that your hard drive controller is NOT configured to operate in “compatibility mode” which can greatly slow data transfer to/from your hard disk and make it almost impossible to record/play audio in SONAR reliably. To do this, go to the Control Panel and double-click on the System icon. Click the Performance tab. At the top of the Performance screen read the entries across from File Systems and Virtual Memory. They both need to say 32-bit. If they mention MS-DOS Compatibility Mode, then your computer has a serious problem, beyond the scope of what a Cakewalk technician can fix. Your computer is processing the audio data very slowly and SONAR will not work properly until the MS-DOS Compatibility Mode problem is eliminated. Help is available on the Microsoft Technical Support Web page at www.microsoft.com/Support. Click on the Support Online link and search for the phrase Troubleshooting MS-DOS Compatibility Mode on Hard Disks. This problem can arise when installing a new hard disk in your computer; if Windows cannot find a suitable driver for the disk, it installs a generic driver and operates in Compatibility Mode.

If you're using a hard disk controller that employs “programmed I/O”, upgrade to a disk controller that uses “bus mastering” instead. (This is sometimes also known as an UltraDMA IDE Controller). The former technique relies on the CPU to transfer the data to/from the hard disk, stealing cycles which the CPU could be sending audio data to/from the sound card. With the latter technique, the hard disk controller itself is primarily responsible for transferring the data to/from the hard disk, relieving the CPU of much of that burden.

Install a faster hard disk. If you're using an IDE- or E-IDE-type hard drive, try to find one which has a lower disk access time (e.g., less than 9msec). Use the Win Tune test application available at www.winmag.com, this diagnostic tool measures your hard drive's uncached transfer rate.