In Cubase VST, the ASIO system detects any changes to the ASIO Multimedia settings, and asks you whether you want the new configuration to be tested. This question will be shown after installation of Cubase VST and after you make any changes to the audio configuration (activating/deactivating ports, changing the buffer sizes, etc.). It can also be run manually by clicking the “Run Simulation” button in the Advanced Options dialog of the ASIO Multimedia Setup. We recommend that you perform this test, to ensure stable audio synchronization.
The test will open all activated audio devices over a short time and try to simulate a Cubase VST operation, using the current ASIO Multimedia settings. It will also check the sync stability of the selected Sync Reference port.
Outside Cubase VST:
This very important procedure is described on page 8.
• Check the audio hardware configuration.
In the ASIO Multimedia Setup control panels:
• Use the “Detect Buffer Size” function to detect proper audio buffer sizes.
• Deactivate ports.
• Change Sync Reference method and port.
• Try changing the global settings (e.g. half duplex or full duplex).
• Perform the manual “Check Buffers and Sync” test.
If audio tracks sometimes turn silent during recording or playback, you are experiencing audio dropouts.
Related information on this subject is also found in the sections: “Why am I experiencing audio crackling/clicks” on page 15, and “How do the different audio cards perform?” on page 20.
Here’s a list of things to check if you experience audio dropouts:
• Decrease the number of colors for the display.
This allows your computer to spend more of its processing time on audio (and MIDI). 16-, 24- or 32-bit true color display settings can severely hamper realtime audio performance on some computer configurations.
• Turn off the Microsoft Office FastFind option.
FastFind should not be enabled since its activities can interrupt all audio processing in the system.
• Don’t use any scheduled background tasks in the Windows Plus package. Functions that operate in the “background” use up valuable processor time needed for processing audio.
• Turn off your screen saver.
It is not recommended to use a screen saver while running Cubase VST. Screen savers with a lot of animation are especially unsuitable since they use up a lot of processing time.
• Turn off the “Auto-Notification” option for the CD-ROM drive.
This option is located in the CD-ROM drive properties page in the Device Manager (System control panel). If this is turned on, the insertion of a CD-ROM can interrupt the audio processing.
• If no audio playback/recording is possible whatsoever, choose “Reset Devices” from the Options menu.
If the audio drop-out occurred because of computer “overload” (i.e. another task took too much processing time away from the audio output), choosing “Reset Devices” from the Options menu may reactivate audio playback. If you are using a poorly written Windows Multimedia audio driver, it might even be necessary to restart Windows completely in order to cure this problem. If this is the case you should try to get a newer audio card driver from the manufacturer.
• Try activating the “Enable Audio only during Play” checkbox in the Audio System Setup dialog in Cubase VST.
When this is activated, Cubase VST stops transmitting audio blocks to the audio hardware as soon as playback is stopped. When playback starts again, communication with the audio hardware is re-opened. This prevents very long continuous audio streams to the hardware, which for some audio hardware may lead to audio glitches, “hiccups” and loss of MIDI/Audio sync due to lost blocks.
q The “Enable Audio only during Play” switch has one drawback: since all audio transfers are stopped when the playback is stopped, any trailing reverb or delay ‘tails’ will be cut off. For the same reason, all input monitoring is disabled in stop mode, as are plug-ins that generate audio by themselves.
There is an additional possible solution to the problem of audio dropouts when using the ASIO Multimedia driver: You might have to increase the number of audio buffers or the buffer size. This is done in the ASIO Multimedia Setup Advanced Options dialog, and we recommend that you use the “Check Buffers and Sync...” function to do it:
1. Open the Audio System dialog and click the ASIO Control Panel button. The basic ASIO Multimedia Setup dialog opens.2. Click on "Advanced Options..." .
The Advanced Options dialog opens. For detailed info about this dialog, please refer to the chapter “Optimizing Audio Performance” in the main documentation.
The “Check Buffers and Sync” function can only test one Port at a time.
4. Click the “Check Buffers and Sync” button.
The “Check Buffers and Sync” dialog opens. At the top of the dialog, the name of the selected Port is displayed.
5. Set a test period with the slider.
We recommend that you select the maximum duration (5 minutes) for the test. Then, a successful test assures that for at least 5 minutes no audio buffers should be lost.
6. Click the Start button to run the test.
The test begins. The duration of the test is indicated by the progress bar below the Test Period slider.
7. Wait until the test is completed or, if the “Buffer lost” value (in the upper left corner of the dialog) is building up rapidly, click the “Stop” button to stop the test. If the test was successful, an alert will tell you so. If Sync or Buffers were lost, you will be informed of what went wrong, and get some suggestions about what you can do to remedy the problem:
• If the “Buffer lost” value builds up, this indicates audio dropouts.Try any of the following methods, and run the test again:
• Increase the number of audio buffers.
• Use the "Detect Buffer Size..." option in the Advanced Options window.
• If you are using the “Sample Position” Sync Reference method, try increasing the Buffer size
• Check that no background tasks currently run on your computer.
P If you use the DMA Block type of Sync Reference, you should not adjust the Block sizes manually! Instead use Detect Buffer Size function in the Advanced Option window.
• If the “Sync lost” value (above the “Buffer lost” value) builds up, this indicates that MIDI to Audio synchronization is unstable.
See page 9.
8. Try out different values until the test is successful.
9. Click Apply Buffer Settings and then OK.
You are returned to the Advanced Settings dialog, with the new settings applied to the selected Port.
10.Now test the new configuration by clicking the “Run Simulation” button in the Advanced Options dialog.
This is the “automatic Sync Test” described earlier, but manually executed. It tests all input and output ports being driven together.
If recording stops for no apparent reason, please try disabling the following while recording audio (see above for a detailed explanation on how to perform these operations):
• Screen Saver.
• Network.
• CD-ROM Autorun.
Graphic cards
Graphic card drivers (e.g for Matrox cards) can block the PCI bus when screen updates occur. Some graphic card manufacturers have discovered that they can increase the card’s performance by designing drivers that send commands over the PCI bus without checking whether the card is ready to receive them or not (ignoring the queue check of the graphic card). If the card is not ready, the PCI bus is blocked until the card can receive the commands. As a result no other activities can occur in the computer, which in turn may cause crackling/clicks (as well as temporary dropouts and channel swapping).
Indication of this kind of problem:• Crackling is more intense when the Arrangement window is updated after the song position pointer reaches the right side of the window (in Follow Song mode).
• Crackling occurs when any of the Transport, Monitor or Master windows are displayed. If they are not displayed no crackling occurs.
• Crackling happens more often when 16-, 24- or 32-bit color display modes are used. In order to solve this problem, you can either simply turn off the PCI performance enhancements in the graphic card driver, get a new and better driver (if available) or change the settings in the driver so that it doesn’t send commands to the card until it is ready to receive them. Here are recommendations for some common graphic card drivers (please contact the manufacturer if your graphic card driver is not mentioned below).
• ET6000 VGA driver
If you are using an ET 6000 VGA driver you should get the latest driver from Tseng labs.
• DV95112 (driver for Hercules Dynamite 128 card)
For the Hercules Dynamite 128 card, there is a driver called DV95112 (Version 1.12). If you want this driver to hold commands until the card is ready, please do the following:
• Matrox Millennium
If you are using the Matrox Millennium, please do the following in order to stop the driver from blocking the PCI bus:
• Matrox Mystique
Owners of Matrox Mystique, please do the following in order to make the driver hold commands until the card is ready to receive them:
1. Go to Screen Properties (right click in main window).
2. Go to Setting Tab and click on the PowerDesk button.
3. Uncheck ”Use Bus Mastering”.
4. Uncheck ”Use Automatic PCI Bus retries”.
• S3 drivers
The staff at S3 have reported that “all” S3 drivers (downloaded from www.s3.com) for all of their VGA cards can be fixed by adding a line in the system.ini file:
1. Find the [display] section in the system.ini file.
2. After [display] add the line “bus-throttle=1” (or “BusThrottle=1”).
3. Save the system.ini file and restart.
Incorrect PCI bus settings in the BIOS can create crackling (especially the “PCI Latency” parameter). Changing PCI settings is a very delicate matter. Consult your computer dealer for assistance.
In addition, on computers equipped with a Pentium Pro processor the “Write Combining” feature can result in audio problems with DMA based sound cards (like SoundBlaster) and Windows Sound System compatible cards (like TerraTec Maestro). If you can, try turning this feature off for increased audio performance. However, not all BIOS setups allow access to this PCI bus setting.
High Speed SCSI cardsHigh performance SCSI cards like Adaptec AHA-2940UW or other Ultra-Wide SCSI host adapters can block the PCI bus because of the high data rate, which may cause crackling/clicks. This usually occurs with bus master audio cards like the Korg 1212 I/O and Event Electronics’ Darla/Gina by Echo.
If you experience crackling/clicks while using a high performance SCSI card, try reducing the maximal transfer rate of the SCSI bus to 10 MB/s.The 10 MB/s setting is still enough for up to 32 simultaneous audio tracks. Please refer to the manual that came with the SCSI card for information on how to change this setting.
In addition, if the computer contains a PCI bridge it might help to put the SCSI and audio card on separate PCI segments. For example; a computer with 6 slots might be implemented as two PCI segments with 3 slots each. If a board has got more than 5 PCI slots it will definitely have a PCI bridge. The board’s manual should explain which slots are on the same segment.
External Word-Clock SyncExternal synchronization of audio differs from synchronizing MIDI. In order to achieve proper synchronization of digital audio signals it is vital that all devices remain locked to a common sampling rate reference clock. One method of achieving this is through a digital reference signal called a word clock.
Unfortunately, different types of digital audio devices (S/PDIF, AES-EBU or ADAT) are not synced to the same type of word clock.Some audio cards that are equipped with different types of digital inputs contain a sample rate converter and can therefore accept non-matching word clocks for the input and the internal processing.
However, if no sample rate converter is involved, occasional clicks may occur. One example is the Korg 1212 I/O card, which will exhibit this problem when the S/PDIF and ADAT inputs are used simultaneously, but the source devices are not synced to a common word clock (for example a CD-Player and an ADAT).
In addition, if a device connected to the digital output of an audio card does not sync to the digital audio clock from the card, the recordings made with that device may contain occasional clicks, even though the original recording doesn’t.
Tempo changes
If you have raised the tempo of a song, after recording audio, some audio events may be interrupted by a following event. This happens when the preceding event has not finished playing before the next one starts. Please change back to the original tempo.
Buffer size/number of buffers in the ASIO Multimedia Setup windowHaving too few and too small buffers may cause stuttering just as it may cause audio dropouts (see: “When using the ASIO Multimedia driver” in the section “What do I do when I experience audio dropouts” on page 12).
Another application is startedIf you launch another application while Cubase VST is running, the audio playback may be temporarily affected.
CPU or disk overload
If you encounter audio stuttering, and the Performance window shows that either the CPU or the disk is overloaded, please decrease the number of audio tracks by muting some, or by performing a “mix-down”. For information on how to perform this operation, please refer to the section: “Mix Down” in the online documentation (Getting Into the Details).
If you try to process an audio file in the Wave Editor and Cubase VST gives you the message “Can't open file”, it probably means that the file is set to “read only” (writeprotected) in Windows. Use the Explorer to change the settings for the particular file.
If you are using an external wave editor together with Cubase VST, you may get the message “Can’t access file” or “Can’t save file” while trying to edit an audio file in the wave editor. If this happens, please turn off the “Play in background” setting in the Preferences window (File menu). This setting may interfere with an external wave editor.