Troubleshooting

Increase your latency settings

1. From the Options menu, choose Preferences. The Preferences dialog is displayed.

2. Select the Audio Device tab and click the Advanced button. The Advanced Audio Configuration dialog is displayed.

3. Select the ASIO driver tab and click the Configure button to display the configuration applet from your hardware manufacturer.

4. Type a new latency value, apply the change, and close the configuration applet to return to the Advanced Audio Configuration dialog.

5. Click the Apply button in the Advanced Audio Configuration dialog.

Turn off other audio devices

You can only use a single ASIO driver at a time, and some ASIO drivers can conflict with other audio driver models (such as WDM and wave drivers).

Getting your computer to play back a complex project can be a bit like walking a tightrope: there's a delicate balance between responsive playback and glitch-free playback. The trick is finding the sweet spot for your hardware.

For more information about setting advanced audio preferences, see Advanced Audio Configuration.

1. From the Options menu, choose Preferences, and then click the Audio Device tab.

2. Click the Advanced button to display the Advanced Audio Configuration dialog for your sound card.

3. Adjust your buffer size until playback is responsive and clear.

4. For wave devices, try raising and lowering from the default settings until you find the sweet spot. Use the Buffer size drop-down list to choose a buffer size in samples, or choose MME to use the Playback buffering setting on the Audio Device tab in the Preferences dialog. You can also try increasing the Audio buffers setting to increase the number of buffers created. As a last resort, choose Time Critical from the Priority drop-down list.

5. For ASIO devices, start with a setting of 2048 samples. If playback is glitch free, you can try decreasing the setting. If you hear glitches, you may need to raise the setting.

TIP Higher sample rates (and bit depths) may require a larger buffer because more data is being put through your device per buffer.

Turn on real-time MIDI monitoring

If you have a MIDI track routed to an external MIDI device, real-time MIDI monitoring must be enabled to allow Acid software to communicate with the MIDI port.

Real-time MIDI monitoring is enabled by default, but if you've turned it off, you can turn it on again by choosing Enable Real-Time MIDI from the Options menu.

When the Enable Real-Time MIDI command is selected, audio plug-ins continue running even when playback is stopped. Turning the command off can conserve processing power, but input from external MIDI controllers will be ignored.

Enable the VST instrument

If you're using a VST instrument, select the Enable button in the Soft Synth Properties window to hear its output.

Try a different soft synth

Unfortunately, some soft synths work better than others. Try routing your soft synth to a different VST instrument.

ASIO sound drivers can cause conflicts with the Microsoft GS Wavetable Synth. To play your project, choose a different device for MIDI playback and verify that no other application is trying to use non-ASIO drivers.

Unfortunately, there is no standard way for a DirectX host application to determine whether a DirectX plug-in is automatable. For this reason, the application does not check a plug-in until you try to use it (just think of the time we're saving you at startup).

After you use a plug-in, the application can determine whether it is automatable and it will appear in the correct folder in the Plug-In Chooser and will be indicated by the icon if it is automatable.

Adjusting these settings can resolve issues with some specific VSTi plug-ins. These settings will vary with your specific configuration and can be modified via the Windows Registry.

Incorrectly modifying the registry can degrade performance or cause serious problems with your operating system. If you're uncertain how to change these settings, please use the defaults.

1. Start the Windows Registry Editor.

2. Browse to the key [HKEY_CURRENT_USER\Software\BorisFX\Acid Pro\2026\Metrics\VSTi Synth].

3. Edit the appropriate DWORD value:

   DWORD	Default Value	Explanation
   FlushOnStopCount	00000000	Some VST instruments (such as FruityLoops) do not flush their buffers on close and will output these buffers the next time you play or render your project. Entering a value in the FlushOnStopCount DWORD allows you to flush up to 500 buffers of audio.
   FrameSize	00000006	Frame size defaults to 6 ms, but can be set as high as 2000 ms. This should rarely need to be modified.

Both of these settings apply to playback, seeking, and rendering. Excessively high values can cause latency that can appear as an application crash. For example, if you set your buffer size to 2000 ms and set Acid software to flush 500 buffers, you'll create a 1000 second hang on every stop, seek, or render.

If you have a MIDI port configured in both Acid software and a ReWire client application, they will conflict when both applications try to access them at the same time.

If you want to use the MIDI port to play synths within a ReWire client, clear the port's check box in the Make these devices available for MIDI track playback and Generate MIDI clock section of MIDI tab in the Preferences dialog.

If you want to use your MIDI port in Acid software, make sure your ReWire client is not configured to use the port.