Soundware Beginners Guides: How to...
...Minimise Latency on your PC.
A common problem faced by people using a home computer to record is a delay when they press a key on a keyboard or speak into a microphone before they hear it through their speakers or headphones. This delay is called latency, and is caused by the time the computer takes to process the incoming sound before it can send it back through an output. Long latency times can be very offputting when recording, especially when overdubbing onto a backing track, and can also make different types of sound tracks played at the same time (eg., a MIDI file, and audio recording and a file running through a VST instrument) appear out of sync with each other.
Unfortunately, there's no way to remove latency completely - but it can in almost all cases be reduced to a manageable level. Latency can be caused by many areas of your computer's setup, so it's important to be sure that everything is configured to be as efficient as possible.
These recommendations are kept very general to make them apply to as many different platforms and operating systems as possible. Any examples given are for PC systems running Windows XP SP2. If you have specific questions about different operating systems or software applications, please contact us and we'll do out best to help.
Causes of Latency:
- Sound Card
Your computer's sound card is the first port of call for an audio or MIDI signal being input into your computer. If you're using a sound card specifically designed for audio recording, it's unlikely that it's causing much latency as this type of card is specially designed to allow as fast a transfer as possible, but if you're using onboard sound or a basic sound card supplied with your computer it might be worth considering an upgrade.
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Even if you do have a pro-audio quality sound card, it can cause problems if you're not using the driver software supplied with it, or if these aren't installed properly. Many sound cards designed for recording use ASIO drivers - these are specifically designed to provide very low latency and should be used wherever possible. If the card comes with a driver CD, install the correct driver for your operating system in accordance with the manufacturer's instructions. If it doesn't come with a CD, check the manufacturer's website for a driver you can download. Avoid using your operating system's default drivers wherever possible - the manufacturer's own drivers are ALWAYS better.
Ninety-nine per cent of all "faults" with sound cards or other audio interfaces are in fact driver problems, so if in doubt, reinstall. If you're installing a new card, consider backing up important files, formatting your hard drive and reinstalling your operating system first - working with a clean system is a lot easier than trying to install new hardware on a machine clogged with old drivers, and can save a lot of time and trouble in the long run.
Once your sound card's drivers are correctly installed, it's important to make sure that they're being used by whatever software you're using to record. Most software like Cubase, Logic, Ableton or Reason will have a "Device Settings" section somewhere that will allow you to check the driver setup for your audio or MIDI devices. Ensure that this is configured to use your sound card's ASIO drivers - these will contain a reference to either the model or manufacturer somewhere in their name. If in doubt, consult your software's help file for harware configuration instructions.
The way your computer system is set up can also have an effect on the latency within your recording software. Latency occurs because your computer cannot process the audio or MIDI signal you are sending it fast enough. The more system resources you are able to devote to audio processing, the faster your machine will be able to process the signal. So, it makes sense to make it easy for your computer to devote as many resources as it can to the job at hand when you're recording.
Make sure that you're running the absolute minimum number of other programs or background services when you're recording. Everything present in your system tray or running in the background is sapping your system's memory and processing power, even if you're not actually using it for anything. This includes your virus scanner and firewall (only exit these when you're not connected to the internet), applications that run by default on startup like MSN messenger, any toolbars that give access to advanced video, mouse or keyboard settings, or anything present in the "startup" folder in your start menu (Microsoft Office tends to put a shortcut here). Find them and get rid of them. You don't need them when you're recording and there's nothing to stop you reloading them manually later. A free startup manager program (a variety are available at www.download.com) can show you which applications are running every time you start your computer and help you to disable anything unnecessary.
*WARNING* Not everything that runs on startup can be safely disabled - most startup manager programs can help you to distinguish between unnecessary applications and essential services. As a rule, if you don't know what it is, don't disable it!
System MaintainenceEven if your computer is correctly set up and you rarely install new software or hardware, it will still need maintaining. Every time you use your computer, new files are being created and deleted again, and in some cases these can build up as junk files. Not only do they take up hard disk space, but they can cause your computer to crash or run slower than it would without them, particularly if new entries have been made to the Windows registry. A system maintainence program can be useful for finding and deleting unnecessary files and registry entries, and can speed your computer up significantly. If you don't want to use one of these, regularly backing up, reformatting and reinstalling your system can keep it in good working order (every 6 months to a year, depending on how much use the machine gets).
A clean, well configured system will generally give you minimum latency. However, there are other ways of tweaking your system to make it run faster. Prioritising Background Services over Programs (in Control Panel - System - Advanced - Performance - Settings - Advanced) will cause the system to devote more resources to audio processing. Reducing the number of visual effects (Control Panel - System - Advanced - Performance - Settings - Visual Effects) will also free up more system resources. Many websites give details of other tweaks, many of which can provide small improvements in performance. As always, back up or create a system restore point before making any changes to your Registry or making any other drastic changes.
HardwareIf you've tried all of the above and are still having problems with latency, it may be that your computer is simply too slow to run your recording software. This may be the case if your system only just matches the minimm system requirements for a piece of software. Always try to make sure that your system matches or if possible exceeds the recommended system requirements for the software you're running - if it doesn't it's possible that you'll experience latency simply because all of your machine's processing power is devoted to running the software, so that not enough is left to process incoming audio.
If you find you need an upgrade, extra RAM will probably give you the most noticeable difference in performance for the least money. After that, upgrading your CPU chip will also make a big difference, but will work out more expensive as you may also need to buy a new motherboard.