Setting Up Audio Devices: Difference between revisions

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== Latency & Sample Rates ==
== Latency & Sample Rates ==


Latency is the time that it takes for sounds output by Renoise to be played on your speakers or headphones. How much of the sound is buffered. The lower the latency, the quicker Renoise will respond to what you play or what you modify in Renoise. So its good to keep the latency low. But lower latencies also require a bit more of CPU so Renoise is not able to transfer the audio “in time”. As soon as this happens, the audio starts to crackle or choke. If you are hearing such unwanted crackles in Renoises sound output, the first thing you should do is increasing the latency in the preferences.
Latency is the time that it takes for sounds output by Renoise to be played on your speakers or headphones. The lower the latency, the quicker Renoise will respond to what you play or modify. So lower latencies are preferable, but they also require more CPU power to maintain. If the CPU becomes overloaded then the audio will start to crackle and choke. If you hear such crackles in the sound output, the first thing you should do is increase the latency via the Preferences menu.


The sample rate defines how “detailed” the sound is calculated and then also delivered to your speakers. So the higher the sample rate is, the more detailed will be the sound. 44100 kHz is the rate that is used in CD players, so that rate offers an excellent playback quality. Everything above that rate often does not result in a noticeable better result, but if you can hear the difference or not, is of course up to you, so your should try it out and to decide by your own. Rates below 44100 are not recommended because they easily sound more “dull” than higher rates.  
The sample rate defines how much detail is contained within the sound that you hear. The higher the sample rate, the more detail. 44,100 Hz is the rate that is used by CD players, so that rate offers an excellent playback quality. Whether higher rates result in a noticeably better listening experience is debatable, but they do offer increased resolution for effects. Rates below 44,100 Hz are not recommended because there is a noticeable reduction in sound quality.  


Another important point is the CPU consumption at different sample rates. Basically doubling the sample rate means a doubled CPU consumption in Renoise, because everything is done at twice the rate. So if you select rates above 44100 you should also be aware of that you may reach your computers processing power limits sooner.
Note that CPU consumption is affected by the sample rates. A doubling of the sample rate roughly corresponds to a doubling of CPU consumption in Renoise, because everything is done at twice the rate. So be aware that using higher rates will reach your computer's processing power limit sooner.

Revision as of 15:28, 9 February 2010

Setting Up Audio Devices

Audio devices are what allow your computer to create the sounds you hear. This is not necessarily a sound-card; it can also be built into your computer's hardware. Whatever does the actual sound output, what you control in Renoise is a driver, which is what communicates with both the hardware and software.


Default Setup

By default, Renoise is configured to use the system's default audio output device at a high latency, ensuring that in most cases Renoise is ready to go and output can be heard. No input device (something you can record with) is selected by default. Because the default settings are often not optimal for your particular machine, you should have a quick look at the Audio Preferences in case adjustments can be made.


Audio Preferences

To change the audio settings in Renoise, select "Edit->Preferences" from the Upper Status Bar. On OSX you will find the "Preferences" in the "Renoise" menu at the very left.

File:Vvoois renoise preferences audio1.png

(Example of the Audio preferences pane on Windows)

For a more detailed explanation of the Audio Preferences, take a look at the Preferences section of the manual, as this only a quick overview on how to set up devices.


Audio Setup on Windows

On Windows you will have the choice between two different audio architectures:

  • Direct Sound: This is the Windows default setup for audio and will work with all devices that are recognised by Windows. It is reliable, but also has a relatively high latency (the time it takes for the sound output by Renoise to be heard). Direct Sound only offers one stereo channel as input or output, so if your sound-card offers multiple audio channels you will not be able to use them in Renoise via this method.
  • ASIO: An audio architecture created specifically for professional audio applications like Renoise. It offers low latencies and combines recording and playback into one driver, making recording more reliable and stable. It also allows software such as Renoise to access multiple channels at once. So if your sound card has more than one output, you can directly address them in various ways when using ASIO.

Because of its many advantages using ASIO is highly recommended. Even if your sound-card does not provide ASIO drivers (your device does not show up in the ASIO device list in Renoise), you could try out a free general ASIO driver for Windows: ASIO4All. This driver will work with most audio hardware, but may not be as reliable as your specific sound-card vendor's official drivers.


Audio Setup on Mac OSX

On OSX there is only one driver architecture present and it will work out of the box on all available Macs. Named Core Audio, it is similiar to ASIO, offering low latencies and allowing the use of multiple soundcard outputs (when present) in Renoise.

To use Core Audio, simply select the device for output and recording and then select the latency and sample rate you want to use. Please see below for a more detailed description of the latency and sample rate setup.


Audio Setup on Linux

On Linux you have the choice between two different architectures:

  • ALSA: This is the default audio architecture on most Linux systems, which should work out of the box in Renoise. In most cases it is very fast and reliable, but may require some fine tuning before being usable. Please see the general comments below for more info about the "tweaking" that is needed for Linux Audio in general.
  • Jack: Not installed by default on many Linux systems, but is still a relatively common and advanced way to access your sound hardware. Jack does not just bridge Renoise to your sound-card, but also allows the routing of audio between multiple applications. Please visit the official Jack audio pages at jackaudio.org for more detailed information.

Configuring Linux for Audio in general: Many Linux distributions are, by default, not optimized to the standards required for real-time audio creation in Renoise. So when using either ALSA or JACK with Renoise it is recommended to:

  • use a real-time kernel
  • configure PAM (/etc/security.conf) to allow Renoise and other applications to create low latency and high priority tasks

Both topics are described in depth in our Linux FAQ. For more on the subject, this general Linux and Audio FAQ is also recommended: linuxaudio.org


Latency & Sample Rates

Latency is the time that it takes for sounds output by Renoise to be played on your speakers or headphones. The lower the latency, the quicker Renoise will respond to what you play or modify. So lower latencies are preferable, but they also require more CPU power to maintain. If the CPU becomes overloaded then the audio will start to crackle and choke. If you hear such crackles in the sound output, the first thing you should do is increase the latency via the Preferences menu.

The sample rate defines how much detail is contained within the sound that you hear. The higher the sample rate, the more detail. 44,100 Hz is the rate that is used by CD players, so that rate offers an excellent playback quality. Whether higher rates result in a noticeably better listening experience is debatable, but they do offer increased resolution for effects. Rates below 44,100 Hz are not recommended because there is a noticeable reduction in sound quality.

Note that CPU consumption is affected by the sample rates. A doubling of the sample rate roughly corresponds to a doubling of CPU consumption in Renoise, because everything is done at twice the rate. So be aware that using higher rates will reach your computer's processing power limit sooner.