Latency (in REAPER)

Latency is the time taken for the recorded sound to be processed by the computer and returned to your headphones. If you have given your computer a lot to process (many tracks and plugin effects) you will hear a very noticeable delay as you record audio making it very difficult to stay in time with your music.

to control latency we can adjust the buffer.block size (how much audio the computer will process before playing back the sound). If we give a low size the audio will play back almost instantly but will start to stutter and make strange noises if we give it too many effects to process. If we give it a large size we can put a lot more effects in our mix but there will be a noticeable delay between hitting the play button or playing a sound on or instrument and hearing it come out of the speackers.

Settings:

For recording: Audio>Device>Block Size: 128 (or 256 or even 512 (but thats the limit before hearing noticable delay)

(render your instrument bus to a Stem and mute originals if you want to save processing power)

For mixing: Audio>Device>Block Size: 1024 (can double this number on large projects with a lot of plugins running: 2048)

The higher the block size number the more that REAPER will pre process the audio. With a high block size there will be a delay after you press play but plugins will run smoother (recording latency would be terrible).