Native Instruments B4 II - Manual (Page 22)

22 – B4 II B4 II
polyphony or number of effects you can add while still retaining glitch-free
audio. So, here are some tips on living with latency.
About Samples and Buffers
Audio cannot be handled continuously by a computer, but has to wait its turn
while other operations are being carried out. As a result, sound cards create
a “buffer,” which can hold a certain number of samples, where data can be
stored and released as needed to create a smooth flow of data. An analogy
would be if you had a hose that didn’t deliver water continuously, but in bursts.
So, you use a holding tank to store the water coming in from the hose, and
have a valve in the tank that releases a steady amount of water in a smooth,
continuous flow.
If the tank (buffer) is large, then you can store more water in case the hose
goes dry for a bit. But it will take longer to fill the bucket, which is equivalent
to latency. A smaller tank takes less time to fill, but the hose had better deliver
water on a pretty continuous basis.
All ASIO audio interfaces and sound cards include a control panel where you
can adjust latency. This may be given as the number of samples per buffer,
as shown in the Terratec EWX control panel:
For example, the Terratec EWX ASIO control panel lets you choose a particular
number of samples/buffer. The display then shows the resulting latency. In
this case, 256 samples/buffer has been selected, giving latency of just under
6 ms at 44.1 kHz. Setting this to 128 samples/buffer will reduce the latency,
but may stress out your computer more.
Some control panels simply show the latency that results from choosing a
particular setting in milliseconds rather than showing samples/buffer.