3.3. Compensating for Latency

3.3.1. Variability

Each FX chain’s latency varies, and depends upon a number of factors.

  1. Inputs and outputs.

    • Analog I/O adds ~1 ms of latency due to the AD/DA converters, while digital I/O adds ~0.02 ms of latency.

    • The USB audio driver adds ~8 ms of latency at 48 kHz / 32 samples. This may vary depending on your computer’s setup.

    • Network audio will add some latency. For Dante, this is configurable.

    • There is an additional but very small latency due to the internal H9000 audio router, which is 3 samples in and 3 samples out, so a total of 6 samples, or 0.125 ms at 48 kHz.

  2. FX Chain structure.

    • FX Chains have four rows and four columns available to load algorithms into.

    • An FX Chain with algorithms loaded into only the top row will add ~1.3 ms of buffering latency.

    • Each additional series algorithm will add another 0.7ms of buffering latency to the entire FX Chain.

    • Four algorithms in series will add a total of ~3.3 ms of buffering latency.

    • The internal FX chain routing compensates for buffering latency, so you will not hear comb-filtering artifacts due to running e.g. 2 series algorithms in parallel with one.

    • A single algorithm in the bottom row will add ~3.3 ms of buffering latency.

  3. Whether any of the algorithms add latency as part of the processing (e.g. a lookahead limiter). In many cases this will be zero.

3.3.2. DAW Latency Compensation

Many digital audio workstations include a device that can virtualize an external hardware effect processor as a plugin. These devices can compensate for the effect processor’s latency, but since the H9000’s latency varies, care must be taken to ensure that changes to the FX chains’ structures do not cause the FX chains’ latency to diverge from the latency that the DAWs’ devices have been calibrated to compensate for. To keep an FX chain’s latency stable, always keep at least one algorithm in the bottom row of the FX chain.

Some of these devices can automatically measure latency. While using this feature, bypass all algorithms in the FX Chain.