The Rhythm Method

• How we experience rhythm is a psycho-acoustic principle called beat induction.

• https://en.wikipedia.org/wiki/Entrainment_(biomusicology)

• Jitter is the timing deviation of a periodic signal in electronics and telecommunications, often in relation to a reference clock source.

• https://en.wikipedia.org/wiki/Jitter

• Jitter is commonly used to report timing errors in very rapid clock sources.

• https://en.wikipedia.org/wiki/Word_clock

• Rhythmic timing stability can also be reported in terms of jitter when discussing electronic music production, hardware and synchronisation.

• Utility devices such as routers and format convertors can introduce jitter depending on design.

Latency

• Latency is the period between a source event and the response in the target.

• https://en.wikipedia.org/wiki/Latency_(engineering)#Audio_latency

• Sequencers and drum machines take time to receive and process external sync.

• Sound generators take time to output audio after receiving a trigger event.

• Utility devices such as routers and format convertors can also introduce latency depending on design.

Numbers

• At a tempo of 120 BPM, continuous 16th event intervals should be 12000 samples when captured at 96kHz or 125ms / 125000µs.

• At a tempo of 120 BPM, continuous 24PPQ MIDI Clock, Din-Sync and Voltage Clock intervals should be 2000 samples when captured at 96kHz or 20.833ms / 20833µs.

• The tests below are measured over a continuous sixty second capture period into a dedicated audio analyser.

• Maximum jitter values reported are the largest push-pull timing deviation between any two consecutive events within the capture period.

• While many devices can be synchronised and / or triggered via MIDI over USB most of the tests here use either 5-Pin MIDI [ Notes / MIDI Clock ], Din-Sync and Voltage Pulses [ Event Triggers / Clock ] as the timing stability of these source formats is relatively simple to verify. The number of variables using USB generated MIDI [ DAW / Host OS / Hubs / Chipsets / USB data format ] and how it is implemented in the slave / receiving device makes this less reliable overall.

• For sound generators, latency values as reported show the average offset between the source trigger event and the generated output signal in the receiving device measured over a continuous sixty second capture period.

• For drum machines and sequencers, latency values as reported show the average offset between the external master sync source and the generated output signal in the slave receiving device measured over a sixty second capture period.

• For drum machines, sequencers and synchronisers, the external sync format, source and timing specifications are provided for reference.

• For sound generators, convertors, routers and transient generators ( EGs and VCAs ) the external trigger format, source and timing specifications are provided for reference also.

• With manufacturers providing software updates over time some of the results listed may have changed.

• Email us if we need to revisit any of these tests :-

• sync@innerclocksystems.com

• Important as it is, timing is only one aspect of music production and many of the devices listed have outstanding qualities beyond the numbers and these are not subjective tests or judgment as to their creative worth as a whole.