Latency
Stringed instrument midi controllers live or die by their latency, so how does the Midi Bass stack up?
Despite the release of several different designs of stringed guitar style midi controllers over the last twenty or so years, development of the Midi Bass has continued to be pushed forward because none of these alternate systems has delivered a real bass that solves the latency challenge.
What is Latency?
In relation to MIDI controllers, latency is the period of time that elapses between the performer playing a note and the target midi instrument playing a sound. Basically we're talking about an unwanted delay between when you play and hear a note.
Before we go any further, please consider the instrument we're dealing with here - Bass. One of two elements integral to the rhythmic components of most music genres. The natural enemy of rhythm is unwanted delay / latency. Low latency is absolutely essential in a bass instrument. In tests, the Midi Bass has exhibited a low and, importantly, consistent latency.
Ultra-low Latency - 5mS/8mS
The Midi Bass offers bassists what are arguably the lowest latency outcomes on a stringed MIDI controller at approximately 5mS (milliseconds) for fixed velocity tracking and 8mS for dynamic velocity tracking. To gain some perspective, consider that sound travels through air at one foot per millisecond, so an additional 8 milliseconds of latency is akin to standing 8 feet further away from your speaker cabinet.
Note: These latency measurements specifically refer to the time it takes for the Midi Bass to analyse and output MIDI data. They don't take into account added latency introduced by other equipment in the rig. For instance, when we plugged the Midi Bass directly into our Nord Micromodular to take these measurements we found that the Nord introduced another 1 millisecond into the overall latency so, in this case, the latency was actually 6mS for fixed velocity tracking and 9mS for dynamic velocity tracking.
Different hardware and software setups will yield varying results in the overall latency. Computers, sound cards, virtual synths, effects, plugins, and hardware synths can all contribute to the overall latency.
Below is a screenshot we captured from a PicoScope digital scope connected directly to the magnetic output of the bass and the output of the Nord synth. The Blue trace is the magnetic pickups of the Midi Bass. The grey trace is the audio output of the Nord Micro Modular synth.
Midi Bass Latency Is Consistent
Latency on the Midi Bass is consistent across the full range of the bass from the highest to the lowest note.This means that notes played on the upper frets of the G-string and an open E will have the same latency.
This consistency is made possible by the fret-sensing neck which determines the pitch of the MIDI performance by analysing the contact made between the strings and frets. This approach to MIDI conversion fundamentally differs from pitch-to-voltage MIDI systems which analyse audio waveforms to determine pitch.
Pitch-to-voltage pitch detection relies on analysing audio waveforms that differ in length according to the pitch of the note. The lower a note the longer the time required to analyse the waveform resulting in variable latencies that increase as the notes get lower. While the latencies produced by pitch-to-voltage MIDI systems are tolerable within the relatively high range of an electric guitar, they are well known to be problematic with the low notes of the bass.
This is not an issue with the Industrial Radio system because the pitch detection component of the MIDI conversion is virtually instantaneous.
About Fixed Velocity & Dynamic Velocity Tracking
You may have noticed that when we talk about the latency of the Midi Bass we provide two different measurements - 5mS for fixed velcoity tracking and 8mS for dynamic velocity tracking.
What's the difference? Fixed velocity tracking refers to MIDI conversion that doesn't try to figure out the dynamics of the performance. With the Midi Bass you can set it so it send a static velocity number for every note. This means that the bass can send the MIDI information faster because it doesn't have to wait to analyse the dynamic content of the signal before sending a MIDI note. Fixed velocity tracking is approximately 5mS (milliseconds) on the Midi Bass.
Dynamic velocity tracking, on the other hand, waits a period of time before sending the MIDI note to properly analyse and determine the dynamics of the actual performance so that the MIDI performance closely mirrors the actual perfromance. Because dynamic velocity tracking requires a little more time for this analysis the latency increases. The latency for dynamic velocity tracking is slightly higher at approximately 8mS on the Midi Bass.
There is also a third way to handle velocity information using the Midi Bass that both keeps the latency lower but providies near full dynamics. If you set the Midi Bass to fixed velocity tracking and send dynamics on a continuos controller it is possible to send the MIDI note at the lower 5mS latency while the velocity is being adjusted by the continuous controller. This approach requires a sound module that supports sending dynamics via a continuous controller and is not appropriate for use with complex sample players that use the velocity information to dynamically select samples. However, this approach works well with most virtual analogue synths.
