• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Real time bass to MIDI solutions

C

cucumis

Dec 12, 2023
91
63
#1
Hello people,

I am working on my bachelor thesis project, a part of which requires detecting what notes a bass player is playing in real time (supposing that only one note is being played at the time) from software.

After trying some existing software libraries (that had an hard time detecting pitch below 70hz reliably, if at all) I decided that the best solution might be using external hardware/software:
  • on the software side, I tried using the ReaTune VST from Reaper to convert pitch to MIDI, to them pipe the output to my software stack: this approach yields decent results, but the delay is not great and the detection is kind of un reliable
  • on the hardware side, I thought about getting one of those guitar/bass to MIDI devices, like this one: sonuus - Music Products Designed in the UK. I do own a BOSS GT-001 and the guitar to midi function on this effect processor is good enough for this project, but it does not work on bass (same detection problem below 70hz as before).
Does anyone here have any experience with real time bass sound to MIDI conversion solutions? (Or even implementingn bass guitar audio pitch detection in software, since thats the end goal).
 
#2
My hardware setup for Pitch-to-MIDI starts with 2 basses fitted with the GK 13pin output (one bass has RMC piezo saddles, the other has Lightwave optical pickups). Next is a Roland GI-20 GK to MIDI converter, which is connected via 5pin MIDI cable to a Roland Integra7 rack module (I also have an XV-5050 in a gig box).

This rig works reasonably well for me, but latency on low notes is still an issue. It just takes a long time for a low note to complete the half (whole?) cycle that the pitch detection algorithm needs to "hear". For some voices (such as piano or drums), the E string below the 7th fret is un-usable. Voices that do well are typically instruments with a slower attack (trombone is a good one).

I also have a Sonuus i2m, which is fun to play with, but it's latency is way too high for live performance with a bass.

On the software side, I've read that Midi Guitar 2 is pretty good, but I have no experience with it.
 
  • Like
Reactions: SteveCS and cucumis
#3
Tosh said:
My hardware setup for Pitch-to-MIDI starts with 2 basses fitted with the GK 13pin output (one bass has RMC piezo saddles, the other has Lightwave optical pickups). Next is a Roland GI-20 GK to MIDI converter, which is connected via 5pin MIDI cable to a Roland Integra7 rack module (I also have an XV-5050 in a gig box).

This rig works reasonably well for me, but latency on low notes is still an issue. It just takes a long time for a low note to complete the half (whole?) cycle that the pitch detection algorithm needs to "hear". For some voices (such as piano or drums), the E string below the 7th fret is un-usable. Voices that do well are typically instruments with a slower attack (trombone is a good one).

I also have a Sonuus i2m, which is fun to play with, but it's latency is way too high for live performance with a bass.

On the software side, I've read that Midi Guitar 2 is pretty good, but I have no experience with it.
Click to expand...
Thanks a lot for the info! Today I tried Midi Guitar 2 and, while it works surprisingly well for this project's purposes, it costs 180 euros including taxes when buying in Italy, which is an absurd price IMO.
Can you give me some estimate on how much delay the Sonuus i2m has? I think it might be my only realistic option (100 euros is already pricy for what its going to be used for).
 
#7
cucumis said:
...
Does anyone here have any experience with real time bass sound to MIDI conversion solutions?
...
Click to expand...

I have tried the Sonnus i2m 'Musicport' device and have to concur with other posters above that the latency with the bass guitar is too high. But that is not really a fault of the device but a natural constraint of the physics. As @Tosh says above, the detection algorithms need at least one full cycle to determine pitch - at 40Hz thats 25ms before the MIDI message can be encoding and transmitted, which also takes time.

I've had better results by playing up the octave then transposing down at the VST, and it is also possible to improve tracking by removing treble and mids which can cause higher-octave 'mistakes' and glitches, but of course neither of these things are good if you want the natural sound of the bass at the same time. I've also found that the tracking is only as good as your technique - any string noises, clanks, squeaks, heavy transients and accidental double-stops can cause spurious triggers and detections or can delay or even mask detection/triggering, so you need to be very clean with both hands. The software allows detection ranges, trigger and transient levels, pitch quantisation and noise gating to be customised into 4 presets, which is useful. EQ/filtering of the input feed can further improve things by removing unwanted top and middle from the input.

upload_2024-4-12_7-56-5.png


On balance the i2m is an effective device given what it is trying to do and the relatively low cost. It works very well with the guitar - hearing a sax or clarinet articulated with guitar-style bends and vibrato creates a very strange feeling of aural hallucination!! On the other hand, I'm not happy yet that it is robust enough for live work when you add in all of the other hardware and software components needed to actually make a sound.
 
  • Like
Reactions: cucumis
#8
JKos said:
What is the MIDI bass on which each fret has individual fret segments for each string for sensing where the string is fretted?
Click to expand...

I remember reading something about that a long time ago but can't recall any details. A remember 'SynthAxe' as endorsed by Allan Holdsworth, and also the Roland 'GR/Hex' pickup system that was polyphonic by detecting each string separately.

@OccasionaLurker As a side-note that may help you finding an improved solution, I do remember playing a Chapman Stick 'GRID' which was MIDI only, and based on a customised Roland GR/Hex system. All 10 strings were 0.008" and tuned to the same note, with overall intrument 'tunings' taken care of by MIDI transposition in the rack-mounted processing unit. The GRID worked really well, partly because of the strings, partly because the playing technique of the Stick which produces a very clean attack and partly because it had no useable native sound of it's own. By using a higher-pitched thin string with clean fast transients the detection time was minimsed and made constant across the whole range which. This and the lack of native sound meant you could compensate to some extent based on what you were actually hearing from the synth. Even with the i2m, playing just the synth sounds without the bass alongside improves how the overall system 'feels'.
 
  • Like
Reactions: cucumis
#9
SteveCS said:
I have tried the Sonnus i2m 'Musicport' device and have to concur with other posters above that the latency with the bass guitar is too high. But that is not really a fault of the device but a natural constraint of the physics. As @Tosh says above, the detection algorithms need at least one full cycle to determine pitch - at 40Hz thats 25ms before the MIDI message can be encoding and transmitted, which also takes time.

I've had better results by playing up the octave then transposing down at the VST, and it is also possible to improve tracking by removing treble and mids which can cause higher-octave 'mistakes' and glitches, but of course neither of these things are good if you want the natural sound of the bass at the same time. I've also found that the tracking is only as good as your technique - any string noises, clanks, squeaks, heavy transients and accidental double-stops can cause spurious triggers and detections or can delay or even mask detection/triggering, so you need to be very clean with both hands. The software allows detection ranges, trigger and transient levels, pitch quantisation and noise gating to be customised into 4 presets, which is useful. EQ/filtering of the input feed can further improve things by removing unwanted top and middle from the input.

View attachment 5415963

On balance the i2m is an effective device given what it is trying to do and the relatively low cost. It works very well with the guitar - hearing a sax or clarinet articulated with guitar-style bends and vibrato creates a very strange feeling of aural hallucination!! On the other hand, I'm not happy yet that it is robust enough for live work when you add in all of the other hardware and software components needed to actually make a sound.
Click to expand...
I think I might go for it, since for my use case, the player only hears the passtrough signal and the MIDI data is used for other functions in software.
 
  • Like
Reactions: SteveCS

Latest posts

Top Bottom
Back