bass guitar issues tracking/latency/incorrect notes

The i2M musicport™ MIDI Converter & Hi-Z USB Audio Interface

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julianrob77
Posts: 1
Joined: Fri Sep 02, 2011 12:25 pm

bass guitar issues tracking/latency/incorrect notes

Post by julianrob77 »

hi

i have followed the troubleshooting provided in the manual, i am using a 5-string ibanez GSR, with the active circuit turned off. there is no clipping, but pretty much every note is tracking wrong (usually a very brief equivalent flat is played, or the wrong octave) in chromatic mode. im just using garageband to test this out initally.

i have tried different pickup combination, with slight reduction in the issue, but as soon as i play at normal speed i.e. for double bass lines played olow on the e string or b string the latency is pretty obvious! very slow indeed. also at higher tempo's the midi note problems are more obvious- again, breif double hits with midi notes and wrong octaves creep in again.

i realize now why every demo has the flute or string sound, played high up on the bass. it only really works there for strings, it seems that when i use a string sound etc via garageband it works much better with less incidental notes. however, chromatic mode and being alble to play this as advertised as a keyboard etc is vital for what i need it for- as i using it as a double bass emulator

any suggestions are appreciated, but i have to say, having gone through all the information on this website and looking at other peoples experiences, i am sorley disappointed.

J
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james
Site Admin
Posts: 1866
Joined: Fri Jun 06, 2008 8:12 pm

Re: bass guitar issues tracking/latency/incorrect notes

Post by james »

Do you really need it in chromatic mode? It you play chromatically in pitch-bend mode, pitch-bend will be used to correct any notes that were mis-detected. This correction is fast and you usually don't notice it (it is faster than the ear detects the pitch, so you can't tell it was initially wrong). Even if you do required chromatic mode, does it track better with pitch-bend enabled?

In chromatic mode, it could be the tuning is a bit off. Most tuners will tune the fundamental tone, but the i2M can't always use that to detect the pitch; sometimes it has to use a harmonic because the level of the fundamental is too low at the start of the note. That's why new strings and good intonation help: the harmonics and fundamental are more in tune with each other. A simple test: try tuning slightly sharp to see if that helps.

Are you experiencing more latency that is normal? If you enable the Latency Test Mode (which can be accessed through the i2M editor using the latest firmware and editor software) it will let you check that the latency is happening inside, or outside, the i2M. For low notes, there is necessarily more latency: a low B has a period of 33ms, and it doesn't start oscillating at that pitch for several ms after you play the note (the string has to accelerate from stationary).
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