Propellerhead Software
  #1  
Old 2012-02-12, 21:37
locomo locomo is offline
 
Join Date: Oct 2011
Posts: 9
MIDI Latency

I am new user with couple of months experience in Reason. ( over 10 yrs exp with audio and MIDI)
I manage quite good any audio latency problems including Neptune etc.

Today I discovered another type of latency that is extremely annoying. I call it MIDI latency and I never thought it was possible.

When triggering MIDI notes from my Oxygen 49 USB keyboard I felt there is a tiny delay between note-on and sound. Audio latency was by accident set to 1024.

I was looking for a solution and I found that Audio latency in prefs has impact on MIDI delay. After setting 128 everything was fine.

But working on a big or even medium project with MIDI and audio is pretty annoying. Sound is terrible because of too tight latency. Setting latency longer I get delay playing software instruments.

This is totally unacceptable.

I don't believe this is happening. No trouble in Logic, Cubase. Audio latency has no impact on MIDI.

I change the soundcard. No effect.

Plz, help!

MacOS SL Reason 6.02, Saffire DSP24, Oxygen49
  #2  
Old 2012-02-12, 22:36
sellyoursoul sellyoursoul is offline
 
Join Date: Apr 2010
Posts: 586
Most likely, what you are perceiving to be a problem isn't due to MIDI latency alone. When recording MIDI, there is audio latency involved. A simplified explanation (don't take this as gospel):

When recording audio, you are dealing with these latencies: A/D converter > Audio input buffer > Additional hardware buffer > Additional software buffer > Audio output buffer > D/A converter

When recording MIDI, you are dealing with these latencies: MIDI > Additional hardware buffer > Additional software buffer > Audio output buffer > D/A converter

Don't go quoting any specifics here, but let's say that converter latency is 1 ms, either A/D or D/A, and that MIDI latency is around 3 ms. Also, let's say that you're working at 1024 sample buffer for the sound device, and a sample rate of 44.1k Hz. Divide the number of samples by the sample rate - 1024/44100 = 23 ms (roughly).

Your total latency when recording MIDI on an optimal setup, that uses no additional hardware and software buffers, at 128/44100 might be: 3 ms MIDI + 3 ms output buffer + 1 ms D/A = 7 ms total latency.

The same setup at 1024/44100 = 3 ms MIDI + 23 ms output buffer + 1 ms D/A = 27 ms total latency.

Keep in mind that 1 ms latency is the equivalent of hearing audio from roughly 1 foot away. If you have 27 ms latency, the sound of your instrument could be perceived as being around 27 feet away from your ears.

One other thing to keep in mind is MIDI latency jitter. I don't know if this is a problem outside of USB MIDI. What it amounts to is that MIDI latency can vary, possibly according to system load, i.e., in one take you might be getting 3 ms MIDI latency, but in another, you might be getting 12 ms MIDI latency.

Any way, I hope that this is somewhat helpful. I'm running on a rough understanding myself, so if anyone notices any glaring mistakes, call me out on it.

Last edited by sellyoursoul; 2012-02-12 at 22:41.
  #3  
Old 2012-02-12, 22:47
locomo locomo is offline
 
Join Date: Oct 2011
Posts: 9
I am not perceiving the latency. The latency really exists!

I noticed that with the experiment:
Triggering quarternotes for some time and checking the key editor (no quantize of course )
The result is:
1024 average 80-100 ticks delay
128 average 5-10 ticks (practically nonexistant)

I dont need to say that with 100 tick delay you cannot properly play on instrument and record live.

The problem is that in Logic such delay doesnt exist.
  #4  
Old 2012-02-12, 23:05
sellyoursoul sellyoursoul is offline
 
Join Date: Apr 2010
Posts: 586
Quote:
Originally Posted by locomo View Post
I am not perceiving the latency. The latency really exists!

I noticed that with the experiment:
Triggering quarternotes for some time and checking the key editor (no quantize of course )
The result is:
1024 average 80-100 ticks delay
128 average 5-10 ticks (practically nonexistant)

I dont need to say that with 100 tick delay you cannot properly play on instrument and record live.

The problem is that in Logic such delay doesnt exist.
Me saying that you are perceiving a problem isn't me saying that the problem doesn't exist. The way that you worded your problem gave me the perception that you were mistaking MIDI latency for audio latency, which is a common thing on recording message boards. Now that you mention the ticks, I see that you weren't making that mistake, and it sounds like you are having a MIDI alignment problem in Reason, as the audio buffer is increased.
 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
R6 midi recording latency? nlduhon General Forum (read only) 7 2011-12-01 05:41
52 Reason / Record Tips - Week 37: Parallel Processing James Bernard Phead User Forum (read only) 36 2010-11-06 23:20
Printing a Score from Reason PimandTips Phead User Forum (read only) 31 2009-04-10 23:56
YAMAHA DD-55 not triggering samples in NN-XT!? Muzak Phead User Forum (read only) 16 2006-01-08 05:36
midi latency bobh23 General Forum (read only) 1 2003-06-13 20:34


All times are GMT +2. The time now is 08:31.