MIDI velocity - increasing volume levels

Posted by: EO3

MIDI velocity - increasing volume levels - 02/16/13 10:08 AM

Hi,

I'm pretty pretty sure this has been talked about, but again - I know it's possible with some tweaking to increase volume levels by increasing MIDI (for instance, when playing we usually don't reach the max 127 , so we can, depending on each music piece, increase volume to get max levels).

If it's understandable what I'm talking about here, maybe someone can share their experiences in a non-tech savy way about this. And does tweaking with MIDI velocity can also temper with audio file, I mean, will it sound somehow different than the orginal recording (except, obviously, louder).

Thanks. p.s. I'm using Ableton Lite 8 + vintage D and kontakt.
Posted by: MacMacMac

Re: MIDI velocity - increasing volume levels - 02/16/13 11:21 AM

To do what you want, you can adjust the velocity curve.
Here's an example:
Posted by: anotherscott

Re: MIDI velocity - increasing volume levels - 02/16/13 11:35 AM

Originally Posted By: EO3
does tweaking with MIDI velocity can also temper with audio file, I mean, will it sound somehow different than the orginal recording (except, obviously, louder).

Yes, changing MIDI velocity will often change the timbre of the sound. In a piano, for the obvious example, it is common for there to be multiple sampled velocity layers, since a piano key struck with more force is not only louder, but also changes in timbre. So if you alter the velocity of a note from, say, 90 to 100, not only will it be louder, but there is some chance that it will be triggering a different piano sample with slightly different sonic characteristics.

Also, keep in mind that if you alter MIDI velocity this way to get more volume, you are effectively limiting the piano's dynamic range. For example, if you raise 90 to 100, what do you do with 100? Let's say you raise it to 110. And you raise 110 to 120. But what do you do with the notes above that? You'll have to compress them all into a small range, because MIDI can't go higher than 127.

If you simply want to increase the volume of a MIDI program, the best way to do it is to see if you can embed a MIDI volume command (CC 7, with whatever value you want, i.e. 127 for max).

Of course the easiest thing is to just turn up the volume on your playback device... I'm guessing that's not an option here because it is combined with some other signal. In that case, it would be worth seeing if there is some way you can separate the MIDI-generated sound from the rest and put it in its own channel in a mixer. Or maybe, instead of raising the level of the MIDI track, you can find a way to lower the level of whatever other sound(s) you are combining it with, to get them into the balance you want, and then again increases the total volume on your playback device.
Posted by: bbent

Re: MIDI velocity - increasing volume levels - 02/16/13 11:55 AM

EO3,

Your post suggests that you may not appreciate the difference between MIDI volume and velocity. If I'm wrong about that, I apologize and you may ignore my answer. If not, read on:

Velocity relates to how fast you press a key down. It is implemented on MIDI keyboards by measuring the time it takes the key to travel from the top to the bottom of the keystroke. MIDI velocity values range from 0 to 127. MIDI tone generators such as samplers, divide the velocity range into a discrete number of ranges, with each range triggering a different sample set. This is intended to emulate how the tone character changes (e.g., harmonic content) on an AP, depending on how hard the AP key is pressed (that is, loudness AND character).

MIDI volume (CC7), on the other hand, only affects the loudness of the MIDI notes, but does not change the character (e.g. harmonic content) of the sound.

Summing up, if you increase the velocity of a note (or group of notes), they become louder AND the character of the sound changes. If you increase the MIDI volume of the note/notes (or simply turn up the amplification volume), the sound simply becomes louder (but the character remains the same).

I'm not familiar with Abelton, but I'm pretty sure you should be able to scale the velocity OR volume of selected MIDI notes. I use Sonar 8.5, and with that I can scale the velocity OR volume for a track or selected notes very easily. One note of caution regarding scaling velocity on a group of notes. Scaling simply multiplies the velocity of the selected notes by a number you control. Since MIDI velocities are limited to 0 to 127, if you multiple by a number that causes velocity saturation (i.e., attempts to make velocity events become larger than 127), then you will lose the dynamics between the now saturated velocity events (i.e., velocity = 127) and the non-saturated events.

Regarding your question about MIDI velocity editing affecting the audio file, if you were asking if the sound of the velocity edited MIDI would change, then the answer is yes. Remember that the MIDI track serves as input data to drive whatever MIDI tone generator (e.g., sampler) you choose. The output of the selected tone generator may be used to create a separate audio track. Velocity affects volume and character of the sound, while volume affects only the perceived loudness of the sound.

I hope that long-winded explanation helps.
Posted by: EO3

Re: MIDI velocity - increasing volume levels - 02/17/13 01:20 PM

Thanks very much for both responses!

First of all, my intentions of increasing MIDI volume is not for playback, but for recording (it's solo piano, so no other sounds involved). I want to get the levels to get as loud end recording levels as possible (of course, as far as quality allows). For playback I can get good enough volume levels configuring playback like suggested.

So, I get it that I should focus on MIDI volume not on velocity.

But should I try to change MIDI setting in Ableton or in Vintage D/kontakt?
In Vintage D there's probably settings that can do that. For instance, there's option "Midi Controller #7 Volume Range"