I'll assume here that the release samples are in their own group.
Because if this the case, you only need to add the volume opcode to the group, and tweak it accordingly.
Make sure the opcode isn't already added to each region.
If you have a multi-velocity layer SFZ, where you have release for each velocity layer, then you can use the opcode for "use last velocity value" in each release <group> , which is sw_vel=previous
for a list of opcodes, and brief explanation for each, go to:
http://www.cakewalk.com/DevXchange/article.aspx?aid=108
See the section AMPLIFIER, and the explanation for "volume"
See the section INPUT CONTROLS and the explanations for "sw_vel", and "trigger"
I recommend you build a test-sfz.lscp file and open that in Fantasia, or whatever front end you're using. Single channel, single midi port in, and default audio out.
Great for testing those SFZ masterpieces...
I'm still learning how to build SFZs, but i will say that for handling all those little bits and pieces of percussion, fragments of sound, etc, SFZ is a great format, and easy to build with, once you get your head around the opcode system, and have a working knowledge of what each one does.
I learnt to put whatever i could into <group> as editing all the regions, one at a time, was really time consuming.
Couple of tips, and this is done with linux as the OS:
Add a document called foo.sfz (foo being your choice of name) to the folder where the samples are.
open a terminal, cd to the same folder, and type:
ls > foo.sfz
This function will dump all the names of documents in the folder to the .sfz file. Remove the line called foo.sfz (ls will dump that one too), and you have a complete list of sample names in the .sfz, without having to type them all one at a time.
So a line might look like:
snare-drum -1.wav
and 4 of them might look like:
snare-drum -1.wav
snare-drum -2.wav
snare-drum -3.wav
snare-drum -4.wav
If you have 4 samples in the file all beginning with "snare" and you don't want to hack them one at a time (who does), then open the replace function in your text editor (i use leafpad for sfz building) to further cut down the admin, and type something like:
in the find text box:
snare
in the replace text box:
<region> sample=snare
select change all at once, and all your samples are now "regionalised", and will look something like:
<region> sample=snare-drum-1.wav
<region> sample=snare-drum-2.wav
<region> sample=snare-drum-3.wav
<region> sample=snare-drum-4.wav
If you're simply assigning a sound to a key, then using the replace function again:
in the find text box:
wav
in the replace text box:
wav key=
do them all at once, and your regions will look something like:
<region> sample=snare-drum-1.wav key=
<region> sample=snare-drum-2.wav key=
<region> sample=snare-drum-3.wav key=
<region> sample=snare-drum-4.wav key=
assign a key to each, using c3=60(midi number)=middle C, as your guide to where on the keyboard you want trigger the samples from. you can use midi numbers or midi names.
<region> sample=snare-drum-1.wav key=60
<region> sample=snare-drum-2.wav key=61
<region> sample=snare-drum-3.wav key=62
<region> sample=snare-drum-4.wav key=63
or:
<region> sample=snare-drum-1.wav key=c3
<region> sample=snare-drum-2.wav key=c#3
<region> sample=snare-drum-3.wav key=d3
<region> sample=snare-drum-4.wav key=d#3
Once you've done this, any control you want over the regions in a group can be added at group level. An sfz file reads from group down, until it hits the next group, and so on...
So our example sfz with a volume adjustment might look something like:
<group>
volume=-5
<region> sample=snare-drum-1.wav key=c3
<region> sample=snare-drum-2.wav key=c#3
<region> sample=snare-drum-3.wav key=d3
<region> sample=snare-drum-4.wav key=d#3
and if the samples cut off too abruptly when you release the midi key, then add a little release:
<group>
volume=-5
ampeg_release=0.3
<region> sample=snare-drum-1.wav key=c3
<region> sample=snare-drum-2.wav key=c#3
<region> sample=snare-drum-3.wav key=d3
<region> sample=snare-drum-4.wav key=d#3
Tweak values to suit.
Hope this helps,
Alex.