Horns
"Don't spit on sidewalk."
Or...
A tip on getting a more realistic brass sound.
Years ago, I bought a book called A Synthesist's Guide to Acoustic Instruments. This was in the late 80s. This book is gold. It has countless tips on how to synthesize realistic instrument sounds. My philosophy has always been is that if you can do a decent job synthesizing real world instruments, you'll be in a better position to synthesize other wordly instruments.
The book focuses on three different synthesis techniques: FM, analog and PD. But the principles described are general enough to apply to just about any synthesis technique.
One of the tips had to do with synthesizing brass sounds. It described the more or less straightforward steps you need to take, such as setting up the filter and filter envelope. One tip I would have never thought of on my own was to use the amplitude envelope to duplicate a the "spit" portion of a brass instrument's attack. The book noted that when brass instrument waveforms are analyzed, many times there is a kind of dead spot immediately after the attack. The attack begins, there is a very, very brief moment where there is a sudden dip in amplitude, then the amplitude quickly rises back up and the waveform enters the decay and sustaion portions of the sound.
To synthesize this, you need a fairly complex amplitude envelope, more complex than your standard ADSR. You need an envelope more like what you would find in a DX7 or CZ-101, or Kawai K5. :-) The envelope needs to have enough sections so that you can create a sudden increase in amplitude at the attack, a sudden dip, and a quick rise back up to the decay portion. From there, the decay section would somewhat slowly fall until reaching the sustain portion. The sustain portion would have an amplitude of say 75%.
Illustrating this with ASCII would look something like this /\/ omitting the decay and sustain portions.
This is a subtle effect, and you have to play around with the envelope settings to get it right, but it does make a difference.