If you set it on the lowest tension and speed setting with breakout mode off, it will not buzz. Any setting past that and it will buzz. People will not be able to hear your loader buzzing when you play in the woods unless you are using high settings or a high breakout mode. I have played in the woods for quite some time using both gangstar'd velocity jrs and virtue'd velocity jrs with no problems or claims of people even being able to hear my loader. I have also played woodsball with many velocity users and never been able to hear the buzzing if they were more than 5 feet away from me.
If anything, its more just a nuissance to you the player having the buzzing going when your playing in the trees.