Speakers Lock grants you more control over your volume, but installs as an ad-supported application; therefore, caution is needed. It will drive your antivirus software up the wall and try to load your computer up with nasty adware. Once you get to the program, itself, it's a little too aggressive with how it takes over your volume; but it performs well.
Since this is an executable program, it might make your antivirus software suspicious. That could be because the program is loaded with nasty add-ons. It tries to change your search and your homepage, and install something called the "Delta" toolbar. Even when these were unchecked during install, it still seemed to sneak a browser extension into Chrome. As for Speakers Lock's actual function, it works decently enough. It lets you set different volume levels based on the time of day. However, you have to turn those off if you want to make your sound any higher or lower during those windows. You can even password protect it to keep someone from messing with the volume, which is a nice feature.
Speakers Lock works as advertised but it requires putting up with a lot of junk. If you don't mind fighting with intruding adware, this application might prove to be useful in situations when you don't want others messing around with your volume level.