ArcadeCab

VolumeTray

The problem
When I built my cabinet many years ago, I didn't design the speaker installation as thoughtfully as I should have. The volume knob was attached to one of the satellites, which I then more-or-less permanently attached to the cab's interior. I set the volume level to a  pleasing setting and adjusted the levels through Windows.  This was fine for most activities but wasn't for MAME. The levels varied greatly between individual games. For example, the cab's sound was perfect for bowling and PacMan, but was much too low for X-men vs. Streetfighter. I had resigned myself to living with that.  That is until I found VolumeTray.

VolumeTray, written by Slav Glory, is a system tray application that allows you to control Windows volume via key mappings. From the site:

VolumeTray supports all volume, recording and other audio mixer controls (master volume, wave, midi, line-in, etc) available in Windows. You can use it instead of standard Windows speaker icon in system tray. Also, you have ability to launch Windows default or custom defined Volume Control and Mulimedia Control Panel applications from VolumeTray utility.

This was perfect for my setup. I was able to map volume up to Pause-Joy1Up, and down to Pause-Joy1Down, and be able to change the volume during any game.

Installation and Setup
Although it is very simple to install, I want to point out a few items of interest that I changed.  Once you download and install the tiny (351Kb) executable, it immediately places two icons in your system tray.  The first shows the volume level of your system.  The second allows you to change the volume with the left- and right-mouse buttons.  This second feature I deactivated for obvious reasons.  I use those two buttons a bit too much for them to also control the volume.  To deactivate, I merely opened the preferences and clicked on the System Tray tab.  I there selected the bottom option, to only display the one volume icon.

Once I did that, I chose what button combination to dedicate to the volume control.  To keep unintentional  use to a minimum, I chose to use the IPac shift key on my machine (Pause) in combination with the player one joystick.  By opening Notepad and trying those two combinations, I discovered that up corresponded to a V and down a W.  On the Hot Keys tab, I enabled the status on the two functions, and entered the correct letters.  After Applying Changes, I tested the functionality by running Mamewah and playing some games.  VolumeTray worked perfectly and did not seem to adversely affect anything.  It worked well.

This application can control many additional sound-related functions on your machine but all I needed was the up/down feature.  In the future I may look at the remainder of its feature set but for now I am very happy. 
If you have no easy way of reaching your speakers' volume knob, you might want to take a look at this very handy application. 

I highly recommend!