sound volume too low on macbook pro

Hello brnstdy,

If you are noticing issues with the speaker volume on your MacBook Pro, you may need to reset the NVRAM:

Your Mac stores certain settings in a special memory area even if it is turned off. On Intel-based Macs, this is stored in memory known as NVRAM; on PowerPC-based Macs, this is stored in memory known as PRAM.

Information stored in NVRAM / PRAM includes:

• Speaker volume
• Screen resolution
• Startup disk selection
• Recent kernel panic information, if any

If you experience issues related to these functions, you may need to reset the NVRAM or PRAM. For example, if your Mac starts up from a startup disk other than the one you've specified in Startup Disk preferences, or if a "question mark" icon appears briefly when your Mac starts up, resetting NVRAM / PRAM may help.

You can use these steps to reset your NVRAM:

Resetting NVRAM / PRAM

1. Shut down your Mac.
2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

After resetting NVRAM or PRAM, you may need to reconfigure your settings for speaker volume, screen resolution, startup disk selection, and time zone information. If issues persist, your Mac's logic board battery (not a portable Mac's rechargeable battery) may need to be replaced. The logic board battery helps retain NVRAM/PRAM settings when your computer is shut down. You can take your Mac to a Mac Genius or Apple Authorized Service Provider to replace the battery on the logic board.

You can find the full article here:

About NVRAM and PRAM

http://support.apple.com/kb/ht1379

Thank you for using Apple Support Communities.

Best,

Sheila M.