Your Mac is capable of both aural and visual wonders. Two system preferences--Sound and Displays--control how those wonders are manifested.
The Sound preference governs the majority of the Mac's audio capabilities--the sound effects it uses, its audio volume, the audio devices the Mac plays audio through, and the input it uses to receive or record audio. The settings for these variables appear on three tabs: Sound Effects, Output, and Input. Let's run through them now.
Sound Effects tab
You know those little beeps and boops your Mac makes when it's unhappy about something--when you've tried to close an application while a dialog box is present or when you've attempted to click something that makes your Mac irritable? Those are rightly called sound effects, and you can configure them on the Sound preference's first tab.
If you'd prefer a different alert sound to the one you're currently hearing, simply select one from the list--it will play when you select it. (Old-time Mac users may favor Sosumi.)
Beneath this list is the 'Play sound effects through' pop-up menu, where you can choose the device that plays the alert sounds. If you're using an iMac or MacBook without attached speakers or a pair of headphones, 'Internal speakers' will be your only choice. However, if you've attached speakers or headphones, they'll appear in this menu as well.
In the 'Alert volume' slider below this area you can configure the volume of any alerts that play. This volume is separate from the Mac's overall output volume.
The 'Play user interface sound effects' option lets you choose whether to play sounds that accompany certain actions. The most obvious of these is the Empty Trash sound. Disable this option and you won't hear the trash-flushing sound.
The 'Play feedback when volume is changed' option is for choosing to play (or not) the little bleeps you hear when you adjust the Mac's volume via the volume keys that appear on the Mac keyboard's top row (F10, F11, and F12).
The 'Output volume' slider is for adjusting the Mac's overall audio volume, and it appears regardless of which tab you choose in the Sound preference. This slider serves the same function as the volume keys I just mentioned. The final option in this tab lets you choose whether to show a volume menu in the Mac's menu bar. With that menu visible, you can adjust your Mac's volume by clicking the menu and dragging a volume slider up or down.
(Tip: If you hold down the Option key and click this menu you can choose your output and input devices, and open Sound preferences directly from the menu.)
You can attach speakers and headphones to your Mac--via either a USB port or the Mac's headphone port. When you do, additional choices will appear in the Output tab. Just choose a device from the list that appears in this window, and any sounds that your Mac makes (except sound effects, if you've configured a different destination for them in the Sound Effects tab) will play from the device you've selected.
Mountain Lion supports something called AirPlay, which is a scheme for sending video and audio over a local network to AirPlay-compatible devices such as Apple's Apple TV set-top box. If you have such an AirPlay-compatible device, it will appear in the list of devices you can play audio through.
Below the list of output destinations is a Balance slider for adjusting how much sound comes through speaker or headphone channels. Drag this slider all the way to the right, and only the right speaker or headphone will sound. Drag it to the left, and you'll hear the left channel from the left speaker or headphone. This adjustment option is handy if you can't plant yourself directly between two speakers and need to pump up the volume on one of them to compensate.
Your Mac can record audio, too. You'll find options for doing so in QuickTime Player as well as in GarageBand. If you have a MacBook or an iMac, you'll see that 'Internal microphone' appears in the list of available input devices in the Input tab. Attach a microphone, headset, or audio interface to your Mac, and it too will appear in the input list. Just choose the input you want to use.
The 'Input volume' slider that appears below this list controls the gain (input level) of the device you're using--in some cases. I add this caveat because you can't control all input devices with this slider. A Mac's internal microphone will use the slider; but if you plug into your Mac a USB microphone that carries a Gain knob, and select it in this tab, you may find that the volume slider disappears, meaning that the system won't work with that microphone.
Regardless of whether this slider is active, the 'Input level' meter should tell you approximately how high your gain is. If you find that it constantly peaks at the top end of the scale, your gain is too high. Lower the gain by using the gain slider or a device's gain control, or back away from the microphone.
If you're using the Mac's built-in microphone, you'll spy a 'Use ambient noise reduction' option below the 'Input level' meter. This feature, which is built into the Mac OS, attempts to filter out constant sounds like air conditioners and street noise. It can do very little with sudden loud noises, however.
Mountain Lion's Displays preference is scaled down in comparison to Displays preferences of old. But it offers most of the same options (and with a few Mac models, some additions).
If you're using a single display you'll see two tabs: Display and Color. In the Display tab, you'll see entries for Resolution, Brightness, and--on recent MacBook models--AirPlay Mirroring.
Resolution: If you have a Mac without a retina display, you have two options within the Resolution area. The first, 'Best for built-in display', allows the operating system to choose the default resolution for your Mac. With my 13-inch MacBook Air, for example, the resolution is 1440 by 900 pixels. A 15-inch MacBook Pro with retina display has a default resolution of 2880 by 1800 pixels.
"Whoa, slow down buckaroo!" you hoot. "What's this resolution thing you're talking about?"
Display resolution is the number of dots (or pixels) in a display, routinely described in terms of width-by-height dimensions. So my MacBook Air has rows of 1440 pixels running from horizontally across the display and columns of 900 pixels running vertically across it.
The higher the display resolution gets, the more detailed the screen's items become. But those items also appear smaller on a higher-resolution display. For example, suppose that a window extends across an area of 640 by 480 pixels. If the total display resolution of your monitor is 1024 by 768 pixels, that window will take up a fair amount of room on the display. But if your monitor's total display resolution is much higher--say, 2880 by 1800 pixels, as it would be on the retina-display MacBook Pro I mentioned earlier--that 640-by-480-pixel window will occupy a much smaller amount of the monitor's overall screen space.
If your Mac's native resolution is not to your liking, you can change it. To do so, select the Scaled option, and a list of available resolutions will appear below it. Click one, and the Mac's display will switch to that resolution. If you choose a lower resolution, the objects on your Mac's screen should appear larger, for the reason I just gave. And as I hinted, those objects will also show less detail and will seem fuzzier than before.
If you have a retina-display MacBook Pro, your Mac's resolution options will be a bit different. When you choose Scaled on a 13-inch MacBook Pro with retina display, for example, you'll see scaled options that equal 680 by 1050, 1440 by 900, 1280 by 800, and 1024 by 640 pixels.
Brightness: The Brightness slider serves the same purpose as the brightness keys on your Mac's keyboard (F1 and F2 on the top row of keys): It lets you adjust the display's brightness up or down.
On laptops and recent iMacs, below the slider, you'll see an 'Automatically adjust brightness' option. This option enables or disables the Mac's ambient light sensor--a sensor that detects how bright the area is around the Mac and adjusts the display's brightness accordingly. With the sensor enabled, your Mac's display won't be overpoweringly bright in a very dark room, as it doesn't need to be for you to see it; but in a very bright room, where the display may be washed out, the sensor will pump up the brightness.
AirPlay Mirroring: Unless you have an iMac (Mid 2011 or newer), a Mac mini (Mid 2011 or newer), a MacBook Air (Mid 2011 or newer), or a MacBook Pro (Early 2011 or newer), you won't see this option in the Displays preference. If you do have one of these Macs, this feature will allow you to wirelessly project what's on your Mac's screen to a second- or third-generation Apple TV (the small black one, not the larger gray model). To use AirPlay Mirroring, simply click its pop-up menu and choose the Apple TV you'd like to project the Mac's image to. We'll discuss the finer points of AirPlay Mirroring in another column.
Regrettably, selecting a system preference option won't change your Mac's countenance from silver to purple. Rather, the Color tab allows you to change the color tone of your Mac's display (technically, you can change its white point and gamma).
In the Color tab, you'll see a few items listed under 'Display profile'. The one currently selected (if you haven't changed it) is the default profile--the one that the OS believes is best suited for your Mac. Try clicking some of the other profiles just to see what happens. As you do, you'll find that the screen's color and tone change: The display will appear brighter or dimmer, and the the color duller or more vibrant. Compare these profiles to the default. If you find one that you prefer, using it isn't a crime.
Note, however, that it changes the color of everything on your Mac's display, including any photos you have. This can be a problem when you print photos, as you may adjust them for a particular profile that looks great on your display but not so good when printed.
I'm going to skip any discussion of the Open Profile button in this tab because it's for geeks only. But let's not leave without taking a look at the Calibrate button.
When you click Calibrate, the Display Calibrator application opens. Within this application, you can tweak the look of your display. In its standard mode, you can choose from a couple of gamma settings and white points; but you probably won't find them terribly useful, as most people don't care for the look they get by changing these options in this way.
If you enable Expert Mode in the first screen and then click Continue, however, the Display Calibrator Assistant will walk you through a variety of options that can yield a display you'll be happier with--particularly if you're using a third-party monitor with your Mac and you're unhappy with its native look. I needn't hold your hand through the process. Just follow the instructions and see what you come up with. Nothing you do will harm the Mac's native display settings. Experiment. If you find something you like, great; if not, just choose the default display profile to return the display to its original look.
About multiple displays
If you are new to the Mac (as most readers of this column undoubtedly are), it's likely that you use a single monitor--either the one that's integrated into your MacBook or iMac, or one you've attached to a Mac mini. But the Mac supports more than one monitor via some kind of additional display port. This may seem like overkill, but I find a multiple-monitor setup indispensable. I keep the application I'm working with on the main monitor, and I place tool palettes or secondary applications on the second monitor.
I mention this not to brag about how the other half lives, but rather to explain that when you attach more than one monitor to your Mac, the Displays preference changes. Instead of two tabs you'll see at least three. The second one is called Arrangement and it governs how the monitors are set up.
This is an advanced topic, and I won't cover it until we've addressed more of the Mac's basics. In the meantime, if you do have more than one monitor, click the Arrangement tab and then click the small question mark icon. Doing so will open the Mac's Help Viewer, which will provide you with more details on configuring multiple displays and projectors attached to your Mac.
Next week: Presenting the printing primer