How to Adjust an Audio System
9 of 10 in Series: The Essentials of Connecting a Home Theater
Get the best possible sound from your audio system by adjusting the A/V receiver (or controller). You need to do the initial setup to make sure that your A/V receiver knows what kind of speakers you’re using, and then you need to adjust the amplification levels for each speaker.
Get out your A/V receiver’s manual before you proceed — your particular receiver may have different terminology. The manual can also help you navigate your receiver’s setup menu system.
Selecting your speaker size
You need to set the speaker size for each group of speakers — center, front (or main), and surrounds. Go to your A/V receiver’s setup or configuration menu and navigate to the menu that lets you select your speaker size. You typically have a choice of Large or Small.
You can use two criteria to select a setting for your speakers:
Frequency range of your speakers (best): If you have access to the manufacturer’s data about your speaker, find out the frequency range at which the manufacturer rates its speakers. If the low end of the speaker’s frequency response is rated below 40 Hz, set your receiver to the Large setting; otherwise, use the Small setting.
Woofer size (not as good): If you don’t know how low your speakers can go, you can use the size of your speaker’s woofers as a rule of thumb. If the woofers are 6 inches or larger, try the Large setting; otherwise, go with the Small setting.
If you don’t have a subwoofer in your system, make sure you set the front speakers to the Large setting and set the subwoofer control to Off. Even if your other speakers are small, you need to select Large here, or you’ll get absolutely no bass from your system.
Setting up surrounds
You need to configure two settings for your surround speakers:
Delay: If all your speakers are the same distance from your listening position, sounds emanating from them arrive at your ears at the same time. That’s a good thing because delays in the arrival of sounds can ruin your sound field. If speakers aren’t equidistant from the listening position, your A/V receiver can compensate with its own delay settings.
Channel balance (or level): Set the sound level of each speaker so that you hear an equal volume from each speaker during testing. If one speaker (or set of speakers) is too loud, you experience an unbalanced sound field while listening to your system.
A growing number of A/V receivers have a built-in calibration tool that uses either a microphone that’s built into the receiver itself or (more commonly) an accessory microphone. With these systems, you can invoke the autocalibration command on the receiver. A computer in the receiver sends out test tones and automatically adjusts the receiver’s settings.
Dealing with old-fashioned stereo sources
Although most movies are designed for surround-sound listening, music is generally recorded in stereo and produced for systems with two speakers. Most A/V receivers let you select whether you want to listen to stereo recordings in one of two modes:
Stereo (or direct) mode: Sound passes through the front left and front right speakers.
Surround mode: Sound passes through all your speakers. A/V receivers can use Dolby Pro Logic II (for 5.1 channel systems), Pro Logic IIx (for 7.1 channel systems), or a custom surround mode.
Most TV shows are broadcast in stereo, and many older movies on DVD or VHS are stereo as well. For movies and TV programming in stereo (not in Dolby Digital or DTS), try using Dolby Pro Logic II/IIx to create surround sound. For listening to CDs, you may prefer stereo mode.