Home Movie Theaters

3. Tone Patrol

Nothing screams, “Smack me upside the head with a two-by-four!” like bass and treble controls turned all the way up. If your speakers are so bad they need that kind of tonal compensation, no tweaks printed here will help your system. Tom suggests that you center all of your receiver’s tone controls and listen that way for at least a week—even if you don’t like it at first. Over-hyped equalization can sound enticing at first, but once you get used to a more natural balance, you’ll hear through the disguise. If you still find that the sound lacks in the highs or the bass, experiment with small boosts or cuts. Fully cranked tone controls are almost never a good idea. (And there’s always the risk of running into one of those two-by-four-wielding audiophiles.)

Cost: Free

4. Set Phase to Stun
If you find that turning the bass control all the way up doesn’t do much to increase the bass in the room, there’s a good chance your speakers are wired out of phase. This essentially means that your left speaker is working overtime to cancel the bass response that the right speaker is producing. It could also mean that your subwoofer is sabotaging your main speakers. Although being out of phase by itself won’t damage speakers and subwoofer, it will harm the reputation of even the best speakers and subs. Plus, it could cause damage to the tweeters if you perpetually crank up the volume and bass control. If you have one of the video test discs mentioned above, check to see if it includes a system phase test. If not, here’s an easy way to hear if your main speakers are in phase:

SETTING THE PHASE

Turn off your subwoofer.

Make sure your AVR’s balance control is centered.

Tune your FM tuner to a frequency that plays nothing but static, use a test tone, or play a music selection with obnoxiously monotonous bass.

Turn the balance control all the way to the left or right.

Turn the balance control back to the center. Repeat as necessary.

If you’re between the speakers and hear more low-frequency content with the balance control to one side rather than in the center position, either your speakers are out of phase or you need your hearing checked. With the system powered down, look for swapped positive and negative wires on the back of the AVR and each speaker. Don’t think you could never hook up your speakers out of phase, because that’s exactly when it will happen.

After you’ve verified (and fixed, if necessary) the phasing of your main speakers, it’s time to find out if your subwoofer is in phase with your mains.

SETTING THE SUBWOOFER

Make sure your AVR’s balance control is centered, crossover settings are as the speaker’s manufacturer recommends, and sub level is at a nominal setting.

Tune your FM tuner to a frequency that plays nothing but static, use a test tone, or play a music selection with obnoxiously monotonous midbass.

Turn on your subwoofer.

Sit in the primary listening position and listen.

If there’s a smooth transition between the main speakers and sub, voilà, you’re done. If there’s a missing or overemphasized range between the main speakers and sub, adjust the phase control on your sub for the best blend possible. If your subwoofer doesn’t have a phase control, you can either move the subwoofer to another spot in the room (see “Crawling for Bass”) or reverse the connections on all of the rest of the speakers in your system to match the subwoofer.

Cost: Free

5. Acoustibration
A lot of AVRs, and increasingly some HTIBs, include built-in automated calibration. If your AVR has the capability, the process is brainlessly simple:

USING AUTOMATED CALIBRATION

Locate the microphone that came with the unit. This is the most difficult part of all.

Plug the microphone into the AVR.

Minimize all extraneous noise in the room.

Follow the instructions, which are usually presented via the front panel or an onscreen display.

Most automated calibration routines take less than 15 minutes (not counting the time it takes to find the microphone). While the results might still benefit from a bit of manual tweaking, it’s a relatively painless way to make sure all the speakers are in phase and have been set with acceptable levels and time delays.

Even without built-in calibration, most AVRs have internal test tones you can use to set the speaker levels manually. The ultra-cheap calibration method is to use your ears to set the levels as you toggle the test tones through each speaker. (Some audiophiles actually prefer to set the levels this way.)

The relatively cheap method requires a sound-level meter. An analog sound-level meter from RadioShack costs $45. (A digital version is available for $5 more, but resist the temptation. Most users find that the analog meter is more intuitive, and it’s easier to achieve useful results.) I’ve seen other meters for less than $30. If you don’t want to spring for a meter, tell a friend who hasn’t read this article that he really needs to own a sound-level meter in order to properly set up his system. After he’s bought one, ask if you can borrow it.

Once you’ve acquired your meter, here are a few guidelines to follow:

SETTING THE LEVELS MANUALLY

Make sure your room is as quiet as possible— no radio, kids, dogs, or washing machines creating audio havoc in the background.

Temporarily turn off the AC or furnace so air blowing through the vents won’t make noise in the room.

Before you check the output levels, set the size of the speakers for each channel (large, small, or none).

Hold the meter at arm’s length in front of you, roughly at ear height. Start with settings of C-Weighting and Slow on your meter, if the options exist.

Aim the business end of the meter toward the ceiling and hold it fairly steady for readings of all but the subwoofer channel.

Some people prefer to crouch behind the listening seat and hold the meter where their head would be; others prefer to sit in the seat and hold the meter in front. Experiment and see what produces the best results for you

As you take readings of the subwoofer, slowly move the meter in a large figure-eight pattern in front of you to average readings over a larger area.

If you don’t like to use the automated rou-tine, don’t worry. There are some calibration discs—including the video calibration discs I mentioned earlier and any theatrical release on a THX-mastered DVD—that include audio tones for setting the output levels.

Anytime you make significant changes to your room (get new furniture, change the layout of the furniture, move the speakers, etc.), you should recalibrate your system. Painting the room doesn’t qualify, but adding or removing picture frames and curtains does.

Cost: Free to $50

6. Learn Anglish
Although there’s no international law that covers it, a number of professional organizations (ITU, AES, NARAS) and companies (Dolby, THX, and others) do have recommendations about the placement of speakers in your home theater. While they don’t agree on every detail, it essentially comes down to this.

Even though your room is most likely rec-tangular, think of the ideal speaker placement in terms of a large circle with you, the listener, in the center and your TV on the circle direct-ly in front of you. Now get out your protractor.

PLACING YOUR SPEAKERS

Each speaker should be on the circle, equidistant from you.

The center channel should be directly in front of you.

Place the front left and right speakers 30 degrees off axis from the center speaker. (Dolby suggests a range of 22 to 30 degrees.)

Place the left and right surround speakers between 90 and 110 degrees off axis.

The LCR speakers should be at ear level, with the surrounds placed between 0 and 15 degrees above ear level.

In a 7.1-channel system, you should position the back surround speakers between 135 and 150 degrees off axis.

This arrangement puts the speakers basically in the same locations that sound engineers use when they remix the soundtracks for DVD or Blu-ray Disc releases.

Cost: Grade-school geometry lesson