1.       Connect the surround speakers and place them to the sides or behind the listening area. This may sound like heresy to audio enthusiasts, but statistics show that a majority of people with surround sound receivers and home-theater-in-a-box systems don’t even bother connecting surround speakers, or connect them and place the speakers on top of or near the front speakers. Yikes! As Gary Altunian’s article “5.1 Channel Audio” in our October/November issue points out, 5.1 (read five point one) channel digital audio soundtracks are available from a number of sources and can envelop the audience in the program. If the action on screen occurs on a busy city street, you’ll hear traffic and other noises come from behind you. As a bus passes by on screen, the sound will follow through the speakers from side to side and front to back. In order for you to take advantage of the soundtrack, however, you need to have at least five speakers (three front and two rear speakers; the point one channel denotes an optional subwoofer or low frequency track) connected to a surround processor. More advanced systems can use even more surround speakers. The Dolby Digital or DTS processor found in nearly all new receivers decodes the digital audio signal from your DVD player, HDTV tuner, cable or satellite receiver and Xbox game console to deliver enveloping surround sound.

Surround speaker placement is important to sound quality but there are as many correct answers to where you should place speakers as there are different types of rooms. Use your surround sound processor’s internal test signal generator to send what’s called “pink noise” (and sounds like radio static) to individual surround speakers, then have a friend move the speakers around while you sit and listen to the results. Some people like to hear the surround sound directly, others, like myself, like a more diffuse, non-localized ambience. You have to try different variations with different program material to find out what works for you. Generally, though, you get the best results if the speakers are to the sides and slightly behind the main listener, at roughly 110 to 120 degree angles from a centerline between the main listener and the TV. The speakers also work best placed a couple feet above the listeners’ heads, firing sound parallel to the ground. Again, different rooms and personal taste will create different results.

For some, just wall-mounting the surround speakers and hiding unsightly wires may seem daunting (or security-deposit breaking). In this case, try placing the speakers on the floor, behind the couch, firing sound up behind the listener, or on a tall stand. Visit your local hardware store for wire tracks and other nifty devices that can hide the wiring without requiring major (read: permanent) wall surgery. The bottom line is, any surround speakers is better than no surround speakers, so do what you have to do to connect them to your system.

2.       Confirm that the speaker system’s polarity is correct. The most common error I see in surround sound system installations is that one or more of the speakers is wired incorrectly. In a typical 5.1 system there can be as many as 20 connections from the amplifier to the speakers alone. No matter how careful you are, there’s a good chance you’ll miss something so it’s a good idea to double check. Typically, a two-conductor speaker wire carries the audio signal from the amplifier to the speaker (many HTIB systems use proprietary connections to eliminate any possible chance of miswiring the system).

It’s important that one conductor connects the amplifier’s positive terminal to the speaker’s positive terminal and that the other conductor connects the amplifier’s negative terminal to the speaker’s negative terminal. If not, the sound will seem diffuse and will lack bass response.

Keeping track of these connections can be difficult over long speaker runs, so speaker wire conductors are always marked in some fashion, either with different colored wiring, a red stripe on one wire, or some ribbed, rubber edging. Use this marking to ensure that your wiring is correct. You can also use test signals found on various DVDs like Digital Video Essentials, Avia, or CDs from Stereophile and numerous car stereo manufacturers. Our favorite is Goldline’s 5.1 Audio Toolkit. Play the same signal through pairs of speakers. Sitting halfway between the two speakers, the sound should seem to emanate from a point midway between the speakers and should have reasonably good bass response (depending on the capabilities of the speakers). Switch the wiring on one of the speakers and listen again. If the sound is diffuse and hard to localize and seems to lack bass response, the wiring for one of the speakers at either the amp or the speaker is reversed and one speaker is playing out of phase with the other. Check the wiring at both points for every speaker until the bass is solid and the imaging is reasonably precise.

3.       Enable the digital audio connection from your DVD player. If your surround-sound receiver always goes into the ProLogic processing mode and never switches to the Dolby Digital mode, even when you know you’re playing a Dolby Digital-equipped DVD, you’re not getting the full effect of 5.1 channel surround sound.

First, make sure you have a digital audio cable between your DVD player and your receiver. This is a single wire with either square-ish black plugs on the end (for Toslink or fiber optic digital audio) or looks like a normal audio connector but is labeled as a coaxial digital audio cable. You probably don’t need an analog connection between your DVD player and your receiver. If you lose the audio signal when you disconnect the analog audio connection, something else is wrong.

Second, check that your DVD is set to output a digital signal from the digital connector. Most players will enable this function by default, but I’ve seen some that don’t, or installers that change the setting. Enter your player’s setup mode and look for the audio settings. The digital audio output should be set for “bitstream” or something similar.

Third, assign your surround receiver’s digital audio input to the DVD player. In some equipment, certain digital audio inputs will default to the DVD video input. In other (read: better) gear you need to assign particular audio and video inputs from the receiver’s back panel (e.g. “digital audio input 1” and “component video 3”) to link up so that when you press the DVD button on the receiver’s front panel or remote control you’ll get the corresponding audio and video signals. Look in the receivers setup menu for the audio configuration.               

Last but not least, make sure your player selects the 5.1 soundtrack on the DVD. Older titles from Sony, Warner Brothers and Fox often default to the DVD’s backup 2-channel soundtrack, even when a 5.1 channel soundtrack is available on the disc and the system is set up for 5.1 playback. It’s asinine, for sure. Fortunately, this no longer seems to be the case and should rarely be an issue.

4.       Balance your surround processor’s speaker level outputs. If one speaker in your system plays substantially louder than any other speaker, the sound of the system will lean heavily towards that dominant speaker and you will offset the balance that the sound engineers originally intended for the program material. You may not even hear sound from other speakers. You want to balance the system so that as you play the same signal through each speaker, you can hear the sound at the same level from a central listening position.

Enable the test tone generator that’s built into all surround-sound processors, which will play pink noise from each speaker. Listen to the noise as it plays through each speaker and adjust the individual trim or volume controls until all the speakers seem to play at the output level. Inexpensive systems often won’t include an internally generated noise for the subwoofer so you may need to play some bass-heavy program material and adjust it on the fly. You can also use test discs, like the aforementioned 5.1 Audio Toolkit, which will offer test signals for all channels.

Humans are surprisingly good at perceiving slight differences in volume level from different speakers and studies have shown that we can adjust these levels by ear quite accurately. We are also surprisingly unsure of ourselves. Fortunately, Radio Shack caters to our neuroses and for a meager $40 we can purchase an SPL or sound pressure level meter. This handy little device measures the volume level of a source and tells you how loud it is in dB-SPL. Theoretically you’ll only need this device once when you set up the system, but this assumes you’ll never upgrade another component ever again and there are other uses for it that we’ll mention later . Besides, you never know when you might need to see if your neighbor’s dog or St. Patrick’s Day party is violating local noise ordinances. It’s a safe investment.

5.       Check your subwoofer’s settings. The point of the subwoofer is to augment the low frequency or bass response of the system, adding weight and depth to the sound. Since low frequency sounds are non-directional, the subwoofer doesn’t need to be prominently located. If you have a subwoofer, there will be at least one, if not two main settings for you to double check. The first setting is the subwoofer’s crossover control, or the point, measured in hertz (Hz) where the low frequencies are cut off from the main speakers and the high frequencies are cut off from the subwoofer. If the crossover is set too low, extremely small main speakers won’t reproduce frequencies low enough to meet with the sound coming from the subwoofer, making the main sound seem disjointed from the bass. If the crossover is set too high, sounds coming from the subwoofer will likely be localized, which will give away the subwoofer’s hidden position and distract the listeners. Ideally, the crossover will be set as low as the frequency response of the main speakers will allow, roughly at 80 Hz but no higher than about 130 Hz. The THX group specifies 80 Hz as their reference crossover point and it’s a good starting point for most systems. If you have small, cube speakers, though, or if the sound seems disjointed, try a higher crossover point.

In 99 percent of all cases, the crossover point should be adjusted through the surround-sound processor. If both the surround processor and the subwoofer have crossover adjustments, and the subwoofer doesn’t have some sort of “crossover bypass” or “direct” input, there’s a chance you will double up or cascade the crossovers. This will create a deeper rift or gap at the crossover point. In this case, set the subwoofer crossover adjustment as high as possible and use the setting in the surround processor.

Just as it’s important to check the polarity for your main speakers, you should check the polarity of the subwoofer relative to the main speakers. Some subwoofers have a phase adjustment that is either infinitely variable, or has several fixed settings. If the subwoofer is out of phase with the main speakers, you’ll get less bass at the crossover point. You want to adjust the phase to create the greatest output. This is difficult to do, though, without some test signals and an SPL meter. Using the 5.1 Audio Toolkit or another test disc, play test tones at the system’s subwoofer crossover frequency and measure the output with the SPL meter. Adjust the phase control on the subwoofer through its range. The setting that creates the loudest output, or the highest reading on the SPL meter at the crossover point is the correct phase adjustment.

6.       Perform a rattle test. When the movie action gets going, it’s not uncommon for intense bass to start vibrating various objects in your room especially if your house is a full of Tiki souvenirs from Hawaiian vacations. The sound of these rattling trinkets make the system seem louder than it really is and can be distracting. Whip out your test disc yet again for another useful tweak.

Set the volume at a normal level then play low frequency tones from the disc. Some discs have sweeps that start at really low bass frequencies and work their way up to higher frequencies. Others just have individual tones that you’ll need to step through. In either case, walk around the room and try to find those items that rattle. Different things will rattle at different frequencies. Use felt, rubber furniture protection pads, museum wax or cut up an old computer mouse pad to try to isolate the items as much as possible. Fill hollow objects with sand and tighten lighting fixtures. Once the room is rattle free, your system will sound cleaner and clearer.

7.       Angle the speakers toward the listeners. It’s natural to assume that a speaker’s primary axis of sound emanates in a straight line from the front surface. This isn’t always true. Speakers often emit the most sound (or just better sound) at some angle up or down from the front surface. You might get better sound from your speakers if you adjust their angle toward the listener either vertically, horizontally or both.

You can play the pink noise generated by your surround-sound processor to find this primary axis, but will likely have better results if you use what’s called “full-frequency” pink noise found on the 5.1 Audio Toolkit DVD. Don’t be shocked if this primary axis is directed towards the floor. Once you find this axis, you can direct it toward the listening area. Test the system with music your familiar with. You may find that pointing the primary axis toward the listening area makes the treble frequencies sound brighter than you’re used to. Adjust the angle to suit your taste.

8.       Move the speakers around the room. There are several facets of speaker and listener placement that are important for different reasons. While I refer to speaker placement for the remainder of this section, the same principles apply to the listening position, as well. In general, moving speakers several inches one direction or another can have a huge impact on sound quality. The closer your speakers are to room boundaries (walls, floors and ceilings), for example, the greater the bass response of the system. The distance between the speakers, various room surfaces and the listener can also affect the quality of sound, as can the position of the speakers and listener relative to the various room dimensions. It can be difficult to keep track of all the variables, just explaining them would take a whole series of articles, but if you experiment with different placement options, you are bound to find something that works well.

Start by moving the speakers toward or away from room boundaries. This will increase or decrease the quantity of bass. Multiple boundaries (i.e. corners) create the greatest output. Moving speakers or listeners closer to a wall or corner can be a good thing if your speakers are small and lack significant bass response. Increasing the main speakers’ bass response may help fill in any gaps between them and a subwoofer, as described in step 5. Larger speakers may not benefit from this bass boost and may in turn sound boomy or thumpy.

Keep in mind that bass quantity does not necessarily equal quality, though. This can be particularly important if you’re dealing with a subwoofer. All rooms have resonant peaks based on the distance between room boundaries. A complete discussion of the interaction between loudspeakers and room resonant modes is far beyond the scope of this article. Check out books like F. Alton Everest’s Master Handbook of Acoustics, or my own Secrets of Home Theater. It never hurts to experiment, though. Just make sure you rebalance the subwoofer’s level using the tips in step 4, before you listen to the system to see if there’s been an improvement in quality, and not just quantity.

You should also try to move the speakers so that they’re not equidistant from various room boundaries. If the left speaker is two feet from the side wall, try to make sure that the speaker is not two feet from the wall behind it and two feet from the floor (or ceiling), as well. Satellite speakers, which play midrange and treble frequencies, often sound best when placed a few feet out from the wall. No matter how far the speaker is from a room boundary, the distance between you, the speaker and any particular boundary will cause certain frequencies to cancel out to some extent thus degrading sound quality. The more varied the distance to each boundary, the more varied the frequencies affected and the more natural the speakers response will be.

9.       Add acoustic treatments or move furnishings to reduce unwanted room reverberations. This gets close to the boundaries of our self-imposed “no replacing equipment” edict, but falls short since you can accommodate many of the ideas through creative use of existing furnishings. Sound coming from your speakers emanates in multiple directions at the same time. The sound that travels directly to your ears arrives prior to the sound that travels in a different direction, reflecting off of nearby surfaces before reaching your ear. If the reflected sounds arrive too soon after the initial, or direct sound, bad things happen that will degrade sound quality. (Yeah, Okay, so I’m generalizing a bit. Just go with me here.) If you can eliminate some of these early reflections, you can improve the clarity and quality of the sound.

Doing so requires that you either place acoustic treatments (thick foam or fabric-covered fiberglass absorbers and hard, varied multi-level, 3-dimensional checkerboard-like diffusers) or sonically equivalent household furnishings (heavy drapes and bookcases) at the early reflection points. You can find these points by imagining that the walls of your room are mirrored (or just have a friend slide a mirror across the wall). In the places where you see reflections of your speakers, you’ll want to add acoustic treatments. You shouldn’t only use absorbers or the room will sound somewhat dead and lifeless. Keep an even mix of absorption and diffusion.

10.    Use an equalizer. Equalizers often get a bad reputation in audio enthusiast magazines, most of which is probably well deserved. In most cases, an equalizer is not your best option, and it should certainly not be used as a substitute to any of the tips mentioned above. Doing so will often cause more harm than good. When you can utilize steps 1 through 9 extensively, however, a parametric equalizer—which offers adjustments for frequency, level and bandwidth—can be put to good use fine-tuning the last ounce of performance from your system. To properly install and calibrate an equalizer for anything other than a subwoofer, however, you need expensive test equipment and knowledge of how to analyze the results. Your best bet is to find a qualified dealer that can measure your room with an audio analyzer that includes at least 12 bands of measurement per octave of sound.

Have more tips? Send them to the editor at mikew@dtvmag.com.