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Home Theatre Speaker Perspective

A Review by: Alphonso Soosay

This is all about placing your Home Theatre Speakers in your listening room correctly as it will compose a remarkable transformation in a way that it will sound as if you are in a “Movie Theatre”. With the creation of “Home Theatres”, a lot of “Home Theatre” end users have found or at least have come to feel that their choice of speaker positioning is pretty much determined by the realities of trying to squeeze a “Movie Theatre” into a living room. And there is some truthfulness in that, since we usually make a start with the Stereo pair of speaker and then place a centre channel speaker right below your big screen and then move on to fit the surround speakers, followed by the .1 subwoofer, within your family listening room area.

With a help of a friend helping to positioning the speakers for you, you should be able to decide the positioning of your speakers so that your speakers will work effectively with your room environment.
Firstly, you should fire up with positioning the front speakers for maximum Hi-Fi musical impact. This sound will put the defining stamp on the way your “Home Theatre” and Stereo system will sound.

Main Speakers:
Firstly, you should fire up with positioning the front speakers for maximum Hi-Fi musical impact. This sound will put the defining stamp on the way your “Home Theatre” and Stereo system will sound.

As a procedure the Left and Right speakers should be separated from each other by a distance that’s a little less than that between the speakers and your seated listening position. You will normally obtain the best imaging and other spatial qualities if your left and right speakers and your normal seating position form an equilateral triangle position.
The optimum placement height for main left and right speakers is normally with their tweeters at about the same height as your ears when you are at your normal seated position. With condensed monitors, there are accessory speaker stands to achieve the right height if you are not using existing cabinets or hi-fi furniture. You can tilt your speakers towards ear level if the proper height is not achievable.
The best high-frequency dispersion, producing the widest “sweet spot” in which you and others can sit and enjoy optimum high-frequency definition, will result when your speaker enclosures are positioned vertically rather than horizontally. If you need to place condensed monitor enclosures horizontally, the speakers will still perform acceptably, but the seating area where you will enjoy optimum sound will become narrower. I suggest you position the tweeters to the outside away from the centre spot. If you are siting equally distant from both speakers, angling the speakers inward about 5 to 10 degrees, it usually produces the best convergence of high frequencies where you listen. Different listening positions may require different angle position.

Room Boundaries with Speaker Relations:
Positioning of your speakers with respect to the walls, floor, and ceiling of your listening room will often affect their sound in major ways. The closer you place speakers to the boundary surfaces of your room, the greater the proportion of Bass in their overall sound. This is due to the enclosing, “focusing” effects of nearby surfaces on longer-wavelength (lower) frequencies. Positioning the speakers near the intersection of two surfaces (wall and wall, wall and floor, or wall and ceiling) will produce more apparent Bass than placement near a single surface. The maximum proportion of Bass is delivered by placement near three intersecting surfaces in a room corner near the floor or ceiling, where the convergence of the two walls and the floor/ceiling produces an amplifying effect that is a bit like that of a deep megaphone effect. And the slightest Bass comes from placing a speaker away from all boundaries. Your own judgment should decide what proportion of Bass response seems right in your room and adjust correctly. Remember, when you are in your room you are the Judge.
The blend of the three dimensions of your room generally will produce at least three points in the room where the frequency response you experience related to a given position (of either the speaker or you) will either greatly increase or almost disappear. The most obvious effects are on low frequencies, but mid-frequency effects are usually at a lower level but are also often present. Keep in mind that very small changes in positioning (of the speakers) may produce major or subtle changes.
Distances of speakers from the walls can make great differences in the number, strength, and particular frequencies of secondary reflections, changing frequency balance, sonic spaciousness, and definition. Most listeners prefer their speakers to be at least a few inches from all walls, but the choice is yours to experiment with your room and make a decision by listening to your preferences. You will have to experience these changes with movement of the distance of speakers.

Relation between you and your Speakers:
Where you sit in relation to your speakers it obviously makes a difference. The proportions of the particular triangle formed by your speakers and you are really of importance. The overall distances involved also matter. As you move further from the speakers, more sound reflected from your room’s surfaces in contrast to the sound coming directly from your speakers reaching your ears, and the original spatial relationships in a recording are changed as your room “takes over.” Sometimes the result is a smooth more “integrated” sound. Other times, it can be a more strident or annoyingly with echoes. yet again, the particular dimensions of your room plays a part. And depending on what seems more realistic and enjoyable to your ears, you may choose to sit at a extreme distance or have close-up, “near-field” sound.
keep in mind that, as mentioned earlier, the proper “toe-in,” the correct speaker height, and a reasonably symmetrical distance from the speakers all tend to work together to deliver the best high-frequency definition and imaging.

Room Boundaries and You in Relation:
Changing your own position with respect to a room’s boundaries may also bring a big effect and sometimes for only a small change. Getting further from the wall behind you may make sound more precise and localized. Getting closer may make sound more “smoother” and integrated. Coming too close to back wall, side wall, or (especially) a corner may trigger a major peak or cancellation of a certain band of frequencies. With concern to your current seating positioning and in a situation where it may not be easy to change your fixed seating location, than you will have to move your speakers positioning.

Please take into account the three relationships we have reviewed, the idea is to manipulate whatever variable is easiest and most productive for improving your listening experience. Make sure to endorse your judgements by listening to a good variety of quality recordings of vocals, acoustic instruments, and soloists, different movies with deep actor’s voices and musical instruments that are easy to recognise tonal balance shifts.

Positioning Surround Speakers:
Generally “Surround Sound” is meant more to create superior depth and overall ambience than to localize effects as coming from a particular spot. This is especially true of Dolby Pro-Logic Surround Sound, in which both surround channels carry the same (monophonic) information and cannot be differentiated from each other. With Dolby Digital and DTS surround sound, there is very definite localization of surround sound effects. How much you prefer to these localized effects vs. overall sonic depth and diffusion is up to your listening preferences. If you are listening to multi-channel music, you may want the maximum localization of instruments. But if your main concern is the surround effects in movies, they it tends to depend more on front-to-back and from side to side movement than on specific localization. You can position and aim your Surround Speakers to produce the effects you prefer with pleasingly diffused effect. Although some individuals prefer to have their surround speakers behind them on stands at ear height, this is (not the way to listen to Surround Sound). For the correct Surround Sound I find it easiest and best to mount compact monitor speakers on the walls, at least two feet above your ear height where you are seated. Look out for matching speaker brackets to make wall-mounting convenient.
If your listening room is small, then aiming the Surround Speakers to diffuse their sound somewhat may produce the best overall surround sensation. Surround Speakers can be mounted, for instance, on the side walls and aimed to bounce sound off the ceiling or rear walls.

The Centre Channel Speaker:
Centre speaker obviously belongs the centre imaging of watching movies. Most centre channel speaker systems are designed for placement preferably right under your TV screen. The front surface of a picture tube is very active in determining the way a centre channel’s sound diffuses, and for this reason most centres are carefully equalized for a position in direct proximity to the tube.
If you have a projection screen, it usually works to place the centre channel speaker directly below the screen, as close as without interfering with the screen or, in the situation of fixed wall-mounted screens, Avoid placing Centre channel speaker above your seated listening position.

Placing Subwoofers:
On the whole listeners, especially those whose tolerance for audio equipment is already strained by acceptance of a pair of highly visible main speakers tend to position the subwoofer wherever they can squeeze it in unnoticeably. If you are critical about low-frequency response, there is quite a bit of useful experimentation you can figure out, especially in combination with the crossover, level, and phase controls of your subwoofer.
So far there is no disagreement among audiophiles that the utmost Bass output from a subwoofer comes from corner placement. Sometimes it still may be too much Bass for your room or your favourite listening spot in the room, but unless you are seated a “null” spot, where radiation from the subwoofer is cancelled or diminished by out-of-phase reflections from elsewhere, there should be plenty of Bass from corner placement. Just in case if you are seated in such a null spot, your only real choices are generally to move either the subwoofer to another location or relocate your listening position until Bass returns to the point that really satisfies you. In a situation like this cranking up the Level control or changing the crossover point almost certainly may not help much. But flipping the Phase control 180 degrees sometimes may make a difference, especially if the null is a product of cancellations caused by interaction with low frequencies from your main speakers. Low frequencies below the 120 Hz position are non-directional; you will not be able to tell that they are not coming from the same general area as the rest of the sound from your speakers even if a Subwoofer is very close to you. So there is no theoretical reason not to place the subwoofer nearby except the obvious one that this placement is the complete opposite of corner placement.

This is where subwoofer controls can become critically important. You may have to turn up not only the level control but also experiment with the crossover control. The phase control can make a vital difference, keep in mind that having to crank up the level of a subwoofer located right next to you may increase the perception of any hum in a recording or piece of audio equipment, or the Subwoofer’s own background hum from grounding or other audio glitches.
Since the objective of most folks who buy Subwoofers is to make sure of ample low frequencies, the only situation most of us will run into that makes subwoofer placement really difficult is the factor that we all fear the “dreadful ” room that just will not let you get satisfying amounts or quality of Bass. There are certain rooms with troublesome dimensions, especially as you approach a perfect room with its door shut. In such a case, the answer for some situation is to try and use two subwoofers, placed carefully to work with each other. This can also be true when the problem is too much, or too uneven Bass. For excellent results from this solution, using of two subwoofers do not have to be similar in power in fact, to use two smaller subwoofers to equal the performance of one with stronger specifications will help solve this problem.

Finally, there are individuals who feel that the best way to find where to position a subwoofer is to place it temporarily right in their favourite sweet spot chair and then walk around the room, checking how the Subwoofer sounds at various points of the room. The idea here is that the point that sounds best as you walk around, nudging your head into corners etc, should be the final place for your subwoofer. It is an interesting theory, this is not the best idea but it works from time to time, again this depends on its room. This idea can be used as last resources of problematic rooms but remember this is not a dependable rule of thumb.

I hope by now you would have noted that I have explained almost as much about Subwoofer placement as we have about other speaker placements combined. This does not suggest that Subwoofers are complicated. It’s a matter of experimenting with subwoofer placements in room situations.  From my experience a high powered subwoofer is such a pleasure when watching action pact movies when used and calibrated with a respectable main speaker where satisfaction is definitely accomplish.
Cheers

Alphonso Soosay
Home Theatre Consultant

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