Knowledge Base

In order for our customers to make an informed decision, we have exclusively created this Knowledge Base so you can learn about different solutions and choose the best one for you!

Where is the best location for a subwoofer? I've heard conflicting answers about corners being both good and bad.

Subwoofer location depends on several issues. 1. The capability of the sub; small subs often lack enough gusto unless placed in the corner, but can become boomy sounding there 2. Room pressurization; A room without doors or with many windows cannot generate cinema level bass without a very capable sub or multiple subs. This is true of large rooms as well. Besides corner placement, another way to maximize the dynamics of a subwoofer is to place it near the listener. This is tricky because of the possibility of speaker localization, that is you might detect the bass is not fully integrated with the soundstage. 3. In most rooms with a suitable subwoofer, a calibrator can calibrate the sub to smooth the response. This involves the alignment of 5 basic elements: 1) Sub level, 2) Sub phase, 3) Sub location, 4) Listener location, 5) Parametric equalization of remaining response anomalies. How are these things calibrated? These are five more questions to be answered. A start is understanding speaker and listener position.

I recently purchased some acoustical panels. The instructions discuss mirror points, what are they?

Mirror points are locations on your walls floor and ceiling that represent the strongest point of reflection for sound between a specific speaker and listener. They are significant because the early reflections of sound, if too strong, can distort the listener’s perception of soundstage focus, clarity and timbral accuracy. A common method to find a mirror point is to sit in your listening chair whilst a friend moves a mirror along a given surface. At the point that you can see the speaker in question in the mirror, the mirror is covering a mirror point. Use of an absorptive or diffusive material at that point on the wall has been shown to significantly improve sound quality.

What is ISF Video Calibration? Go to Top

In short, video calibration adjusts the electronic systems of your video display to produce an accurate picture. What is an accurate picture? An accurate picture is one that correctly reproduces what the producer/director intended. When TV programs are produced, transferred from film, broadcast or cut to DVD, the process is precisely monitored on video displays calibrated to industry standards established by the Imaging Science Foundation (ISF). Your video display cannot accurately reproduce these images unless it is calibrated to the same industry standards. The Imaging Science Foundation (ISF) is an organization founded in 1994 that is devoted to providing the means for the consumers display to be calibrated to industry standards through a community of certified calibrationists. Certification is obtained through testing after attendance at an ISF seminar. The ISF teaches a systems approach that considers all elements of the video system in obtaining the right picture (an accurate picture), the whole picture (maximum resolution, minimum overscan) and nothing but the picture (reduction of video noise and artifacts).

What is the HAA?

The Home Acoustics Alliance is primarily a provider of AV Industry specific training. Their core competencies include consulting, acoustical training and support services for our clients who include manufacturers, AV Contractors, and Retail Stores. Our mission is to improve the state of Home Theater industry installation technology by promoting a professional and scientific approach to achieving good sound.

What is the Acoustic Design Review (ADR)?

It is a quick straightforward review of the design of your room and system layout conducted by a trained HAA Calibrator. It is not possible to achieve good sound quality if the system is poorly laid out or limited by the room’s acoustics. The ADR process is a site survey of your listening room in person or via detailed drawings.

How much amplifier power do I need? Go to Top

For an audiophile who listens at lower levels, RMS power is often not their first consideration. Sound quality and transient power output are more important. However, in the Home Theater, there is little substitute for high power combined with efficient speakers. The elusive combination of audiophile grade elegance and cinema level SPL is the holy grail of most high end consumer manufacturers. I won’t join the debate over whom if any companies have achieved this goal. I will say that the manufacturer of high power amplifiers has evolved to a degree that I can live with many of today’s big amps sonically without longing too much for my little tube amp. On the assumption of a quality built amp and speakers of typical sensitivity (87 to 92 dB) there is much benefit to purchasing as much power as you can within your budget. Be sure that the speakers do not lose their audiophile sound at higher levels. You know speakers can “clip” too.

Why does it matter where I put my LCR speakers for good sound? I hear the dramatic changes in tone at every position.

Speaker placement depends on several issues; 1) is the speaker full range or a small LCR, 2) Wife Acceptance Factor (WAF). If you have full control of issue two let’s look at issue one. The response of a full range speaker depends on low frequency calibration, upper bass calibration and soundstage calibration. I separate these categories because often the best placement to optimize each of these is different. Therefore, a final placement is usually a compromise. For low frequencies, modes create the biggest response distortions and, unfortunately, the placement rules are the same as a subwoofer. This makes achieving optimized deep bass response most difficult because of the odd room positions often required for smooth deep bass. For a “small” speaker using bass management relieves the speaker of the requirement to reproduce deep bass (the subwoofers job now). This means a “small” speaker can often work better closer to the wall than a full range speaker might thus simplifying the calibration process. Full range speakers can sound great but require more care and time to set them up properly, and often, “best location” is well away from the front wall. Upper bass is a little more manageable since boundary interference is the usual problem. Boundary effects are going to happen so to make corrections one must vary the distance between the low frequency driver and the floor versus the rear wall, versus the side wall; all surfaces. Our goal will be to smooth the response below 500 Hz. This can be done experimentally by moving the speaker subtly side to side and back and forth until a smooth response is achieved. The last issue is the soundstage. Here the rule is set the right and left speaker’s optimum distance apart and the proper toe-in. A common rule of thumb is to separate the speakers by 45 to 60 degrees as measured from the central listening position or sweet spot. Experiment until you achieve the best clarity, focus, and envelopment. For toe-in, gradually point the speakers toward the listener until best spaciousness versus focus is achieved. Above all, do not block any speaker especially the center channel. This eliminates focus and clarity, and that is why you purchase better equipment in the first place; if you can't see a speaker from the listening position, you've set them up wrong.

Why do room dimensions effect sound quality?

Room dimensions as a single variable are not as important as the calibration of a system for good sound. Part of the calibration process is making corrections for distortions caused by room interaction. This means that in spite of a poorly dimensioned room, a home theater can sound good. There are limitations to this assertion, in that rooms that are designed with similar dimensions for length, width and height exaggerate the distortion of certain frequencies to a degree that may not be completely removed by calibration. It is also true that a correctly dimensioned room will be easier to calibrate for good sound than one that is less than optimized. The best advice is to avoid the use of a sledge hammer on an existing room unless your face an extreme problem but if building a new room, consider rightsizing it. For exceptionally small rooms, dimensions can be of limited importance other than when height, width or length is identical. Here, rooms can distort bass so much that even a "correctly dimensioned" room may have problems requiring radical subwoofer positions or equalization to eliminate.

What is audio calibration and why do I need it? Go to Top

Audio calibration is the process of balancing your systems loudness, frequency response, and the interaction between all speakers in the system and the room in which it is contained. If we look at the response of your system, any deviation from a smooth response results in audible distortion. Some distortions are more palitable than others but all are unwanted. The calibration process is designed to eliminate each distortion ultimately producing an end sonic result faithful to the original recording. The industry has standards that are designed to make sure the product produced in the studio sounds the same in the cinema and in your home theater. The calibration process ultimately aligns the home theater with the original post-production room where the sound of the movie was crafted.

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