In a recent company newsletter Anthony Grimani of Grimani Systems cited some of his biggest home theater frustrations, and not surprisingly, smooth bass topped his list. Speaking from his vast experience as an expert acoustician, including collaborations with the Grammy Winning producer/engineer Keith Olsen whose credits include major artists such as Ozzy Osbourne, Grateful Dead, Heart, Santana and Fleetwood Mac, as well as his executive roles with Dolby and Lucasfilm THX, Grimani states that “bumpy bass” with some frequencies louder than others is one of his top concerns when evaluating home theaters.
Grimani is not alone with his concerns. Manufacturers including Core Brands’ family of audio products, which includes SpeakerCraft, Proficient Audio, ELAN and Sunfire, as well as well-known manufacturers like Harman, top pro and home audio companies like Radial Engineering’s Primacoustic brand, and top industry educators like Gerry Lemay, founder, Home Acoustics Alliance (HAA), all emphasize the importance of acoustics in the role of audio quality in the home.
Getting the Professional Experience
Realistically speaking it is not always possible to recreate the same pristine environments that people like Jack Joseph Puig and Tony Maserati record in or Bob Ludwig masters in, but it is not unrealistic to maximize the environment you have.
James Wright, business development for Primacoustic, says that ideally dealers should do their best to recreate those pristine environments, but in those cases in which they can’t, they should make the best out of the situation.
“To accurately record and mix a project the audio engineer needs to hear precisely what is being reproduced by the speakers,” says Wright. “Likewise, to enjoy a recording as intended by the engineer, producer and artist, a similar level of accuracy is required. Room anomalies such as reverberation, slap echo and standing waves cloud the impression of the audio program. Acoustic treatment—specifically absorption and diffusion have been used for many years to achieve an accurate listening environment in studios … EQ [equalization] is used to compensate for problems with the loudspeaker and audio system, but it is not able to address concerns related to echo, reverberations or standing waves. EQ can ‘personalize’ the listening experience by boosting or cutting frequencies, but it is not able to defeat anomalies created by room structure and reflective surfaces. Only absorption and diffusion can help with these issues.”
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Focusing on the issues that Grimani cited in his newsletter, Kevin Voecks, manager, product development, Harman Luxury Audio, says that Harman has put a great deal of research into the topic of home audio playback, and over the years it has gone to great lengths to quantify the impact of room acoustics and the dynamic compression of audio content.
Voecks says the best way to retain dynamics is to allow loudspeakers to reproduce audio without constraint. Addressing Grimani’s concerns, Voecks notes that subwoofers are the best way to reproduce the lowest octaves of sound, and subwoofers offer the advantage of optimum placement to playback a narrow band of frequencies.
“Below roughly 400Hz the listening room acoustics, along with the locations of the speakers and listeners completely dominate the sound quality,” says Voecks. “Since there is no way to standardize the endless variety of listening rooms, we must be certain the speakers themselves are neutral. Only then can the in-room response be addressed — [and this is done] through [speaker] placement, mechanical acoustic devices and/or equalization. Since the effects of nearby boundaries are more predictable, we offer electrical compensation in some of our products to provide a means to ‘tune’ the speakers for the specific application or environment. Above 400Hz the loudspeaker dominates what is heard. However, it is still impacted by the room.”
What You Should Be Doing Differently
For nearly 20 years Gerry Lemay, director, Home Acoustics Alliance (HAA), has trained the electronics industry in how to identify and correct the problems of acoustics in the home. Over time Lemay explains the curriculum has evolved to keep pace with the latest trends and technologies, and more importantly for many dealers, the organization has put a greater emphasis on a hands-on learning approach for participants.
“HAA is a unique training experience from two perspectives,” says Lemay. “Our training is primarily hands-on or better put ears-on. Seventy-five percent of the training involves hands-on work and each technical change to the design is reviewed not only by measurement, but by listening, particularly during our Level II training. I think it’s fair to say that few AV pros will have an opportunity to step-by-step hear what incremental changes in the design or calibration of the system sound like. This creates a new perspective on the design and selling of home sound systems [the training works well for two-channel as well]. Students are empowered to teach their clients about the actual effect of various design mistakes.
“This also gives them a new mandate to explain that the brunt of the job for creating high performance sound depends on the home theater designer and calibrator. In other words, you might be able to buy the equipment through the Internet but you can’t buy their expertise anywhere but from them. The second unique element to HAA is the experience itself. The classes are intentionally kept small with no more than six students in a theater for the Level II [training]. The problem solving aspect puts the onus on the team to develop solutions based upon their Level I training. Mistakes are good things that we learn from. In many cases, team members retain communication with each other and often connect with other HAA calibrators.”
Lemay, like other experts including Grimani, commend the rise in awareness that automatic EQ systems have provided the topic of acoustics, but the experts state these technologies are not a cure all for a poor room environment. Lemay says these products can be used in tandem with other solutions to solve problems dealers encounter within a home space, but they cannot be the sole source of acoustical correction.
“I think the biggest challenge toward promoting the reliance of the performance on the home theater contractor has been the explosion of automated calibration tools,” says Lemay. “HAA does not discourage the use of automated systems. We note that they can be highly useful, but understand — you can’t truly calibrate a poorly designed system. The design, proper function, and final tuning of the system are best done by experienced hands and ears, with the automation as a tool not a total solution.”
Some of the things dealers can do beyond the use of these auto EQ tools Grimani says include making sure a system within a room does not reinforce those bad acoustical issues.
“See, the problem is that bass sound waves are long. When they approach the same length as the room, the lower frequencies build up into very obvious sound peaks with slow decay. The sound gets muddy. Even if it’s loud, it lacks punch. Your client’s room dimensions and the placement of your subwoofers both play a huge role in this phenomenon,” Grimani explains in the newsletter. “Make sure the room proportions are those that avoid multiple buildups, and then carefully place and tune the subwoofer for the smoothest and tightest bass. This is easily accomplished by running the system with the sub on a dolly while you move it around the room measuring frequency response. Then place the sub where the response is smoothest and loudest with the best low-frequency extension.”
Going further, Grimani adds that using multiple subwoofers placed symmetrically across from one another can help to smoothen low-frequency performance. Moreover, he says the implementation of four subwoofers, with a sub in each corner is the best approach if possible.
Ultimately, a blunt Grimani states that installers bear a role in how clients’ installed systems perform.
“But you, dear integrator, have a large role and responsibility here,” admits Grimani. “It is past time to get flipping real about being a professional. Understand that properly integrating the gear to the room — at any price point — increases your role in engineering and execution. And you better be aware of the pitfalls and learn to get it right every time.”
Dealers interested in learning more about the integration of subwoofers into home theaters and whole-house audio systems can take part in Sunfire and CE Pro’s webinar on March 23: Why Proper Subwoofer Integration is Critical in Whole-House Audio Systems and Home Theaters.