“Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans”
Facebook Youtube Twitter instagram pinterest

Active Room Correction: A Primer to Audyssey MultEQ Pro

by Patrick Hart September 30, 2006

Introduction
Ultimate audio performance within the listening area starts with the loudspeakers and the room.

Audyssey's Sound Equalizer is the company's first branded, flagship statement product. In working with the MultEQ Pro software over the last couple of months it has become apparent to this author that the ASE's power and flexibility can be best exploited, as far as overall system sound quality and balance are concerned, if careful attention is first paid to speaker selection, placement, and positioning. Often, passive room treatments, themselves carefully selected and placed are also recommended.

Once sound waves leave your speakers' cones only time and absorptive materials within your room can actually attenuate the sound's energy . By contrast the Sound Equalizer forms its linear response listening area by actively manipulating and refocusing acoustic room energy. It does not take sound energy away within the time envelope it operates. Thus passive room treatment is considered a welcome complement to the Sound Equalizer. Empty, highly reverberant rooms need not apply.

Before the Audyssey Sound Equalizer I had spent years reading reviewers' impressions of how loudspeakers "sounded" in their rooms. And I must admit that once one follows the impressions of a given reviewer for a while and contrasts his writings with real world listening of the same loudspeaker (preferably in one's own room) it can become easier to get something out of someone else's words on a page.

I think of myself as more fortunate than most in reviewing loudspeakers and room designs having done both for a living for a good part of my career. I recently purchased the three Infinity Beta 10s, which are the featured L/C/Rs in Part Two of this review, three years after I had designed them. It had been three years since I had listened to them, among three other similarly priced competitors, double blind (and in mono) on the front-and-center shuffler platform in Harman's Multichannel Listening Lab.

The sound I hear from these long-in-production versions of the Beta 10s is essentially what I remembered from listening double-blind, and far away from any boundaries, in Harman's ultra quiet Listening Lab. But now I'm hearing that same distinctly clear and linear Beta 10 character at my comfortable sofa listening position. The big difference is that the Beta 10s are now placed against my living room's corner walls!

This type of acoustic wizardry is possible via the patented and patent-pending Audyssey technologies built into this ASE flagship product. So in the interest of full disclosure I would be remiss if I did not include a thorough review of my own room and speaker layout.

In my home theater area I have attempted as close a correlation as possible between my room and speaker layout and a movie sound mixing stage. Use the following recommendations for speaker placement and configuration even without the Audyssey Sound Equalizer and you'll edge much closer to the intended and immersive theater sound. Then insert the Audyssey Sound Equalizer and…oh, that's our dedicated review of Audyssey MultEQ Pro System (coming soon).

The First Goal of Home Theater Installation: Satisfy both clients and their kids

Making a profit while satisfying your clients with a his-and-her new home theater or media room installation is a matter that involves starting with a well thought out, documented and pre-approved design, keeping to a realistic project schedule (by executing the design in a timely manner) and having every aspect of the new system perform to the customers' highest expectations from the get-go.

Members on CEDIA's Electronic Systems Designer track taking Anthony Grimani's class on "Acoustical Treatment" then Dr. Floyd Toole's class on "The Room and the Loudspeaker" in succession will quickly realize that these two classes conspire to highlight one of the largest potential disconnects between husband and wife before the project even begins:

  • How intrusive (she asks) will the speakers (and especially any room treatments) be on the homeowners' room and
  • When all speakers are discreetly installed and the electronics buttoned up will the audio system's sound live up to the both homeowners' and their kids' expectations?

To my mind it was my wife Lynette who wrote the ecstatic conclusive review for Audyssey's new stand-alone Sound Equalizer. It happened the first evening, just after I inserted this acoustic alchemy machine into my home system and ran through the straightforward calibration routine using my computer and the requisite Audyssey Installer Kit ($325).

Whether dancing around our sofa to Joan Osborne's version of Heat Wave from "Standing in the Shadows of Motown" or insisting on hearing the entire Roy Orbison "Black & White Night" DVD (a first!) I knew my more significant partner was dancing to the music within the expanded, flat-response "acoustic bubble" generated by the Sound Equalizer's MultEQ Pro software. (Not to our 6.2 channel surround system. And certainly not to Roy 's small image as he was presented over our interim and too-small-for-the-living-room 32" Sony HDTV.)

clip_image001_053.jpg

Sofa back looking from left front speaker. Rear JBL SP5 5 ¼" two-ways in lit corner on right . Glass curios do not rattle thanks to Quakehold. Rare 1956 tube RCA "Magic Eye" AM-FM-SW-1-SW2 radio has 3 front speakers and a speaker on each side. Sounds absolutely beautiful!

There was more to my wife's dance though, much more. As she whirled around our dual purpose living/home theater room her side glances were noting that I hadn't changed anything else in the room. Her prized (and highly vibration-prone) porcelain and glass souvenirs, gathered over many years of travels, were still in place on their glass shelves over the wine rack situated just six feet behind our sofa. (Thanks! Quakehold) Plus, she noted, I hadn't removed any of the tchotchkes that reside on our glass coffee table or over our fireplace mantel. Nor had I added any passive absorption or diffuser panels. And best of all, our modest and color-matched in-wall surround speakers hadn't been replaced. They remain as unobtrusive as ever; 5.25" JBL two-ways, color matched and blended into her faux Tuscan-style walls in the only areas she graciously allowed me to place them. The Audyssey acoustic alchemy machine had received the highest recommendation my wife's "golden ears".

Passive acoustical treatments support active Sound Equalization

Custom installation companies who have their own showrooms have usually considered themselves ahead of the game. They can present a well integrated (read: possibly some hidden passive room treatment) and calibrated example of a "typical" A/V Media room with which to sell their expertise.

What this author has found, though, is that you may get the couple to enter an unfamiliar room but still have difficulty in getting the couple to sit down in the sweet spot to listen to and view the marvel that is high performance A/V. And once the female partner sits down she may immediately start thinking about the fight her iPod-generation kids will put up for that same sweet spot when the parents aren't around. In short, the "every seat a good seat" audio goal as taught in John Dahl's and Anthony Grimani's CEDIA courses has been an elusive one at best.

Careful measurement from multiple positions, attempting to "average out" to a best case "flat response" often requires hours. And pros Dahl and Grimani will be the first to point out the adverse effect one parametrically equalized change at one position usually has on another position. Here is the point at which an install can become "stalled". Tweaking time adds up. And calibration to "That's as good as we can get in your room, sir." is not the type of end-of-project scenario any custom installation professional likes to build into an upfront bid.

Fortunately, the latest research in the field of acoustics and psychoacoustics in home surround sound listening areas indicates a great proportion of listening rooms may have a low enough reverberation time (0.3-0.6 seconds) to preclude extensive passive treatment. What this means is that it is still not possible for any active room correction device to operate effectively in sparsely decorated rooms. For example, rooms with all wood floors and few hard surfaced pieces of furniture, as often depicted in ads for A/V gear would most likely raise the reverberation time above the 0.6 second soft threshold.

In my home theater/living room case which is the subject of this Audyssey sound Equalizer review, I would suggest paying close attention to the corner near-wall positioning of the L/C/Rs, the distance to the listening area around the sofa, and the diffusive surfaces that make up both the front and rear hemispheres into which the entire A/V/Room system operates.

 

Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!