The Biggest Home Theater Audio Mistakes

A good home theater experience starts with clean and intelligible dialogue, and I see lots of mistakes there. Here are the most common:

home theater audio mistakes

1) All the speakers are in the ceiling, pointing down at the floor

Having sound firing down 15 feet in front of you puts you so far off axis from the speakers that the dialogue will sound mumbled, and the sense of surround-sound imaging is pretty much lost. You’d actually be better off with mono sound!

 

2) A traditional horizontal center speaker laid down on its side

It might look alright, but most of these woofer-tweeter-woofer speakers create holes of sound at the seats to the left and right of the center. That can sound OK if you’re in the middle seat, but dialogue will sound mushy elsewhere. Get a 3-way center speaker instead, or one with a 2-½-way crossover design.

 

3) A projection system without an acoustically transparent screen

This setup forces you to place the center speaker either below or above the screen—or worse, have speakers both above and below. The dialogue won’t be coming from the picture, and it will sound bad because the speaker will be too close to the floor or ceiling. There are some very good woven screens that won’t affect either the sound or the picture—get one, and put the speaker where it belongs.

 

4) No equalization

All speakers are affected by the room’s acoustical thumbprint. The dialogue can suffer from excessive bass and there can be missing midrange. You need to equalize out these spectral errors—tune it or lose it! Many auto-EQ schemes do a poor job of correcting these issues, so you might want to go with manual EQ and a decent analyzer (check out roomeqwizard.com) or have a pro do it for you.

 

And here’s my last piece of advice: Mind the center-speaker dialogue quality before you worry about choosing and placing the other speakers!

Anthony Grimani

A former executive at Dolby and Lucasfilm THX, Anthony Grimani is an expert in home
theater acoustics & design. He developed the Home THX program and invented the
revolutionary Surround EX 6.1-channel audio format. He is co-founder of Grimani
Systems
in Novato, CA.

2 Comments
  • John Bishhop

    Cool Tony, good to see your presence on the RAYVA blog. Now for a counterpoint to your well articulated points.
    1. Yep, but it all depends on the axial response of the speakers themselves, good and bad are out there. Still, ceiling speakers today are best left to their part in hemispherical audio.
    2. Nope, and let’s not indict horizontal designs. Acoustical holes appear from driver interaction in vertical design as well, The 4th order LR Xovers famously addressed that in the 70’s.
    3. Screens that have texture damage inter pixel contrast such that 2k becomes 1k net on the screen (seen in test patterns and illustrated in JKP training). 4K pixel structures are damaged even more from the small pixel size relative to surface texture. Joe Kane referred to this as ‘depth of modulation’. I explain it thusly; ‘think of a black pixel surrounded by white. The light scatter turns the black to gray, and sharpness (resolution) is lost’. This is easily seen in res patterns like bursts and single pixel checkerboard patterns. From this we know that the hierarchy in picture quality is; good = woven, better = microperf on Snowmatte, and best = Snowmatte opaque, full retention of display resolution. The visual res loss of AT screens is significant, undeniable, and easy to demonstrate. Sonically I suggest that vertical localization is a happy human benefit to this issue. We can’t detect discrete changes in vertical acoustical position in less than 15 – 20 degrees angular change; aka minimum audible angle in the parlance of psycho-acoustics. Our ears, separated horizontally, allow a minimum audible angle of 3 degrees, and professional audio folks often demonstrate 1 degree of position shift detection. For all that, whenever possible, retain the 30% improvement in image clarity, sharpness and depth, for the nominal sonic trade off of not putting speakers behind a screen. Most speaker design engineers prefer the grille off anyway, for good reason!
    4. He who equalizes least, equalizes best. And all that that implies:-)
    Happy trails T, see you in San Diego.

    August 3, 2017 at 11:33 pm
  • I am always interested in advice and comments on Hone Theaters. I have been doing this for 44 years now and 20 in the heirloom quality seating business. The failure of dealers and integrators to research the seating the way they do everything else is disheartening. There is more inferior product being produced off-shore by pretenders who have purchased defunct American legendary furniture manufacturers names and shipping in disposable recliners. Like anything else we represent to the client as high quality that justifies the investment and trust they rely on with you, you either ignore the category, allow the client to fend for themselves at the local discount big box store or allow the designer to reap the huge profit opportunity in this category! I feel like one, “crying in the wilderness,” with little support from the industry trade publications or an opportunity to educate and work as a partner in this category. There are big two or three of us who have the experience, understanding and expertise to deliver product at the level at which their client is expecting… not just a chair with a cup holder…

    August 6, 2017 at 4:51 pm