by Alan Lofft (bio)
If you've acquired a flat-panel HDTV plasma or LCD display, chances are the sound quality of the display's puny internal speakers is abysmal, and you'll want to upgrade it sooner rather than later.
It only makes sense to match the stunning clarity of your HDTV's visual presentation with similarly awe-inducing sound quality. Even if you've already graduated to some type of external speakers or surround system, there are ways to enhance the overall experience. Here's a list of tips ranging from the ultra-basic to the more elaborate, any of which will show you how to improve TV sound:
While I've always advocated spending as much on the audio presentation as you do on the hi-def flat-panel display, I understand there are inevitable financial factors that come into play. You can minimize costs by simply adding a pair of good bookshelf speakers or in-wall or on-wall speakers and a basic AV receiver. Use the display's analog line-level audio output jacks to connect to the auxiliary line inputs on the stereo amp or AV receiver. You'll be amazed at the improvement in your tv sound system.
On the advice of well-meaning friends or even some electronics retailers, you mounted your "rear" surround speakers on the back wall. Wrong. In a 5.1- or 7.1-channel home theater system, the left and right surround speakers should go on each wall to the sides of the seating area (and a little behind) ideally about 3 feet or more above ear level when you are seated.
The fundamental reason for side placement of surround speakers, besides the fact that Dolby Labs advise it, is that the 5.1-channel soundtracks for movies are mixed with the surround speakers above ear level at each side of the mixing theater or studio, just like in large movie theaters. And since we are trying to replicate or mimic the acoustic sound field that we experience in a cinema and hear what the sound engineers and the director heard when they panned and mixed the directional effects for motion pictures, surround speakers properly belong on each side wall of your home theater, above ear level.
A 7.1-channel system adds two extra rear surround speakers that are intended for the back wall behind the listening area at about the same height as the side-wall surrounds.
There really is nothing quite like the impact and beauty of a big-screen flat-panel High Definition TV 46 inches or larger (diagonally) or a video projector that can enlarge video images to 8 or 10 feet across. If you've been "getting along" with your aging 27-inch CRT (tube) TV or trying to eke out the last few years of service from your current analog set, it's time to give yourself and your family the pleasures of HDTV and a bigger screen. It doesn't have to be huge.
Unless you sit really close to an HD display (like 3 feet away), I've found that a 46-inch screen or larger (diagonal measurement) will deliver the stunning clarity and experience that HDTV is capable of. Anything smaller just doesn't have room for the millions of pixels necessary to demonstrate the HDTV superiority over old analog Standard Def TV.
Unless you're tone-deaf and couldn't care less about sound quality or the finer things in life like a beautifully accurate high-fidelity tv sound system, then a major improvement is possible if you dump the HTIB (Home Theater in a Box) or "Soundbar" on the kids, and get a real hi-fi surround system. It needn't cost the earth. Start simple with a pair of Axiom M3 bookshelf speakers ($368/pair delivered, and available in standard version, in-wall, or on-wall) and an entry-level Dolby 5.1 Surround receiver (about $300).
Add the center-channel speaker, surround speakers and a subwoofer later on as your budget permits.
The center-channel speaker in any home theater surround system or movie theater carries virtually all of the movie performers' dialog as well as singers' vocals in concert videos plus music in 5.1 channel playback. That's a challenging task; therefore the intelligibility of movie dialog and naturalness of singers' vocals is highly dependent on the neutrality and transparency of the center channel speaker.
You might be using a mix of different speaker brands in your home theater system; if so, it's unlikely the center speaker is a close tonal match to your main left and right front speakers. You'll get a big upgrade in overall sound quality by retiring the old center and getting the same brand of center speaker as the main channels. If, for financial reasons, you want to use a couple of old bookshelf speakers as surrounds, the tonal match of surrounds is less critical than the center, so relegate the old bookshelf models to surround duties until you can afford to replace them with a dedicated multi-directional bipolar surround speaker like Axiom's QS8 "quadpolar" surrounds.
While big floor-standing tower speakers are able to reproduce quite deep bass in music and movie soundtracks, they can never unearth the ultra-low frequencies with the same authority and power as a dedicated subwoofer can.
Subwoofers by nature (except for some small ones) tend to have greater internal volume and larger drivers, plus very powerful dedicated amplifiers of several hundred watts or more. That combination of internal volume, a big driver and large amplifier is unbeatable in reproducing frequencies of movie special effects -- earthquakes, pod footsteps (remake of "War of The Worlds"), spaceship sounds and explosions -- as well as delivering deep bass drum and pipe-organ low frequencies that are simply beyond the reach of tower speakers.
The laws of physics can't be broken: to get hugely powerful bass, you need a big box, big driver and large amplifier (it is possible to get very low frequencies from a smaller box but the trade-off is output; the small subwoofer capable of 20-Hz low frequencies won't play very loud in large rooms.)
Newcomers to home theater sometimes buy a subwoofer, plunk it down in the room and are disappointed with the deep bass output. A subwoofer in a room must be located in a preferred position to maximize the deep bass output and avoid "standing waves" that may cancel bass output where your couch is located. You can't just drop the subwoofer where you want it and expect it to perform at its best.
To overcome potential disappointment, do the subwoofer crawl: Place the subwoofer where the couch or chair is, play a movie or CD with deep bass effects, and crawl around the perimeter of the room until you find several possible locations where you hear bass that is deep, smooth and powerful (but not overwhelming; that can also be produced by standing waves and room modes). Mark the location with some masking tape, then move the subwoofer to one of those spots. Now sit in your chair or couch and listen to the deep bass. It should sound just as it did in the locations you marked.
Modern Dolby and dts movie soundtracks often contain beautifully recorded and engineered sound quality. Consumers often forget that 5.1-channel Dolby Digital is also the audio standard for High Definition TV and is available on many popular television series and music specials as well as most HD sports broadcasts. The jump in realism possible by following some or all of the above tips to upgrade your TV audio and video experience will only add to your enjoyment of modern HDTV programs and multi-channel sound while you improve TV sound clarity.
Have questions about maximizing your home theater or video experience? Remember, Axiom's team of audio/video experts are always happy to help you get the most from your system. Call or email our friendly, non-commissioned sales staff about your tv surround sound any time to take advantage of their 30 years of experience in A/V.