BioLinks® Audio Forum

Muddy center channel?

BioDaddy — Fri, 25 Sep 2009 19:33:07 +0000

Is the dialog muddy and sometimes unintelligible coming from the center channel in your home theater system? Does your spouse or significant other say, “Turn it up” or, “What did he say?”

Several audio discussion forums have addressed questions like,

“I hated how I had to crank up my speakers to be able to hear dialogue in one scene and then have to turn them down in an action packed scene so they wouldn’t be blown out.”
“Dialogue on movies is unintelligible and you cannot hear a thing people are saying. I have to put English language dialogue on the screen in order to follow the movie when I can’t completely crank the stereo.”
“The sound is a bit ‘muddy’. Dialog doesn’t seem as clear as it could be, and I sometimes feel like I’m missing part of what is being said. I even had my hearing checked to see if I had a problem. I didn’t, thank goodness…”
“I can’t hear speech that well. No matter if it is Dolby Digital, DTS, or whatever. The speech gets washed out by the surround sounds (not necessarily the surround speakers themselves). I thought all I needed to do was to increase the volume of the center speaker and that would take care of it. NOPE! It didn’t. I even checked and calibrated all surround speakers to be exact with a sound level meter and pumped the center channel even louder. No good. I checked my connections on the back of the receiver to make sure each speaker was hooked up correctly and all is correct. When I get close to the center speaker, it sounds like it is also letting sounds other than voice/speech come through. I thought the center was supposed to only have speech coming through it. What can I do to remedy this problem? Many thanks in advance!’
(My center channel speaker): “It’s not good enough to really be happy with it, but not bad enough to replace it. I’ll wait for some divine intervention.” Read on… it is here already!

Suggestions for solving the problem are all over the map:

Purchase a better center channel speaker (how much better will solve the problem?)
Purchase a better receiver (same as above)
Check the front speakers’ polarity (that is not the problem)
Try room treatments (they’re expensive, fail the WAF test and won’t solve the problem)
Increase the volume in the center speaker (that’s not the problem nor the solution; also fails the WAF test)

There is mounting evidence that the problem begins with both the Dolby Digital® and DTS® multiple channel data encoding and compression techniques and ends with the home theater receiver/processor’s ability to resolve the mountain of information adequately. No question, the market is getting very competitive with the home theater surround sound starter receivers. Manufacturers of HT receivers tend to sacrifice the quality of the amplifier and the processor sections by offering so many other features. This is especially true with the home theater in-a-box packages that compound the problem with a less-than mid-fi CC speaker.

What if you could add a simple dialog augmentation (corrective/clarifying/enhancement) device that…

could be wired in parallel with the existing center channel speaker
was a passive module that required no additional power supply or amp
is “discreet” – passes the WAF test
creates crystal clear dialog using any receiver or speaker
smoothes out speaker response of all front channels
is so inexpensive that it would fit anybody’s budget

Does this sound like another “Mission Impossible” task for audio engineers?

Dialog Augmentation Device added to any standard loudspeaker

“Discreet Loudspeaker” defined

BioDaddy — Wed, 23 Sep 2009 22:56:11 +0000

In terms of loudspeaker design, “discreet” refers to both its subtle appearance plus the audio disappearing act it performs in the listening environment. The WAF rule requires that a speaker never draw attention to itself visually and not have to be played loud for enjoyment. Hi-fidelity standards require that a speaker never draw attention to itself aurally; i.e., the sound stage should be natural, realistic and not sound like it is beamed at you from inside a box.

Heard but not seen

BioDaddy — Wed, 23 Sep 2009 22:36:59 +0000

Long, long ago, in a place far, far away, children were once taught to be “seen but not heard” in public places or during family gatherings. Likewise, the WAF (Wife Acceptance Factor) dictates that loudspeakers are to be “heard but not seen” in the home. Despite the money spent for large tower or furniture-grade speakers, there still might be another price to pay. Unless there is a separate media room available for these lovely works of art, then the WAF probably kicks in. If the spouse or significant other views them as loud monstrosities that will not be brought into the home, what are your options?

It is almost universally agreed that small mini-monitor bookshelf speakers are not up to the hi-fidelity standards for either audiophiles or serious home theater enthusiasts. Is such a diminutive little prodigy now available that can finally stand toe-to-toe with the big boys? Could it give a sterling audio performance at an economical price? Surely that would be a paradigm shift in itself; but how about some totally unique, bonus features such as:

Front channels can be hidden behind the TV
Surrounds can be hidden behind pictures on a shelf or on the floor beneath furniture
Aiming is not critical – point up, sideways or backwards
Sweet spot expands to every listening position
Play at low volume and still hear crystal clear, full spectrum of frequencies

Does conventional speaker designs make this a “mission impossible” or has some new technology been discovered that the prestigious audio community has grossly overlooked …or ignored?

What is a “Discreet” Subwoofer?

BioDaddy — Sun, 13 Sep 2009 15:57:55 +0000

Discreet Subwoofer: a/k/a the anti-subwoofer factor

(The best sound heard from a subwoofer is no sound at all)

First and foremost is the need for a subwoofer to provide adequate deep bass augmentation (enhancement) to any speakers from mini-monitors to full range, high-end tower systems. This goes for home theater as well as music – two-channel stereo or 5.1 surround sound. Unquestionably, the small fries need a lot of help at the bottom end but so do most of the big boys.

In terms of performance criteria, there is far more at stake in any loudspeaker system than sound pressure level, frequency response and low distortion. Some audiophiles have given up on hearing the full audio spectrum that really low bass contributes to music because a discrete subwoofer can be obnoxious if it is not discreet. Double talk? Not really.

A discreet subwoofer can be a critical component in high definition, natural sound reproduction; but only when it integrates with the other speakers does it help achieve the realism of live audio.

We want clean, deep, tight bass but not unless it is blending with the entire speaker system without calling attention to itself. HDTV lets you see the image through a window as opposed to on the screen. So, why shouldn’t hi-definition audio demand that you hear the music, not the speaker?

Put another way, it’s what a subwoofer doesn’t do rather than what it does do that matters most. More double talk? Nope. Setting aside technical design parameters, in an ideal world of speaker performance there should be no sound whatsoever heard from a subwoofer itself. The box should be completely transparent to the sound – the anti-subwoofer factor.

Why this phenomenon is never mentioned nor described by professional speaker reviewers and acoustical engineers is an enigma. Is it because, like antimatter, it really doesn’t exist? No, it is real alright, and it matters; you just have to experience it firsthand to believe it.

It goes to how well the sub “voices” (or integrates) with the other speakers. This includes the front two main speakers in a stereo system and, additionally, the center channel and rear channels in a home theater surround sound system. Not to be confused with “blending”, integration has to do with hearing the bass imaged in the correct speaker and emanating only from the correct channel where it was recorded.

For music, if a bass guitar was on the left side of the soundstage then that is precisely where should be heard – in the left speaker. If a kick drum was located in center stage, then it will be heard there even in a two-channel stereo system’s phantom image. And, when a pipe organ hits that glorious low C it is voiced in all your speakers. With home theater, if there’s thunder or an explosion in a rear channel, it should sound like the sub is voicing with that surround speaker. This phenomenon has never been heard (or heard of) by most folks.

You can place your head next to a mini monitor or any speaker that is incapable of deep bass and if it is voicing with the subwoofer as described, you will only hear the sub’s bass coming from that speaker! Once the anti-subwoofer factor is auditioned, it is unbelievable that a speaker that small is really capable of reproducing bass that low… and it’s really not! The sub is just integrating with the little fellow. Conversely, if you stick your head close to an anti-subwoofer you will hear nothing. How discreet is that?

The anti-subwoofer factor enhances and reinforces the sound stage making it as close to live and natural that any speaker can reproduce. Total sound immersion experienced with a discreet subwoofer – the anti-subwoofer factor – is what I am talking about. Could this be the “Holy Grail” of high definition sound that we all seek at the bottom end?