center channels

[lewisaj]

what does it mean exactly when a center channel is "matched" to the front speakers? i want to replace my rc-3 with an rc-7 or even a klf-c7. my front channels are rf-3's. will this cause problems? im always wanting i new center channel, because i primarily watch movies with my speakers, almost no 2 channel stereo music. not that the rc-3 isnt a great speaker. thanks for the information.

[HornEd]

Well, lewisaj, you raise an interesting topic and one that has been the source of many different personal tastes. You might use the Forum search capabilities to explore them. But, here's my take...

The most common form of center matching is to match the component speakers (tweeter, mid-range & woofer) of the Right and Left Mains as close as possible to the component speakers of the Center. The object is to gain a close "tone & timbre" match so that there is not an audio SHIFT when the same sound source moves from one side of the screen to the other.

Personally, I tend to side with the current crop of audio engineers who mix DVD's and multi-channel music with the expectation that all five speakers in a 5.1 configuration will be identical speakers. While it is clear that not everyone has the room configuration, speaker budget to do that, or decorating freedom to do that, it is generally best to talk of audio ideals first as a step in understanding necessary compromises.

Tone and timbre issues should also include the raw cubic inches, sealed and ported issues, tapered array aspects, and distance from the floor... or any other issue that alters the character of a speaker's sound. Clearly, the more transparent sounds are from speaker-to-speaker the better. The more localization of sound appears to come from a direction rather than a specific speaker... the more life-like the HT experience becomes.

In my HT system, for example, I have six KLF-30 speakers, including a specially customized KLF-30 that allows it to be placed atop the 65" HDTV. It is a "matched" center by most standards... but a difference in tone and timbre can be detected... mostly due to the proximity of the floor and the effect that has on the woofers sound character.

Having a Center that matches the Mains is far more important than "tone & timbre" shifts when it comes to HT. 5.1 programming puts most of the sound into the center channel (upwards of 75% of the total sound to all speakers!) in order to better anchor sounds to the action on the screen. Thus, the biggest benefit that I received from customizing the KLF-30 center was a dramatic increase in center channel dynamics that made movies come alive as they do in today's high-tech theaters.

Of course to achieve the high-tech theater effect, one should also have an "adequate" subwoofer that can reach the Dolby Digital Reference Level of 121 dB's that not even all professional theaters can. Obviously, that does not mean that anyone is expected to sit in a room at ear bleeding volume levels... it means that the sound system has the capability to match the range recorded in a Dolby Digital DVD... where loud sounds can occur for just a fraction of a second... just enough for realistic effects without substantial ear discomfort.

Creating sounds below about 80Hz generally requires more specialization than most full range speakers have. In deed, most cone woofers have a narrow frequency band where sound is distorted... it can be found in the frequencies where lower mid-range meets upper bass. That is part of the reason most "SMALL" settings on receivers roll off full range speakers around 90Hz.

Sounds below about 80Hz are also "non-directional" when not "colored" by localization harmonics in a less than perfect speaker. Thus a good HT subwoofer should produce tight, accurate, and ample low bass to seamlessly integrate with the five (or more) full-range speakers in your configuration. When correctly set up, your ears will pick up localization of an explosion from its above 80Hz portion of the sound from the speaker(s)... and your mind will seamlessly associate the low bass from the subwoofer(s) as coming from the same direction.

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It is a worthwhile exercise to set your receiver for a Phantom Center channel (i.e., no center speaker) and you will note that your right and left main become suddenly more pronounced and produce the illusion of a center channel when you are directly in the middle of your sweet spot. It is a great effect... but it tends to be diminished by moving your head one way or another. A good Center match will provide that wonderful natural sound experience across a broader cross section of your sweet spot.

Essentially, center matching brings up the illusive issue of soundstage in the front array... generally referring to the overall effect of the Left, Center & Right Mains. Most people prefer the usually mutually exclusive effects of a wide soundstage AND dialogue well anchored to the screen.

This can be achieved by having the Right and Left Mains close to the screen and Front Effects speakers mounted one to three feet outside of the Main Speakers... with their tweeters about five to six feet above the floor. Upscale Yamaha receivers have Front Effects built into their DSP programming... and to more closely match them to the R/C/L Mains, I have used KLF-C7's, ordinarily known as the correct center for KLF-30's.

Of course, using five or six identical speakers not only provide the potential to hear a film the way the sound engineers intended... but also provide the best "tone & timbre" match for sound pans that "move" from the back to the front... and visa versa.

While the foregoing comments are "on target" for modern DVD and SACD mixing techniques, a word should be added for getting more out of sound sources that are less acoustically rich than 5.1 (or above)... like ProLogic or stereo found in most cable TV broadcasts and older recorded media. Speakers that spray surround sound channels around the room to create multiple sound reflections (ambient sound) create the sound illusion of a broader rear soundstage. Like the "bass boost" on a boom box or the "special DSP effects" of an upscale bells & whistles receiver... some people prefer giving the recording engineers' mix a boost in the backside.

And, that's okay... because building your own HT should be an exercise in your personal taste and not a subject for flaming rhetoric on this Forum. However, personal taste is built on experience... and surprisingly low percentage of people have heard a truly well matched home theater system like the one that, my hero, Q-Man has.

Truly matching a Center to your Mains, lewisaj is an important first step in having a well matched HT System... and targeting what that is before you upgrade into it will enhance the quality of Klipsch life in your household. -HornED

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Photo update soon! -HornEd

This message has been edited by HornEd on 04-22-2002 at 08:25 AM

[soundog]

Great post, Ed.

You should consider a second career as a writer for HT magazines.

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Soundog's HT Systems

[lewisaj]

thanks alot horn-ed, thats got to be the best, most comprehensive answer ive ever gotten off of any forum on any subject. thanks for taking the time to do it.

[HornEd]

Well, lewisaj You did ask "what does it mean exactly when a center channel is "matched" to the front speakers?"... and I try to answer such questions as well as I can. Glad you enjoyed it!

Soundog, I consider that a mighty observation since I hold your audio and life accomplishments in high esteem. Confidentially, I have written professionally since I had a byline in the San Francisco Examiner at age 16. So, with nearly a half century of experience, I owe it to the Forum Vets like you to reach down and try to do a little better... and not to forget that there are newbies who need a nudge toward better understanding. After all I have learned on this forum, it is the least that I can do. -HornED

[Huhuru]

HornEd

Would like to thank you personally that I have learned a lot from your posts. I also learned from other members which I have also thanked personally.

Good Klips

Huhuru

[avman]

hornEd...if modern dvd's are being mixed,as you suggest,on the premise that a CONSUMER has 5(or more) full-range speakers ideally located in their room,then there are alot of dissapointed consumers/dillusional audio engineers out there.i sell way more satellite/subwoofer systems than anything, yet almost all of my speaker sales start off with 'full size speakers sound best'-hey-i'm trying-then on to large and small bookshelf/sub systems, sat/sub systems, and-alas-the dreaded bose acoustiMESS systems. sacd on ANYTHING less than a klf-30 or similar speaker must really sound bad,and usually does, especially on 2-ch sacd which has NO sub signal. if sony thinks sacd is going to 'take off', they had better find some sub signals and put 'em on the discs, because most people-granted sacd player buyers are more aware of what a good speaker is-don't have full-range speakers. what do you base your premise that this full-range all-around speaker set-up is what the sound mixers are basing their work on? avman.

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1-pair klf 30's

c-7 center

ksps-6 surrounds

RSW-15

sony strda-777ES receiver upgraded to v.2.02 including virtual matrix 6.1

sony playstation 2

sony dvpnc 650-v 5-disc dvd/cd/SACD changer

dishnetwork model 6000 HD sat rcvr w/digital off-air tuner

sony kv36xbr450 high-definition 4:3 tv

sharp xv-z1u lcd projector w/84" 4:3 sharp screen

Bello'international Italian-made a/v furniture

panamax max dbs+5 surge protector/power conditioner

monster cable and nxg interconnects/12 gua.speaker wire

KLIPSCH-So Good It Hz!

[HornEd]

Excellent question, Avman... and the answer is a study in simple pragmatism... and one that I have answered before. So far, there is no way to mix DVD's or multi-channel music (particularly SACD which spells it out) to fit all the many variables of speaker types and monopole, dipole, tripole or WDST, emasculated centers, etc. So, the simplest answer it to mix the sound to five (or six) discrete channels for identical speakers... which allows them to mix what becomes ambient sound from monopole speakers.

By doing this, speaker manufacturers have a consistent approach with which to work... as does the home theater or multi-channel music enthusiast. I understand SACD specifies using five identical speakers... again, the purpose is to cut down the variables. Any speaker manufacturer can provide five identical speakers... so it is a standard that favors no particular manufacturer.

Clearly, there are people who prefer to use all kinds of speaker configurations and placements... and if it pleases them... then so be it. Just because something is done one way doesn't mean the consumer has to respect it. The audio engineers who mix the DVD's have set this common mixing standard and we are probably all better off for it. -HornED

[boa12]

ed, i thought the thx standard that it seems most go by always called for 5 identical speaks & a sub. problem is it's 5 smallish sat-type speaks & a sub which none of us klipschers adhere to.

thanks to that we have the 80hz cross standard, so w/ our towers of low bass producing power doesn't that make us all thx-misfits?

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My Home Systems Page

This message has been edited by boa12 on 04-22-2002 at 10:41 PM

[HornEd]

You bring up an interesting point, Boa. Klipsch, whose pro-theater market is second only to JBL if memory serves, tried very hard to embrace the

THX "standard"... but, in the end that "standard" was pretty well abandoned by everyone but George Lucas whose firm invented THX as a profit center. Firms that used the THX designation conformed to this set of standards and paid royalties to Lucas for doing so.

The discussion of matching centers that I posted above in this thread does NOT take into account the fading THX standards with its tricked up approach to creating sprayed ambience and accentuated bass. Your system and mine render THX mixed films better than they would if our systems conformed to the Lucas "standard" IMHO.

In the approximately 300 movie titles in my collection, less than 10% are mixed to THX standards, and the ratio is much, much lower on newer films by other than Lucas Films. The popular but "long-in-the-tooth" set-up DVD Video Essentials was somewhat "THX friendly" but was primarily "Dolby ProLogic" oriented... but even they drew the line when it came to matching centers. Their DVD depicts a floor-standing Center identical with the floor-standing Mains sitting atop the TV. Not the best solution, certainly, but one that they make a case for in spite of the heat they deservedly got from the WAF aspect.

Yes, Boa, Klipschers who would like a trip down THX®-Certified memory lane can check out http://www.finest1.com/klipsch/thx.html in all their glory. Note that the KT-LCR (vertically oriented Left, Center, Right identical mains - like those in Video Essentials), KT-DS (di-polar with exponential "cones" rather than "horns"... these had duplicate speakers in the front and the back and were designed to be mounted to the walls from the side... also as depicted in Video Essentials), KT-SW (15" sub with x-over to filter bass from Mains). All were available in a genuine (THX?) "whitewash" finish.

The venerable and still popular, wedge-shaped, "Wide Dispersion Technology" KSP-S6's seem to be a logical extension and decided improvement on the KT-DS concept and was free of the heavy royalty payments for THX certification. The migration to a single woofer facing the addition sweet spot and horn tweeters in the wedges became the actual Klipsch trademarked WDST standard to cope with a wide variety of transitional mixing standards in a less revealing way.

Of course, Boa, you and I have our share of the Klipsch of Yesteryear in our respective use of KLF-30's and Cornwalls... and even newly made Klipsch Minion, SteveP, is a strong advocate of KSP-S6 ambiance. But the discontinued THX Certified series products seem a lot less popular topics on this Forum.

Thanks for the recognition that Centers should be the equals of Mains in the front array, George Lucas, but, unlike the THX approach, my ears prefer the Rear Array match the Mains as well! -HornED