Quote Originally Posted by bfalls
I'm curious about your horizontal center speaker statement. What's the reasoning? Why is vertical better than horizontal? My center is identical in configuration to the mid/high portion of my mains. It has rounded edges and I have it sitting forward of the of the plane of my LCD display, so I don't have to worry edge deflection. It's below the LCD with a carpeted floor, so floor and ceiling reflection isn't a problem. How would my center be better vertical than horizontal?

Your statement is pretty general. I understand the value of controlled horizontal dispersion with the front speakers, but your statement doesn't take into account spacing. I have my mains set 9' apart. What about horn-loaded speakers? Horn configuration vary in dispersion patterns. Putting a horn with 60/40 vertical orientation on its side would sound totally different.

With the center channel responsible for a large percentage of what comes from the front, how is a speaker with a single mid/low driver better sonically than the two woofer center's extended frequency response?
The perfect setup for HT or multi-channel sound is to have all three speakers across the front be the same identical speaker in the same orientation giving the smoothest sound spread. In your case (9' spread) as in most it is important to always have speakers with an excellent horizontal dispersion pattern.

Unfortunately this is many times not practical due to the necessity to place the center channel speaker on top of or just below the display on a shelf and usually on its side in order to fit or look good. The usual tweeter plus mid/bass driver arrangement doesn’t work well for a center speaker as the sound axis will be skewed due to the speaker being placed on its side rather than in the normal upright position.

Thus the d’Appolito configuration was used for center channel speakers. It consists of two mid/bass drivers with a tweeter in between. The problem expereinced with this array is an effect called lobing. It somewhat affects all speakers with separate drivers, however, it is most significant in the dispersion patterns of d’Appolito configured speakers which have the two mid/bass drivers operating in the same frequency range. These speakers off axis tend to sum and cancel each other not the same at different angles. A listener in the center sweet spot seat might hear a flat frequency response, while listeners in the sides seats don't.

That is why I suggested to him to not place the C-100 speaker on its side. Some might comment that you lose a little power handling ability versus the dual mid/bass driver mentioned above. This is a minor price to pay for the improved sound across the front soundstage for all listeners.

You asked: " How would my center be better vertical than horizontal?" Of course it would not since it is a center channel designed speaker intended to be palced on its side. In R.G.'s case he is considering using a normally desgined bookshelf configuration and only in this case would you place it vertically. Using the same speaker across the front usually only works for rather small speakers. In my case I have a fairly small condo living room with 3 small Axiom M2 booshelf speakers for LCR which look great and fit in perfectly. They have very high power handling ability matched with a powerful sub and play as loud as my neighbors can stand.

You also mention: "With the center channel responsible for a large percentage of what comes from the front, how is a speaker with a single mid/low driver better sonically than the two woofer center's extended frequency response?" I somewhat disagree about the center handling the large percentage of the sound. I use my 5.1 system for music as well as movies and all three speakers are very active. The old comment that the center channel handles mostly dialog only is old school in modern movies. I think you might have been confused when you mentioned "extended frquency response" above. They have higher power handling but if they cover the same frequency range the they would have the same response.

I actually perfer music over a 5.1 configuration versus plain 2 channel stereo. This comment will raise lots of eyebrows here. My comment presumes the 5.1 system is setup very precisely within close tolerances +/- 0.5 decibles output for all speakers using a sound level meter. It must also have perfectly matched timbre/voice speakers all around. I have tested this out many times for myself and others and they all agree on my findings in my setup. The 5.1 sound adds a natural ambience that lends itself to the perceived naturalness of the perfomance environment in most recordings. Those that disagree almost invaribly have mismatched or poorly calibrated systems.

Hope this clarifies my comments. I in no way pretend to be a speaker design expert but only have learned this from extensive reading from professional sources and my own trial and error.

RR6