How big should center spkr be to set to "large"?

The following applies to high resolution speakers rather than midfi gear:

Setting the center channel to "large" is better sounding regardless of how small your center speaker is because when you set your receiver/processor to "small", the receiver inserts a high-pass filter, usually steep-slope and not of the greatest quality, to remove the deep bass and protect your center channel. Having this filter in the signal path to your center will degrade sound quality noticeably if you have a very high quality center loudspeaker and equally capable electronics. Less revealing speakers and systems will not be as sensitive to the insertion of this filter because of the qualitative limitations of the speaker's own crossover along with the limited transparency of the electronics.

"Setting the center channel to "large" is better sounding regardless of how small your center speaker is because when you set your receiver/processor to "small", the receiver inserts a high-pass filter, usually steep-slope and not of the greatest quality, to remove the deep bass and protect your center channel."

Dave, thanks for the response and info. I surmise that what you describe is happening with my Sony DA4ES receiver that I am using as processor.

I noticed something else I don't like when using the center speaker, whether set to large OR small. And that is a loss of ambience details, compare to setting the receiver center channel setting to "none". I was switching back and forth, and when I am set to "none" and the sound is just from the front L/R, there is a lot more sense of space and background ambient noises in the mix(example, traffic and city sounds).

It seems like a good processor would retain that spacial information even through a center channel speaker, or would still direct it to the front L/R. Are there any processors that pull this off very well?

I am starting to get an itch for a processor, but the Sony has so dang many features I like, it will be hard to find a processor that has them, phono input and TWO multi-channel inputs(I have HDDVD and a Universal player) just to name a couple.

A good processor makes a world of difference, but I might recommend another setup technique that will help.

Set the delay on your center speaker for an additional 3-5ms. With most processors you have to lie about the distance your center is away from you (say it's 3-5 feet closer than it actually is) in your surround setup menu. Most people have either have their center channel too close relative to their mains, or haven't set up the delay properly on their processor. I have found that even when the center is equidistant from you as your mains, the soundstage depth is compromised and the center speaker doesn't blend properly. The additional 3-5ms of delay solves this, as would moving the center 3-5 feet back from what is normally considered the "proper" location.

This has been a very interesting discussion. If you guys don't mind, I would like to piggyback instead of starting my own thread. I have a Monitor Audio Gold setup, with a sub and everything set to small. The Gold Center (GRLCR) has a "rated" low frequency extension of 40 hz. I just got a Sunfire Cinema Grand (200 x 5) amp and am using my HK receiver as a pre-pro. With 6 1/2" drivers, I have no illusions that it will play loud with 40 hz information, but I am debating with the added power from my new amp, if it would make sense to use a 60 hz crossover instead of 80 hz.

Any thoughts on this?
Thanks
Greg

Greg -

IMO, start with 80hz, switch to 60 hz and see which one you like best. You may could use either and it may not make a difference.