Best Bang for the Buck on a Used Center Speaker???

You can't just go for the best bang for the buck. You need to stick with the center speaker of the same brand.

NHT AC-2 center channel speaker. The unit mated with the 2.9 and flagship 3.3 series by NHT. Fast, detailed and accurate. Buying used in and of itself will give you much bang for the buck. If you cannot find the same brand and series of your mains, go for something better.

IMHO, More expensive, less expensive, it doen't really matter. The center channel should be "voiced" the same as the fronts, so as not to draw attention to itself (same sensitivity, impedence, etc., etc.)Therefore, same brand, and designated for center channel useage is best.

IMO, the center chnl should be the exact same speaker as the front L/R. If possible, all three fronts should maintain matching tweeter heights. None of the center speaker being placed several feet higher or lower than the mains, causing tonal "panning" issues.

The theory (THX) was to obtain narrow width from the center audio chnl, but pending domestic screen/seating position, most of the so-called "Center-Chnl" speakers with woofer-tweeter-woofer driver arrangements, are subject to substancial frequency roll-off due to limited off-axis responce in the horizontal plane. They work great in the vertical axis (limited height with full imaging width), but suffer greatly if listening +/- 10 degrees off center in the horizontal. Check the speaker specs for dispersion "windows".

Several big recording studios using ATC, B&W, JBL, etc. use this approach, along with tons of larger "projection" home HT installations. Don't be fooled by articals claiming the center chnl is limited to dialog only. Tons of media now incorporates full bandwidth through all 5.1 chnls. By right, the ultimate would be 5 or 6 matching full bandwidth speakers, providing you can position yourself dead center, and your room's accoustics are evenly balanced for speaker voice-matching.

Many feel that CC speakers are just another marketing ploy, generating serious $$$ in sales off the uneducated masses. Look at all the HT brochures/articles/etc, depicting the CC speaker placement. What's wrong with their placement?

Good luck