Originally Posted by tnkgill
Hello All.... Great forum... It's hard to get a handle on all this customization!! I've got a very junior question. I have the Klipsch Quintet III surround system with a Klipsch Synergy 12 Sub... Since the frequency response of the speakers is 120 hz - 23 khz, should I set the crossover for my Sub at 120 hz to pick up what the speakers can't handle and also set my crossover in the MCACC at 120??? (or whatever is closest)... If I set the crossover to 100 hz, am I missing the 100 hz - 120 hz range that isn't accounted for by either the Sub or the speakers???
You wouldn't be "missing the 100Hz - 120Hz range," you would only experience a slight dip in that relatively narrow range. Speaker response doesn't stop abruptly at the specified +/-3dB point, it just rolls off. Most speakers will have another octave or so of "usable" response below that point (manufacturer speak for "faint-but-audible"
). The same applies to the crossover. It isn't a brick wall. Both speakers and sub are active in the other's range.
In most rooms you not likely to detect the dip by ear, as there are dips throughout the audio spectrum of similar magnitude brought on by the speakers' positioning and interaction with the room itself, to say nothing of the speaker's internal crossovers. They don't bother people because they don't know about them. And most people find dips far less audibly offensive than peaks.
I'm not sure I have this right, but as I understand the Klipsch Quintet III, the 120Hz +/- 3dB point only applies to the surrounds; the fronts go to 80Hz. If true, that makes it even less of a concern, as the surrounds seldom carry qualitatively critical information. You have more latitude with them than with the fronts. Plus, MCACC may help smooth out the dip a little. I had surrounds that had a 120Hz rating in my system for several years. I used an 80Hz crossover, and never noticed anything amiss.
On the other hand, if it bothers you, you can always experiment. If the subwoofer is centered and/or near the mains, you might find a 150Hz crossover workable, although that does carry some risk of localization.