Axiom Home Page Forums General Discussion Home Theater Hole at the bottom of the center channel?

Why is it that the VP100 and VP150 center speakers are tuned to drop off at 95 and 85 Hz, respectively, when male vocals that they are supposed to "anchor" can reach lower. I would be interested in complementing M22ti main speakers. Why would it not be better to use a third M22ti, which reaches to 60 Hz?

If the commonly recommended crossover to the subwoofer is set at 80 Hz, it would seem that there is a hole in the center channel if the "center" speakers are deployed.

i am not exactly sure, but i dont know many male voices that reach below 80hz. sure 80hz and lower can be achieved through singing, but most singing is played through the L/R channels

Several people think it's best to use a vertical center channel, and it's certainly ideal to use identical speakers for at least the fronts. However, the appearance/placement factor is a stopping point in most cases. Interesting point about the hole, though. I had assumed that the male voice didn't touch 80 Hz, but apparently, I'm wrong. Hmm.

hmm
i always thought a deep voice could reach 80hz when singing. maybe i am wrong
80hz is not reached in normal speech at the very least

if it 80hz is reachable, your average 300 dollar tv would miss half of what is being said.

You must, I say, you must be thinking of FOG Horn Leg Horn ?? :-)

that's not exactly true. The human voice is not a simple tone, but is made up of a fundamental -- think of it as the foundation tone -- with harmonics layered onto it. If you played back a recording of a person speaking and slowly filtered out frequencies starting from lowest to the highest, you would still be able to hear what was being spoken pretty well until you got into the upper frequency ranges (above 1500 kHz). The human brain does a good job of recreating the fundamental from the harmonics.

The telephone, for example, transmits a very low-fidelity signal (limited to between 200 - 3400 Hz) that is still completely intelligible.

Naturally, you wouldn't want your center channel to miss out on any portion of the human voice, but sounds below 80 Hz do not contribute to the intelligibility of human speech and can be safely diverted to other channels or the sub.

Yes, as Peter says, the human voice has a whole bunch of harmonics above its basic pitch, which varies roughly from 100-300Hz. The voice pitch of course can be varied, such as in singing, from a little below 100Hz to way above 300Hz. So far as the center speaker goes though, it's supposed to mainly be there to anchor speech to the TV screen, so output below 100 Hz isn't really important. What's more important is that the upper harmonics of the basic speech pitch which are what give speech its intelligibility(called the formant frequencies)running from about 500-4,000Hz and having most effect around 2,000Hz, are reproduced well.

The bottom line is that it wouldn't really matter if the center speaker had a slight depression in the 80-90Hz area. Use the 80Hz crossover.

After I posted this, I noticed that the question was asked and answered -- although perhaps not definitively -- over in the Technical forum: http://www.axiomaudio.com/boards/showflat.php?Cat=&Board=tech&Number=27293&page=2&view=collapsed&sb=5&o=0&fpart=