Center channel freq's

[hydro]

Hi All
Can anyone tell me the freq's that the center channel need to make I have been to the Dolby site and the say that all 5 speakers should be identical, but I have never seen the center the same as the rest. In fact the center is always a 2-way. so I assume the it is not required to make the fun range but how much?
Thanks in advance Joe

 

[Swerd]

Can anyone tell me the freq's that the center channel need to make I have been to the Dolby site and the say that all 5 speakers should be identical, but I have never seen the center the same as the rest. In fact the center is always a 2-way. so I assume the it is not required to make the full range but how much?

Bass below about 80-100 Hz is not necessary for the center speaker in movies. The main center-channel content in movies is dialog. Bass response for voices is just not needed. For those sound effects that do move across the front, a subwoofer will fill in the bass missing from the center speaker. In fact, it is more important that the center speaker have midrange and treble response and dispersion that is similar to or better than the other two front speakers. That way the front sound stage doesn't have a hole in the middle.

My system uses full range front left and right speakers, but my center and rear channels are small 2-way speakers that have 4½" midwoofers. On my HT receiver, I set them to small and use an 80 Hz crossover setting.

For people who must have 5 channel music, all bets are off. But many people, including myself, don't have the space or want to spend the money for full range speakers in all 5 (or more) positions.

 

[MACCA350]

A couple years ago I changed my center to the same as my L/R towers. Personally I'll never have a smaller center again.

cheers

 

[Pyrrho]

The center channel needs to go down at least as low as the crossover setting in your receiver/processor. Typically, it should be solid (-3 dB) down to 80 Hz or lower (the lower, the better, but it is not essential that it go lower than this).

I personally use identical speakers all around (you don't have to purchase a package set; you can purchase 3 or 4 pairs of speakers and use them). I will never again use a speaker that is different for the center channel, as there is no voice matching better than an identical speaker. In my case, they are all two way "bookshelf" speakers:

http://www.kellsieavdesign.com/products/Leisure2SE.htm

The deep bass is handled by my subwoofer.

If you have a TV that uses a CRT (picture tube), you will need to be concerned about magnetic shielding if you want the speaker placed close to the CRT, though it depends on how close, the exact TV, and the exact magnetic properties of the speaker. With any other kind of TV, magnetic shielding (aka "video shielding") is unnecessary.

 

[j_garcia]

I use 5 identical speakers too. They are all -3dB at 55Hz and I use an 80Hz x-over. A crossover is not an all or nothing kind of thing, there is a slope associated with the crossover and sound is reduced above or below the crossover point as you move away from that point. The center should be capable of some output to approximately one octave below the crossover point. So for 80Hz, theoretically something that had output to about 40Hz would be desirable, though around 50-60Hz should still work well because the natural rolloff of the speaker will combine with the x-over and they should generally still blend well.