Comb filtering and center channels

3db

3db

Audioholic Overlord
Ratings
3,635 11 12
#1
Its a really nice demonstration using pink noise. I wish they would have used some music with both male and female vocals to drive the point home. Pink noise is still to abstract for me to understand.

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shadyJ

Speaker of the House
Ratings
5,159 34 17
#2
Pink noise or white noise is the right tone to use for this. It is the playing of all frequencies simultaneously. It would be more difficult to discern the effects of comb filtering with a vocal. You need to use wide band content to really heard this effect clearly, like a full orchestra, but its still better with a noise color.

Keep in mind that demo is more severe than you would hear in a real MTM since that affects all frequency bands. That effect would especially be evident in the small wavelengths of tweeter bands, but that would not occur in an MTM center since it only has one tweeter.

By the way, you can do this same trick with an MTM center speaker by simply having someone rotate the speaker with a listener in a single location. That will let you know how much your center is affected by this phenomena. If you want to know what it looks like, see some of my center channel reviews. Look at this graph for instance, where the lobing causes patterns that make this graph look almost like a palm tree:
 
gene

gene

Audioholics Master Chief
Administrator
Ratings
4,807 25 9
#3
The only company I know of that promotes dual center channels is Axiom. IMO, the only time dual centers make sense is in an Auro 3D setup where the 2 centers are discrete channels (ear level vs height),NOT a single mono source.
 
3db

3db

Audioholic Overlord
Ratings
3,635 11 12
#4
Pink noise or white noise is the right tone to use for this. It is the playing of all frequencies simultaneously. It would be more difficult to discern the effects of comb filtering with a vocal. You need to use wide band content to really heard this effect clearly, like a full orchestra, but its still better with a noise color.
SInce pink noise/white noise is wide band, signicantly wider than that of an orchestra and its using this colored noise to demonstrate comb filtering, is it really that much of an issue in everyday HT life? Is it even audible?
 
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shadyJ

Speaker of the House
Ratings
5,159 34 17
#5
SInce pink noise/white noise is wide band, signicantly wider than that of an orchestra and its using this colored noise to demonstrate comb filtering, is it really that much of an issue in everyday HT life? Is it even audible?
Comb filtering can definitely affect the sound quality. Colored noises will make the effects very audible, but they can still be heard with regular content.
 

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