Axiom Home Page Forums General Discussion Technical Questions From HT Shack a question maybe for Ian or Alan

SolidState,

I found your quote from Winston Churchill quite apropos. The question is; are you going to begin to accept the truth or are you going to hurry off? The comb filtering you are talking about is in fact a measurement artifact that at worst is not audible and at best is something two ears and a brain quite like. You could start to enlighten yourself by reading "Comb Filtering -- Popular Misconceptions" in our May '09 Axiom AudioFile newsletter:

http://www.axiomaudio.com/archives/may2009.html#feature

If you find comb filtering to be a problem, why are you listening in stereo or multi-channel? You would need to listen to everything in mono to avoid this artifact. To put an even finer point on it; even if you could hear this artifact it would manifest itself in a cancellation of higher frequencies; less high frequency information would not equal more sibilance. Comb filtering measured with a microphone never adds information.

At Axiom we do not produce new models for the sake of having something new. We prefer to continuously improve the models we have, which produces much better results for our customers’ listening experiences. Besides the plethora of improvements we have made to our various models over the past decade we have also introduced the EP500, EP600, EP400, EP800, A1400, Audiobytes, the entire W series, the entire T series, and more. Just another truth for you to either accept or hurry off about.

To sum up: Comb filtering is a measurement artifact of stereo listening. It's always occurring, and our brain and ears ignore the combing effects that are easily measured by a microphone. A brain and two ears are not a microphone. Our research at Axiom and that of many world authorities show that comb filtering is not detrimental to accurate loudspeaker sound reproduction; at worst, it’s irrelevant, at best it actually adds a pleasurable element of spaciousness to stereo and surround sound.

Alan Lofft

Hi kuro,

While combing effects are easily heard using a pink-noise test signal (and are measureable), they are not significant or audible with music or soundtrack playback.

Moreoever, any speaker or two speakers produce comb-filtering effects. Try it with one speaker and pink noise. As you move your head slightly to one side or the other--only a few inches are necessary-- the arrival times of sounds to each of your ears change as your head changes position and the distance from the speaker driver to each ear changes, resulting in audible comb-filtering effects. You'll hear the high-frequency content alternately increase and decrease because of cancellation and reinforcement.

The notion of time-coherency when put to the test under controlled listening conditions is a lot of high-end blather not based on scientifically controlled listening tests.

It simply doesn't matter with music or soundtrack playback. If we were all ultra-sensitive to combing effects with musical playback from loudspeakers, we'd all be complaining. It would be intolerable.

Regards,

Either way, you cannot lose if choosing between Paradigm and Axiom. They are both excellent companies which make well engineered speakers.
Cheers,
JJ