In Reply to: RE: Questions for JA on the "sound" of truly "time-aligned" speakers with perfect step response posted by Charles Hansen on September 28, 2017 at 19:20:26:
9/29/2017
Hi Charlie and all,
These are great topics!
It's a bit unclear if the OP actually wants to know about "time-aligned" speakers, or "phase-coherent" crossovers, or what. He asked multiple questions. They are not all the same thing. So, we're all just kinda going from there. And, the thread went a bit cock-eyed - getting into "room correction". So, I'm just going to "go with the flow."
Charlie, I'm not directing this reply to you, but rather, to the many audiophiles and "semi-pros" who read this thread. I'm just trying to follow the thread path.
Many of these folks haven't ever even read a book or scientific paper on the topic.
So, anyway...
You CAN'T fix a room's sound with EQ. EQ can only change what's put into it.
You CAN improve a speaker's frequency response with EQ.
You CAN'T fix a speaker's ringing or decay characteristics with EQ.
You CAN improve a speaker's phase characteristics.
You CAN screw up the phase relationships among the harmonics of a sound so that the waveform looks completely different, but you probably won't hear a difference.
All of this is in the professional literature, from at least the 1940s through the present day. It's been studied six ways to Sunday over and over.
In a nutshell, we humans are quite sensitive to differences in amplitude. We're also fairly sensitive to differences in frequency. We are NOT very sensitive to differences in phase between/among harmonically-related tones. We are sensitive to dissonance between two frequencies.
With regard to your comment about ear training, that is very true! We often "don't know" until it's put right in front of our face/ears. A perfect example for audiophiles and musicians is mastering engineer Bob Ludwig's presentation at the AES in 2014. He started with a very compressed / lossy sound clip which obviously didn't sound good and the initial transients of sounds were clipped, and then played progressively less compressed clips. By the 4th sound clip, we could still hear the artifacts of the lossy compression, even though, without knowing what to listen for, we might not have noticed it previously. Yes, ear/brain training/awareness is important for critical listening!
In this light, I'll re-visit comments from other knowledgeable posters:
:)
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Dave K wrote:
I've tried correction of the in-room response, and the results were bad. I've also tried correction above 200 Hz based on a gated outdoor measurement, and the results were better than stock in some ways, worse in some ways, but not a conclusive improvement.
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bwaslo wrote:
Phase correcting room effects is doomed to failure, you can only do it on the direct response from a speaker.
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Dave K wrote:
What surprised me a little bit was that doing an impulse response correction based on a time gated pseudo-anechoic measurement didn't necessarily improve things.
So I'm mostly just curious what you think is a best practice when it comes to correcting a passive loudspeaker via DSP.
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bwaslo wrote:
I can't say that the phase correction makes much of a difference to me, sometimes I think I can hear it, other times not.
Sighted test, identified which was being used. A little over a third of the members though they sounded different,
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Inmate51 comment:
Even though the listeners knew which setting was used, only ONE THIRD of them were confident that they heard a difference. I suspect that that percentage would go down significantly if they didn't know which setting was being used.
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Charles Hansen wrote:
there are also plenty of other brands that people like well enough to buy that are definitely *not* "phase coherent".
On the other hand, it may just be a case of ear-training.
each person's hearing sensitivity varies as does their preference for the importance of specific parameters.
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Inmate51 comment:
Ear training is definitely essential to being aware of a wide variety of audio characteristics. As a classically trained musician, don't even get me started. Good recording and mixing engineers also understand various aspects of a sound.
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Inmate51 comment:
EQ'ing a sound system for desirable sound quality in many parts of the listening area works pretty well outdoors and in large rooms such as churches, auditoriums, and arenas. But EQ'ing in a small room, such as a home living room or home theater is an exercise in futility, because the room plays such an important role at all frequencies - largely because of the density of reflections and the way our hearing interprets the received sound.
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I may have made a mistake or left something out. Feel free to tell me.
:)
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Follow Ups
- Perception of Sound - Inmate51 21:12:29 09/29/17 (5)
- RE: Perception of Sound - Dave_K 13:43:01 10/01/17 (2)
- RE: Perception of Sound - Inmate51 15:29:52 10/01/17 (1)
- RE: Perception of Sound - Inmate51 11:55:28 10/13/17 (0)
- RE: Perception of Sound - fantja 04:52:26 09/30/17 (1)
- RE: Perception of Sound - Inmate51 06:03:45 09/30/17 (0)