Originally Posted by Ethan Winer
Thank you, and this is why I asked (honestly) what the difference is between what Amir posts and what a typical forum troll posts out of boredom.
Well, I extend my apology to you for tiring your eyes with my posts Ethan. I am happy to answer your question since you honestly want to know.
Let's take the topic at hand, and your post specifically. You put up that graph above as to say, "look, you need one of my products. Don't you see it causes these peaks and valleys you want to fix?" I must say, it is quite clever. Unfortunately the science is not what it seems:
1. You show a microphone and what a computer is analyzing. You are asking us to examine it with our eyes, not ears. Same as what people do with expensive cables by the way
2. If we look at what the ears hear, we have to start with the fact that two signals arrive. One for each ear. Why would you represent that with one microphone?
3. The right ear hears the reflections from the right wall directly. The left ear however, hears it after your head which is in the way filters it. Put your hands loosely on ears and notice how the sound becomes muffled. Same thing happens with your head in that some of the high frequencies are filtered. So spectrally the two ears are hearing very different signals. Again, this is not reflected on your single microphone measurement devoid of the effect of the head (so called Head-Related Transfer Function or HRTF).
4. Your ears are separated by some distance. So the combination of direct and reflection that the right ear hears, is NOT the same combination that the left ear hears. The reflection has farther to travel for the ear not facing the reflection. When you change the timing, the comb filtering changes since the phase of the indirect waveform changes and hence, the cancellation and additions occur differently. Again, your single microphone setup doesn’t show this at all.
5. There is not just one reflection in the room. The sound hits all the surfaces multiple times and keeps coming back. So in reality, we are talking about many signals summing and subtracting. This tends to fill in the valleys.
6. In real life, we hear these reflections all the time. We are indoors predominantly. The brain has an adaptive mechanism that lets it separate constant transformation that the room applies (if we are stationary) versus the dynamic changing nature of the content you play. It takes differing signals that arrive in each ear per above and sums them to a signal that is mostly devoid of the variations above. It performs non-intuitive things like giving more priority to faint reflections. Net, net, the brain has a very significant role here. There is no way you can expect the typical person reading a forum post or your graph to be aware of all of these factors and take them into account as they look at that graph.
7. If you are playing multi-channel music and movies, dialed in them is ambient information. Research shows that these cues overwhelm fair amount of room reflections. Indeed, our ability to hear artifacts in general goes down as the number of channels increases.
And it is not just me saying these things. Our virtual resident expert, Dr. Toole says it too:” * In double-blind listening tests where listeners compare music with and without side-wall reflections, the results consistently indicate a preference for the reflections.
* Listeners given the opportunity to adjust the sound level of the reflection to maximize "preference" choose levels that are above the levels of the natural room reflections.
* BUT -- this relies on the speakers and wall surfaces that yield direct and reflected sounds that are similar in spectrum.”
He then says pros recording things tend to be more sensitive to reflections.
That aside, whatever negative attribute is left from comb filtering and side-reflections, there appears to be strong positives perceptually, none of which is evident from your graphs, web site, or forum posts. I think that is a problem worthy of discussion.
You are a man who always demands objective proof for audio claims. Yet, you put up that graph on your site to convince people this is a problem when proper science and double blind testing indicates otherwise.
Now it is OK for experts to disagree. It is our job then as readers to decide who has proven their case better. So if you don’t mind, it would be great in your next post to read the results of double blind tests you have run and published that point to efficacy of getting rid of side-reflections/comb-filtering. I also appreciate hearing how your knowledge of psychoacoustics supersedes the work of others above.
I'm mostly retired, yet I don't have even 1/10th the time to spend posting as Amir apparently does.
Please Ethan. Don’t go there
. You post on countless forums. I only post on two and right now on AVS, this one thread only. Yes, I love to interact with like-minded people. I like to see my understanding challenged so that I can see if I can prove them (if not, then I don’t know them well enough and go back to study some more). What I don’t like to hear is another forum addict telling me he is more sober than me.
I truly don't understand what Amir objects to in these (many) threads, or why feels he must "correct" various "misinformation" he believes he sees. It's like, "Dude, exactly what is your point?"
Please see above. And thanks in advance
And I'm still waiting to see waterfalls and/or RT60 plots of a typical home-size room that would not be improved by adding acoustic treatment.
Can you please point to relevance of RT60 in our home listening environment? BTW, I did address the rest of that point the last time you asked that