I don't think Dave was saying that the only effect of dipoles was the front wall reflection and its presence would automatically make all music sound like that. Maybe I need to reread, but I certainly don't think that's what he meant. I think he was just showing what that front reflection does to the sound wave. I'd actually be interested in hearing a swept sine wave instead of the pink noise. That's an effect I'm very familiar with using dipoles for measurements and it's easily audible as a comb in room. With music, I can't say I've heard it to be honest. Deward might say I was deaf however.
I really think 90% of the issues I had with dipoles had to do with my design--the familiar polar response bubble seen with the Orion. I was unable to really toe my speakers in or the tonal balance was just terrible and extremely bright--Dave is right on with that. A narrow bass pattern with a broad upper mid response would seem reasonable that is might sound bright and with a vague image, but incredibly spacious. Sometimes that sounded like extreme detail and it was great. Mostly it just stunk and actually always sounded a little thin even though the bass is smoother. My guess is that's just the polar/power response. In a larger room and better pattern with front wall treatment, it would seem reasonable that performance could be improved. Or remove the front wall like Pano did. Of course in a large room, the dipole bass will require more money to work well.
All in perspective,
Dan
I really think 90% of the issues I had with dipoles had to do with my design--the familiar polar response bubble seen with the Orion. I was unable to really toe my speakers in or the tonal balance was just terrible and extremely bright--Dave is right on with that. A narrow bass pattern with a broad upper mid response would seem reasonable that is might sound bright and with a vague image, but incredibly spacious. Sometimes that sounded like extreme detail and it was great. Mostly it just stunk and actually always sounded a little thin even though the bass is smoother. My guess is that's just the polar/power response. In a larger room and better pattern with front wall treatment, it would seem reasonable that performance could be improved. Or remove the front wall like Pano did. Of course in a large room, the dipole bass will require more money to work well.
All in perspective,
Dan
Far enough apart that they were viewed as distinct elements with neither influencing the other, rather than being perceived as a single source with with a comb filtered combined response.
Even with my stereo pair of speakers 50 degrees apart I hear comb filtering between them if I shift off the center line. They are not independent speakers with no influence on each other as long as the signals between them are correlated.
It is a common observation of trials of sources and reflections that with a source in the front and reflection to the side the effect is of source widening or increase is a sense of space (depends on delays, etc.). With both sources to the front the perception is one of change of response.
David S.
I think just about any front of house engineer can tell you this. It's a common effect. The more you turn it up, the more you hear the room.
The same effect can be heard in small rooms that are untreated. It's not hard to hear. Talk softly or shout.
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Frank, we are simply not on the same page, so I will leave it at that.
BTW, I had seen that conference report by Geddes. I am afraid that I stopped reading when he confused the terms non-linearity and distortion. In my book, a physicist would never use the term "linear distortion". In fact I was confused that he would do that. But that's another topic (or not).
I don't have a lot of experience with amplification in commercial venues. I first noticed the effect with unamplified powerful singers in smallish or highly reverberant rooms. It was not pleasant, as it would actually stimulate ear's self distortion: The elves, Snap, Crackle, and Pop would present themselves.
Not likely . . . there is, so far, insufficient information to make that determination.
But I certainly wouldn't say you are deaf simply because you can't hear something that doesn't exist . . .
A "distinct elements with neither influencing the other" would be an echo. 30-50ms or more. Everything below 2ms is direct sound. Everything in between can be anything from image broadening, added spaciousness, timbral change or masking. Looking at a single reflection in isolation is of great interest in psychoacoustics but it doesn't reveal what is happening when listening to speakers in acoustically small rooms.
Hi Frank
My only caution would be to point out that our study was limited to very small time delays, well within the fusion zone, and I am not sure that your comments would still be correct for longer delay times. We just did not do that study.
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I must admit, though (with a nod to Dave and Dan), that when listening to conversation at a coctail party the people standing 5 feet from a wall do sound a little . . . "hollow" . . . (and I can't be the only one to have noticed this effect . . .) . . .
What's the date today ? ? ? Oh, wait . . .
What's the date today ? ? ? Oh, wait . . .
My terminology is precisely correct. Even Toole uses the term "linear distortion". I never get the terms "nonlinearity" and "distortion" mixed up - they are different things. I am affraid that it is your position that "distortion" means "nonlinear" that is the incorrect one. Have you read Toole? He uses these terms in precisely this same manner.
A linear filter "distorts" the waveform. Group delay "distorts" the waveform, but both are none-the-less linear. I would have prefered that "distortion" meant "nonlinear", to me that used to be true, but it has evolved that this is not true any longer. In any publication before the AES you must distinctly note whether the "distortion" is "linear" or "nonlinear". That's simply a fact of life in the business today.
So go back and finish reading the paper. You might learn something.
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Parameters can now be quite similar to Earl's recommendations, ie with high frequency gating at 8ms, WE=1, low F gating 150ms :
no, just download the soft http://www.ohl.to/audio/downloads/align2.zip
You get the octave scripts in the files directory.
To use the soft, you'll have to install octave (similar to Mathlab but free, scripts are mostly compatible between both), see link in the help.
And then you can adapt the script to your needs if basic parameters in Align2 are not ideal for you. I also added one "custom" display so anybody can add its own script and calculations on impulse responses (ie for Elias to add his gammatone wavelet 😉
I know I'm not the best to write comprehensive help files (my softs are mostly for my own needs) so everybody can ask if there are problems of install or use.
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Yesterday, I reconfigured my system so I could give "ambiophonics" a test drive, and after a couple of hours, had it dialed in enough to make a judgement about it and (by comparison) typical stereo reproduction.
And my conclusion(s)? Stereo reproduction is so flawed that the debate about spaciousness and front walls is just plain superfluous when you have an 800lb gorilla (stereo presentation) sitting in the room with you. To be fair, ambiophonics has its own set of warts that can't be made over - physics won't allow it. But in comparison, arguing the subtleties of speaker placement in a traditional stereo set up is truly like trying to put lipstick on a pig (or gorilla, in this example). Well recorded and simply miked acoustic music listened to in ambiophonics can be a jaw dropping experience, and has made me rethink what direction I'll be taking in terms of speaker design.
It makes the whole "is flat correct?" debate seem pretty trivial.
...just my opinion.
...god am I hung over.
And my conclusion(s)? Stereo reproduction is so flawed that the debate about spaciousness and front walls is just plain superfluous when you have an 800lb gorilla (stereo presentation) sitting in the room with you. To be fair, ambiophonics has its own set of warts that can't be made over - physics won't allow it. But in comparison, arguing the subtleties of speaker placement in a traditional stereo set up is truly like trying to put lipstick on a pig (or gorilla, in this example). Well recorded and simply miked acoustic music listened to in ambiophonics can be a jaw dropping experience, and has made me rethink what direction I'll be taking in terms of speaker design.
It makes the whole "is flat correct?" debate seem pretty trivial.
...just my opinion.
...god am I hung over.
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