Psychoacoustics

Re: Psychoacoustics

Is what you're asking for achievable ?

If there is a noticable delay between the two sounds it's well, noticeable and probably like a slapback sound. Not ideal.

In this specific case the delay will (by definition) be inaudible.

You'll need to get your speakers delayed to within HAAS specifications. This means that one source cannot be more than 10db more than the other so, it may mean that the speaker system must be close in volume to that of the original acoustic source. Is that enough volume for the venue ? Maybe if it's intimate.

10dB in this case is a huge amount of sound. We're talking about peak sound levels of around 85dB @ the mix position.......more reinforcement than amplification. And yes, I would consider this to be both musically and socially "intimate" sound.

But then seating positions will vary distance to the speakers and original acoustic source -part two of HAAS, timing must be under 40ms or so. So getting it right in one spot doesn't mean it's right in another. Then again, intimate venue, maybe.

My .02

Andrew

Textbook says that delay becomes audible as an effect at around 10ms. In my experimentation I begin to notice it a bit around 8ms with 11ms my personal threshhold of "effectiveness". In my application, the delay difference involved between the players position and the secondary (reinforcing) wave is well under 8 ms, most often around 3ms. In my experience with "psycoacoustics" a ms here or there is forgivable. Also please note that within the 10dB window you cite (from Haas) it is not so much the volume of the sound(s) that assigns the "position/presence" to the source but the arrival time. A quieter source arriving prior to a "second wave" will be perceived as the original sound thereby appearing to the listener to come from said original source......and location. This is the desired result.

So if the speakers are 6 feet ahead of the performer(s), a delay time of approximately 8.5ms (5.32ms to get 6' back + 3ms to give the original sound wave perceived precedence) should yield the desired result.

We're dealing with perception here, so straight out measurements take a back seat. As long as the sound is perceived to be emanating from the original source/position, we have achieved the objective. Again I state that in my case I am dealing mainly with acoustic music, jazz and bluegrass......NOT rock.

DR
 
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Re: Psychoacoustics

You'll need to get your speakers delayed to within HAAS specifications. This means that one source cannot be more than 10db more than the other

Andrew
That is one point that is often overlooked.

You cannot simply use delay to force localization or imaging. If you don't have a REFERENCE or source that is of suficient level (in relation to the level of the delayed loudspeaker), all the delay in the world will not force you to believe that the sound is coming from a different location (other than the loudspeaker).

You HAVE to have a direct sound to "lock onto".
 
Re: Psychoacoustics

Ivan....

We posted simultaneously. Please see the post prior to yours for the explanation of my specific case and application.

DR
 
Re: Psychoacoustics

I was going to post yesterday about the relative levels.My thought was to pick a generic listening position and establish the unamplified level at that point and then bring up the reinforced level until the image shifts to the speakers, and then try to push back the image with delay.
 
Re: Psychoacoustics

IIRC there was a pretty comprehensive AES paper on the subject of level vs. delay for localization in the context of a pan in a stereo mix. This paper was a few decades ago and I don't recall which decade, let alone which year. But the truth is out there Muldar...

JR