GoodSoundClub - Romy the Cat's Audio Site

Rerurn to Romy the Cat's Site

In the Forum: Horn-Loaded Speakers
In the Thread: If you were to start from scratch, what horn system would you build?

Post Subject: From psychoacoustical point of viewPosted by haralanov on: 2/15/2012

My primary interests (when I do purely technical listening) are in the field of psychoacoustics and the last 2 years I spent a lot of time investigating how the brain reacts to differently arranged sound sources. The interesting thing is that the ear prefers slightly asymmetric arrangement when there are two symmetric sources of sound in context of a third. That means if your/my midrange driver is in the center of a virtual clock, the upperbass channels should not be positioned at 6 and 12 o’clock, but they should point at 7 and 1 o’clock. This way they totally disappear for the brain, not drawing attention to themselves. But if there is only one upperbass channel, the situation is quite different – it should be positioned strictly on the vertical axis, at 6 o’clock (in the way you use it in your Macondo). With four upper bass channels, the situation is different again. In this case the brain does not recognize the upper/lower pair of horns as horizontal sound sources, but it treats each of them in context of the midrange channel and in the same time it creates mental picture of the whole their sound. And because there are another two upper bass drivers/horns below the midrange channel, they destroy the illusion there are 2 horizontally arranged sound sources over the midrange channel, because the brain accepts the sound of the 4 drivers as a sound that is coming from one very large round driver with build in MF channel in its center. In the same way the upper 2 sound sources destroy the illusion there are 2 horizontally arranged sound sources under the MF channel. In the moment when you remove either the upper or lower 2 drivers, the brain will automatically recognize the remaining two as a horizontal source of sound…

So it’s quite complex, but once one gets the whole picture, he can very easily arrange his channels in the smartest possible way, completely fooling his brain there is more than one source of sound (his main/midrange channel) in his acoustic system. In order to get the effect of completely fooling the brain, there should be two HF sources, which are symmetrically asymmetrical (it is not nonsense) in context of the main channel (again at 1 and 7 o’clock for the left side of the acoustic system and at 11 and 5 o'clock for the right side)… It is so convincing, that they do not draw attention to themselves even if the entire left or right stereo channel is turned off (!).

And there is one thing for sure - the ear/brain does not like when there are sound sources in the horizontal plane from the left and right side of the midrange channel. It immediately detects them, burning a lot of "processing power" to neutralize the devastating psyhoacoustical effect of their wrong position and the whole convincing illusion of realistic and super coherent sound source becomes totally fucked up because of that (cheers Goto users :-))…

I agree the using of huge midbass horns in the way I illustrated requires quite a big/wide listening room, but the thread is named “building a HORN system from scratch”, that’s why I showed how I would build a full horn loaded system if I have to build it. IF I had to build it, I would not start such an oversized project without first building a huge dedicated room…

Best regards,
P. Haralanov

Rerurn to Romy the Cat's Site