Phase Wavelengths Intro

So I was getting reasdy for my seminar here in Mexico city. About an hour before and I find that the graphics were mislabeled. Particularly problem was the one that had the wrong autocad backrground – the acoustical cancelled where the phase lines showed IN PHASE. OOOPPPPPPPs. Sorry. Should be fixed now.

So I got ahead of myself with last post, showing some of the eartly results of my latest venture: phase mapping to help predict and understand speaker array behavior. I have been very and soon some of the data will show up here. But first an introduction to the basic item driving this: wavelength. What we will using here are concentric circles, scaled to wavelength – and MOST importantly adjusted for phase delay. When you have a single speaker you will see concentric circles coming outward from it (by see it i mean HERE) – if you see these at a job, consult a physician.    The circles are scaled to wavelength. If you place another speaker it has its own set of circles.  Where they meet – they are in phase – when they are half a wave apart – they are 180 degrees out. 

So I have now a library of 48 sets of circles scaled to 125 Hz. They can then be rescaled to other freqs.   Now we can start to put them to use…………….

Now here is where it gets rough. When you delay a speaker we know it changes the places in the room where we add and cancel. But how can we see that?  Delay does NOT move the center of the speaker’s radiation. Nor does it change the size of the wavelength. What it does is modify where the race starts from, by elapsing PART of the wavelength electronically. The rings show the distance required to turn 360 degrees (1 wave). It we delay it 180 degrees, we have a head start. The 1st cycle is completed in half the physical distance. From then on it continues to turn at the regular rate – but that head start changes where in the room cycles match.  It is late here – this is again just a preview……………..

So I have now a library of 48 sets of circles scaled to 125 Hz. They can then be rescaled to other freqs.   Now we can start to put them to use…………….

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