Parametric speakers? What do we think?

[markeebee]

Ok, amp thing rather than stompbox.  Forgive me.

They have these parametric speaker arrays at the petrol station I use.  While you're standing at the pump, they play you some awful local radio station.  Take half a step to one side.....you can't hear a thing.  Nothing.  It's like magic.

So, I was wondering whether it might be possible to use them in an amp for home use.  Like, if you stand directly in front you get some trouser-flapping riffage, but everybody in the house/apartment/bathroom who is outside of the sound beam can't hear a thing.

Here's an article:

http://www.proavmagazine.com/audiovisual-equipment/can-you-hear-me-now.aspx

And here's a vendor of kits, with a schematic and layout for the requisite modulator:

http://zao.jp/radio/parametric/index_e.php


I was thinking of adding this to the ever-expanding list of projects to get around to sometime, unless anybody can advise against.

Any thoughts?

[newfish]

That's a cracking idea.

Similar concept to the 'sonic weaponary' thing I reckon.

Would be *very* useful for late-night practice.

[Mark Hammer]

First, when I think of how many thousands of words I have read over the years about the many brilliant ways people have devised to improve dispersion in speakers, and the many different things folks have done (e.g., the Visual Sound "hubcaps", rounded corners on cabinets, the BOSE 901 approach to using more speakers for reflecting than for direct, etc.), it is downright funny to think of people working on speakers that deliberately do NOT disperse.

Second, some form of that would be kind of cool for speakers at work.

Third, I can't see much application to the live rock context, though one might imagine its possible role in more artsy installations, where changing the orientation of what you are looking at - perhaps by turning your body 40 degrees - would change what you hear.

Fourth, I'm not seeing any immediate use for loud music listening or playing, simply because we don't see enough capacity for air movement in those arrays.

[petemoore]

  Vague descriptions always bother me, that and/or vague interpretations...ie maybe I'm missing something.
  Seems like the wave is being added to as it goes 'down the chute', shooting the wave in a way that makes it not disperse like...waves always dispersed.
  Assuming it is possible [just for discussion...assuming it is impossible might be as good a starting point]...it just seems that a 'shot-wave' that shoots past where normal waves would disperse [when leaving the waveguide or whatever else, front of a cabinet], would be noticably more 'intense' and 'hard' [like when waveguides are used to help 'project' HF's [or mids, or lows].
  Intense and hard [assuming on assumptions already] might not be bad either, then soft and spongy distortion might be a good match.
  Only thing is it sounds expensive and new. Expensive might even be ok if new was understandably and signifigantly 'improved' in actual use. New might even be ok if after 10 years 'new' still works and is in actual use.
  Or, you get to risk the expense and newness of the design [trying out new type speakers with guitars tended to be one of the quickest ways to find the weak spot in a speaker design], understanding the long-goings or shortcomings of the basic or modified design before anyone else.