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<blockquote data-quote="Jay Barracato" data-source="post: 92334" data-attributes="member: 24">Re: Cardioid Subs in a Smaller venue.A pair of point sources work perfectly in simulation because the simulation is written to work perfectly with a pair of point sources.Since no real source is a point source that argument doesn&#039;t go far. A number of years ago (2010?) someone did an experiment that lead to a fairly extensive discussion on the SynAudCom list about this phenonema. Once again, if two drivers are close enough to do work on the same air but are out of polarity (i.e. one driver pushes on the air while the other pulls), the net transfer of work to the air approaches zero, the impedence of each driver drastically drops, and the energy put into the driver by the amp is mostly converted to heat. At high levels this can rapidly burn up drivers which is why I proposed it as a thought problem and said don&#039;t do this for real. If I recall the original discussion, when the phenomena was first discussed, a wave property argument was proposed but that did not hold up to close analysis. Then the more engineering minded folks proposed the change in impedence argument. On the other hand, my background is more pure science than engineering, so I approached the problem as a conservation of energy problem, which lead to the explanation based on work that I have given.If there is no need for a barrier or a larger physical separation, then you should be able to set up the classic three box array with all three drivers facing forward with appropriate delay and polarity. Practical experience shows this doesn&#039;t work; hence, the search for a deeper understanding.</blockquote>

[QUOTE="Jay Barracato, post: 92334, member: 24"] Re: Cardioid Subs in a Smaller venue. A pair of point sources work perfectly in simulation because the simulation is written to work perfectly with a pair of point sources. Since no real source is a point source that argument doesn't go far. A number of years ago (2010?) someone did an experiment that lead to a fairly extensive discussion on the SynAudCom list about this phenonema. Once again, if two drivers are close enough to do work on the same air but are out of polarity (i.e. one driver pushes on the air while the other pulls), the net transfer of work to the air approaches zero, the impedence of each driver drastically drops, and the energy put into the driver by the amp is mostly converted to heat. At high levels this can rapidly burn up drivers which is why I proposed it as a thought problem and said don't do this for real. If I recall the original discussion, when the phenomena was first discussed, a wave property argument was proposed but that did not hold up to close analysis. Then the more engineering minded folks proposed the change in impedence argument. On the other hand, my background is more pure science than engineering, so I approached the problem as a conservation of energy problem, which lead to the explanation based on work that I have given. If there is no need for a barrier or a larger physical separation, then you should be able to set up the classic three box array with all three drivers facing forward with appropriate delay and polarity. Practical experience shows this doesn't work; hence, the search for a deeper understanding. [/QUOTE]

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