Feedback: Where did the 1 kHz tone come from? (Daniel Rowan )

Subject: Feedback: Where did the 1 kHz tone come from?
From:    Daniel Rowan  <dr(at)ISVR.SOTON.AC.UK>
Date:    Sun, 29 Sep 2002 10:18:08 +0100

Hi list Many thanks to all those who responded to my question. For those interested, here is a summary of the feedback I had: (1) The phenomenon is well documented. (2) The audible f2-f1 DP is unlikely to arise from within the auditory system and is measurable in the room using standard techniques. (3) The most likely sources are (a) transducer distortion and/or (b) non-linearities within the air, producing a DP with a highly position specific amplitude. The latter source has been exploited in commerical audio equipment. The impression I got is that the SPL of the primaries required to produce a significant 1 kHz DP is much higher than implied in the desciption my colleague here originally brought to my attention, which is partly why we initially dismissed the transducer distortion. I had no idea the air was sufficiently non-linear at high SPLs to produce audible intermodulation distortion! Many thanks for all the feedback. Best wishes Daniel ************************************************* Daniel Rowan MSc Research Student Institute of Sound and Vibration Research University of Southampton University Road Southampton SO17 1BJ England, UK Tel: 023 80594968 Email: dr(at) *************************************************

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