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<blockquote data-quote="Mark DeArman" data-source="post: 49466" data-attributes="member: 950">Re: Need subs that will do 20hz-40hzA late follow up to the test drive for the McCauley M421.&nbsp; I did take a number of these boxes and measure their response curves with some different microphones.&nbsp; If the 0dB point is taken to be 30Hz they show a -3dB point of 26.5dB and a -6dB point of 24.5.&nbsp; With almost +6dB 0.5 Oct wide at 70Hz.&nbsp; I will enclose the files here.[edit]These were measured at the airport on the ground with a clear 300ft radius in all directions.&nbsp; Each loudspeaker was driven with a channel of a Lab fp14000 so the measurement is actually 4W of input power.&nbsp; No DSP was inline to avoid any AC coupling problems in the low frequency.&nbsp; The SPL was calculated from 30 cycles at each frequency step.&nbsp; The recorded measurement length was set so that at each frequency there would be no bin spill in the FFT which could cause errors in the low frequency.[ATTACH]150279[/ATTACH][ATTACH]150278[/ATTACH]</blockquote>

[QUOTE="Mark DeArman, post: 49466, member: 950"] Re: Need subs that will do 20hz-40hz A late follow up to the test drive for the McCauley M421. I did take a number of these boxes and measure their response curves with some different microphones. If the 0dB point is taken to be 30Hz they show a -3dB point of 26.5dB and a -6dB point of 24.5. With almost +6dB 0.5 Oct wide at 70Hz. I will enclose the files here. [[I]edit[/I]] These were measured at the airport on the ground with a clear 300ft radius in all directions. Each loudspeaker was driven with a channel of a Lab fp14000 so the measurement is actually 4W of input power. No DSP was inline to avoid any AC coupling problems in the low frequency. The SPL was calculated from 30 cycles at each frequency step. The recorded measurement length was set so that at each frequency there would be no bin spill in the FFT which could cause errors in the low frequency. [ATTACH=CONFIG]150279.vB5-legacyid=3319[/ATTACH] [ATTACH]150278.vB5-legacyid=3318[/ATTACH] [/QUOTE]

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