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QRD well width always 50mm ?
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December 17, 2022 - 12:20 pm
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I recently bought the “build plans package” and I can see that the well width is always 50mm wide regardless of what QRD number. Did you come to the conclusion that this is a resonable top frequency limit of diffusion or is there any other limitations that I should keep in mind if going for another well width? I have a listening position that’s 450cm away from the front wall. 50mm’s well width would set the upper limit at ~ 3,5khz and if that’s sufficient there would be no need for me to go forward with a project looking at a 38mm well width (~4,5khz).

Best regards. Bengt Dahlberg

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December 19, 2022 - 6:34 am
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The well width determines the upper limit of the prime number frequency response. A 2″ well width is 3,450 Hz. If you require a higher frequency response limit then you can decrease the width. However, keep in mind that you have to build units where you need to get your fingers inside the wells in order to assemble.

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December 19, 2022 - 12:57 pm
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Thanks for the response. If I require a higher frequency limit was kind of the question. If measurents and objective listening (experience) has lead you to the conclusion that 3,5k is sufficient then be it. No need for complicated builds if there is no real benefit i guess.

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December 19, 2022 - 2:49 pm
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It is best to use the 2″ wide @ 3,450 hz. upper limit. If you desire a higher response, you can add fractals to the 2″ well widths. Fractals are mini diffusers with 1/2″ wide wells.

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December 20, 2022 - 1:53 am
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OK, thanks.

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