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Xenon · 27th September 2009

6 N23 arrays built now.

I am adding to the original page of photos (post #55). (Direct link here.) I'll add shots of the N19 later, and units, installed. I have a copy of REQ and hope to get room measurements, prior/post installation.

If we did this again we'd change the frame design to include all wells, and still have the first and last cover left/right frame members. We are able to cut up to @ 0.5mm accuracy on the table saw, at the limit -- 1.0mm is more reasonable using a metal T-square.

An important point: We needed to add 0.6mm for each well-segment to the length, for actual fit. So our total length is 13.2mm over theoretical. We had to adapt the frames a bit. We no longer need bar clamps -- a brick inside keeps things in place. It takes about 2 hours to fill a frame, and perhaps 45 minutes to face it (with everything pre-cut). And a lot of glue.

The fronts are pretty, the depths accurate to about 1mm. We don't have a scale but an array is easily picked up. 8-9kg (17-20lbs.)? Questions, suggestions?

* Note to Collo -- your post #19 presents an elegant solution using N17/I17. I didn't choose it for two reasons. First, those frames are small at 72.25cm (extra work, time and cost building smaller frames). Though it's possible to put 1.5 periods in a frame, just not so easy (or modular). The second issue is how well 5 periods are going to perform in a small room, say compared with the N23/N19 combination. I felt that, with a short mic-to-diffusor distance, individual (and neighboring) arrays might have a greater effect, as there isn't room for a wavefront from the entire array to cohere before hitting side walls, absorption, and what-have you. I leaned toward the possibility of higher resolution (a more polar pattern, possibly) with the N23/N19. This is just intuition or a whim, as I have nothing more to go on. From my reading, it seems that, short of actual trials and room measurements, a 'best' solution is unclear. And there is a limiting factor in that the room is rather small to begin with (not ideal). Our main goal has been to create a sense of a larger space, better micing than with a flat/absorber wall, and to balance absorption with diffusion so as not to create too dead a space. Diffusion arrays in small rooms -- hmmm.

27th September 2009	#58
Xenon Gear nut Joined: Jul 2008 Location: Japan Posts: 77 Thread Starter	6 N23 arrays built now. I am adding to the original page of photos (post #55). (Direct link here.) I'll add shots of the N19 later, and units, installed. I have a copy of REQ and hope to get room measurements, prior/post installation. If we did this again we'd change the frame design to include all wells, and still have the first and last cover left/right frame members. We are able to cut up to @ 0.5mm accuracy on the table saw, at the limit -- 1.0mm is more reasonable using a metal T-square. An important point: We needed to add 0.6mm for each well-segment to the length, for actual fit. So our total length is 13.2mm over theoretical. We had to adapt the frames a bit. We no longer need bar clamps -- a brick inside keeps things in place. It takes about 2 hours to fill a frame, and perhaps 45 minutes to face it (with everything pre-cut). And a lot of glue. The fronts are pretty, the depths accurate to about 1mm. We don't have a scale but an array is easily picked up. 8-9kg (17-20lbs.)? Questions, suggestions? * Note to Collo -- your post #19 presents an elegant solution using N17/I17. I didn't choose it for two reasons. First, those frames are small at 72.25cm (extra work, time and cost building smaller frames). Though it's possible to put 1.5 periods in a frame, just not so easy (or modular). The second issue is how well 5 periods are going to perform in a small room, say compared with the N23/N19 combination. I felt that, with a short mic-to-diffusor distance, individual (and neighboring) arrays might have a greater effect, as there isn't room for a wavefront from the entire array to cohere before hitting side walls, absorption, and what-have you. I leaned toward the possibility of higher resolution (a more polar pattern, possibly) with the N23/N19. This is just intuition or a whim, as I have nothing more to go on. From my reading, it seems that, short of actual trials and room measurements, a 'best' solution is unclear. And there is a limiting factor in that the room is rather small to begin with (not ideal). Our main goal has been to create a sense of a larger space, better micing than with a flat/absorber wall, and to balance absorption with diffusion so as not to create too dead a space. Diffusion arrays in small rooms -- hmmm.