In Reply to: RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics posted by Satie on March 2, 2017 at 11:42:08:
I didn't try them further back because the woofers were in the way, but I did try another angle in an attempt to minimize sidewall reflections. It didn't work as well for reasons I don't know. I think the next step is to experiment nore systematically, beginning with MGbert's ray tracing diagram, but of course I'll have to figure out how to accommodate the woofer panels.
Extension of the board behind the MT panel -- I'm guessing the more the merrier because at lower frequencies you're going to get diffraction so the barrier will be effective only when it's large compared to the wavelength. I just had them extended sufficiently to completely block the reflection of the panels in the mirror, so a few inches beyond the actual driver.
Extension of the board in front of the panel -- if you look at the photo from the listening seat, you can see that they were extending in front for the RFZ experiment they didn't occlude the drivers at all. For that purpose, flush with the front would presumably be better because you wouldn't get diffraction at the proximate edge.
In the parallax barrier experiment, I had the boards positioned so that I could see the tweeter with the proximate eye but not the distal one. One of the reasons it may not have worked as well as MGBert's setup is that he was using MMG's, which have a lower XO to the tweeter -- my barriers were only effective from 3 kHz up. Interesting about the effect of the sidewalls. Mine are both irregular and reflective, not sure how to characterize them.
Why did you give up on your barrier? I still have some other options -- Fresnel reflector (which however is a major production), polycylindrical diffusors (but again, that's a major production since to preserve the window, I'd need to bend Plexiglas), and of course the QRD's. Or I could just move to somewhere with a bigger listening room. :-|
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Follow Ups
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 13:16:49 03/02/17 (11)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - st.chelvam@gmail.com 19:05:55 03/02/17 (10)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 04:56:01 03/03/17 (9)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - STC 01:51:36 03/04/17 (8)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 06:42:20 03/04/17 (7)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - STC 18:57:10 03/05/17 (5)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 20:10:27 03/05/17 (4)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - STC 16:49:33 03/07/17 (3)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 18:36:56 03/07/17 (2)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - STC 18:59:58 03/07/17 (1)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - josh358 05:32:40 03/08/17 (0)
- RE: Another First Reflection Trap (FRT) Adventure : Quasi-Ambiophonics - STC 07:15:16 03/04/17 (0)