Excellent work Matthias. And good, astute observations!
I haven't published any specs for these "winged" rigs yet, but over
the last few months I've begun to narrow down my thinking about
dimensions that seem to deliver the best results -- at least to my
ear. At this time, I tend to favor mic spacing of about 5" (12.5 - 13
cm); vertical and horizontal "wing" boundaries should probably be the
same as each other at about 2 - 2.5" (5 - 6 cm) (and there seems to be
no need for the 45-degree cuts at the leading edge of the vertical
boundaries); a setback distance from the leading edge of about 2" (5
cm) seems to work nicely for mics approximately the diameter of MKH
8020 and AT3032/AT4022.
Note: Be sure to mount your mics tightly into the intersection of the
vertical and horizontal boundaries (your photos show them some
distance away due to your mounting hardware... you need to get them
right down there next to the boundaries).
Finally, these rigs have a definite upward orientation. That would
explain the increased room verb in your test. Assuming yours was
stationed horizontally for this test, it would have been picking up
many more reflections off the ceiling than the PBB array. Tipping the
rig forward will usually orient its main focus more directly on the
desired sound sources.
Thanks again for your hard work and insightful testing,
Curt Olson
PS: I should probably add these comments to my web page soon, along
with photos of a more recent rig.
Matthias Eberl wrote:
> 1. Comparison of Winged Olson Rig and PBBA with two Sennheiser MKH
> 8020
> Posted by: "Matthias Eberl"
> Date: Wed Feb 23, 2011 9:01 am ((PST))
>
> Finally the Sennheiser Stereo Set arrived and I was able to build
> two stereo rigs. I made a
> simple test setup in a quiet room, here is a audio slideshow showing
> the results:
>
> http://rufposten.de/daten/stereo_test_feb_2011/
>
> Some thoughts:
>
> - When using speakers for playback, the PBBA delivers a more
> detailed imagination of the
> outer positions as the Olson Rig. When using headphones, the olson
> rig was more accurate.
> - The Olson Rig moves everything more to the center, which is
> audible especially in the direct
> comparison.
> - The recordings with the Olson Rig have more reverb, wich is
> probably increased because
> the room walls were parallel to the boundaries. So the room is more
> present, what I definitly
> like. This effect is overdone by a offset of 6cm (2.4") to the front
> tough.
> - Both rigs outperform the simple stereo setup of the R=F8de NT4 by far.
>
> That's all my untrained ear could hear. Would love to read your
> comments.
>
> (A discreet rumbling on some recordings stems from the passing
> tramway. )
>
> Matthias
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