Modifying sjoko gobo design

[baadc0de]

So, some time ago I've poked John about a gobo design and he linked me this one he did for Sjoko:
http://www.johnlsayers.com/Studio/Image ... /sjoko.pdf

In studying the design I noticed that the original purpose is drum gobos and that they are designed to be wide instead of tall. I'm looking for a general gobo that I can use mainly to isolate vocals and other standing instruments like brass from the rest of the room / noise / musicians. What (apart from rotating the trap) would I need to do to modify this trap for general usage? Or is this already general usage and there is no difference (aside from orientation) from a drums gobo to a generic gobo?

I have also asked a local acoustics expert on this specific gobo plan and he has the following to say:
- the reflective side is "unhealthy" and diffusion would be more appropriate there
- what's the worth of the slot resonator if a slab of rockwool would absorb the same

So take these with a grain of salt, I'm just a hack who'd like to have some well made, relatively cheap gobos and I and my friends can DIY them from plans, however I have no idea about acoustics and as such can't value and compare plans appropriately.

Thanks in advance,
B.

[gullfo]

the reflective side - using a slat panel for example - is different in terms of absorption range and support for HF. most times you make gobos with one absorptive and one "live" side so you can change them around. a packing blanket toss over the gobo when you need to dampen the live sides. standing vertically - make sure it is stable - ie. a good sturdy base to prevent tipping. they can be very heavy and you don't want them falling over on people or equipment. a window is also an option to allow people to see through it...

[baadc0de]

I'm sorry if I presented the question wrongly, maybe this would be more clear: "Why use slot panels (absorption) on the 'live' side instead of diffusion?"

Sure, the trap needs to be stable. So, the design is good to go as is, just rotate the trap (I can easily manufacture 2m x 1.4m gobos with the larger dimension being height ofcourse). The slats would be made horizontal in this case, I assume? Should the slats arrangement be changed for other instruments, i.e. vocals, brass - usually not drums.

[gullfo]

the slats provide a hard surface and absorption. they are somewhat diffuse. you could make the slots vertical, angled, or horizontal. you wouldn't necessarily target a specific instrument - more looking for broadband effects. you could also make something like the MyDesign where you have diffuser / absorbers over broadband (or just plain old absorption).

[baadc0de]

Wow gulfo, this looks nice.

It looks very very similar to how the room walls were treated by the MyRoom technique in Serbia when I went to visit recently. I was impressed with the small but exact sounding listening rooms, though I didn't have the opportunity to record anything in those rooms. Looks cool though

How far do you think one would have to be from this gobo in order to not get diffusion artifacts in recordings?

Thanks,
B.

[gullfo]

probably not far since it's highly absorptive and you would likely be using cartiod or unidirection mics...