Gobo advise needed

[anemicrock]

Hi guys I was wondering if someone can help me out. I have just landed my first commercial property which was last used as a recording studio. The owner has left a few things behind (no kick ass mics I'm afraid) but a few gobos and other handy things.

Now on to my question. The gobos are 4ft wide and 78 inches tall but they are made out of wood. No acoustic foam in the middle. Nothing. Just a big flat wood surface. Are these usable? I mean sure they can block out some sound but are their flat surfaces going to cause me more problems than good?

Should I cut the middle out and stuff some rockwool in there or something?

I was mainly thinking of using them around the drums.

Thanks in advance.

[Smithcok]

Mass is key for gobos that will actually isolate, so big heavy wood gobos are a great start.

For my own DIY gobos, I chose to use plywood+drywall for the mass, but put 703 insulation on one side (thereby making one reflective and one absorptive side).

Can you post a picture of one? Perhaps there is an easy way to mount some 703 (or rockwool, etc.) on one side.

[anemicrock]

will do. I'll have to wait til tomorrow now as it's 1 am here and Im at home. Thanks for your help.

Kev

[jwl]

How heavy are they? I wonder what's inside the wood.

Pics would be good.

A lot of people like reversible gobos, ie, absorptive on one side and reflective on the other. Personally I prefer them absorptive on both sides.

[anemicrock]

Sorry if the pics are too large but here ya go. There solid wood on the middle and there are 2 side pieces.

Hope this helps.

Thanks in advance.

[Weasel9992]

Well...they don't look too useful on either front. They're not massive enough to reduce bleed much, and their basically just another flat surface to worry about in terms of comb filtering. Maybe you could put some diffusion on one side and something soft on the other...?

Frank

[Ethan Winer]

Originally Posted by anemicrock

Should I cut the middle out and stuff some rockwool in there or something?

Yes. Especially if you plan to use them around drums where absorption is better than reflection. Also, don't expect much isolation from any gobo at low frequencies. Mids and highs can be blocked and absorbed easily, but lows go right around the side and over the top, as well as through.

--Ethan

[anemicrock]

Cool thanks guys for the info.

As far as Isolation goes I'm not that worried as I will be tracking drums solo anyway. Never track live with other instruments in the same room as I have an iso room for cabs etc.

I think it's ruffly 4 inches thick so I gues the best thing to do then is cut the middle out and throw some rockwool in there.

If you guys think it would be better to buy something better or different then please let me know.

Thanks again.

Kev

[Smithcok]

If their current 4" thickness is filled with plywood, then that's a great start to massiveness. If its just a sheet or two with space (etc) in the middle, you may want more mass.

Personally, I'd consider taking 1x8" lumber (or even two pieces of a smaller dimension for even more room) and making a bigger frame around the current 4" frame. That would give you a few inches on either side which then you could fill with either more mass and/or absorption It should be able to be blended into the original look of the gobos fairly easily.

[anemicrock]

I'm pretty sure it's solid all the way through. It has has like a center piece witch I can't tell what wood is being used and then there is a thin piece on the surface of both sides.

I like your idea and might try it but it might be easier to just make new ones I'm not sure yet.

[Mulmany]

Hey, make it into a QRD on one side and 6 inch absorption on the other. It looks like you have enough of a base to make 10 inch well depths for the diffusion. It would really let you vary the acoustic signature of the live room.

Thats what I would do.

[jwl]

quickest solution I can see? get something like a 4" holesaw and cut holes in the center section. Or, just completely hollow it out as said.

Then put a 4" slab of rockwool on each side of it, cover with cloth, etc etc.

[anemicrock]

Thanks again guys. I think I might just try cutting out the middle and fill it with rockwool.

Mulmany do you have any pictures of your suggestion?

Thanks.

[spm_gl]

There's really no point in cutting them up, just stick some rockwool/foam/etc. on both sides and cover it with fabric, then you at least have a portable absorber.

[Weasel9992]

Originally Posted by Mulmany

Hey, make it into a QRD on one side and 6 inch absorption on the other. It looks like you have enough of a base to make 10 inch well depths for the diffusion. It would really let you vary the acoustic signature of the live room.

Thats what I would do.

That's what I'd do too...don't do a soft surface on both sides. A mobile gobo should have a soft side and a reflective side. They're much more useful that way.

Frank

[anemicrock]

Basically I want to do something like these. But are the backs of them solid or do you guys think the backs of them are just a thin piece of chio board or something?

[Mulmany]

why do you want to do that?

You just moved into the place right?

Do you know what the space sounds like yet?

If you want pics of what Frank and I are saying Search the forum for QRD.

[anemicrock]

Well those are basically what your suggesting anyway. It looks like it anyway.

I'm going to keep the base and work off of that as the current one is nowhere near 6" deep. I have to make a new frame regardless just to do that so....

[jwl]

Originally Posted by spm_gl

There's really no point in cutting them up, just stick some rockwool/foam/etc. on both sides and cover it with fabric, then you at least have a portable absorber.

Actually, if you don't cut them then it will limit their absorption at low frequencies. An absorber like this (a velocity absorber) depends on sound passing through the absorption in order to absorb the lower frequencies. The barrier prevents sound from moving through it; therefore any sound with a wavelength longer than the panel will diffract around the sound. This is useful for gobos if iso while tracking is your goal. However if you want to maximize absorption, especially at lower frequencies, then cut holes in it before slapping it with rockwool.

[jwl]

Originally Posted by Weasel9992

That's what I'd do too...don't do a soft surface on both sides. A mobile gobo should have a soft side and a reflective side. They're much more useful that way.

Frank, this is largely a matter of taste/preference, but I disagree. Several years ago I built reversible gobos like this. They are very effective, but NEVER ONCE have I been glad there is a reflective side. Every single time I wish it was absorptive on both sides.

Gobos are usually placed close to both the sound source (drums, amps, acoustic guitars, singers, etc) and the microphone. In my experience, the last thing you want is a reflective surface very close to the source AND the microphone. The only way to make it work is to "aim" the reflections away from the mic, which limits flexibility with placement. If it were absorptive it wouldn't matter, and you could place gobos where they are most effective, and not where they have to be aimed.

On the other hand, if you have something like a large live room, then reversible panels near the walls (away from the sound source and mics) make sense to control/adjust the acoustics in the room.

[anemicrock]

Thanks guys again for your help.

Jwl, you mentioned having a reflective surface on the back is not such a good thing unless it's away from the source.

The pics I posted above are around the drum kit at NRG, does that seem right to you as they have a reflective surface?

I'm not trying to be a wise guy just actually trying to understand your point a bit better.

[Glenn Kuras]

Originally Posted by jwl

Frank, this is largely a matter of taste/preference, but I disagree. Several years ago I built reversible gobos like this. They are very effective, but NEVER ONCE have I been glad there is a reflective side. Every single time I wish it was absorptive on both sides.

Gobos are usually placed close to both the sound source (drums, amps, acoustic guitars, singers, etc) and the microphone. In my experience, the last thing you want is a reflective surface very close to the source AND the microphone. The only way to make it work is to "aim" the reflections away from the mic, which limits flexibility with placement. If it were absorptive it wouldn't matter, and you could place gobos where they are most effective, and not where they have to be aimed.

On the other hand, if you have something like a large live room, then reversible panels near the walls (away from the sound source and mics) make sense to control/adjust the acoustics in the room.

I agree with you but he was talking about using diffusion on one side, which I think could be a cool way to go about it.

[anemicrock]

Hey guys. I decided to make new ones myself. I'll post pics soon.

I made them 17 cm deep enough so 3 rockwool slabs will stack on top of each other. There 4 ft wide and 8 ft tall with a thin piece of wood to go on the back.

I'm interested in making 2 more but using diffusion instead of bass traps but was wondering how useful or how needed I guess they would be to place around the drum kit?

Should I go this route or just use more traps?

Thanks in advance.

[Glenn Kuras]

I'm interested in making 2 more but using diffusion instead of bass traps but was wondering how useful or how needed I guess they would be to place around the drum kit?

Should I go this route or just use more traps?

The diffusion thing would work but you may not use it as much as you think. The safe bet would be to stick with absorption on each side, but it really is up to you.

Glenn

[anemicrock]

Cool. Good to hear that all traps will do the job.

Out of curiosity, I would ask what benefits diffusion around the kit would lend as opposed to all traps but I guess there is probably another thread for that?

[jwl]

Originally Posted by anemicrock

Thanks guys again for your help.

Jwl, you mentioned having a reflective surface on the back is not such a good thing unless it's away from the source.

The pics I posted above are around the drum kit at NRG, does that seem right to you as they have a reflective surface?

I'm not trying to be a wise guy just actually trying to understand your point a bit better.

From what I can see, the absorptive sides of the gobos are facing the drum kit in those pics.

I was referring to facing the reflective side TOWARD the drum kit/mics. I haven't had much luck with this myself. It always sounds better absorptive side inward, which is why I prefer absorption on both sides.

[jwl]

Originally Posted by anemicrock

Cool. Good to hear that all traps will do the job.

Out of curiosity, I would ask what benefits diffusion around the kit would lend as opposed to all traps but I guess there is probably another thread for that?

Diffusion generally works best a certain distance away from the sound source, and with enough surface are to treat a large wall. That said, I've used diffusors close to a recording, particularly with acoustic guitar, with good results.

For more on what diffusion sounds like up close, see our video:

RealTraps - All About Diffusion

[Weasel9992]

Originally Posted by jwl

Frank, this is largely a matter of taste/preference, but I disagree. Several years ago I built reversible gobos like this. They are very effective, but NEVER ONCE have I been glad there is a reflective side. Every single time I wish it was absorptive on both sides.

....and just to show the OP the wide range of experience, I almost ALWAYS prefer the reflective side out in front of a drum kit and acoustic guitars. I like the absorptive side facing vocalists and electric cabs. As Glenn said, by "reflective" I mean using diffusion, not leaving a flat surface. It can work either way though...it's purely based on preference and the room characteristics. Absorption is just as valid an approach, so I'm not in any way saying that James is "wrong" or anything.

Frank

[anemicrock]

Weasel9992, Again good to hear. I hues it's just what you prefer then and not a must.

I'll try to post some pics of the room and where I have the drums and traps placed soon as well as some audio clips.

Thanks again guys for all the help.

[jwl]

Originally Posted by Weasel9992

It can work either way though...it's purely based on preference and the room characteristics. Absorption is just as valid an approach.

Agreed. One is not right or wrong, they just produce different sounds. Depends on the characteristics of the room, timbre of the instrument, what the song needs, etc etc.

But more often than not, absorption works best in my experience.