portable anti-echo device: what's wrong with this?

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powerdog

Veteran
Being a die-hard DIY'er, I've come up with this idea for shooting head shots and medium c-u's in large, reverberant locations. Before I waste time and money, I invite all to tear the idea apart (or, even better, improve upon it)!

1. Take two moving blankets.
2. Build two frames same size as blankets, out of PVC or some other light structural material. (For transport, you'd have to be able to break them down or fold them up somehow.)
3. Add feet to the frames, and preferably some vertical adjustment function.
4. At the location, position them in a "V" shape (as seen from above.)
5. Place camera at narrow end of V.
6. Place "talent" at wide end, adjusting frames/blankets so they're just wide enough to clear the lens and at least some of each blanket is above head-height.
7. Hang boom mic up and over one of frames, in front of talent.
8. Result: shot shows talent and whatever part of background is behind him.
 
well, i could see that helping, but not being "anti echo" as such. You still get reverb off ceiling and floor and back wall and etc etc etc.

At the end of the day, I think your system might be too much of a pain in the ass to set up on anything but the most controlled set, with lots of time and help, and only in locations that suite it. The V shape should be good, Id imagine.

Heres maybe a mod: setup small, metal grommets in the corners of the blankets, and develop some kind of clip system to clip the blankets to C-stands. You'll need 3 stands to get the type of thing you're going for, but whats cool is that you can make more complicated reverb traps with more stands and blankets.

Unfortunately theres no magic method for killing reverb except for deadening the location by an amount that mathematically absorbs the reverb for the sound source in the environment.
 
This is so far beyond me.

For an extremely portable solution, how about,

unknowncomic1.jpg



You may have to tape over the mouth hole, though.
 
Powerdog... I've been doing something similar to this for a while. It helps but it depends on the situation. The moving/sound blankets only take you so far. I bought 16 wool blankets because they were the most dense and if I use all 16 of them I start to effect the room pretty well. I've been wanting to sew some of them into sleeves so I can slip in the 2" structural foam (pink or blue) like you see at Home Depot or Lowe's for building insulation. (Not the fiberglass... I mean the foam board). Costco sells some nice 1/2" thick foam flooring that interlocks and that makes a pretty good floor echo control at a low cost. Plus it breaks down to be reasonably portable. All of this stuff... if it is going to do much... will be a couple loads all by itself. If I bring everything I have for sound control it's several trips and half a pickup bed. It takes a lot of this stuff to really make a difference.

This is another good time for me to plug the Manfrotto 3398B stands. I love these... you can boom sound in a locked down shot... or you can raise the stand as high as possible and devide the boom arm distance out the front and back... and then lay a couple of your sound blankets across the horizontal boom arm. It works okay and you can move the stands around to find the best placement for echos.

But with all this never forget that a good acoustic space is easier to find then create. The only time I start with all this nonsense is when the location isn't flexible.
 
Matt, the quantity required for a large space is discouraging. I don't have a pickup truck, just a Honda Accord for me and my equipment. That's not going to change. Neither is the fact that I have no one to help with lugging and setting up stuff.

This is mostly a joke, but does anyone know if Serious Magic Ultra includes a laboratory background?
 
A few thoughts:

Blankets have to be really thick and heavy to absorb low frequences. Like 1/4 wavelength...

Acoustic blankets work best near the reflecting surfaces (the walls).

The original V-idea does not do anything for floor, ceiling and back wall reflections, it leaks a lot.

Making a huge mattebox like this makes lighting difficult.

Summa summarum: would really close miking be easier?
 
Petrus, that's what I"m thinking now. Use my lav, get it really close to the guy's mouth, and accept that the sound isn't going to be ideal. It's too bad that echo is such a tough problem.
 
I had this idea a while back for setting up blankets without using tape, or stands.

Anyone know those little suction cup type things that you get (in small scale) on little toys for the car?

Wouldnt it be cool if you could get really big ones to fit through the grommets on the corners of sound blankets? Hey presto, instant clip on blankets!

If they were really heavyduty, you could probably give the blanket a little clearance from the wall, too...
 
Sounds good for certain situations. For me, if subject and I are near the front of a 1000" x 1000" lab -- complete with hard countertops, sinks, test equipment, floors, etc -- blankets on side/back walls are too far away to do much.
 
Fun idea powerdog. :)

Of course G&E will never go for it. You can wait all day for the grips to set up the lights before you place your blankets, baffles, etc, it won't matter. The second you choose a spot for something, the DP will want to put a flag, light, cookie, or bounce right where you want to be. :thumbdown:

As Tim said, a couple of C-stands and blankets will give you the same effect plus allow you to move it around on the whim of our lord and master DP (jk, nothing but love for the cinematographer :happy: ).

Cheers
 
Wabbit, since the grips, DP, cinematographer, director, etc. are all one person -- me -- I'm sure I can count on cooperation!
 
Your Concern About Echo

Your Concern About Echo

Powerdog.

First of all, I cant believe there is a room 1000' x 1000'
Assuming this is true, dont bother acoustically treating the environment with "furny pads," acoustic panels, etc. Throw a restaurant style "rug" down to eliminate feet noises and partially deaden "echo" of the voice. Split tracks with the lav mic. dialed all the way right and the camera mic., mounted shotgun or overhead boom all the way left. Check your levels prior to actual taping, making sure the speaker is using same level he will during actual shot. Pay particular attention to a lav which is not suseptible to clothing noise or contact with any props or hand action during the shot. If the talent is wearing a tie, insistist on a "windsor knot" and mount the lav through the knot and hidden in the "dimple" in the center- "West Wing Mount." Mic facing down is okay since these mics are Omnidirectional. Cable is fed up the collar and around the back to the transmitter. .Another method that I like is hidden under the collar flap and around to the back in the same way. Lavs dont pick up much room echo so dont worry about it, especially since you are the whole crew, but take care of the sound FIRST so you are not distracted by it later. Make sure you are not "blowing up" the transmitter's level (gain structure starts with a hot but not too hot level in the first stage- the transmitter).
I am a very tweaky sound guy who goes above and beyond the call to deaden very reflective rooms. In the feature world, among the experienced pros I apprenticed under, it is a given that deadening footsteps and reflective surfaces creates a cleaner dialogue track that Post can sweeten any way they seem fit. If you are cutting between close shots and wide, room tone is used to fill in the blanks and reverb added as necessary. Grab 30 seconds of "room tone" if you can.
The presence of people in the room will deaden some of the "echo," but once again, a properly mounted Lav mic with correct level is the most important thing. Turn ALC OFF on the DVX. Better yet, hire a pro soundguy.
I might be available that day.
 
ALC off?... Ive reckon the limiter should be on: its only gonna save your ass if you dont have a sound guy to continually check levels.
 
I couldn't hire a pro dogwalker for what I'm being paid. Anyway, good advice that I'll print out. BTW, footsteps aren't a problem...we can throw other people out of the lab, and my subject is standing still. Don't know the exact size of the room either, but it's a large chemistry lab in a major university.
 
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