Question about eliminating room echo.

H

harmonica44

I am about to shoot my first real short soon, and could use some advice. I had a sound guy but he dropped out for personal reasons cause of a family crisis, he had to go back home for. I keep reading that you have to use blankets or some sort of covers to mask the echo, when using a shotgun mic indoors. But the question is how much blanket? Like say the person holding the boom, is pointing the mic above the actor, pointing almost straight down towards the actors mouth. This means it will be pointed almost straight down to the floor. So since the shotgun is very directional, it will pick up the noises from the floor, a lot more than anywhere else, as I understand it.

Does this mean that I have to cover the whole floor, or just a certain amount, around the pick up direction of the mic? Or what do I have to do exactly? I've been practicing but still haven't quite got the hang of it. Thanks.
 
Sort by date Sort by votes
Add a blanket at a time until the problem goes away. Start on the floor first since its the easiest, then the wall behind the camera, and so on . . .

If you're concerned about echo then I have high hopes for your film! :)
 
Upvote 0 Downvote
It's not just from the direction the mic is pointing, sounds bounce off all of the hard surfaces in the room. You have hundreds of thousands of sound reflections entering the mic milliseconds apart with varying frequency content at varying volumes. This is the classic "roomy" sound. Because shotgun mics are designed to pick up sound only from the front it actually exaggerates this effect. The acoustics/physics are long and involved.

You hang a dozen or so sound blankets around the three sides that are not in the shot and put carpeting on the floor. Don't pull the blankets tight, give them lots of folds to soak up the sound.
 
Upvote 0 Downvote
Okay thanks. I might have to use blankets for the floor too, if I can't get enough carpet. I only notice the echo in the kitchen though. I will be shooting some of it at my house. So there is probably echo in the other rooms, but it's hard to tell. Is this echo more noticeable if it's played through bigger speakers? I have been playing it back through my computer speakers, which are the size of small boom box's speakers.
 
Upvote 0 Downvote
Unless your room is treated, and you're using accurate monitors, critical istening is virtually impossible. Your best bet would be to listen using quality headphones. If the listening room isn't properly treated, it will be impossible to determine what reverb is in the source, and what reverb is coming from the listening environment.

When I do shoots in kitchens, I stuff blankets above kitchen cabinets, and sometimes even in the cabinets, as well has hang from stands out of frame.

What also helps in highly reverberant environments is to discuss with the director the possibility of having the actors speak with less volume. The less acoustic energy entering the environment, the less there is to bounce around. If the scene calls for yelling or aggressive dialog, then you'll have to rely on the blankets alone.

FYI, I've recently added 15 blankets to my inventory, and have encountered situations where I could have used 30.

harmonica44 said:
Okay thanks. I might have to use blankets for the floor too, if I can't get enough carpet. I only notice the echo in the kitchen though. I will be shooting some of it at my house. So there is probably echo in the other rooms, but it's hard to tell. Is this echo more noticeable if it's played through bigger speakers? I have been playing it back through my computer speakers, which are the size of small boom box's speakers.
Click to expand...
 
Last edited:
Upvote 0 Downvote
Rugs or blankets on floor when out of frame, blankets on walls when out of frame, mic as close as possible to the talent at all times (without getting in frame).

Also, in the end, to really do it right you normally isolate all the dialogue and lay it over the top of a clean room tone, not using the room sound you got on set. That may be pretty adavnced audio for a first short, but just so you know there is a way fiilms get that "perfect" sound.
 
Upvote 0 Downvote
harmonica44 said:
Okay thanks. I might have to use blankets for the floor too, if I can't get enough carpet. I only notice the echo in the kitchen though. I will be shooting some of it at my house. So there is probably echo in the other rooms, but it's hard to tell. Is this echo more noticeable if it's played through bigger speakers? I have been playing it back through my computer speakers, which are the size of small boom box's speakers.
Click to expand...

I hate to be brutal but I sometimes wonder if you actually read my posts. I'll try one more time.

The amount of echo in any given recording has nothing to do with the speakers you are using. You may perceive it more in one listening environment than another, but the recording remains exactly the same.

Unless it's an anechoic chamber, all rooms have echo issues. Period, end of discussion.

The more bare, hard surfaces there are in the room the more echo there will be.

Because of the way microphones work the effect is greatly exaggerated.

Because of the way shotgun mics work the echo effect is even more greatly exaggerated than when using other types of mics.

To mitigate the echo effect you need to put as much sound absorbent materials into the space as possible.

To mitigate the echo effect the correct mic needs to be chosen for each situation.

To mitigate the echo effect the chosen mic needs to be in as close to the talent as possible while remaining outside the frame.

To mitigate the echo effect the mic needs to be aimed properly.

Got it?
 
Upvote 0 Downvote
I use a heavy comforter and egg crate squares that are held just out of frame. If shooting in a kitchen or other echoey room, I have my boom op mic from above and below and use whichever one provides the least amount of echo (well, as best as I can determine through headphones).

Oh a side note, if shooting indoors, don't forget to turn off the air conditioning and unplug appliances like refrigerators when recording dialog. Oh, and I have everyone turn off cell phones completely, as I've had GSM phones create the famous "GSM buzz" in my audio. Echo isn't your only enemy.

Good luck!
 
Upvote 0 Downvote
Alcove Audio said:
I hate to be brutal but I sometimes wonder if you actually read my posts. I'll try one more time.

The amount of echo in any given recording has nothing to do with the speakers you are using. You may perceive it more in one listening environment than another, but the recording remains exactly the same.

Unless it's an anechoic chamber, all rooms have echo issues. Period, end of discussion.

The more bare, hard surfaces there are in the room the more echo there will be.

Because of the way microphones work the effect is greatly exaggerated.

Because of the way shotgun mics work the echo effect is even more greatly exaggerated than when using other types of mics.

To mitigate the echo effect you need to put as much sound absorbent materials into the space as possible.

To mitigate the echo effect the correct mic needs to be chosen for each situation.

To mitigate the echo effect the chosen mic needs to be in as close to the talent as possible while remaining outside the frame.

To mitigate the echo effect the mic needs to be aimed properly.

Got it?
Click to expand...

So you're saying I need to think about sound and not ignore it until the very last second?

/sarcasm
 
Upvote 0 Downvote
voodoogmr said:
Oh a side note, if shooting indoors, don't forget to turn off the air conditioning and unplug appliances like refrigerators when recording dialog. Oh, and I have everyone turn off cell phones completely, as I've had GSM phones create the famous "GSM buzz" in my audio. Echo isn't your only enemy.
Click to expand...
Oh, wow. That's smart. I hadn't considered the AC & fridge being interference suppliers but now that you've said it - DUH!
Thanks.

And the goofy sh!t you learn from this wonderful IT board: "GSM buzz"
http://www.eetimes.com/design/microwave-rf-design/4019057/Minimize-GSM-buzz-noise-in-mobile-phones

Never heard of it.
Now I know something else to anticipate.

Rockin'.
Cool. :cool:
Thanks, again. :)


dlevanchuk said:
Also, leave your keys in the fridge, that way you wont forget to turn fridge back on, and piss of property owners ;)
Click to expand...
LOL!
Deal!
 
Last edited:
Upvote 0 Downvote
dlevanchuk said:
Also, leave your keys in the fridge, that way you wont forget to turn fridge back on, and piss of property owners ;)
Click to expand...

Thats a great idea for remembering anything. I do that if i need to take something important to work or whatever, leave my phone or keys by said item. Never fails, unless there's a hangover involved.

I don't know much about teh echo but I would say maybe opening a window in your room if you don't have a block party on teh day of shooting to let some of teh echo escape or maybe outside noise to combat the echo - would this work? I dk but perhaps an attempt is in order?
 
Upvote 0 Downvote
@OP I still hold that you should just get on with making your short and not worry too much about all the technical detail. By this rate, you are never going to make anything!

It's not the technical details aren't important, it's just that this is your first short. You can choose and get familiar with that, then for your next short, you learn something else.

Edit: And like Alcove, i do wonder sometimes if you are actually taking in all the suggestions everyone's been giving. Because if you are, they should be far more than sufficient for you to work with.
 
Last edited:
Upvote 0 Downvote
Alcove Audio said:
I hate to be brutal but I sometimes wonder if you actually read my posts. I'll try one more time.

The amount of echo in any given recording has nothing to do with the speakers you are using. You may perceive it more in one listening environment than another, but the recording remains exactly the same.

Unless it's an anechoic chamber, all rooms have echo issues. Period, end of discussion.

The more bare, hard surfaces there are in the room the more echo there will be.

Because of the way microphones work the effect is greatly exaggerated.

Because of the way shotgun mics work the echo effect is even more greatly exaggerated than when using other types of mics.

To mitigate the echo effect you need to put as much sound absorbent materials into the space as possible.

To mitigate the echo effect the correct mic needs to be chosen for each situation.

To mitigate the echo effect the chosen mic needs to be in as close to the talent as possible while remaining outside the frame.

To mitigate the echo effect the mic needs to be aimed properly.

Got it?
Click to expand...

Okay thanks. Yeah I try to take to all the advice given to me and it's greatly appreciated. I already new about turning off AC and fridge, and to isolate the dialogue separately from the background noise, but this blanket thing is new to me. I wanted to get a cardiod mic way back, but none of the stores where I lived had ones that were recommended to me, so I didn't know if they were what I would need. I guess I should have ordered one off of Amazon, but I got caught up in all the other parts of making a short. The sound guy also said he would prefer to use my shotgun, as he has had echo problems with cardioids in his experience, so I left that up to him. But now that he can't do it, it's up to me. I'll do my best with the shotgun, and try to get enough blankets.

I know there will always be echo but I don't want there to be too much of course. My sound guy and I have listened through speakers and headphones, and have not found much echoes while practicing, except for in the kitchen where it was noticeably bad. I will do what you people say. Thanks. If something goes wrong with the echo I guess there is always fixing it in post with ADR. Now that I know to you use blankets there are some shots I will have to plan more carefully.

Here's two more recent samples, and I'm about to record to more.

http://soundcloud.com/harmonica44/b11h51m51s17jun2011

http://soundcloud.com/harmonica44/b11h57m20s17jun2011

It seems the closer I put the mic the actors mouth, the less echo I get, from what I can tell in playback. Not that that's a solution, I'm just saying it what helps a bit. Thanks for all the advice and feedback.
 
Last edited:
Upvote 0 Downvote
Bang_Head.gif
banging_head.gif
hb.gif
 
Upvote 0 Downvote
You must log in or register to reply here.
Back
Top