avoiding room echo
 

My kit comprises Canon XH-G1 I have a Sennheiser ME66, an Edirol R09 and a Sennheiser lav. mic (not sure of the model) I have access to a Sennheiser wireless mic system.

I just completed a test shoot in someone's home, a very ordinary livingroom about 20ft x12ft 8ft or so ceiling height, the room is carpeted with heavy curtains and quite a lot of furnishings in the room yet.... on playback I'm getting what I call room echo, like I've switched on Hall effect on my 5.1 sound system. It is only slightly improved with the wireless set-up and lav mic, but it is still there and a very different sound from the voice-over narration that cuts in and out of the 'interview'.

I am recording the voice-over using the ME66 direct recording to the footage in Sony Vegas Pro9

what can I do?

How close is the mic to your mouth (or whoever's mouth) during the narration, and how close is it to the interview subjects?

If you intend for your narration to sound like the room does, you need to record room tone and lay that underneath narration. If you want to make the room sound "dry" during your interviews you are probably going to need to hang sound blankets.

I prefer the sound of a live room as long as I can close mic. Keeps everything from sounding like it was recorded in a sound booth.

OK. The "room echo" effect is called reverb. It's caused by the sound absorption properties of the room; actually, the lack of absorption. The mic matters. The fact that it's a lav isn't enough. There are two popular Senny lavs that are sold. One is an ME 2 omni and the other is an ME 2 cardioid. You want the cardioid to minimize the reverb effect. I'd expect a cardioid lav to do better than the ME66. Treating the room like Perrone suggests will help.

Shotguns in a reflective environment such as you're working in are bad news. You really need to switch to a hypercardioid mic instead, as well as treating the space with sound blankets to absorb those reflections. You might also try your lav but again, taking steps to deaden the space are going to be needed there as well/

Les, a cardioid lav might help a little with the reverb but not much as they usually create more problems than they solve. With a cardioid, each little head movement on the part of the talent causes a change in the timbre of the voice as they go off mic and come back on again. Cardioids are pretty well limited to sound reinforcement applications where feedback control takes precedence over consistent sound quality. Still, either one migh be better than the 'gun.

Maybe in live events where the speaker moves around a lot but I assumed this was a sit down interview type of thing in this discussion. I've used the cardioid ME2 in 50-100 interviews/teleprompted deliveries and I haven't experienced the effect you describe at all. FOr me it has just the right amount of room noise yet doesn't pick up the stuff in other rooms or outside.

Normally this should sound ok... even with a shotgun, however that would not be my first pick for interiors.. or narration for that matter. Is the room carpeted?
Do you have two of more mics on at the same time? For instance an open mic 10 ft. away from the spot mic, (lav OR boom) would result in a very annoying 10 millisecond delay. (appox.)
Disable all but one of the audio tracks on your NLE. A stereo track would need to be split into two mono and panned center, with one muted or removed. (This takes about 5 seconds with Vegas Pro)

Thanks to all for your helpful replies - I have some testing to do!!

I thought getting to grips with a semi-pro camera was tough love but audio is a whole new ball game requiring far more knowledge, forethought and planning not to mention the experience of being able to predict what a take will sound like when all the variables are brought together phew!!!........I'm sure I'll be back±

(This takes about 5 seconds with Vegas Pro) .. Addendum: 5 seconds.. If you're slow!

Right-click the audio event on the time-line, select: 'Channels' > choose 'Left', 'Right' or 'Both'.

Selecting 'Left' or 'Right' will playback as a single-channel (mono) file. (panned center by default, and that's where you would want it for dialog)
Selecting 'Both' would return it to it's original two-channel stereo file state. This is all non-destructive and does not change or re-render the original file.

Are there any fundamental rules when recording room tone? Recently, I used a H4n to record various room tones. I used the H4n's in-built pair of speakers pointing in one direction of the room, and used a shotgun mic pointing to another part of the room. While capturing the room tone that way, I was thinking 'is this it? Is this how you record room tone?'

Is there a specific term/jargon for recording dialogue in a live room, rather than in a studio? Just interested.

Cheers :)

The Sennheiser ME66 is NOT an indoor mic, and should never be used in a reflective environment.

For indoor home or office environments I would choose either a good hyper-cardioid like the Audio Technica 4053B or AKG CK93, or a shotgun mic that is made for indoor work like the Rode NTG-3, Sennheiser 416, or Sanken CS-1 or CS-3e. This assumes you have a boom-op to handle the mic work.

Otherwise a good cardioid lav or in a pinch the TRAM TR-50 with the mic face turned towards the vampire clip can help to isolate the person speaking from the room sound.

You might want to record the room ambient sound on a separate channel in case you want to mix in a little additional room sound in post.

No, that is not how you capture room tone. First get clear on the idea that "room tone" and "ambient sounds" are two entirely different concepts. Room tone is the "sound of silence", the timbre of the space that you're working in. You record it with exactly the same setup and mic position that you use for recording dialog. All the cast and crew in their normal places for the scene but silent and stationary, and roll sound for a minute or so. Hopefully your location is quiet enough that there are no ambient sounds recorded with your room tone. It should literally be the sound of no sounds at all. It's used to underlay gaps in the production sound where there is a cut - otherwise you would hear a gap in the random noise. There's a different sound to a recording of nothing and blank tape or empty file. Ambient sound, OTOH, is the sounds of the environment - conversation mumble and the clink of dishes in a restaurant, water mumuring in a stream that the lovers are picnicing alongside, wind through the grass in the prairy. Abience can be recorded anytime and anyplace using whatever equipment gives you the best recording of it.

Nice explanation on RT Steve.
The biggest challenge is keeping the cast & crew from talking and shuffling around.

Nice explanation but I have to add that sometimes room tone and ambient sound are sort of one in the same. For instance if you were doing an interview in an uncontrolled space for say a documentary or reality show. An example might be an interview that takes place in a restaurant, shopping area, or even a factory. You would want the sound of what's happening in the background without talking to make it easier to cut up the interview. Also, even in a "quiet" space other sounds will intrude. If you stop down for every single thing you will never complete the shoot. For instance shooting in an outdoor area that might have random planes, automobile traffic, children playing etc. In that case you want the silence plus a bit of the random noises that came in during the interview. Always hard to get because it always gets much quieter when you don't want it to. You would of course keep the mics in the same position and level as they were for the interview. Of course its up to the sound person to determine when something is too loud to deal with and stop down.
Bernie

Sure, any constant background sound during an interview or scene could be considered RT.

Steve, Rick and Bernie, thanks a bunch for your contributions. I am the sort of learner who loves to know the finer details, and this is helping.

I'm a little confused when I think of the following work scenario I recently was a part of:

- I recorded dialogue through a boom mic. I noticed after various shots and takes a distinctive fridge hum. (My bad indeed; should have killed the fridge: next time!)

- I then recorded RT with the fridge on. My justification was that the fridge hum was, relatively speaking, the " the sound of silence" in that room.

Firstly, in that scenario, did I record room tone, or did I record ambiance? And are the definitions that strict in professional settings?

Finally, did I make the right decision to record RT/ambiance with the fridge on, considering that the fridge was on while recording dialogue?

Cheers!
Miggy

In this instance you did both. Sometimes room tone and ambiance are one in the same. That's what I was trying to explain. The main difference I guess is the mic technique used. Room tone is recorded with the same rmic/mics in the same position as when the scene or interview was recorded. Just no talking or fidgeting. Ambiance can be recorded like room tone, or with totally different placement and/or mics depending on what you're going to use it for.
The main thing is to think about how your sound will be used in post, and proceed accordingly.
Best,
Bernie

I would say you did the right move. The idea of room tone is so in post, when you take a continuous speech and cut it in the middle resulting in a gap -- "Give me the blanket, I'm cold" is edited to "Give me the blanket ..... I'm cold!" -- you have the same sound that is already in between the syllables of the words available to bridge the inserted space instead of just "dead tape." It serves to keep the speech from dropping out of the visual space and coming back in unnaturally. There was fridge hum during the dialog so it would sound unnatural for it to be missing during any pauses inserted in editing.

So were you actually IN the fridge? No wonder you could hear it humming.

:-)

Hi All,
I would like to ask a question regarding the use of roomtone in post.Lets say in the edit suite one was to take the roomtone recording which includes the fridge noise and reverse the phase and then mix it with the original recording, would the fridge noise be then silenced by phase cancellation? Thanks in advance,Neil

In some cases, but not usually with dialog on the same track.
That's the principle of many of the NR tools and why they're costly.