In a few days I will have to record dialogue for a short film. The set is build in an old warehouse. How can I avoid room reverb ?

Of course I will use radio mics but what type of microphone I need for the boom? I have a good selection of mics at my disposal. I often use the Schoeps CMIT 5u or Neumann KM150. Is it a good choice for this work ? What about the microphone placement ?

Thanks in advance for your advices.

  • 1
    Try researching/asking this over on jwsoundgroup.net also. Ton of seasoned pro sound mixers over there that can help you sort production issues like this out. Jun 18, 2013 at 21:20

4 Answers 4


As georgi said, knowing the frame will be (and actually always is) very important. Being able to get the mic even just 1 foot closer will be a noticeable improvement.

As for sound blankets/baffles, it depends on the space. If it's huge and open, then putting up baffles and keeping them out of shot might be too much effort for minimal gains. One thing you could try is having some sound blankets on C-stands, and putting them up in front of the surface that'll reflect the most sound to the front of your pickup pattern. So, basically, ignore surfaces that are off mic. This will still involve a lot of dicking around between set ups, so it's up to you to determine if it's worthwhile or not. Maybe you can arrange a visit to the location to record a few tests?

Mic wise, i'd suggest going with the Schoeps because it's a shotgun. This is a bit beyond my level of experience on set, but i believe a shotgun would be better than a hypercardioid in a large, reflective interior. Also, it would be fantastic if you could get a hold of some radio mics. I know we all like the perspective given by booms, but radio mics will give your sound post people more choices. And choices are good.

Finally, do your best to get hold of a script marked up with which slate covers what. Like this one. I love it when i get these, because when i'm looking for alts, i can see which lines are in which slate. Depending on how consistent the performances are, maybe your dialogue editor can use lines from the CUs for the wide shots (which will have more reflections). Where i'm from, it's usually continuity (aka script supervisor) who'll have these, so if you're on a low budget skeleton crew, it might not be feasible.

Also, bring some balloons or a cap gun so you can record IRs for each set up. They'll be super handy for foley and ADR.

Hope that helps!

  • Is there any good free software to process balloons or cap guns bursts ? I know Altiverb includes such tool, are there any alternatives ? Jun 19, 2013 at 8:03
  • @Simon Sorry, i'm not sure. I use Waves IR1, and it just lets you load your own IRs. I can't speak for other software though. Maybe someone else can help, but as far as i know, there aren't any great free convolution reverbs. Jun 19, 2013 at 18:06
  • @Simon You don't need to process the balloon burst, you can just load it straight into a convolution reverb as a Wav. Recommended reading for convolution reverb stuff: designingsound.org/2012/12/recording-impulse-responses Jun 20, 2013 at 8:28

The frame lines will be crucial, so good communication with DoP. How about hanging some blankets off-camera? You can go wild treating the space, but how much of that will be practical?

p.s. can you treat the floor?


My answer falls under the category of "fix it in post". If all else fails (and I do hope you exercise all options during production), then UNVEIL from Zynaptiq absolutely works miracles.


Another "fix it in post" solution is this box, which IMHO is nothing short of straight-up voodoo and black magic:


I have no idea how it does what it does but I'm so happy that it does it.

  • I may have to pick your brain on this one - my experience was fruitless and dissapointing compared to my other favorite noise suppression methods. Maybe I'm totally missing the boat on some key info or technique Jun 19, 2013 at 5:11
  • @Stavrosound: yup, you're definitely missing something if you're not seeing dramatic results with this plug. Used it on the last film and it basically saved the production track. Downvotes, really? Jun 19, 2013 at 6:41
  • Considering this is a low budget short film, I don't believe they will buy this plug in post ... So I will do my best at the shooting ! Jun 19, 2013 at 7:07
  • @Jay Hmm, we may need to dork out on this sometime if you're up for it. I'm quite curious as to what I'm missing. The only thing I got out of it was it sounded like EQ bands all-or-nothing - wasn't hearing the sound 'lift' forward from any broadband noise as it's advertised to do or make anything recede pleasantly from the target sound source. Jun 19, 2013 at 7:46
  • @Stavrosound, when I first started experimenting with the demo I found that certain parameters could be tweaked very, very slightly before things turned ugly, while others could be cranked all the way to "11" and still yield amazing results. Definitely takes a little time, not a "learn noise" and "extract noise" kind of plug. Jun 20, 2013 at 5:43

The main expedient is a directional microphone setup. Really directional. Start with a shotgun and use micscreens for further shielding of sound from wrong directions and/or diffuse sound. Don't forget the vertical direction: ceiling and floor make for a lot of reflections.

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