Air Duct sound in b.g.

[Richard Crowley]

Can you cover the HVAC grille during recording? Since you disclosed nothing about the room or the length of the recording shots/sessions, we have no idea whether that would be practical for you.

Or is the noise more low-frequency rumble conducted through the ceiling/walls and not coming out of the grille? If the noise if low frequency, then it is more practical to filter out with a low-cut (high-pass) filter. But broad-band noise (hiss, whooshing sounds, etc.) are impossible to FILTER because they are occuring at THE SAME frequency as the signal of interest (the speech).

Can you get the mic a lot closer to the subject(s?) Like use a mic(s) in front of the subject(s)? Or a headset mic on the subject? Proximity is your friend. The closer the mic is to the talent, the better the signal-to-noise ratio will be. And that includes ambient noise from HVAC. Again, since we know nothing of what you are shooting or why you are using an overhead boom, we don’t know how practical this would be for your situation.

Of course you can also look for a more quiet location to record, or cover the background noise with music or perhaps other options depending on what you are trying to do.

[Ty Ford]

Hello Craig,

Richard has provided you with a wealth of possibilities.

I’ll add the following. The CMC641 is very directional. Sometimes it’s a case of angle the mic away from the noise. A CMC641 can point straight down, even slightly backwards.

Sometimes, a lav on the chest works better because it’s on the body, especially if the body is between the mic and the noise. The distance between the lav and the mouth can be shorter than between the CMC641 and the mouth.

Izotope RX3 Advanced (and now new RX4) is very good at canceling out steady noise. You do need someone who knows how to tweek it, but it can be very effective. I also have had impressive results with FCP X’s noise reduction in cases where the noise is not that loud.

Regards,

Ty Ford
Cow Audio Forum Leader

Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog

[Craig Alan]

Thanks Ty. Been trying to post a video with the noise from the duct but I can’t find the thing after I encoded it. Done this before but I guess I forget. Where is the file on the cow?

This Video is being Re-Encoded. Please check back in 5-10 minutes.

nothing happens and unlike when I embed a photo I don’t see the code even after that message goes away

Mac Pro, macbook pro, Imacs (i7); Canon 5D Mark III/70D, Panasonic AG-HPX170/AG-HPX250P, Canon HV40, Sony Z7U/VX2000/PD170; FCP 6 certified; FCP X write professionally for a variety of media; teach video production in L.A.

[Ty Ford]

Hi Craig,

Boy, you ask a very good question. I’m pretty mystified by that process myself. Don’t know why it has to be so hard.

Have you tried something simple like dropping a Youtube or other link in?

Regards,

Ty Ford
Cow Audio Forum Leader

Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford’s Blog

[Craig Alan]

cow server went down last night. here it is.

studio noise

Mac Pro, macbook pro, Imacs (i7); Canon 5D Mark III/70D, Panasonic AG-HPX170/AG-HPX250P, Canon HV40, Sony Z7U/VX2000/PD170; FCP 6 certified; FCP X write professionally for a variety of media; teach video production in L.A.

[Craig Alan]

[Ty Ford] ” I also have had impressive results with FCP X’s noise reduction”

what is ‘noise reduction’ called? don’t see it under audio effects.

Mac Pro, macbook pro, Imacs (i7); Canon 5D Mark III/70D, Panasonic AG-HPX170/AG-HPX250P, Canon HV40, Sony Z7U/VX2000/PD170; FCP 6 certified; FCP X write professionally for a variety of media; teach video production in L.A.

[Richard Crowley]

Sorry, a recording of noise by itself is actually useless without the reference to the normal signal level.
Not clear why you would want to record in such a noisy room? Is audio not important to the production?
We hope that level ramp at the beginning is not an indication that you are using auto-level here?

[Richard Crowley]

Software noise reduction is only a last-ditch method of salvaging otherwise useless dialog for something where quality is not important. It should NEVER EVER be used as as substitute for recording the audio properly to begin with. That includes selecting a quiet-enough location, selecting the proper microphone for the job, and positioning it at the proper distance form the subject.

Having to apply software noise-reduction in post production is an admission of major failure during production. IME, I categorically reject the very notion of trying to do this as a pre-planned part of any production. If audio is important, then select a location that is not audio-hostile.

If that categorizes me as hard-nosed and inflexible, then so be it. If the producer wants to compromise on the audio track, then they can find somebody else to do a marginal job.

[Craig Alan]

I increased the gain of the noise in FC so you could hear it clearly in terms of a possible filter that would help reduce it. It’s not my choice to have air continue to be pushed through the ducts even when the thermostats are off. It’s a studio; it’s where we shoot.

I will be meeting with rep from thermostat company to see if something can be done to isolate the so that the system turns off completely when we turn it off.

here’s an audio clip with voices.

studio noise 2

not auto gain. left and right set independently.

Mac Pro, macbook pro, Imacs (i7); Canon 5D Mark III/70D, Panasonic AG-HPX170/AG-HPX250P, Canon HV40, Sony Z7U/VX2000/PD170; FCP 6 certified; FCP X write professionally for a variety of media; teach video production in L.A.

[John Fishback]

I just upgraded to iZotope RX 4 Advanced. It’s amazingly good. There’s a module that does adaptive dialog noise reduction. You can almost set it and forget it. I believe this module is now available in the regular (and less expensive) RX 4. I recently used the whole program to restore a 60 year-old vinyl recording and while that takes a bit of effort, the results are outstanding. RX roundtrips from Pro Tools, but also is a standalone app. At the moment there’s a bug if you want to send from FCPX, but they’re working on that. I had slightly boomy sound in a video setup recently and the De-Verb module cleared it right up. It’s a great piece of software. BTW, I’m not connected in any way to iZotope, but have used the software since its introduction and it just keeps getting better.

John

MacPro 8-core 2.8GHz, 16 GB RAM, OS 10.9.4, QT10.1, Kona 3, Dual Cinema 23, ATI Radeon HD 5870, 24″ TV-Logic Monitor, ATTO ExpressSAS R380 RAID Adapter, PDE enclosure with 8-drive 6TB RAID 5
FCP-X 10.1.3, Motion 5.0.7, Compressor 4.0.7
FCS 3 (FCP 7.0.3, Motion 4.0.3, Comp 3.5.3, DVDSP 4.2.2, Color 1.5.3)

Pro Tools HD 10 w SYNC IO & 192 Digital I/O, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec DSP Monitors, Prima CDQ120 ISDN