Another dumb question from the noob of the month :) - Soundproofing

richke

richke

Well-known member
I have another thread where people are helping me with a hissing noise in my audio and I noticed someone saying the sound setup was off and that my audio was bouncing all around the room. I understand what he is talking about but where do I start? I see foam I can buy but does some just hang on to it behind the camera during the shot or what?

So I'm looking for a how to so to speak. Anyone have any where I can start. I checked the web and they say what I can buy but I don;t know how to apply it...if that makes any sense.

Thanks again,
Rich
 
The "roomy" tone is an issue with the mic itself. A shotgun (lobar pick-up pattern) mic is supposed to have a great degree of off-axis rejection, meaning that is doesn't pick up sounds from the sides. Using a mic with a cardioid pick-up pattern will greatly reduce the "roomy" effect.

Instead of asking dozens of haphazard questions to resolve specific issues do some focused research. Sit down and learn about audio practices and which tools are appropriate for specific applications.

You can use my blog as a starting place:

http://blogs.myspace.com/index.cfm?fuseaction=blog.ListAll&friendId=111888913

Then lose yourself at filmsound.org (all about sound for film) and jwsound.net (a site for production sound professionals) for a few days.


BTW, soundproofing is isolating the room from exterior sounds and, conversely, reducing the sound heard outside of the room; sound treatment is the practice of reducing the ambient "bounce" of the room and/or taming frequencies to create a "flat" response environment for audio monitoring.
 
richke said:
I see foam I can buy but does some just hang on to it behind the camera during the shot or what?
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The kind of acoustic foam panelling you seem to be describing is designed treat reflections in studio spaces. Such products are typically designed for permanent installation, and are ill-suited to the needs of most location productions.

If you're looking for something inexpensive that you can quickly set up to take the edge off of an acoustically nasty location, get yourself a bunch of those quilted furniture-moving blankets. Sew some grommets into the edges and you'll be able to use those 3M adhesive hooks to quickly cover walls that are out of frame.

However, as Unclebob pointed out, room acoustics are only part of the problem. One of the great ironies of shotgun mics is that while they're great at rejecting off-axis noises, they tend to exaggerate room reverb. If you're going to use a shotgun mic on an interior shot, then you're going to have to get those acoustics under control AND be very careful about mic placement (on-axis, nice and close).
 
As others have said, theres a world of difference between soundproofing and sound treatment.

Soundproofing generally involves some serious construction. Building rooms within rooms, floating floors, and all sorts of fun stuff. Check out John Sayer's Forum, tons of advice there on studio construction.

Sound treatments can help a little, but if you're not able to fit a basic $150 converter into your budget, you're not going to be able to buy enough foam to properly treat the room. Again, it's intended for permanent installation. You can grab a bunch of sound blankets to hang up which can help out a little, but you'll get better results if you use a hypercardioid mic rather than anything with an interference tube design. Even those dirt cheap CAD mics Noiz posted about the other day could be an option for just getting started.

I think at this point I think you'd be best off picking up some books, and/or the DVD sold on this site. And of course, check out the stickies and do some searching (That should be this board's motto). Taking the time now to study some of the basics will save you a lot of time and money in the long run.

And remember, the only dumb question is the one you don't ask. (Well, that and "I want perfect sound and I have $12.95, what mic do i buy?")
 
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From - UB - The "roomy" tone is an issue with the mic itself. A shotgun (lobar pick-up pattern) mic is supposed to have a great degree of off-axis rejection, meaning that is doesn't pick up sounds from the sides. Using a mic with a cardioid pick-up pattern will greatly reduce the "roomy" effect.

CRAP!!!! I thought when I was buying a shotgun "Condensor" mic it was the same as a cardioid pick-up mic. I must have gotten the words confused. Crap! So If I shoot indoors 90-95% of the time I shouldn't have bought a shotgun mic?

Also I'm reading your myspace page now. This is what I am looking for. I need a place to start and this will be very helpful indeed. Thanks!
 
Soundproofing is vague. There's two things studios due, Isolate (best way being a box in a box or floating room) in order to keep sound from bleeding in and out the room, diffusion, and absorption.

Your problem (if room not mic related) is treatable with proper diffusion and absorption. Uneven surfaces diffuse. Porous, soft materials absorb.

Different surfaces reflect sound differently though. People usually use wood in diffusors and foam (non-flammable always) for absorption.

Auralex have nice cheap solutions, I like the max-wall, used to use those, two that I'd set up in a corner (work alone, and its fairly quiet where i used to be).

Low frequencies are pretty big, physically, and they cause trouble in corners, places you want to absorb in if you want a dead room sound. Your high end will be easier to treat, as the waves are smaller and decay faster.

Let me know what you end up doing.

My old boss had one room with a wood frame built, fabric stretched tencm away from each wall/ceiling. Very dry sound.

Do you want your room to be dry? or to have a certain character? important question to think about imo.

cheers

t
 
yeah dude. no shotgun. large diaphragm condenser in the middle and two overheads if you're going all out, and if not i swear to you in the right room an sm57/58 could do wonders more than a shotgun.
 
richke said:
CRAP!!!! I thought when I was buying a shotgun "Condensor" mic it was the same as a cardioid pick-up mic.
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Nope.

"Condensor" refers to the way the microphone converts vibrations into electrical signals (as opposed to a "dynamic" mic, for example). Condensor (or "capacitor") mics are available in pretty much any pickup pattern.

Cardioid or Hypercardioid pickups are typically preferred for reflective interiors.

richke said:
So If I shoot indoors 90-95% of the time I shouldn't have bought a shotgun mic?
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I wouldn't say that. A shotgun mic is an indispensable tool in many situations, including a number of interior scenarios. However, it may have been naive to assume that one mic would work for all situations. Moreover, a shotgun mic CAN be work just fine in an interior, provided you're very careful about mic placement and the location isn't too reflective.

Those forum stickies can save you a fortune, as can the various other educational materials mentioned. I would also add that renting gear before buying it can save you from some potentially nasty surprises.
 
SMuir said:
Nope.

"Condensor" refers to the way the microphone converts vibrations into electrical signals (as opposed to a "dynamic" mic, for example). Condensor (or "capacitor") mics are available in pretty much any pickup pattern.

Cardioid or Hypercardioid pickups are typically preferred for reflective interiors.


I wouldn't say that. A shotgun mic is an indispensable tool in many situations, including a number of interior scenarios. However, it may have been naive to assume that one mic would work for all situations. Moreover, a shotgun mic CAN be work just fine in an interior, provided you're very careful about mic placement and the location isn't too reflective.

Those forum stickies can save you a fortune, as can the various other educational materials mentioned. I would also add that renting gear before buying it can save you from some potentially nasty surprises.
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Thanks for the info. Sucks I never really wanted to get into audio at all. I was just trying to get some stuff so I had the equipment for someone else to run who had some minor experience. But I'm finding he isn't much help either. So now I'm LEARNING!!! :)

People have tried to help before but really never recommended anything I could afford so I did what I could with the info I was told and stumbled across.

I will make this work!!!!! :)
 
greymog said:
yeah dude. no shotgun. large diaphragm condenser in the middle and two overheads if you're going all out, and if not i swear to you in the right room an sm57/58 could do wonders more than a shotgun.
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Are we still talking about production dialogue? The setup you describe sounds better suited to mic'ing a band, and singularly ill-advised for most production sound situations.

My apologies if I misunderstood the post.
 
The recommendation was for a cardioid or hypercardioid for indoor work. The CAD mic that Noiz posted was the CAD CM217. You'd have to ask how 'good' this would be for voice from the folks who would know, but for $59 a pair from the following source, if it is 'good enough', $25 for a mic to get you on, can't be all that bad...


http://pro-audio.musiciansfriend.com/product/CAD-CM217-Condenser-Mic-Buy-One-Get-One-FREE?sku=271324

The same site has the item you found at Guitar Center, for about the same price:

http://pro-audio.musiciansfriend.com/product/CAD-GXL3000-Microphone?sku=270366
 
SMuir said:
Are we still talking about production dialogue? The setup you describe sounds better suited to mic'ing a band, and singularly ill-advised for most production sound situations.

My apologies if I misunderstood the post.
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This isn't for a band. It is for short films I do that usually contain a lot of dialog.
 
JordanBlock said:
Yeah, Greymog's advice seems to be more for drum overheads. Large diaphragm condensers aren't going to be a great idea for production, generally.
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that's what I kinda figured after reading. I am going to work with getting used to my shotgun and go from there. In the other thread it is helping me get rid of the hiss...but this is more to help out with my setup on location which is typically in a kitchen, living room(with wood floors and bare walls).

So I think UB has pointed me to the right direction. I just got freaked out when they said "NO SHOTGUN!" :)
 
It's true that a shotgun is generally not the best mic for indoors, but you can still improve the sound you're getting with it, at least a little. You'd still get a better result with a more appropriate mic for the room, but hey, that's not always an option. I'm pretty sure there's a thread or two on portable acoustic treatments on the John Sayers board I linked earlier.

Cover up those bare walls / floors that that aren't in the shot. Experiment to find the best place in the room to set up, there will be places in the room that sound better than others.

If you don't already have good headphones, get some. Sony MDR7506 or Sennheiser HD280 are the most recomended for production work.
 
greymog said:
yeah dude. no shotgun. large diaphragm condenser in the middle and two overheads if you're going all out,
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Large diaphragm mics are, again, for a different application. Just "hanging" mics to capture production sound is a pretty lazy way to do it and will not capture the best sound. If it works so well why don't professional production sound people use this technique? Because it's far from the best option. I would like to hear some of your work.

greymog said:
...and if not i swear to you in the right room an sm57/58 could do wonders more than a shotgun.
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A Shure SM57 or -58 is not a good option for production sound. They are meant for close-in music applications. Being dynamic mics they require a fair amount of gain to reproduce properly and increasing the gain on the budget mic pres, etc. will just increase the noise problems he has delineated in another thread.

Richke - From which vendor did you purchase the gear? You will have to check their return policies to see if you can return anything.

Just as an aside... you should buy on a regular basis from an established, reputable vendor. Having established that relationship you should get better recommendations on gear, easier returns and better deals (and may have avoided some of your current problems). My continuing loyalty to my vendors/salespeople has reaped enormous benefits. When my studio was flooded my guys at Sweetwater and B&H got me copies of receipts for insurance purposes, and assisted me in getting free reauthorizations for my iLok, saving me thousands - which I, of course, spent on more gear - and they gave me some extraordinary deals.
 
It's the first thing I bought and I bought it on ebay from musiciansadvocate. I'm still getting misxed info on whether the shotgun is good or bad. I know another film guy who does features and he loves my mic I bought and says it will work. So I'm going to get an external recorder and hook that up and see how it sounds. If the buzzing is gone then I will move to your Myspace info(which was awesome) and start getting the room sounding better.

I can return and they seem cool about it...but I'm going to try one more thing before I go that route.
 
I would upgrade the NTG-1 to the NTG-2. The NTG-2 uses an internal battery to supply its own phantom power. Get the Da Link that Noiz2 recommended in the other thread. You can return all the rest of the stuff. That's all you really need to get started. (KISS - Keep It Simple, Stupid.) Your biggest problem would be controlling the audio levels with the camera controls and monitoring the audio while you are shooting.
 
unclebob6958 said:
I would upgrade the NTG-1 to the NTG-2. The NTG-2 uses an internal battery to supply its own phantom power. Get the Da Link that Noiz2 recommended in the other thread. You can return all the rest of the stuff. That's all you really need to get started. (KISS - Keep It Simple, Stupid.) Your biggest problem would be controlling the audio levels with the camera controls and monitoring the audio while you are shooting.
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The abiltiy to monitor my audio has just made me think maybe I need something more than just the cable. Sure if everything works it's cheap but how am I supposed to know what we captured if I can't hear it. With onboard it was known...I knew how it was going to sound but with external mic you have bumping sounds that could occur and I don;t want to find that out in the next day of editing.
 
This is tricky. You are getting good advice. The problem is we're all supplying advice based on guessing what you are trying to do. Give us some information.

The room you ar working in, what size is it, what are the walls made of? Anything in the room that will absorb sound - like sofas, beds etc? How far away from the talent will the mics need to be - as in, can they be seen, and placed close, or because you don't want them in shot, they must be further away.

Answer these questions and we can move on a bit.

Probably worth a few comments on using rifles in rooms. One of the main advantages of shotgun mics is that they have a narrower acceptance angle, meaning that sounds coming from other than the main direction are attenuated. You can then add a little gain to bring the distant sound level up to a more respectable level. Inside, one snag is that if you are in a room with hard, reflective walls, then sound bounces around. Worse of all is that walls tend to be parallel to each other meaning that sound bounces back and forth across the room. As the mic will be pointing at these reflective surfaces then what you can do is try to control these a little behind your subject, as any of these bounce arounds will also be recorded - generating that characteristic 'boxy' sound that small rooms have.

The thing you can do is try to control these reflections. Very rough and ready methods often produce really worthwhile solutions. As sound bouncing around is the main cause of the boxiness, try hanging something like a duvet up behind the camera as high as you can get it. Microphone stands come in quite handy here. This removes reflections from the wall behind bouncing back at the other. You can hear the difference it makes. Looks damn silly, but so what?

Duvets have little effect on low frequencies, but do tame higher ones fairly well.

So a shotgun mic is never a wasted investment, but the sound it produces could be unpleasant because of the environment. Cardioids and hyper-cardioids just need to work closer in, but this usually means the ratio of wanted to unwanted sound favours the wanted. To explain, a shotgun 4 feet from the subject, might have the reflected sound from the wall 4 feet behind the subject quite clearly heard, where as a cardioid 1 foot from the subject won't hear very much from the wall as its 4 times the distance away. If you double distance, you quarter the level - so a cardioid can sound cleaner. If you did the same test in a field, with no reflections, then there won't be reflections, making the shotgun more useful, and of course, invisible. Indoors, things don't work the same way.
 
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