Newbie In sound need help

[Ong Wan Shu]

hi all,

Gonna make a short film soon and need some advice. 1st of all, let me share my bad experience on sound on my previous short film.

I managed to borrow a mic with a boom. Because I know nuts about mic then,i told my fren that I just need a mic with boom. So he gave me a boom, with this mic that has a dome around it. THe dome is long,about 50-60cm long.

The result was not what I wanted. The shoot was in the 7th storey of a 24 floor apartment,and while the conversations can be heard,the mic also picked up a lot a lot of unwanted noise like traffic noise from the road beside the apartment,and some humming sound which later I heard from fren its the sound of eletricity current in the cables.

THis time round, this place I go is able to rent me 3 x Sony 77b clip on mics. He says it is best choice for conversation and to kill the environmental sound.(THis time the shoot is indoor,and i really dun want the air con sound,cable sound etc). However,another guy suggest to me that using a boom with the mics is better because when the actors are not speaking,it will be TOTAL silence, not even some "atomsphere" sound. He says it will sound "fake" in his opinion. After some thought, i realize there will be points i need this atomsphere. eg. Foot steps sounds, magazine flipping sound,closing of the small cosmetic powder box.

I shld be shooting with DVX100, 24p standard.

My question is

1) IF i use the boom, and its pick up pattern of the surrounding is so much that the atomsphere sound rivals the conversation, can it be save in post production? As in can i accentuate the conversation and dimmer the atomsphere in post untill its acceptable? If so, is there any website that teach me the basics on this? I can't afford to buy books from the States or Amazon from where I am. I shld be using either premiere 6 or FCP3.

2) ANyone can recommend a few models of boom mics that pick up sound more from a direction but just a bit from surrounding? the last thing i need is a mic that picks up at the extreme ends. Only 1 direction only or global pick up. Is there a mic that I can adjust this pattern according to my needs? I may be able to find the mic from my fren if you guys can name me a few models (not the super high end ones of coz)

2) Can I use the sony 77b to pick up the sound of foot steps? since the part when they are walking, theres no conversation.What I tot was just leave the mic on the floor where its out of frame.

3) If the guy has this mic clip near his neck, can the mic pick up sound of a magazine filpping in front of him? same for the small cosmetic powder box closing in front of a lady after powdering her nose.

4) Any "cheating" method to create the atomsphere sound? I want some atomsphere sound BUT not the air-con and cables noise.

5) Personally, i dun hear atompsheric sounds from the films i watch.(Maybe i am not aware,i am more a visual person than sound) Is it really that weird that there is REAL SILENCE (not even atomspheric sound) in a film?

Thanks a lot!!!

Cheers
Wan Shu

[Martin Garrison]

Ong,

You need to keep in mind that all microphones pick up sounds from all directions. Some microphones are louder from the front half than the back half (cardioid), but the sounds will still be there. The best way to emphasize one sound over another, is to have your mic closer to the sound you want to hear, and further from the sound you don't want to hear.

[Mike Butler]

Question 1: If the dialogue is buried in background noise, it is very difficult to pull it out. Using a directional (cardioid) mic will help if it is aimed directly at the desired source, AND as Martin points out, is close to the wanted source. I mean really close. In fact, whenever possible I like to use a lavalier mic on the person's shirt collar if I can make it not look too conspicuous. The whole idea of the boom is to get the mic really close to the person speaking, just outside of the frame (you will have to tell your boom operator when the mic is visible in the shot so he can pull out just far enough). Even then you won't have TOTAL silence. But hum is avoidable, you need to have good quality audio cables that are properly grounded.

As for question 5, if you are watching films, keep in mind that there is extensive audio work done after the film is shot, and the final audio doesn't resemble what went down on the original shots. Footsteps and other sound effects are the results of many hours of work by Foley artists and Foley mixers. You can also record sound effects and add them in when editing.

You can achieve dead silence too when you want it, just by turning down or turning off the audio in FCP or Premiere when you want to. But you're right, it may sound "fake" without some atmosphere (otherwise known as room tone). If you want you can record some footage of the room when nothing is going on, then add it back in while editing. If there is too much outside noise from traffic or other things, you may have to think about moving production to a quieter location.

[Ong Wan Shu]

hi Mike,

A few more questions.

1) "But hum is avoidable, you need to have good quality audio cables that are properly grounded"

What kind of audio cables are grounded well enough to avoid hum?

2) "If you want you can record some footage of the room when nothing is going on, then add it back in while editing."

The way i understand this is that during editing,the real conversation will be in 1 audio channel,then the room tone is imported into another audio channel.And i will be able to adjust how loud i want the room tone relative to the real conversation. Did i understand this correctly?

3) I read from another website that in order to prevent hum, one way is to make sure the audio cables are not near any power cables. So will to help if i run my camera on rechargeable batteries? But the lights on the set have to be power by cables,how do the sound pple overcome that?

THanks for all your help!!!

[Mike Butler]

Hi OWS,

1) Well, definitely make sure you are using proper mic cables, these are shielded, preferably of the balanced type (the kind that use XLR connectors) if your equipment is compatible with this. Get the best quality you can find. Always make sure the plugs are plugged in securely and are free from dirt or corrosion. Shorter is better than longer as a rule, but you also want them long enough to route them away from sources of hum and noise. (see #3)

2) Yes, that's right. Editing is where you have the opportunity to make adjustments. Just remember that it is easier to add sounds as needed than to take out unwanted sounds that are recorded. I suggest that until you have had lots of practice, to center the pan (make the sound mono rather than stereo), it will be a lot easier to manage. If you add music, that can be in stereo.

3) Yes, keep audio lines separated from power mains as much as possible. Especially avoid running them parallel alongside one another, it acts like a transformer and the hum sneaks in. Electric motors (especially big ones like in air conditioners) are another thing to keep them away from. Running the camera on battery may help you if the camera power supply is inadequately filtered (leaving a little AC ripple in your DC voltage). You can test this by trying recording some footage on battery power and then some on mains power then comparing. Actually, FCP has audio filters to remove hum , but like I said it's harder to take out unwanted sounds once they are recorded.

[Ong Wan Shu]

hi mike,

Thanks for the answers. However, another question.

Whats the difference between recording in mono and stereo?

I think my other time with the bad experience i had i recorded in stereo although these is a mono option on the mic.

cheers
Wan Shu

[Mike Butler]

The simple answer is that stereo is recorded on two tracks and mono is on one. I avoid stereo mics whenever possible (too gimmicky for me) and invest in quality single microphones. If I really need 2-track recording I'll use 2 separate mics, it's too hard to place a stereo mic where it's best for both voices. The one exception I'll make is for those fans of certain bands which allow audience to record their concerts, you'll see a lot of stereo mics up on mic poles (plugged into portable DAT recorders). Any Allman Brothers Band enthusiasts here (Bro-heads)?

Don't be surprised to find out that a movie you are watching had its dialogue recorded in mono, and whatever dimensional sound imageing it has was added in post.

[Ong Wan Shu]

Many Thanks!!!