Shooting audio in a bass heavy enviro

D

dog666

Member
I have been shooting a music documentary with my mic plugged directly into my DVX 100A camera, and my levels are not peaking, I try and keep them in the the yellow at the highest. My problem is that this style of music is VERY bass heavy (Dubstep) and when I go to look at the footage, certain tracks that the dj's play are distorted (cause the bass is real heavy) but the levels aren't peaking at all.

What kind of mic do I need that can handle this situation? Are there mics made specifically for handling heavy bass? Or is there some other way around this problem?
 
1. Are you sure the bass wasn't distorted in the situation? It often is at concerts...

2. Your mic may have been distorting. Try a dynamic mic with a high SPL rating!
 
The first problem you're facing is one of monitoring. The camera's VU meters will tell you if the track is overloading, but they tell you squat about what you're actually recording. A good pair of closed-back headphones are absolutely essential, doubly so since you're shooting musical footage. Loud music will cut right through the standard-issue Sony MDR-7506 headset, so you really need a pair of Remote Audio's HN-7506 isolation headphones. Recording audio without monitoring headphones is rather like shooting video without looking at the view-finder.

It sounds like you're running into problems with high SPL (sound pressure level) recording. Condensor and back-electric condensor mics have a "max SPL" rating (measured in dB) in their spec sheet. Once you exceed that SPL, you'll start hearing distortion from the mic itself, regardless of the rest of your signal chain. Some microphones have a "pad" (eg. -10 dB) that can be switched in for excessive sound levels. It would be helpful to know what specific mic you're using, so that we all can reccomend any quick-and-easy fixes. However, odds are you'll have to rethink your mic'ing strategy.

Dynamic mics tend to be much happier in high-SPL situations, often being used to close-mic kick drums and amplifier cabinets. If you're recording in a high SPL situation, a good dynamic will be your best friend. My go-to mic for the loud stuff is an Electrovoice 635a(b), They're cheap, camera-friendly (as a handheld interview mic), very easy to position (omnidirectional pattern), resistant to handling and wind noise, and insanely durable. As with most dynamic mics, their output level is pretty low, noisey and dull-sounding when compared to a good condensor mic. However, get it in close to something really loud and it becomes loads of fun. If you can get it in close to the nearest speaker stack, you'll be partying. It would also work well mounted on-camera, although the omni pattern will tend to pick up more room reverb. If at all possible, position the mic as close as possible to the sound source.

The Shure SM-58 or SM-57 would also be good choices, though their cardioid pickup pattern will make positioning a bit more fiddly. Up-close and on-axis, they'll sound brighter and richer than the 635, but positioning them is comparatively difficult. They're also nowhere near as useful as the 635, which makes a great handheld mic.

[looks around to make sure noone else is listening]

I tell you what, I've got a bit of a secret weapon for recording bass-heavy music. Most of the mic's that find their way into production sound kits are geared towards vocal recording, and as such they stop being very useful down around 80 Hz. For deep bass... I mean really thunderous, teeth rattling, bass that'll suck the air right out of the room... you need a slightly different strategy. If you already have a mic to look after the "normal" frequency range, try connecting a kick-drum mic to you're second audio track. An AKG D-112, for example, won't give you much high- or mid-frequency detail, but it'll catch all that huge bottom end down to around 16 Hz.
 
Hey thanks for the feedback. I forgot to mention I also have for a second recording source, a fostex fr-2le digital recorder, but that also is giving the feedback, so I'm positive it is the mics I am using, I have 2, Audio Technica AT-897 condenser mics, one for the camera, and one for the recorder. (the recorder sounds beautiful in normal circumstances.) I will definitely look into these suggestions and thanks!
 
You mentioned "feedback"... are you referring to "distortion", or are you picking up an oscillation somewhere?

The AT-897's are the likeliest culprits. Their max SPL is 129 dB, but that drops down to 115 dB if you're using the internal battery rather than phantom power. They're decent dialogue mics, but they'll be easily overloaded in a live music environment.

When you're shooting a live music performance, there are a number of ways to go about mic'ing and recording it. If you can get a "dry" line-level feed from the sound reinforcment mixer, you should give that a try. As for mic placement, there are two basic strategies: mic the speakers or mic the crowd. Mic'ing the crowd (eg. a stereo pair on a mic stand or on-camera) is a great way to get the that "you are there" feel with the ambience of the venue and the crowd, but you may well loose that tight up-close sound depending on where you set up. On the other hand, mic'ing the speakers can provide a bigger, more intense sound, at the cost of the atmosphere of the venue.

For best results, a combination of strategies could be used. For example: use an SM-57 and a D112 to mic the closest speaker stack, and set up a pair of 635's on stands about 50cm apart, above and behind the camera, parallel with the stage. This would take up all four available tracks (2 on the camera, 2 on the FR-2le), but it would give you a great deal of flexibility in the mix.
 
Heh, I could read Stephen's posts all day long...

I'd like to throw in the venerable Electro Voice RE20 as it has a foot in both the voice and instrument close-mic world. There's actually a used one on B&H for 299 as we type. Those things are tanks.
 
You must log in or register to reply here.
Back
Top