a bit of dilemma which mic to use?

K

kono

New member
hi,
i recently bought the edirol r-1 recorder. and i'm looking for a good quality mic for him. my main work is recording lectures. i can put the mic infront of the lecturer 12"-20" away from him, who sits during the whole lecture.
i have a couple of dilemmas which i need your help:
i want to mic to be as small as possible - which means maybe a lav one. i also want to pickup only the lecturer without any ambient noise (vents, a/c, audience questions ect...) - here i don't know what will give me this result. maybe the mic being a dynamic one, so lav is not much of an option cause most of then are condenser type. or maybe it can be a condenser one with cardioid pattern (which i listened to some sample's of this kind of mic and they pickup more ambient noise than i want to). maybe it's another characteristic of "sensetivity" so i should get less sens. mic?

bottom line, which mic should i use and it will be small enough to fit my pocket and also record only only the lecturer?

i'm enclosing the edirol r-1 specs:

Audio Input/Output
Input
(1/8" phone jack : plug-in powered compatible type)


Dynamic Range: 83dB

S:N 93 dB


Nominal Input Level (adjustable)
Mic input: -40dBu
(input level set to maximum)

Line input: -10dBu
(input level set to maximum)


Input Impedance
Mic input: 6.8 k ohms
Line input: 100 k-ohm


Maximum Output Level (adjustable)
9 dBu (output volume set to maximum)


Recommended Load Impedance
32 ohms


Frequency Response
20 Hz--20 kHz (+/- 2dBu)


Residual Noise Level
(input level set to maximum/output
volume set to maximum)
-84dBu


Signal Processing
AD/DA conversion 24 bit / 44.1 kHz


Power Supply
AC adaptor (included) or Battery Rechargeable Ni-MH AA x 2 or Alkaline AA x 2. R-1 has no charge function
 
no i can't for a couple of reasons. his table should be clear, and the edirol is quite big. second, you can't compare the quality i'll get from external mic to the internal mic's although they are good. and there are more reasons. i need ext. mic.
 
As far as avoiding background noise, the best mic on the planet aint gonna save you. Controlling your environment and getting the mic as close as possilbe to the sounds you want to hear (ie your lecturer) are going to make the difference.

Inverse square law=as you double the distance from the sound source the sound pressure becomes 6 db less. So each time you half the distance you increase the db by 6 compared to competing sounds (4' to 2' increase 6db, 2' to 1' increase 6db, 1' to 6" increase 6 db, etc).

The HVAC is something you would like to have control of. Turning off the A/C, if possible, (very often not) is only way to completely eliminate it.

Good luck.
 
I'd first try a lav mic clipped very close to his mouth. Sure, it's condensor with an omni pattern, but in my experience a lav works very well when clipped close to the mouth, attenuating many "environmental" type noises. Good luck.
 
I don't know if this will apply or if it is even practical but I remembered reading that the best way to isolate a subject from any surrounding noise (when using a shotgun, but it stands to reason it would apply to most mics) is to point the mic down toward the speaker or up toward him. Hope it helps. This is all I have on the matter. Let us know what your decision was and how well it worked. :thumbup:

One more thought...a lav dangling a bit from the acoustical tiles directly above the speakers' chair or lectern?

http://www.equipmentemporium.com/Tips on use of boompole.htm

The best way to isolate the person from the background is to boom them from above, so that the line of sight of the mic runs towards the person’s mouth and then towards the ground. (It is safe to assume that the ground or floor is not as noise producing as the background.)

Finally, the camera lens has the ability to SEE much further than even the best shotgun microphones can HEAR. A long lens can easily frame a tight close-up of a person’s face from 50 feet away; but the only thing that a mic would pick up at that same distance would be general background ambiance of everything in the entire wide scene. To achieve good sound, you have to get the mic as close as possible to the action!

Boom it from above if you can.

Overhead miking from a fishpole or studio boom is the most favored technique in the feature/TV/commercial industry. It is probably the best choice 90% of the time.
Generally, overhead miking will yield the most natural sounding dialogue with the least amount of mixing and editing effort.

It provides a pleasant blend when there are multiple actors involved. Two, three, even a small group of people interacting can all be recorded from a single mic.

A mic on a fishpole or boom allows for a fair amount of physical activity and movement by the talent. Actors are free to enter and exit a scene, move around, jump around, climb around, etc. There are no trailing mic cables to inhibit their range of motion. Nor are there the frustrations of dealing with finicky wireless mic systems with their inherent problems of environmental RF interference.

An overhead mic will pick up sufficient sound effects, footsteps, and hand-prop noise to give the soundtrack a full texture. Because the faces are closer to the mic, dialogue will dominate the track, but other sound effects will still be audible.

Audio perspective is easier to maintain with an overhead mic. On a wide master shot, the mic tends to be higher so that the resulting dialogue seems thinner and more “distant”. On close-ups, the mic can be lowered giving the sound much greater presence and “nearness” to the screen.

But what if there are physical obstructions in the set that prevent deploying a microphone from overhead?

That brings us to the next option: Boom miking from underneath. The boom mic can be aimed upwards at the talent from knee, thigh, or waist level with good results. The sound will be slightly more bassy than miking from overhead, but still quite usable and acceptable. Note that a mic aimed up at a person tends to pick up more of the chest cavity, thus accounting for the increase in bass.
Click to expand...
 
hi everybody, thanks for the mic placement tips ect.. apart from this what i need is recommendations on specific models of mic, that will be great. thanks.
 
kono said:
no i can't for a couple of reasons. his table should be clear, and the edirol is quite big. second, you can't compare the quality i'll get from external mic to the internal mic's although they are good. and there are more reasons. i need ext. mic.
Click to expand...

Will the subject be aware he/she is being recorded or will he be an unwitting accomplice like Eddie Murphy's, Kit Ramsey in the hilariously funny, "Bowfinger."

25s.jpg


And would you really be Steve Martin???
:thumbsup:
 
i read good opinions about the B6. but the thing is that it's omni, and i thought that for reducing backround noise i should use a cardioid one. no?
i also gathered a list of some cardioid lav. any recommendations:SONICSTUDIO LAPEL MIC, CORE SOUND CSB or LCB, SENNEHEISER ME104, AT-853-SP, MICROPHONE MADNESS MM-HLSC-LAPEL based on Sennheiser MKE-40 capsule, SHURE MX185BP, AUDIO TECHNICA AT831B, AKG LM 3 L + AKG CK31.

thanks.
 
so, what omni can you offer me?
just for the mention, i'm no cardioid fan, it's just that i need to cancel as much backround noise as possible. if there are other options than cardioid mics i'll be glad to here about them.
 
yeah alright, but what about backround noise canceling. i guess the omni's will be bad for this, no?
 
I refer you back to the Inverse Square rule. 99 percent of lav use is omni. What makes them "work" is how close they are to the subject.

No mic "cancels" background noise, all it does is attenuate it slightly. Most of work put into getting rid of background sound is getting the mic in tight and "controling" background noise.

To sum up: you do not want a cardiod lav. :)
 
so i was thinking maybe about a regular cardioid mic like one from AKG SE391 or maybe the SENNEHEISER K6 system. they are not that big, and i think they have good quality? any suggesions? other companies maybe?
 
kono--
I'm not trying to give you a hard time, but an omnidirectional lavalier placed close to the lecturer's mouth is about as good as you can get. If you need a podium mic, the Shure SM-58 is a popular model. Using a shotgun for a lecture is absurd. The Sennheiser K6/ME64 combo is about 8 inches long.

Your best solution is to do what soundmen do for lectures: we use omni-directional lavs. If you want to try something different, by all means, go ahead.. It's the only way to learn. But, I think you'll come around to using a lav for this particular application in the end. Remember, the people recommending the lav probably own several and know when to use them.. It's pretty decent advice if I say so myself.


kono said:
i want to mic to be as small as possible - which means maybe a lav one.

bottom line, which mic should i use and it will be small enough to fit my pocket and also record only only the lecturer?
Click to expand...

kono said:
so i was thinking maybe about a regular cardioid mic like one from AKG SE391 or maybe the SENNEHEISER K6 system. they are not that big...
Click to expand...
 
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