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Nathan P

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First off, I'd like to say that this forum is an awesome resource, It will probably save me a chunk of change! Next, I have a few questions. I read through Greenmachine's entire tutorial thread, and am sold after hearing his recordings, they are every bit as good or better than the recordings I've heard from the $70 AT Pro 24 I was previously sold on getting (Probably still will, just for portability, maybe get it as a gift for Christmas or something). Now, I'm going to be using them to get greatly enhanced sound from my camcorder, and also for recording my vocals and guitar for the songs I've written. I was wondering how to mount them to the camcorder? I don't have an accessory shoe, I've seen things that mount to the tripod mount, and I really like them, but how would I get the stereo separation without my head in between? I'll be building some small shock mounts for them of course, how far apart do they need to be? What can I use to get the separation? The camcorder is a Canon Elura 100, so I don't want something completely massive mounted to my rather small camcorder.

Thanks,

Nathan

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how would I get the stereo separation without my head in between? I'll be building some small shock mounts for them of course, how far apart do they need to be?

It's nice to have your head (or something vertical) in between, but you'll get good stereo separation without it, just by putting the mics six inches apart. Your brain decodes some very subtle differences between the signals from each mic.

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I know the problem, my camcorder's (omnidirectional?) mics were also placed with virtually no distance in between, both directing upwards, not even angled to the sides. The stereo seperation was virtually non-existing and directing them upwards didn't exactly help to preserve fidelity either.

What i did was to replace these built-in mics with a 3.5 mm stereo jack for an external microphone. For convenience i use a DIY T-mic with approx. 20 cm between the elements. For highest fidelity, i "wear" the mics close to my ears (HRTF, head as a separator).

I did a test with mic placement a while ago:

http://forums.minidisc.org/index.php?showtopic=11297

http://www.taperssection.com/ is also a good place for anything mic related.

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My camcorder has a 3.5mm jack for external mics, so no mods neccessary, thank God. (Way to expensive thing to modify for my tastes, at least when it's new). I may just try doing it on my head, but I was hoping to get something mounted to the camera so I could move more freely. I ordered 4 of the 61A capsules, and I'm going to build a battery box for them (Even with a volume control to be put into mic in, it will give me much more flexibility, and lower chance of distortion, plus, I can always plug straight in if need be). I'll probably build one set into a head mounted system (Maybe mount them to a pair of wrap around headphones or something), and another I'll play with. Is there any problem with the head mounted units when you move? I'm afraid that if I turn my head too much etc. I'll get too much noise. When mounted to the camcorder a shock mount is neccessary to isolate the mic from movements and the sound of the motors in the camcorder, I don't know if your body would make as much noises. Wouldn't that look funny, tiny shockmounts mounted to your glasses :D

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You're hit on the major problems with recording with head mounted mics Nathan. They give you a great sound if you have a good setup but yes you might get some noise from cables moving and also you need to keep your head pointed in the right direction to get the proper sound.

It certainly can be done as many prove all the time. It just takes some discipline and a good setup that will minimize cable noise. It mainly takes some practice working out the bugs after you get your equipment.

You can find lots of good advice on how to get it done on this board and others. If you set your mind to do it can give you great sound. Nothing is as realistic as a binural mic setup but in answer to another of your questions yes it does matter if you play it back on speakers. You might lose that "sounds like you're really there" quality to some extent if you play back the sound with speakers.

Also it does matter if you actually use your head as the mount for the mics. Just placing mics a few inches apart is not quite the same as mounting mics essentially at the point your ears pick up the sound. You do get some blocked sounds from the opposite side when your mics are mounted near your ears so again it mimics the natural setup of your ears better than anything else.

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What are the best things to do to minimize cable noise etc? What is an easy way to mount the mics (I don't wear glasses) to your head? Oh, I have no choice on the speakers, most of my video will be going to my class's graduation video, can't have everyone with headphones. I do know what you mean on the "Like your really there" thing, I was listening to one of Greenmachine's recordings, and I actually looked around a few times cause I thought my mom was calling me when someone in the recording shouted.

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I don't wear glasses either, but for recording i do. ;) I was lucky to find sunglasses without any darkening effect (reading glasses without magnification would be nice too i guess). Although i try to be disciplined (i.e. not too move too much) during a recording, cable noise is really a non-issue most of the time with this setup.

For speaker playback i'd suggest to use the same (or a similar) miking technique, but to move closer to the source, i.e. not to include too much room reverberations, otherwise it will sound too muddy if played back via speakers in a room. It is this "room in a room" effect that gives you the impression of a muddy sound. For headphone listening, far miking is usually o.k. or even preferred.

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FWIW Nathan I have heard of people mounting mics to a hat too. It doesn't look quite as strange as wearing sunglasses in a dark concert setting. :) Some people mount the mics to an over the head headphone mount. People like the headphones that put the headphone speakers into your ears sideways because the speakers can essentially be replaced with mics and it's hard to tell the difference. Of course it looks a little strange to be wearing headphones at a concert too. Also the kind of headphones that mount directly to your ear can be used to mount the mics. If your hair is long enough to cover your ears it's really hard to see the mics with that setup.

The only problem you might have with the Nady is that it is kinda long to mount to a camera. You can get some bouncing if you don't have a good clip holding it up. Also it is a very sensitive mic and it can pick up quite a bit of reflected sound because of this. Using an inline volume control or an attenuator will solve most of that problem. It's a decent mic but all mics have their shortcomings. I'd just make sure you got in some practice moving your camera around with the mic mounted to make sure you aren't getting a lot of noise with the clip you're using. I connected my camera to my home stereo and tried out my clip so I could hear what caused noise and what didn't.

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Clip? I will be using an L-bracket and making a good shockmount for the Nady. I chose it over the AT Pro 24 because of the frequency response, I do alot of music, and I can't have the bottom octaves chopped off, 30hz is much better than 100hz, this is especially emphasized by being in the low end, 20hz-40hz is one octave, so the Pro 24 wouldn't be recording between 2 and 3 octaves that the Nady would pick up. I know this has it's disadvantages, wind noise etc., but it's worth it I think. Because I'm using an L Bracket, I'm not worried about the mic length anyway.

Oh, I'll probably mount the headphones to a pair of Sony behind the head "street style" headphones from Wal-Mart. I've been using these phones for a few years, and for $14 they give good sound, so I can monitor when I want, and also they are very secure on your head. I'll probably make the mics removable, as versatility is important to me.

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A "clip" is a holder for a mic. A shock mount isolates the mic from any vibration noise etc. but it too technically has a clip as a part of the design. It's just a term that I guess isn't as common as some other terms. The clip part of the mount needs to be longer to deal with a longer mic well. It will keep the mic from bouncing around a lot. Some designs of shock mounts can allow the mic to bounce too which can introduce noise. I'm sure you'll figure out a good way to deal with that possibility since you're building your own mount.

Here's a website where they use the term "clip" quite a bit if you're interested. Sorry for the confusion.

The headphone mount sounds like a good idea. If the over the head part of the headphones isn't too thick it's possible to hide it under your hair or a hat or whatever. These are common stealth recording techniques.

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Actually, it goes behind my head, I would mount it to the part that wraps up and over your ear, before it attaches to the headphones themselves. Oh, I just got the capsules in today, they're smaller than I expected! I'm really excited to get these things working. What's the best way to match them? I don't have anything with levels to check with at home, but I can use some of the equipment at Church or School to do it.

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About the matching: Connect two capsules, hold them as close together as possible, play back a constant test signal through one loudspeaker (could be a sine, saw square wave, noise, etc., try at different frequencies). Put your MD recorder in record mode with manual levels. Move the capsules forward and backward to/from the loudspeaker while observing the record level meter. The two dots should rise and fall relatively simultaneously (in the upper region, which has approx. 2dB between the dots, in lower regions the resolution is much lower). Monitor the signal with (preferably closed) headphones. In a quiet surrounding (turn off the test signal), turn up the levels of the recorder and make sure the self-noise from both channels sounds relatively similar. This method works relatively well for its simplicity. Be careful/fast when (de)connecting the capsules, they're relatively heat sensitive, excessive heat can damage them.

Oh, and by the way, i have experimented with headphone mounting a while ago. the results were not so promising, got plenty of handling noise (of course this depends which kind of headphones you use, how you mount the mics, how you lead the cable, etc.. Glasses mounting gave much quieter results.

By the way #2: Live monitoring is a no-no with headphone mounted mics, you will get lots of (acoustic) feedback, which will also be on the recording.

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Something else to try is a dummy head if you aren't concerned with stealth recording. Sennheiser made them years ago, as well you can go get a foam head from a hat making shop, or get a store to give you a display head.

The advantage of a spare head is that you can place it optimaly and don't have to worry about cable noises etc.

Just my $.02 worth,

Bob

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Well, My battery Box is finished, and it works fine, but I didn't have such good luck with the mics. I tried to solder them with my old soldering tip, which is messed up, and they overheated and have no sensitivity left, I can blow right into it or put it into my mouth and it barely sounds. I quit while I was behind and bought a new tip before I started on the batt box, much better! The solder actually melts! Anyway, the batt box turned out great, although I burned myself good covering it in hot glue. I used carbon film resistors and nonpolarized caps, but it still works, fine, I didn't bother matching the resistors for this, on a video you won't be able to tell anyway. I have 1 working mic, and it sounds great, but the other three I bought got ruined. One had it's contact ripped off when I was trying to bend the wire on it (Oops) the other two were destroyed by my soldering tip (I tried to sharpen it as it got bent, and I guess it was plated with something solder sticks to, the inner metal was anti solder or something), so I have to buy a few more. Oh, if you guys need a cheap connector for the batt and can't find the batts like greenmachine had, you can find some 9V batts that have circuit board like end plates instead of paper (Fibergalss reinforced, I got mine from an energizer), I just soldered it onto the board and hot glued it and it works fine. My board is rather larger than yours greenmachine, but it works so I'm happy. Anyway, I'll order those mics and let you guys know how it works when I get them!

Oh, I found out that my camera doesn't have a powered mic output, it says it requires a battery powered mic. Does this mean it's line level?

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