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Re: Microphone on a limited budget?

Subject: Re: Microphone on a limited budget?
From: Walter Knapp <>
Date: Sun, 27 Oct 2002 13:02:40 -0500
hilly512000 wrote:
> I am about to buy a reasonable quality Mic, and really do not know 
> much about what is on the (Australian) market. The budget is limited 
> and I kind of liked the look of the Sony stereo condensers. 
> Does anyone have any recomendations, either for or against? This is 
> just a fun thing for me at the moment, I am recording onto tape and 
> am into recording frogs for species identification. Any advice is 
> apreciated.

Well, it really depends somewhat on what you mean by limited budget. If 
really limited, a homemade parabolic will give you about the most bang 
for the buck. It's hard to build a good stereo one, however, if you have 
to have stereo.

The sony MS stereo mics, particularly the ECM-MS957 are pretty good for 
close in work, say 5 - 10'. You can pick up from greater distances, but 
unless the frogs are loud, not all that far. They have a nice stereo 
field. I like MS stereo better than the XY type as the mid mic is 
pointing at your aiming point so gets optimum quality. In XY both mics 
are pointing off to the side, so at mid you are picking up off axis on 
both mics. This can work ok with higher quality mics, but low end mics 
are often not that good off axis.

The distance limitations will be the primary problem with any regular 
type microphone. They are all designed to work best at a few feet.

If you cannot get that close to the frogs you probably will be having to 
think about a parabolic mic or a shotgun mic with preamp. The parabolic 
is cheaper than the shotgun route if you build your own. Hardest part is 
finding a reflector, and I've no idea about sources in Australia on 
this. Edmund Scientific does sell a aluminum reflector, and the telinga 
reflector bought as a spare part will work very well. Some small radio 
reflectors can be used if they are parabolic and light enough. The 
Edmund one is designed for a solar cooker, another area to check. Be 
sure your reflector is no smaller than 50 - 60 cm. Low frequencies will 
be limited by the size, the larger the size the lower the frequency it 
will provide good gain for. At the same time, the larger the reflector 
the more unwieldy it becomes. So there is a compromise range that works 
well.

It is possible to make up a mold and make a fiberglass reflector. It's 
hard to make them light, and it's a lot of work. It is important that 
the shape be parabolic, which precludes the more common spherical shapes.

I put up a page on one concept for making mountings and so on:
http://frogrecordist.home.mindspring.com/docs/quickparabolic.html
The same page also contains a photo of one I made and used for a number 
of years. To record frogs for site documentation. I now use a Telinga 
Pro V with DAT Stereo element for that.

Obviously the better the mic the better the recording can be, but the 
parabolic provides considerable gain before the mic. So even fairly low 
quality mics will work reasonably well, particularly for species 
identification, where mic noise is not as objectionable as for 
entertainment recordings. The design above uses a Sony tie tac mic. Any 
small mic is worth trying.

If you go the shotgun route, they don't provide any extra gain over 
regular mics, just limit the angle of acceptance. So, to pick up at 
distance you have to use considerable amplification. Only mics with very 
low self noise can do this at all well, and most recorders don't have 
preamps that will provide clean gain at that level. That leads to 
expensive low noise, high sensitivity shotgun mics coupled with a 
separate low noise mic preamp. A fair amount of money.

Walt





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