[Top] [All Lists]

Re: Esoteric Mic Builds: Multi-style Capsule SASS

Subject: Re: Esoteric Mic Builds: Multi-style Capsule SASS
From: "Peter Shute" pshute2
Date: Mon Feb 26, 2018 2:23 am ((PST))
You could get two bat detectors, but if they're heterodyne then I guess you=
'd have to make sure the mixing frequency is exactly the same on both. I se=
e there's at least one stereo bat detector available.

Peter Shute

Sent from my iPhone

On 26 Feb 2018, at 8:21 pm, <=> [naturerecordists] <<naturere=
>> wrote:

Good point, Gianni. At those shorter wavelengths, capsule spacing  starts t=
o matter a lot more. Mexican free tailed bats call between 40 and 75kHz. At=
 the low end, around, 48kHz and 20C temperatures, the wavelength is only 7.=
Message: 3cm. 
Subject: The EM258 capsules are 6mm in diameter, so basically I'd be right in t=
he mess of things, and it would only get worse at the higher frequencies. I=
'll build these using one capsule per channel.

Peter, I'd like to try recording in stereo. I'm not sold on the idea of ful=
l spectrum audio, but I really would like to try recording in stereo. The C=
ongress Street Bridge, in particular, lets you get within a few feet of the=
 bats as they head out to hunt. Depending on where I can set things and sti=
ll get rid of the background traffic noise, it could prove to be a rare rec=
ording opportunity (for me, anyway). I can always pick a channel to get a m=
ono signal. But if I can get decent stereo separation, it would be nice to =
have the ability to record it that way.

Vicki, I'm planning to use a Zoom F8. It has the ability to do PiP, but at =
this point all my microphones are wired for P48. This is a hold-over from m=
y previous recorder, which had noisier preamps on the 3.5mm inputs than on =
the XLR inputs. But with the number of inputs on the F8 it's worked in my f=
avor so far. I was planning to wire this the same way.

I used a pair of EM258 capsules for a stealth recording rig some years ago.=
 I hot glued a pair of them to the earpieces of some reading glasses and co=
vered everything up with a Croakies band that also hid the cord routing dow=
n to my recorder. They sound a little more harsh in the high end than the E=
M172 capsules and have a higher noise floor, but if I remember right they'r=
e a little hotter as well so it's not a huge problem for louder subjects. I=
 haven't used those glasses mics much in the last few years though, so I mi=
ght pirate the capsules for this build. (Long story. I have a neuromotor co=
ndition that means I never stop moving or making noise, so having mics atta=
ched to my head just didn't work out.)

Gregory, thanks for the reminder of the noise floor on these. I was leaning=
 toward running separate wires so I can pick which frequency domain I want =
to play with. This is just one more reason to do that. I can always try to =
merge them in post to get full spectrum audio, but since the bat calls will=
 need to be frequency shifted in order to be heard, I'm not sure there's mu=
ch point in wiring things to one set of connectors, anyway.

Thanks for all the input!


<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU