short titless

February 1, 2006 1:37 PM

Spyfilter: Suppose I wanted to rig up a room with a few microphones in order to covertly record conversations, etc, and I want to spend less then $100. I understand the general concepts, but what stuff would I need to buy? I realize there are legal issues, but let's assume that won't be a problem in this situation, since the person will have signed a (lawyer-aproved) release at some point.

Are there any cheap, and *small* wireless microphones capable of picking up someone's speech in a meter or so away in a relatively quite room? Are there any cheap 4-track recorders that I could use? Or should I just use a cheap stereo tapedeck (with two mics)?

What kind of software would I need to do to post process and improve the quality if things don't turn out perfectly? How would I master this down to a stereo recording on my computer?

What else should I keep in mind?

TIA.

posted by Paris Hilton to technology (19 comments total)

Not to be an arse, but if you have a release, why bother with all the cloak & dagger? (This is, by the way, a serious question.) I'd just buy a $25 mini cassette/digital recorder and have done with it.
posted by Emperor SnooKloze at 1:45 PM on February 1, 2006

If you have a computer, it may be really cheap or even free. You know how computers often come with the dinky little mic that no one uses unless they play games with voice? Well, no one expects it to be recording their conversations. I had a dinky little mic, came with a Creative sound card I think, and quality was shitty but voices were generally not hard to understand.

I suppose you could find some software to do voice activated recording and record directly to MP3s, I was lazy and just recorded huge wav files and opened them up in an editor to look for where people were talking.

Of course, it doesn't work if your mark will be using the computer, but otherwise it's pretty covert. Another problem: I believe typing sounds at that pretty much completely masked the conversation.
posted by TheOnlyCoolTim at 1:50 PM on February 1, 2006

wiretap pro for the mac will do sound activated recording. I think I'll leave mine running and find out what the custodial staff thinks of my messy office.
posted by mecran01 at 2:04 PM on February 1, 2006

You need to watch this (it's quite instructional in places).
posted by cillit bang at 2:16 PM on February 1, 2006

I didn't realize that about the short title, I assumed it only showed up in the titlebar of the browser.

As far as doing it with a dinky computer mic, but in my experience the sound quality totally sucks on those if you're not right in front of the mic. I'd like something that could be hidden under a sofa, and I'd like multitrack recording, at least two channels.
posted by Paris Hilton at 2:18 PM on February 1, 2006

Oh, and I'd buy a bunch of cheap generic MP3 players to do the recording.
posted by cillit bang at 2:18 PM on February 1, 2006

With a wireless mic I could use the PC though. Figuring out how to get it recorded after its in electronic form is the easy part. The mic-ing is what's got me stumped.
posted by Paris Hilton at 2:20 PM on February 1, 2006

I realize there are legal issues, but let's assume that won't be a problem in this situation, since the person will have signed a (lawyer-aproved) release at some point.

How ethical do you think this is, regardless of legal issues? I am with the Emperor. Get a cheapie recorder and put it in plain sight. Are you recording a baby sitter or something?
posted by caddis at 2:38 PM on February 1, 2006

Hidden camera shows tape first and get releases later. Whether it's ethical or not depends completely on what's done with the recording if they don't want you to use it. (And the situation of course. Hidden cameras in bathrooms are probably always bad.)
posted by joegester at 3:22 PM on February 1, 2006

Sound quality of any recording made with a mic in under the couch is going to suck. Condenser mics will pick up every sound in the room and lots of background noise as well. Directional mics won't pick up anything. For under $100 bucks you don't have many options anyway.
posted by doctor_negative at 3:26 PM on February 1, 2006

True, Joegester, but I know from experiance that a visual recording in a public place and an aurial one are not one and the same. For some reason there are different laws regarding (perhaps because you can't steal product with your voice). I honestly don't know why, but I think there may be different standards (this call may be monitered for quality assurance...).
posted by TrueVox at 4:36 PM on February 1, 2006

The keywords here are "room transmitters". Within your budget, you're looking at a pair of FM transmitters at about £40 each. They consist of little more than a microphone, battery and transmitter and will broadcast whatever the microphone picks up to a FM radio at a range of around 100 meters. Broadcast range, reception etc. can be patchy - best to do a test first in the same room, if possible. Also, microphone placement is key - if you just stick it under a sofa, everything will sound like it's recorded underwater.

For greater range and quality, look for a UHF transmitter and receiver - these go 500 metres and more.

This advice is for informational purposes only etc.
posted by blag at 5:13 PM on February 1, 2006

a PZM mic hidden in the light fixture should probably do fine. Then it's just a matter of unobtrusive cords heading out of the room to a convenient computer.
posted by dirtynumbangelboy at 6:11 PM on February 1, 2006

Paris, just curious. Why are you wanting to do this?
posted by JamesMessick at 8:00 PM on February 1, 2006

I agree with dirtynumbangelboy, a PZM microphone is the way to go - simple explanation of how they work here.
posted by joshuaconner at 2:02 AM on February 2, 2006

This is ask.metafilter, not judge.metafilter. So please provide answers to his questions, not question his questions.
posted by eas98 at 7:56 AM on February 2, 2006

No.
posted by caddis at 8:15 AM on February 2, 2006

One of the things I love about metafilter is a sense of community that respects ethics.

I want to know what my answer will be used for, and I believe others do as well.

A question about the ethics behind this situation should be expected. Mefi isn't around to help people commit unethical acts.
posted by Jomoma at 8:21 AM on February 2, 2006

What Jomoma said. That's what I really meant, but Jomoma's articulation was far better.
posted by caddis at 8:26 AM on February 2, 2006