Outdoor listening installations

Would appreciate some advice on this project.  I'm putting together a proposal for a series of outdoor sound installations in a nature park.  a couple of the installations will be places where you can plug in headphones to listen to certain sounds captured live from a microphone in an interesting place- for example a hydrophone in a pond.  The plan is that the mic will be hooked up to 3.5 jack sockets and listerners will be able to plug in their own headphones.  Now obviously there needs to be some amplification because the mic signal level will be far too quiet to hear on headphones. I need a power amp that will be powered through a solar panel.  My question is, shall I just use a headphone amp, like the Behringer ha400 or make my own power amp circuit? I need to be able to make everything sturdy and fit into a weather proof junction box to protect it from the elements. I have done some experiments with an LM386 power amp module but there was so much background noise and it didn't pick up the mic level at all (may have been a problem with the mic I was using,it was a crappy little lapel mic.- I did get a signal from a piezo disc but it was again really crackly and noisy.)  If it is best to build a circuit with a power amp module, could people make suggestions of ones that will sound good and clean, and work with stereo headphones.  Thanks a lot Ash

Topic by AshtonM4   |  last reply


Hidden camera and listening devices

Could someone please let me know if I’m looking on the wrong spots or if someone knows of a way of building or buying a good device for finding hidden cameras and or listening devices also please.

Question by Jjpseismic   |  last reply


listening device for bird watching.

Listening device for bird watching,having the following specification:1.handheld,battery operated.2.frequency operation in audible frequency range.3.minimum of 30bB signal amplication.4.volume control for final outout stage.5.automatic gain control.6.10 second recording of sound,non volatile storade.7.two output sockets for headsets,5mm jack plug sockets.8.5 hour operational capabilities on one set of batteries.9.On/Off switch with LED indication.10.LEd to indicate recording.11.LED to indicate playback.?

Question by  


Using headphones for listening to tv.?

My panasonic tv does not have bluetooth. I have new Marley headphones. Theywork well but not when the channel says Dolby or no good with Netflix as they appear to all transmit in Dolby. I purchased both a digital to analogue converter and bluetooth transmitter as advised but still cannot get Netflix audio or those channels using Dolby. Is it because bluetooth will not transmit analogue??

Question by BarryN16   |  last reply


Radio Mod?

I would like to mod a handheld radio (or even a analogue tv but radio would be better) to get to listen to higher frequencies than normally available. I'd Like to hit the 1420Mhz mark approximately but with little electrical engineering or architecture experience, I'm not certain how? Which might make a TV easier to get there as UHF covers that right? (still safer to play with a battery powered radio than a 240V powered one) I figured there is someone out there with the ability to figure out what components need changing? The variable resistor that tunes it perhaps? If you'd rather post an instructable I'll follow that or just tell me what needs replacing with what? Any Ideas?? Thanks

Question by Mr E Man   |  last reply


How do i calculate the size of a dish i need for a specif frequency, specifically around 95 mhz?

How do i do so? I plan on making a home made radio telescope, but i just want to block out non-space made noise.

Question by natman3400   |  last reply


what is a listening device for Bird Watching? Answered

I want to know why there must be a listening device for bird watching and what is the use of it.

Question by    |  last reply


Contact microphone to listen to finger-taps

My idea is to attach a contact microphone to the wrist to listen to finger-taps and determine which fingers produce the taps. Assumptions: - The tap sound propagates along the bones like in tubes,  - Each finger produces a characteristic sound signal. - Pattern recognition of sound signals identifies the sound and the finger that produces it. Any help? Thanks

Question by brian.s   |  last reply


EVP quality, tele listening amp.

Hallo friends, Please show me a schematic diagram of a highly sensative amplifier, or hearing aid that I can use as a telescopic remote spy hearing instrument. Something as sensitive as the EVP paranormal audio recorder. I tried this circuit but doesnt work :( http://www.extremecircuits.net/2009/07/hearing-aid.html Please guide me to a circuit that actually worked for you. see you thanks

Topic by ketan7s   |  last reply


Looking for instructions on a sound masker to defeat listening bugs?

I have a friend who is going through a rough divorce and we think it is quite likely that he has bugged her house. He has used electronic bugs in the past, his daughter is mentally and physically handicapped and he put it on her wheel chair to hear what happened during her first day of middle school. I am looking for cheap instructions on how to build a device to detect it and/or instructions on a device like you read about in espionage books that produces noise that makes anything a bug picks up unintelligible.

Question by Shadow13!   |  last reply


Help needed to install small remote listening device in to a child's battery operated toy

Hi I'm new to this site, I need help in installing a small remote listening device (simcard type) into my child's toy, I already have the device and the toy which I'm going to use, the toy is battery operated, I just want to know how I would connect both items so listening device receives power from toy batteries. Listening device dose have its own power supply but it runs out of power after a few hours. can any one help

Topic by Alik112   |  last reply



What frequency are aircrafts flying out of gatwick and could these listen to it ?

Http://cgi.ebay.co.uk/Omega-Multi-Band-Radio-Scanner-Icon-3-Air-Band-Marine-/120600101374?cmd=ViewItem&pt;=UK_ConsumerElectronics_SpecialistRadioEquipment_SM&hash;=item1c145381fe#ht_500wt_1154

Question by wizzywoo   |  last reply


CAN YOU RECORD OFF PANDORA ON TO YOUR IPAD 2 IF YOUR LISTENING TO PANDORA ON YOUR IPAD2 ? Answered

IS THERE A WAY TO LISTEN AND RECORD MUSIC FROM PANDORA RADIO USEING THE SAME DEVICE? IPAD 2

Question by LITTLE_MOUSE   |  last reply


I am looking for a device that will listen for a smoke alarm to go off.

All it needs to do is have an indicator that trips when the alarm goes off.  I replace smoke detectors that give faulse alarms but I am never there to hear them.  There are two sounds they make, one is a chirp (low Battery) and a full alarm very loud.?

Question by drvolt   |  last reply


how do I put a microphone at a bird feeder and listen in the house?

This would be very similar to a baby monitor.  Is there a way to transmit the signal from outside to inside the house?

Question by Petie   |  last reply


need ideas,suffestions and advices on this project: listening device for bird watching

Having the following specification:1.handheld,battery operated.2.frequency operation in audible frequency range.3.minimum of 30bB signal amplication.4.volume control for final outout stage.5.automatic gain control.6.10 second recording of sound,non volatile storade.7.two output sockets for headsets,5mm jack plug sockets.8.5 hour operational capabilities on one set of batteries.9.On/Off switch with LED indication.10.LEd to indicate recording.11.LED to indicate playback

Question by abrinah   |  last reply


I need away to use my blue tooth ear piece as a transmitter to another blue tooth ear piece.

I need to be able to listen from a short distance away. sort of a spy device.  having its own coded freq. would be helpful too.

Question by Demascus   |  last reply


Is there something that be done to basic speakers to make them waterproof/resistant?

I have a 2-speaker sound system that I would love to listen to when showering, but I worry about humidity damage,  Does anyone know a simple way to make it safe to listen to in the bathroom?  If there's other issue that I hand;t thought of let me know.

Question by Schmetterling2013   |  last reply


can i block the singing part in a song to just hear the instruments?

I was wondering if its possible to use a mixer to cancel out the singing in a song so that you can only hear the instruments? i want to listen to the different instrumenst so that i can learn how to play the part just by listening, but its kind of difficult with the singing as the main sound. and if you can, is it a certaing type of mixer that you can connect to a computer?

Question by santista19   |  last reply


what other websites are there other than you tube? Answered

My parents blocked youtube and i need to listen to music and watch videos

Question by justus198   |  last reply


qusten ? Answered

Turn up your speakers   listen to this http://www.youtube.com/watch?v=ZHUGeuMm45w i would like to make a device to play this noise endlsey at high voulme 

Question by tinker234   |  last reply



How to build/convert a portable radio to receive air traffic control transmissions?

Hello everyone!  Recently I took a trip and flew with United Airlines, they have a really cool feature where one of the music channels that you can listen to through your headphones is actually the pilots talking with the control tower.  It was really fun listening to them and I started to wonder how hard it would be to modify or build a radio (hopefully something portable) that could receive these transmissions so I could listen to them anytime.   As I understand it most air traffic transmissions are on frequencies 108 - 136MHz.  Are they different in Canada (where I live)?  I would assume they are the same internationally...  but what do I know.  Thanks! 

Question by liam2317   |  last reply


How to protect the conversation in the house from evasdropping using microphone listening through walls?

My house is townhouse, walls are made of concrete, 6 inches thick. The next house beside my house shares the same walls with my house. I think he put the microphone through walls because even I just whispered he can hear it and know every conversation in my house. Please instruct me the countermeasure or cheap DIY device that work effectively to protect this situation. Thank you

Question by    |  last reply


SDR - Software Defined Radio, are you hooked?

Using a cheap USB dongle and an antenna everyone can listen to broadcasts.This includes HAM radio, VHF, UHF, DAB, data servives, satellite communications and even the ISS.Pagers can be listed too if you still find someone using them but getting the latest weather might be nice as well.What are you listening to, what data do you decode?What is you best story in regards to your SDR experience?Prefered programs?

Question by Downunder35m 


Raspberry Pi sensing audio?

Hi all -- I have been programming all kinds of things all my life, but I have never had a chance to build a program that responds to audio input.  Suddenly: Dancing Baby Groot.  I have a great idea for an algorithm for making a very clever and funky Dancing Baby Groot using Raspberry Pi or Arduino -- if I can figure out how to get the processor to "listen" to audio input. How would I get one of those processors (or any processor) to "listen" to the mic and translate it into either digital or analog data which one could then plunder to figure out the tempo and beat in order to get Baby Groot to Dance?  I am 100% sure I can do the plundering (because it works on digital files) if I can get the processor to "listen" to the mic and create a file of numbers which represent the music being played. Any suggestions?

Topic by TheFrankTurk   |  last reply


How to record more music from Napster?

Hello, I have a 60$ annual account at Napster and I have 60MP3s/year for free and of course I can listen unlimited music on my playlist on Napster.  My problem is that I have already downloaded those 60MP3 at the beginning of the year and now I cannot download any song and I was wondering if there is other possibility to record or save somehow music from Napster on my pc and transfer them on my phone so that I can listen to them all the time? Thanks

Question by Powdeer   |  last reply


Headphone Specifications? Answered

I am looking to purchase some headphones and the three main specs are: Hz - KHz, THD, and Ohms. What do they each mean? Please be very specific. (In terms of when I am listening to music)

Question by jacobdlyon   |  last reply


arduino secret knock lock

Found a project where this guy uses an Arduino to detect a selected kncock pattern to unlock a door. Clever, though i hope no one is listening when it's being set! found here

Topic by mikeasaurus   |  last reply


How to convert a 2G sims operating device to a 4G?

I have 2 GSM 2G Sims card  listening devices which is not capable to work on 3g or 4g network.. Since cell phone companies now require a 4g sims card and the listening devices have not advance to work on the 3G or 4G network, I need to convert my device to work on a gsm/wcdma.  The problem is that I don't have an older sims card.  AT&T; and T-Model are stating I have to get their 4G sims.  And I can't find a cell phone company still operating on Edge (2g ).  Can anyone help? Here's a link to show the 2 devices: http://www.ebay.com/itm/spy-GSM-Two-Way-Audio-Device-Sim-Ear-Bug-quad-band-/300559438536?pt=LH_DefaultDomain_0&hash;=item45fabd12c8 http://www.ebay.com/itm/Power-Plug-Adapter-style-spy-gsm-bug-audio-voice-Surveillance-device-TC300-/300609991817?pt=LH_DefaultDomain_0&hash;=item45fdc07489     Thank you

Question by chamilton7562   |  last reply


Basic info on the Rasberry Pi

I heard that you can install Android on a Rasberry Pi. Could I get one and do that and be able to do these three things?? 1. Download apps and use them 2. Go to the internet 3. Listen to music Thanks!

Topic by HavocRC   |  last reply


What is this thing?

I picked this up for 5 bucks at a garage sale. It looks like an old phone device but the part you would speak and listen into is missing. The one label that it has is too damaged for me to read it. Any ideas on what this is?

Question by WhatWasIthinking   |  last reply


Can someone help me with this schematic? Answered

I found this schematic for an amplified listener from www.Biotele.com and I'm having trouble finding c4 in this circuit, a 5n cap.  I'm wondering what its purpose is and what range of values could i use to replace it?

Question by DemonicRoss   |  last reply


Another source of info and ideas

Although this forum gets very technical at times, it can still be a great source of ideas and specs. Here is the link to the FTF (Freescale Tech Forum).With a very long video located here: Video Link for those that wish to listen to a lecture :-)

Topic by Goodhart   |  last reply


How to place a sub woofer for a better sound response?

How to keep it on the floor? Close to a wall? How to adjust equalizer for the best bass and treble response ? How can I assume that I'm listening to good quality sounds(music) ? Thanx a lot.

Question by Jagath   |  last reply


Is it possible to produce a sound wave that makes us experience silence?

What I mean is: a computer or whatever produces that sound and we can't listen to anything, not even our own speach. That would make us experience TOTAL silence. Is it physically possible? That would rock. :) Thanks, Pedrotome

Question by pedrotome   |  last reply


how can i make a cheap and easy bugging device which is small and easy to hide? Answered

I want to make a battery operated, small bugging device that is easy to hide and can record or transmit sound to a listening device....just for when i'm...bored...just for....fun....

Question by paulskinback   |  last reply


what do you do if your sound controll on your computer doesnt work??

Because i try to listen to music but it tells me something is wrong with my sound controll? where is the sound controll localed? how do you fix it

Question by jasmine farrior   |  last reply


Are tube type amps really better than solid state type amps? Answered

A question below reminded me of this. My friend and neighbor plays a guitar and has been going on about how great his new Fender tube amp is and how much better it sounds than the solid state amp he previously used. Truthfully, I've listened to him play on both (he's no Chet Atkins for sure) and I can't discern much, if any difference. I've done a little research and heard words like, "warmer,"  "more vibrant" and "louder" used to describe the difference. With the exception of louder, most of these descriptions are not actually measurable. Is there a way to definitively say tubes are better, or is it just a subjective quality that depends upon the ear of the listener?

Question by Burf   |  last reply


Problems with USB Port on Homemade speaker box, why can't I listen to music and charge at the same time?

Okay, so I have a speaker box that I made myself with a kitted 7w audio amp. I put that in a box with a decent 4 inch speaker, and that was working great. Then I decided that I really need to add some sound reactive lights, so I got a TIP31 transistor and hooked that up along with a 7805 5v regulator to a USB port so I can charge my devices with it. So, the USB port works great, and so does the speakers and lights. But *not* when I plug in my device to charge while it playing music through the 3.5mm audio jack. It gives off this weird fuzzy sound, but still charges. On my multi meter it shows continuity between the USB port and the audio input and speaker, so I first thought that maybe I didn't have something grounded quite right, but it all appears to be set up right. Is there some sort of filter I can set up so that I can charge one device and play music at the same time on the same device? Or would need to set up the two circuits on different power sources? I would really rather not do that for the simple fact of trying to keep it simple... Here's my schematic of it (sorry about it being sloppy, I did it rather quickly but everything on there should be right). Here's a better quality picture of the schematic

Question by froggyman   |  last reply


Is using PCB in a radio circuit a problem? Answered

I am making this FM bug: https://www.instructables.com/id/FM-Listening-Bug-Kit/ . I decided that I would use this instructable as my first PCB creation. However, I read that the copper creates small capacitors and would ruin the circuit. Would this be a problem on PCB?

Question by seraine   |  last reply


Please help me that how to control a robot coding Answered

Please help me ~ ! please help me about my arduno robot plat form that (a nano) it's can't reset itself by interrupt or reset itself per 200 ms automatically. in order to RUN(move) and LISTEN(receive command) at the same time!

Question by David_Lin   |  last reply


Individual volume on computers

I was wondering. Is it possible, with or without hardware so I can browse the internet without volume, for listen to music at the same times on Itunes, and hear it. Basically, is it possible to not here sounds on the internet without turning my whole computer volume off? Google was no help.

Topic by Rock Soldier   |  last reply


a instrument of my own...

Ive been listening to quite a bit of 8-bit sounding techno and such. And i really wanted to know if there was a way to make a computer keyboard make diferent pitched "beep" and "boops" of sorts. is there anyway to do this? http://www.youtube.com/watch?v=_Twokr090WM

Topic by astrozombies138   |  last reply


set up a small-range radio station ?

I want to set up something like a radio station in my college for my department so that we can deliver the messages through that and my fellow mates can listen to it in a FM receiver (in their mobile). How can i do it in the cheapest way possible?

Question by navinn_11   |  last reply


DELAY MY RADIO!

I love baseball.  I want to watch the World Series on TV, but I don't want to listen to the TV announcers.  I want to listen to the radio broadcast instead.*  Problem is, the "live" TV arrives 1-2 seconds after the radio.  Which means I hear about the deep flyball to left before I see it. And that takes the fun out of watching the game. So, I'm wondering if I can add an adjustable delay to the sound from my radio, to sync up with the picture.  I can sacrifice a boom box or other radio for this if nec. Or some other solution? (I can record both and sync 'em up later using video editing software, but that's not practical). * for baseball fans:  it's the choice between the Buck/McCarver team (perfectly boring & perfectly obnoxious) and Jon Miller/Joe Morgan radio team (passionate and fun).

Question by willz   |  last reply


MP3 books to ZUNE

I just got a Zune, I like to listen to recorded books while I work, which is reasonably easy to do with the Zune interface software and most books on CD. THE PROBLEM is books recorded as MP3 files. Strangely enough here is an "MP3 Player" that cannot handle MP3 data directly... At least this is my experience so far. Placing a MP3 recorded book CD in the drive and while I CAN listen to it on the laptop using Zune's Software interface. Trying to transfer the files to the Zune unit creates error files that are unusable and so far I have not been able to remove from the Zune. Admittedly I'm a newbe to the Zune but have been using computers since the Atari 800 came out too many years ago for me to admit to...ANY help would be appreciated. Possibly there's something I just have not found as yet.

Topic by 24kgold   |  last reply


Interfacing a robot with landline phones? Answered

What i would like is that i have an answering machine at home that starts after a certain amount of rings. What i want is that when the machine answers the robots listens in and waits for a certain sequence of keys to be pushed. It will then send the tone 1 down the line and somehow i would also like the cal to be ended(but that isn't necessary).

Question by wee_man   |  last reply


please help me! record player question! need help setting up!

ok i just got a record player,some records, and a pyle p999 phono preamp for christmas. the output is a red and white cord. is there any way to listen to it without getting a amplifier?

Question by madrobot3600   |  last reply