Listen through walls

[zachtheterrible]

I wanna listen through a regular wall. how do i do it? :lol: thanx

 

[Someone Electro]

put your ear an the wall. :lol: meaby puting a microphone inside a plastic dish and insulating it from the sound in the room youre in.Then freed the microphones output thru an high gain amp and in to some earphones.

 

[grrr_arrghh]

wine glasses are supposed to work well

 

[chemelec]

Many Many Years ago, (About 1970) In Vancouver, Canada: A company was Making and Selling a device called a "Rolland Star Transducer".

It was in essence a Speaker, but it had a Screw-Bolt in place of the diaphram cone. It was plastic encased and completely water proof. And you could screw it onto a wall, attach it to a window or even into the side of a Swimming Pool, Under water.

Whatever you attached it to, That Object became the Speaker cone.
Because of the size of a wall, the sound seemed to come from Everywhere. Definately Not "Hi Fi" as a wall would have a Good Bass response and a Window or Cement would have a Higher Frequency Response, BUT a really "Neat Effect Sound Effect". Two Walls for Stereo, a Fantastic Effect.

One Problem was any Loose boards in the wall and it would Rattle.
Or in an Apartment, Your Wall was also your Neighbours. How to Drive them Crazy!

Additionally using this as a Speaker Mic, It worked Fantastic to listen in to conversations in other rooms or apartments.

Unfortunately this device is No Longer made and doing a search on the internet, Doesn't come up with any results.

At one time I also Modified a regular speaker in a simular way and it worked pretty good. Biggest problem was a good web to hold the cone centered and how to attach the screw bolt. I used a Perferated ABS Plastic that I laithed out.

Just thought some of you might be interested to attempt to try this.

Enjoy All, Take care.......Gary

 

[zachtheterrible]

already tried the plastic dish . i think im gonna try building the parabolic dish amplifier on chemelec's website n hook that up 2 the wall. havent tried the wine glass.

i looked @ how 2 modify a speaker 2 be a mic on ur website chemelec. Do you just hook up the speaker as if it were a mic? Or are those two circuits meant for a speaker?

 

[panic mode]

hey zach...
does this mean you got the FM transmitter project completed
or this is another aproach to same problem?

 

[zachtheterrible]

does this mean you got the FM transmitter project completed
or this is another aproach to same problem?

YES!!! IT DOES, FINALLY!!! It works great. What i was having problems with was that there was not enough power. Turns out though, all i need 2 do is get a better receiver. I ordered 3 TDA7000 fm receiver chips 2day and am going 2 make my own. i found some really good plans 4 it on the net.

The reason i wanna listen through walls is i dont wanna get caught if the radio gets turned on. :lol: