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[SPUD GUN]

Guys I would like to build a low frequency emitter capable of 20hz what is easiest way and cheapest

 

[Audioguru]

20Hz has a waveshape (sine, square, triangle, sawtooth or others).
20Hz also has a peak-to-peak voltage and current.
Your 20Hz has none of these important specifications.

 

[hevans1944]

@SPUD GUN: As @Audioguru said in his post #2 above, you have failed to mention ANY of the important characteristics of "a low frequency emitter capable of 20hz." Perhaps you could get a used guitar and remove all except the heaviest string, which produces the lowest note. Then tune that string to produce a decaying 20Hz note when plucked. Or purchase a steel tuning fork whose "natural" frequency is somewhat lower than 20Hz and carefully file the two tines until the tuning fork vibrates at 20Hz when struck sharply. If you want an electronic solution, construct a simple Wien-bridge oscillator. If you want some really good advice, please tell us wtf you want to DO and leave the how-to-do-it to the forum members who respond. Personally, I like the idea of using an open pipe, cut to be resonant at 20Hz, and excited with low-pressure compressed air... like a pipe organ.

 

[SPUD GUN]

@SPUD GUN: As @Audioguru said in his post #2 above, you have failed to mention ANY of the important characteristics of "a low frequency emitter capable of 20hz." Perhaps you could get a used guitar and remove all except the heaviest string, which produces the lowest note. Then tune that string to produce a decaying 20Hz note when plucked. Or purchase a steel tuning fork whose "natural" frequency is somewhat lower than 20Hz and carefully file the two tines until the tuning fork vibrates at 20Hz when struck sharply. If you want an electronic solution, construct a simple Wien-bridge oscillator. If you want some really good advice, please tell us wtf you want to DO and leave the how-to-do-it to the forum members who respond. Personally, I like the idea of using an open pipe, cut to be resonant at 20Hz, and excited with low-pressure compressed air... like a pipe organ.

I'm getting severely harassed from neighbours an simply want to be left alone

 

[kellys_eye]

I'm getting severely harassed from neighbours an simply want to be left alone

If your intent is 'torment' them with subsonic audio then you'll be getting far more attention from them if they find out it's you doing it. If you are being 'harassed' then you have a legal standing and should be able to seek legal assistance - have you tried?

 

[hevans1944]

Watch the "modern" version of "War of the Worlds" with Tom Cruise. The "fog horn" sound effects produced by the aliens is awesome. You might be able to reproduce the same effect with a few loudspeakers and a kilowatt or so of intermittent audio power, all driven by a "loop" recorder that will "play" the "fog horn" loop at random intervals between midnight and four in the morning... be sure to locate the loudspeakers in randomly dispersed locations to minimize location detection. Also randomly distribute which loudspeakers actually emit the "fog horn" sound and when they do it. This could be an application for battery-powered Bluetooth interface for the loudspeakers. You might want to camouflage the loudspeakers...

 

[hevans1944]

Not to "jump the shark" too far, but does anyone here know how to make a really cheap CO₂ detector?

 

[hevans1944]

Not to "jump the shark" too far, but does anyone here know how to make a really cheap CO₂ detector?

Never-mind!

 

[atemple492]

I recommend opting for a simple DIY approach. Begin by sourcing a quality speaker with a frequency response that covers the 20Hz range. Look for surplus or second-hand options to keep costs down. Next, construct a basic enclosure using plywood or MDF, ensuring it's appropriately sized to accommodate the speaker and optimise low-frequency performance. Employ a basic amplifier with an adjustable low-pass filter to drive the speaker. You can find affordable amplifier kits online or consider repurposing an old stereo receiver. Finally, invest in a reliable signal generator to provide a clean 20Hz signal source.

 

[danadak]

Not to "jump the shark" too far, but does anyone here know how to make a really cheap CO₂ detector?

I use these sensors in a web based system :

https://www.olimex.com/Products/Components/Sensors/_resources/SNS-MQ-sensors.pdf

Regards, Dana.

 

[hevans1944]

@danadak:

Thanks, Dana, but I don't remember why I wanted an el-cheapo CO2 detector. Maybe to test the carbonation of a Sodastream thingy I have? But thank you for the link to the sensors.

 

[davenn]

Thread closed
We wont condone illegal activities or harassment of neighbours on the site

I'm getting severely harassed from neighbours an simply want to be left alone

Please seek legal/police advice

thread closed