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subliminals question

PostPosted: April 30th, 2013, 5:56 am
by Busenman
There are manny threads about to make subliminals may be with audacity.
but what's about the other way, is it also possible to make subliminal massages in a file hearable again?

May be that's the wrong section for this question, so excuse me. nevertheless thanks for your answer

PostPosted: April 30th, 2013, 6:28 am
by Fizbin
It depends on how you're making the subliminal. If you are simply adjusting levels and putting the file under another, audible, track, it is pretty difficult to extract the original message.

If you're using an ultrasonic frequency shift, that is reversible, though the fidelity depends a lot on the sound going in.

This piece of Nyquist script will decode most common ultrasonic subs:

(setq carrier {your carrier here})
(lowpass8 (mult 2 s (hzosc carrier)) 8000)

replace {your carrier here} with the frequency base used in the original conversion. You may need to experiment to zero in on it, and it could be different for each file.

you are right

PostPosted: April 30th, 2013, 7:22 am
by Busenman
if you say it is difficult, mostly impossible to revocer if it is only a hidden subliminal in de main file

however, sometimes if i view files with audacity and look at the spektrum i see that there are truly subliminals at an higher frequnece besides the normal part.

my question now how to extract this subliminal, may only hear the sublimal and what is said there. is it just a reverse of making subs, or what can i do.

i have tried, but without success.

nevertheless thanks for your answer

PostPosted: May 3rd, 2013, 1:29 pm
by Fizbin
The idea for an ultrasonic over an audible would be to first strip out the audible with a high-pass filter having a sharp cutoff curve, probably above 12,000 hz, then use the Nyquist I provided to decode the ultrasonic.

You might need to amplify at different stages. Don't use noise reduction until you have at least intelligible output.

Set your working sample rate as high as you can.

Try frequencies between 14,000 and 20,000 as the decoding frequency.

PostPosted: August 2nd, 2013, 3:12 pm
by Mandrache
For audible frequency subliminal I believe you can simply cut off the louder sound and then increase the volume of the file, or if it is in a different voice, it will have a slightly different tones, and you can simply increase the audio of a portion of the part you want that doesn't interlap with the masking/audible while setting everything else to minimum. Maybe use Equalizer by Nevi in Winamp. Haven't tried it though.