MP3’s don’t contain ultrasonic sound. [Important]


#1

I have been researching on ultrasonic sound and found out the highest possible quality MP3 has a cuttoff at like 15khz which means an mp3 does not contain audio above 15khz which is a lower frequency than ultrasonic so what is in the mp3 in the shop?


#2

That’s not true – 15khz is just a recommended standard cutoff for music producers and audio engineers intending to release their music on CD and radio. During the mixing and mastering stage, it’s recommended to EQ / filter out “useless” frequencies to free up space in the mix to make it sound clearer and decrease the load on their software / hardware.

Some mp3 encoders will do this by default and simply kill off anything above 15khz, but when you use a more advanced audio engineering program, you can bypass all of those default features and select what you want. Here’s Frequensee’s analysis of LIMITLESS, as played in mp3 format on a Macbook Pro. Note, there is no hard limit at 15khz. You can also test this for yourself on any of our ultrasonic tracks if you use Frequensee (free on Google Play, $1 on the Apple App Store).


#3

Apologies for not answering sooner. in that time it wouldn’t add much to disscussion.

Yes i tested your subs with Frequnsee app. but most people are not fund of ultrasonic and mp3s mixed. I understand you need to provide a format that everyone can use and easy to download but there are better suited formats for this kind of product. I’m still researching to get a better understanding on this. at the end of the day you can decide what’s best for your business.

Appericiate the hard work and passion.


#4

Most of this comes from the fact that lossy compression (like MP3) tries to cut corners somewhere. Cutting at the inaudible ranges was easiest. But it can be controlled, and often is nowadays. Less compression, but solid enough sound.

Still, it led to the wide popularity of FLAC and a lossless format for these kinds of files. I admit it has been so bred into me, I still find myself asking the same question you did: why use a lossy format for files where not a bit should be lost?

Of course, nowadays a new question has arisen: does BlueTooth compression harm the soundtrack?


#5

Not to be argumentative, but mp3 works exceptionally well for subliminals. The format gets a bad rap because of the heavy handed compression music companies used back in the day to conserve data. That was the appeal of mp3 then – it was a lossy format that was able to serve music as cheaply as possible. We’re talking about a time when bandwidth was exceptionally expensive. We don’t have this problem now, so we don’t compress our files nearly as much.

When we tested .mp3 against .wav and .flac, we didn’t see much – if any – changes in results.


#6

Yeah I remember back in the day when they were doing real audio files and it would take like 20 min to download a 3min audio lol. An mp3 that’s roughly an hour encoded at 320Mbps 48kh about 100 mb in size would take a good 9 hrs to download on dialup. That’s what the problem was. I know the encoding is good just by analyzing the file.