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Wednesday, 29 October 2014 13:43

Don't you change the way music was intended? Yes, that's the whole point

Most musicians have been taught to tune their instruments to A=440. They don't know any alternative, as this is not taught in music school.
Example: follow any guitar lessons, and you'll learn to tune your guitar to A=440. Why it is 440, and not any other frequency, is never taught.

If musicians went as far as to duplicate the research as done by Maria Renold, which was documented in her book Intervals, Scales, Tones and the Concert Pitch C = 128 HZ, they would probably use A=432 as a tuning standard.

Here's the full conclusion of her study: http://432evo.be/documents/pdf/study.pdf

If A=432 sounds so great, why isn't it used as the standard?

  1. A=440 was chosen as the world's standard: ISO 16
  2. musicians are not taught about any other tuning, unless they follow music history classes, which most contemporary artists don't
  3. even if they would have done their research, and they wanted to tune a whole orchestra to A=432, it would be very difficult
  4. many contemporary instruments cannot be tuned to A=432, from Roel Hollander's blog:

Examples of instruments without pitch change capabilities are: Wurlitzer and Hammond Organ, Fender Rhodes, idiophone instruments (such as Vibraphone, Xylophone, Marimba, Glockenspiel) and instruments made out of one piece (Didgeridoo, Panflute, Ocarina, et cetera).

Examples of instruments with insufficient pitch change capabilities (from 440Hz to 432Hz) are conical wind and brass instruments: Saxophone (and variants: Tubax. Conn-O-Sax, Saxello, Aulochrome), French Horn, Flugelhorn, Tuba, et cetera.

The sax cannot be retuned to A=432 without a complete redesign of the instrument.

Wouldn't it be better to produce directly in A=432?

Certainly, but it is impossible to adopt this on a wide scale:

  1. it would take an enormous effort to convince all your favorite artists to play again in A=432
  2. not all instruments can be tuned to A=432
  3. 432 Hz productions are rather limited. Here's one from Geert Huinink, the producer behind DJ Tiësto

which is the gap the 432 EVO product is currently filling: it allows to have a sense what music in A=432 would have sounded.
Better would be to produce directly in A=432, but it will never happen on a large scale.

I read some study says 432 Hz actually sounds worse!

There are several ways to change music from A=440 to A=432.

1. pitch shift

The first way, is to use pitch shift, while keeping the duration of the track constant. This lowers the pitch, but keeps the tempo identical.
This method is known to have resolution loss, kills the upper harmonics, make acoustical instruments sound fake, ....

We don't use this method, as mentioned in the history of the 432 EVO
Unfortunately, this is the method used on most youtube demo's that feature converted tracks into A=432

One implementation of this method is:

$ sox your_440Hz_music_file.wav your_432Hz_music_file.wav pitch -31

Furthermore, scientific research using this flawed pitch shift method, only confirms what we already found years ago: don't use pitch shift.

This was the same method used by Max Delissen, a Dutch reviewer. When we confronted him with the fact that we suspected he was using the flawed pitch shift method, he confirmed he was using pitch shift and replied that he would need to redo his research. Instead of redoing his research, he did not do the research and tried to debunk us in an article.

But he apparantly failed, as all music lovers that visit our store, are convinced when they hear the A=432 effect.

Some try to get 432 Hz via jriver's pitch shift, but this will lead to the same degraded sound quality as explained here.

Furthermore some competitors try to attack us by claiming they don't use pitch shift, and insinuating that we do, but we don't:

It literally says "No pitch control software" and "we don't need tricks to improve the sound". It proves their design is inferior as they cannot improve the sound, while 90% of listeners prefer 432 Hz. So either their hardware is so low quality that the difference cannot be heard, or their attemp to mimick our 432 Hz has completely failed.

2. speed shift

Who remembers the Lenco 75? We had one in the 70's. We still have it somewhere. It had one feature that actually shows how we do our A=432 conversion. When DJ's speed-up or slow-down the record to beatmix, the sound doesn't get killed like the flawed pitch shift method. It just sounds faster or slower.

So our 432 Hz method does exactly the same as playing a record on the good old Lenco at a slightly lower speed.  We lower the speed in the digital domain, to map A=440 back to A=432. This lowers the pitch and tempo accordingly. 6moons reviewed our method and confirmed that is was free of artefacts. It took us three years to implement an algorithm that was both very efficient and free or artefacts.

Furthermore, we organised focus groups with 60 candidates listening to 60 tracks, played in the original, and then slowed down to A=432. Then we counted the number of dots for each form, and count the number of tracks preferred in A=432 or A=440. 58/60 preferred the A=432 version, which is about 95%.

A year later, we discovered Maria Renold came to the same conclusion, but by using real acoustical instruments, and 2.000 test candidates.

Which means the test can be peer reviewed, as long as you don't use the flawed pitch shift method that will introduce a lot or artefacts.

You can never get the exact slowdown! It doesn't matter ...

Max Delissen, a Dutch reviewer, went as far as to claim that you can never get the required slowdown:

Zei hij nou bij benadering? Dat klopt ja… Het vervelende is namelijk dat het percentage (1.818181812) waarmee je 440 moet verlagen om 432 te krijgen een repeterende decimale breuk bevat.

Which means

Did he say by approximation ? Yes that's right... The annoying part is that the percentage (1.818181812) used to slowdown 440 to get 432, is a repeating decimal fraction.

While he has a point, it's another debunk attempt that doesn't even matter.

While the initial method mapped A=440 to A=432.036 nobody noticed the .036 Hz error (it used -1.81%).

This was later confirmed, when our method was refined using much more precision, and the error now being 9.276446453104316e-7 Hz (that's ..... 0,0000009 Hz instead of 0,36 Hz) nobody could hear any difference between both methods!

Furthermore, we doubt many musicians can tune their original A=440 acoustic instrument having less than a .036 Hz deviation from the A=440 target.
We did many hearing tests, and we consider ourselves to have "exceptional hearing", we are in the 94th percentile for the pitch test:

Which means only 6% have better hearing.
Not many will be able to tune to 0.1 Hz correctly (the right end of the chart), so let's no argue about 0.036 Hz or even 0,0000009 Hz.

We consider the "repeating decimal fraction" argument hereby debunked.

More attempts to create uncertainty & doubt

This video was created in trying to debunk 432 Hz, but this guy is a champion in misdirection.


He plays tracks in A=432 and A=440 (one factor that changes) but also changes the key of the tracks, so actually changing 2 factors, without disclosing the second factor.

Here a correct shootout, with only one factor changed:


Can you back these pitch shift vs speed shift claims?

Sure we can. Here's a one minute 16/44.1 stereo wav track:

16/44.1 stereo WAV

  1. a.wav Original
  2. b.wav 432 EVO speed method
  3. c.wav pitch shift method
  4. d.wav foobar speed method

Looking at a vs b.wav, you can clearly see the track get's longer. It is the same as slowing down a record player:

while when using the pitch shift method (track c), the track doesn't get longer:

a.wav and b.wav should not contain any audible artefacts, except that b.wav is slightly slower

c.wav has artefacts
d.wav has artefacts

Note that d also uses the speed method, but this proves not all 432 Hz conversion methods are the same quality.
We invested three years into our current method and it is without artefacts.

I have absolut hearing for tempo, will I get used to this?

Unless you play a track in repeat, and than listen to our A=432 method, you may notice that it is different. It will actually sound better!
But do people really find the slower tempo annoying? NO

buy / rent any hollywood movie as a PAL DVD, and it will play 4% faster (24 Hz becomes 25 Hz, which has 2:2 pulldown so it becomes 50 Hz on your PAL TV)
Nobody ever complained about this, even those who criticize us, watch movies in PAL with the speedup!

So the answer is: this is probably some debunk argument for the sport of debunking.

Doesn't your method sounds better because it is played slower? NO

The trick is to map the A to A=432. When instruments are tuned higher than A=440, slowing down by -1.82% will not improve the sound drastically.

One example is the Open Goldberg Variations. We went as far as asking the Open Goldberg Variations team which tuning they used for their sponsored Bösendorfer Grand Imperial, in order to double check our own findings how to retune the Open Goldberg Variations which are a free 24/96 lossless download. Looking at the FAQ, it seems that you can order this piano in different A tunings:

"The pianos are manufactured in the factory at a tuning pitch of A443 Hertz, however it may be altered between A440 Hertz and A445 Hertz according to need."

We verified that they use the A=443 tuning, so by setting our plugin to A=443 as base frequency, the sound of the piano became even more "Grand".

So when an instrument is tuned at A=443, slowing it down by -1.82% will map the A to A=435
This will not sound as good as correctly slowing it down, so A=443 becomes A=432

This is why we added the "speedo" mod.

One of our Antwerp customers asks to change the plugin to assume a base frequency of A=441 instead of A=440. This was a fair remark also made by 6moons, so we decided to write this feature. 2 hours of coding and the first proof of concept was working.

Users can select the base frequency of the plugin to operate on, from A=440 to A=445. There are even sites for classical lovers to find the A tuning of their favorite orchestra. Most modern pop/rock/electonic/dance/jazz is produced at A=440 Hz, but classical orchestra's tend to tune even higher than A=440.

Our Antwerp customer for which we implemented the base frequency on which our plugin works, is a skilled trombone player, wo also knows how to tune his trombone in A=432.
Here's his reaction about the sound of our solution:

Dear Frederic,

I just finished installing your last EVO 432 update and my player/server is running right now. You’ve really flabbergasted me by the improvement of the 432hz. sound. Being a musician for over 40 years I perfectly know the sound of all acoustic instruments … and I can tell you, your EVO 432 server is getting close to perfection. Never in my life I heard cymbals sound like this, or a violin in high register demonstrating all it’s over and undertones, never sounding sharp, the same for the trumpets, they keep their pitch in the high, but that copper feel is still there. To me it sounds like the real stuff at a good rehearsal. I’ve become a EVO 432 addict ……. There’s only one problem with your server ……. It hurts switching it off.

Antwerp, 23 oct. 2014

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Last Updated on Wednesday, 17 August 2016 01:04