Forums > MaxMSP

Different Temperaments – A 441, 442 etc

July 26, 2009 | 10:39 am

Hi everyone,

Apologies if this sounds basic. I’ve built a little tuner as a part of some picth analysis patches that I’m working on. Maybe I’m having a brain freeze, but I’m stuck on how to shift the reference pitch of A 440 to other temperaments such as 441 or 442. I would imagine that this would entail adding a constant decimal value to each integer midi note value…. would this be a correct assumption?? As the ftom object only converts to midi notes in integers I’m a little stuck as to how to find a constant value shift for each different tuning.

If anybody has a thought on how to achieve this that’d be great..

Thanks again,

Ben


July 26, 2009 | 11:05 am

Here’s a patch showing the maths going on inside the [mtof] and [ftom] objects. I’ve included an inlet where you can set the reference pitch of A to something other than 440Hz. I hope it helps.

lh

– Pasted Max Patch, click to expand. –

July 26, 2009 | 11:31 am

– Pasted Max Patch, click to expand. –

July 26, 2009 | 12:18 pm

Thanks to you both for the patches.. they really help a lot. My maths is not that great so I guess I wouldn’t have sorted this out with simple head scratching alone! But now that I have the maths I’ll look into it properly to understand the conversion properly.

Thanks so much,

Ben



o s
July 26, 2009 | 1:02 pm

you should also take a look at the Ejies

http://www.e–j.com/?page_id=42

there you have the ej.mtof object:

"MIDI to Frequency (with tuning adjustment, works for lists)"

hth

ole


July 26, 2009 | 2:05 pm
emeidos wrote on Sun, 26 July 2009 03:39
As the ftom object only converts to midi notes in integers

Actually if you put a floating point argument into ftom it will generate MIDI values with a decimal point deviation from 12tet. For instance 441Hz out puts the MIDI note value 69.04 which is A plus 4 cents.



Eli
July 26, 2009 | 3:24 pm

Another way is to change the "base" attribute of the [mtof] and [ftom] objects- check out the help files for each and open the "tuning" sub patch.

Eli


July 26, 2009 | 4:59 pm

Right, since Max 5, there’s the base attribute, plus mtof/ftom also accepts lists.


July 26, 2009 | 7:13 pm

excellent
i had not noticed that feature

– Pasted Max Patch, click to expand. –

July 27, 2009 | 3:46 am

Thanks to all for your input that’s great!! Now I have a few options to consider.

(Oh and Emmanuel – I was up to see Paul Clift’s Work at the Centquatre last month – really unique and interesting performance!!)

Cheers,

Ben


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