Octave Range: 2' 4' 8' 16' 32'

[garranimal]

Noobish question maybe, but always wondered what exactly does this naming convention mean and where does it come from? Does 8' = 440 Hz proper middle C? It seems to follow that whatever 2' means, the next octave is double the value, 4', just like the 12-tone scale octave is double the hertz. What do I properly call the units (the apostrophe) of this convention. The synth manuals I have never make mention as its always assumed and taken for granted.

Andromeda gets away from this strange convention altogether and calls the oscillator frequency for what it is.

[jupiter8]

The naming convention comes from pipe organs where different lengths (or is it diameters ? Anyways it's linked to the size) would give you different pitches. Which one is which,i don't know but should be fairly easy to find out.

[Z]

Different pitch registers of pipe organs are measured in feet. Each octave is doubled in length.

[garranimal]

LOL that's what I get for not really being into organs.

[Clavier]

Also, the shorter the pipe, the higher the pitch. While even number increments go in doubles by the octave, there are fractional increments too which play at a third, fouth, fith, seventh, etc. Middle C on the 8' setting is the same as middle C on a piano.

[Hair]

Just found this page on the subject too, more in depth for those interested: http://www.die-orgelseite.de/fusszahlen_e.htm

[Ian S]

Basically the 8 foot range is the "fundamental" one, so if you play middle C, you hear middle C (440Hz is the A above middle C). 4' is an octave higher, 16' an octave lower, & so on. As others have said, the convention comes from pipe organs, & a Hammond (or clone drawbar organ) has 9 footages to play with: 16', 8', 5 1/3', 4', 2 2/3', 2', 1 3/5'. 1 1/3', & 1' (though on most, with the exception of the Yamaha SK series, 5 1/3' is the second drawbar, & 8' the third). 5 1/3' is a fifth above 8', so if you play C you get the G above, 2 2/3' is a fifth above 4', 1 3/5' is a major third above 2', & 1 1/5' is a fifth above 2'.

If you find anything with a 64' range, make sure your speakers have a very good bass response, & move any fragile objects from nearby shelves & tables My Spectrum goes down to 64' on both VCOs, and also has sub-octaves...

[Clavier]

I believe 64' is an 8Hz tone. That's lower than most subwoofers can go.

[OriginalJambo]

I believe 64' is an 8Hz tone. That's lower than most subwoofers can go.

Not quite.

If A at 8' = 440 Hz then
16' = 220 Hz
32' = 110 Hz
64' = 55 Hz

A good sub should be able to handle 55 Hz no problem. In fact a good set of studio near-field monitors might even be able to go that low.

In fact a very crude formula to calculate all the fundamental frequencies of all footages playing an A note could be:

f(A)=440 x 2(^n)

Where n is the octave register represented by an integer (n=0 would obviously give a value of 440).

[Ian S]

That's the A above middle C though, consider that a 5-octave keyboard has another 2 As below that, at (for 64') 27.5Hz & 13.75Hz. Get down to the bottom C on the same keyboard & you're down around 8Hz, definitely sub-audio; bring pitch modulation in & you're going to be giving your LFO a run for its money

[OriginalJambo]

That's the A above middle C though, consider that a 5-octave keyboard has another 2 As below that, at (for 64') 27.5Hz & 13.75Hz. Get down to the bottom C on the same keyboard & you're down around 8Hz, definitely sub-audio; bring pitch modulation in & you're going to be giving your LFO a run for its money

Ah, that makes sense.

I don't think you'll be able to hear it right enough, but feeling it is another matter entirely. Brown note anyone?

[Ian S]

So imagine my Spectrum at 64' on both VCOs with sub-octaves running, if I turned that up enough you'd probably feel it in Scotland

[Clavier]

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