Detuning OSCs on the TI

[n***N]

I was trying to detune 2 osc's by +3 cents on my TI. then realized that there is nothing in the manual showcasing what the values 0-127 on the "detune 2/3" paramter represent. I contacted Access and they told me there is no physical values and no table showcasing by how much the OSCs are detuned. WTF!?

Can someone help me out with this? How do i detune two osc's by exactly 3 cents?

Cheers!

[Ditherman]

Just use your ears and count the 'beating' between the detuned frequencies....3 cents detuned will beat 6 times per second. Basic amplitude modulation.

[n***N]

Originally Posted by Ditherman

Just use your ears and count the 'beating' between the detuned frequencies....3 cents detuned will beat 6 times per second. Basic amplitude modulation.

How am I suppose to count 6 beatings per second? isnt that impossible?

Looking at the Voyager interface, its crystal clear.

[DannyMac]

Mail the boys at access I'm sure they will give u an answer

[iangomes]

Originally Posted by DannyMac

Mail the boys at access I'm sure they will give u an answer

op:
I contacted Access and they told me there is no physical values and no table showcasing by how much the OSCs are detuned. WTF!?

[chrisso]

You could still use your ears.
Older style synth didn't offer numerical values, you just twiddled the oscillator knobs until it sounded how you wanted it.
Would the sound be adversely effected if the detuning was 4 or 5 cents instead of the desired 3?

[shadowfac]

Originally Posted by Ditherman

Just use your ears and count the 'beating' between the detuned frequencies....3 cents detuned will beat 6 times per second. Basic amplitude modulation.

Ok, I'm intrigued by this. Could you explain, with all the possible technical details, why having two oscillators detuned by 3 cents would result in a 6 Hz beating? I mean, according to this:

Beat (acoustics) - Wikipedia, the free encyclopedia

the beating frequency is the difference of the frequencies of the oscillators. If that difference is always 3 cents, then the beating frequency should depend on which note is being played.

Maybe you meant playing a specific note, although for a 6 Hz beating, one would have to play a very high note (3459.5 Hz, between G# and A on the 8th octave); it would be better to play a lower note (C# or D on the octave above middle-C) so that the beating is around 1 sec (easier to count).

[n***N]

Originally Posted by chrisso

Would the sound be adversely effected if the detuning was 4 or 5 cents instead of the desired 3?

Yes, it would! Detuning by even values actually introduces more harmonics.

Its usually odd values, and the more it is, the wider and thicker the sound. Therefore if you detune by 5 cents instead of 3, it will sound different.

On the Voyager interface, there is a dedicated knob just for detuning by odd cents in +/- 3,5,7... Thats what I need! Whatever tho, I guess I will see the values people used when stripping down the presets.

[chrisso]

It's the value I'm on about, not the pos/neg.
Actually, detuning is by definition lowering the pitch.
And you can still use your ear to determine how thick you want the sound.

[n***N]

Originally Posted by chrisso

It's the value I'm on about, not the pos/neg.
Actually, detuning is by definition lowering the pitch.
And you can still use your ear to determine how thick you want the sound.

oops!

I meant even/odd instead of positive/negative. lol

[chrisso]

OK, now I get you.

[shadowfac]

Originally Posted by n***N

Yes, it would! Detuning by even values actually introduces more harmonics.

Again, could you support this with some theory? I'm probably missing something here, but I really don't see how detuning by an even amount of cents would introduce more harmonics than odd amounts.

[soundsubs]

according to my (somewhat) digital tuner, the TI bends +~60 cents with a full 127 value on oscillator 2. therefore using simple math (and my simple eyeball/ear) +3 cents youre looking for is about a value of 6.35, or 6 in TI speak. this is if the scale of the pot is linear.

yes, its implemented better on my moog voyager. and the TI should have had the same oscillator control of pitch with knobs like the virus b and a and c do.

but i still use the TI a ton in my tracks.

[n***N]

Originally Posted by soundsubs

according to my (somewhat) digital tuner, the TI bends +~60 cents with a full 127 value on oscillator 2. therefore using simple math (and my simple eyeball/ear) +3 cents youre looking for is about a value of 6.35, or 6 in TI speak. this is if the scale of the pot is linear.

yes, its implemented better on my moog voyager. and the TI should have had the same oscillator control of pitch with knobs like the virus b and a and c do.

but i still use the TI a ton in my tracks.

thanks a lot!

Have you tried a value of 6 on the TI, and a value of 3 on the voyager? Did the beating sound really similar?

btw here is another question:

when I detune two OSCs on the TI and feed them to the ring mod, put the ring mod volume to 127, the result is rather strange. In reality, feeding 2 freqs into a ring mod, should produce a subtle signal. Where in my case for some reason, it actually sounds like its being modulated by a sin LFO. I checked every possible mod destination, the LFOs are not even active. There is NOTHING being modulated. I dont understand why it sounds like that. When I press sync, this whole LFO sound goes away, but then that kills the beating, doesnt it. WEIRD.

[chrisso]

Well I'm in agreement with shadowfac, I've never heard any evidence or read anything about positive or negative values, even or odd. For years, players have twiddled knobs until the sound is good.
I'm not anal about this kind of thing, so I'm prepared to accept I haven't looked into the technical aspect of detuning in great detail.

Originally Posted by n***N

when I detune two OSCs on the TI and feed them to the ring mod, put the ring mod volume to 127, the result is rather strange. In reality, feeding 2 freqs into a ring mod, should produce a subtle signal. Where in my case for some reason, it actually sounds like its being modulated by a sin LFO. I checked every possible mod destination, the LFOs are not even active. There is NOTHING being modulated. I dont understand why it sounds like that. When I press sync, this whole LFO sound goes away, but then that kills the beating, doesnt it. WEIRD.

Hmm, not weird.
One oscillator is modulating the other inside the ring modulator, when you press sync you are nullifying the detune and linking the pitch of one oscillator to another, so nothing is modulating (hence 'the LFO sound goes away').
Also, ring modulators are very reactionary. It's not an exact science to predict ring mod results IMO. It depends what waveforms you are using, the pitch of each oscillator and the octave range you are working in.
Oscillator syncing and ring modulator theory are all basic synth programming 101.
So I'm amazed you seem to be in the dark about their effects, but absolutely set on the odd number detuning rule.
I suggest you throw out your rules and preconceptions and go back to basic synth programming with a good book or online tutorial.

[n***N]

Originally Posted by chrisso

One oscillator is modulating the other inside the ring modulator,

nope! thats FM

Nothing is being modulated. RING MOD is a simple calculation, which based on 2 oscs at different frequencies:

(1) diff = high freq 'minus' low freq

(2) low freq + diff

(1) = New Fundmanetal
(2) = New harmonic

(1) + (2) = New tone, with no presence of the original signals ('high freq', 'low freq')

This new tone is the output of the ring mod, so there should be no modulation. I heard examples of ring mod, and it never sounded modulated.

[chrisso]

And if you sync the OSC's you lose one of the 'different frequencies' to quote you.

FM or not, Ring Modulation is about a carrier and a modulator. In this case you are using two Oscillators, one in each role.

[chrisso]

Originally Posted by n***N

I heard examples of ring mod, and it never sounded modulated.

I think you are too hung up on theory and numerals.
How can something not be modulated if it is called 'Ring Modulation'?


If you are hearing an LFO effect, it is likely the modulating Osc is at too low a pitch. LFO = Low Frequency Oscillator.
Ring Mod with two very similar sounding and tuned OSC's usually sounds a little like FM; slightly metallic, with some unpredictable variance in overall pitch.

[shadowfac]

Originally Posted by n***N

nope! thats FM

Nothing is being modulated. RING MOD is a simple calculation, which based on 2 oscs at different frequencies:

(1) diff = high freq 'minus' low freq

(2) low freq + diff

(1) = New Fundmanetal
(2) = New harmonic

(1) + (2) = New tone, with no presence of the original signals ('high freq', 'low freq')

This new tone is the output of the ring mod, so there should be no modulation. I heard examples of ring mod, and it never sounded modulated.

Err... do you notice that, according to your math, (2) = high freq? I guess you meant (2) = 2 * low freq + diff ?

Also, you cannot call (1) a fundamental and (2) an harmonic, because they may not be harmonically related (e.g., (2) is not necessarily a multiple of (1)).

Ring modulation is a form of amplitude modulation (e.g., the product of the signals), where the modulator can take negative values. For two sinusoidals with frequencies A and B, the output is a pair of sinusoidals whose frequencies are A+B and A-B. In the case of non-sinusoidal signals, you just multiply the partials pair-wise. However, in a digital synth, the sum of partials may go beyond Nyquist, and thus aliasing may easily occur, even if the oscillators are band-limited.

In any case, if two oscillators are detuned by a specific amount in cents, then the detuning amount in Hz will depend on which note is played. Therefore, if you ring-modulate those oscillators, the relation between the resulting frequencies (sum and difference of partials) will change from note to note, making the sound more harmonic or less harmonic, depending on which notes you play.

[chrisso]

What he said.

[shadowfac]

Originally Posted by chrisso

What he said.

That's the thing with being a geek. You cannot help it sometimes.

[n***N]

Originally Posted by shadowfac

Err... do you notice that, according to your math, (2) = high freq? I guess you meant (2) = 2 * low freq + diff ?

Also, you cannot call (1) a fundamental and (2) an harmonic, because they may not be harmonically related (e.g., (2) is not necessarily a multiple of (1)).

Ring modulation is a form of amplitude modulation (e.g., the product of the signals), where the modulator can take negative values. For two sinusoidals with frequencies A and B, the output is a pair of sinusoidals whose frequencies are A+B and A-B. In the case of non-sinusoidal signals, you just multiply the partials pair-wise. However, in a digital synth, the sum of partials may go beyond Nyquist, and thus aliasing may easily occur, even if the oscillators are band-limited.

In any case, if two oscillators are detuned by a specific amount in cents, then the detuning amount in Hz will depend on which note is played. Therefore, if you ring-modulate those oscillators, the relation between the resulting frequencies (sum and difference of partials) will change from note to note, making the sound more harmonic or less harmonic, depending on which notes you play.

No.

(2) means step 2. Use your logic, and see that (2) is being refered to again as the new harmonic. If you know what ring mod means, you should know what that step means. And No, its not (2)*anything!

You obviously did not get my message.

Read it again man, its ok.

im outta here.

[shadowfac]

Originally Posted by n***N

No.

(2) means step 2. Use your logic, and see that (2) is being refered to again as the new harmonic. If you know what ring mod means, you should know what that step means. And No, its not (2)*anything!

You obviously did not get my message.

Read it again man, its ok.

Ok, I read it again. It still didn't make sense. Let's see:

Originally Posted by n***N

Nothing is being modulated.

Sure. I guess someone chose the name "ring modulator" just because it sounded nice.

Originally Posted by n***N

RING MOD is a simple calculation, which based on 2 oscs at different frequencies:

This much is true, however, the oscillators don't need to be at different frequencies.

The simple calculation is simply the time-domain product of the signals. If the input signals are two sinusoids with frequencies A and B, it's easy to see (using trigonometric identities) that

cos(At) * cos(Bt) = [cos((A+B)t) + cos((A-B)t)] / 2

therefore, the output of the ring modulator are two sinusoidals with frequencies A+B and A-B, and with half the amplitude of the original signals.

Originally Posted by n***N

(1) diff = high freq 'minus' low freq

(2) low freq + diff

(1) = New Fundmanetal
(2) = New harmonic

(1) + (2) = New tone, with no presence of the original signals ('high freq', 'low freq')

First, the output of a ring modulator is not "a" tone. When the inputs are two sinusoidals (e.g., two tones), the output will also be composed of two tones, whose frequencies are the sum and difference of the frequencies of the original tones.

Now, what you call the "new fundamental" is basically the difference of frequencies. But what you call the "new harmonic" is equal to what you call "high freq". Do the math: if diff = high freq - low freq, then high freq = low freq + diff = new harmonic. This contradicts your next sentence where you say the ring mod output does not contain the original frequencies (which is true unless one of the input signals is a DC).

Moreover, the terms "fundamental" and "harmonic" are not being properly used here. A "harmonic" is a certain multiple of the "fundamental"; however, the output tones of a ring modulator are typically inharmonic.

By the way, when there is no harmonic relation between two sinusoidals, they're usually called "partials" or "components".

Originally Posted by n***N

This new tone is the output of the ring mod, so there should be no modulation. I heard examples of ring mod, and it never sounded modulated.

Again, the output is not a single tone. But even if it was, it is the result of a certain type of modulation.

You also say you have "heard examples of ring mod". Does that mean you have not actually done it yourself? I would also like to know how do you think a "modulated" sound should sound. Various forms of modulation (especially at audio rates) are commonly used to shape the timbre of a sound, without the timbre necessarily changing over time, but the results can certainly be heard.

For more information, I suggest the following reading:

SYNTH SECRETS

Ring modulation - Wikipedia, the free encyclopedia

[chrisso]

Also, basic Ring Modulation is often performed with 2 x Sine waves.
But you can use anything, a drum loop and an oscillator, a microphone and an oscillator. It's all Ring Mod, and not confined to a strict set of numerical rules.

[shadowfac]

Originally Posted by n***N

btw here is another question:

when I detune two OSCs on the TI and feed them to the ring mod, put the ring mod volume to 127, the result is rather strange. In reality, feeding 2 freqs into a ring mod, should produce a subtle signal. Where in my case for some reason, it actually sounds like its being modulated by a sin LFO. I checked every possible mod destination, the LFOs are not even active. There is NOTHING being modulated. I dont understand why it sounds like that. When I press sync, this whole LFO sound goes away, but then that kills the beating, doesnt it. WEIRD.

I think I found the problem. Did you turn the level of the oscillators all the way down in the mixer, so you only hear the ring modulated signal?

If the level of the oscillators is up, and they are detuned, then you will always hear beating; not because of the ring mod, but because of the oscillators themselves. And of course, when you sync the oscillators, you will force them to have the same frequency and thus the beating will disappear. But if you turn the oscillators all the way down and only leave the ring mod signal, you should not hear any beating (e.g., perceptible changes in volume).

[n***N]

Originally Posted by shadowfac

I think I found the problem. Did you turn the level of the oscillators all the way down in the mixer, so you only hear the ring modulated signal?

Yes, I did.

It just sounds like the amplitude (volume) is being modulated by a sin wave. It goes to full loudness, and then slowly to silence, and then slowly back to full loudness. [Im talking about the ring modulated signal].