reaktor filters

I am currently creating a reaktor subtractive synth with a high pass filter and a low pass filter. I have them both set to visible with ranges of 20-20,000 and stepsize of 1. This is to give a full range of the spectrum and accurate control of the cutoff. But when i try changing the cutoff it doesn't seem to work properly.. it seems to jump.. and even the cutoff on the visual seems to jump in and out of the screen. I cant seem to get it working.. any ideas why? thumbnails below show my settings and setup.

 

I can see that your mouse resolution needs to be higher. 19980 to be exact.

You may want to consider expressing the frequency logarithmically (as pitch numbers).

Or, if you don't wish to abandon expressing the frequency in hz, create a fine control knob (for example, from 0 to 100 step size 1 mouse resolution 1) as well as a coarse control knob (for example, from 0 to 20,000 step size 100 mouse resolution 200) and add the two.

 

how do i express logarithmically? in hz just seemed logical!

 

Use MIDI pitch numbers (0-127) as your units for a knob control, then convert to hz using an Expon (F) module. Sweeping the frequency will sound much more natural if you set the cutoff frequency in this way (logarithmically).

Using a fine control knob will definitely give you more accuracy. You can have a fine control with units from -0.5 to 0.5 with 0.01 step size (or -1 to 1 or 0 to 1 depending on personal preference). Then, just add that to the pitch number before converting to hz. That should give you all the accuracy you need (unless maybe you're playing with interference patterns).

If you must know the frequency in hz, just attach a numeric readout module to the output of the Expon (F) module.
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The reason why hz don't really work that well is that your brain interprets the interval from 10khz to 20khz to be the same size as 5khz to 10khz, 2.5khz to 5khz, 1.25khz to 2.5khz, ... , 40hz to 80hz, 20hz to 40hz, etc.

So, your hz knob divides the interval 10khz to 20khz into 10,000 steps whereas it divides the interval 20hz to 40hz into just 20 steps. In other words, the top octave of your hz control has 500 times the resolution as the bottom octave.

Also, changing the cutoff frequency from 50hz to 150hz makes a much bigger difference than changing from 10khz to 10.1khz. You'll find that when sweeping the cutoff frequency in the upper ranges you'll need to turn the knob much further to make just a small difference in the sound. Also, towards the lower end of the spectrum you'll notice that just a small movement changes the sound by a lot (probably too much).

 

Something which hasn't been said explicitly here is that the built in filter modules do take their pitch in MIDI Note Number format.

Anywhere where you see the 'P' input this is the case.

If you see an 'F' input, this takes the value in Hz. You will see FM variants of the same filters which offer this functionality

Another handy thing to try is that if you right click on the input, then select 'create control', it will create a control usually with the most appropriate settings. In the case of the filters, it usually creates a knob that ranges from 20 to 120 - roughly the most audible range of the MIDI Note spectrum.

 

i cant seem to get the numeric reader working. whenever i connect the output of expo (f) to it a red X appears. it would just make it easier for me to see the freq in Hz aspecially as im trying to use the same thing on a sine osc.. and want to see the frequency of each sine. any ideas?



Also whilst i'm here... anyone know of their is a frequency shifter module anywhere?

cheers again guys!

 

Numeric Readout modules only accept monophonic input. Put an Event V.C. All module (in the Auxiliary menu) in front of the Numeric Readout module.

Or, make the Expo(F) monophonic by right clicking on it and selecting monophonic.

Monophonic modules only accept monophonic signals. A module is monophonic if the colored square is red, and polyphonic if the colored square is yellow. Most modules can be set to monophonic or polyphonic, Numeric Readout modules are an exception. (there are quite a few other exceptions)

 

there is a very good Frequency Shifter Macro in the Reaktor 5 Library.

and there is at least one or two in the User Library.

sowari