Hi there!

I'm looking for high/low cut objects. What I mean with "cut" is that for example the highcut filter hat a gain of 1 BELOW the given cutofffrequency and a gain of 0 ABOVE and equal to the cutof freq.

I hope you understand what i mean

Thanks in advance

check out these:

bp~
hip~
lop~
vcf~

thank you for you reply

i know these, but sadly, they don't do the job I want them to.

If i build this patch:

osc~ -> lop~ 100 -> hip~ 50 then i would still hear something if i sent "40" to the oscilator.
Also, if you check the help screen for hip~/lop~ then you will see that frequencies below/above will still be audible - they will just be alot lower in volume.

So - thats not what I'm actually looking for.

What i need is a filter that could for example cut all frequencies above 100hz and below 50hz, so that i only hear those.

....so you would need a band pass filter

The problem you are having describes the slope of the filter cutoff response. A basic [bp~] is only 6db/octave rolloff (or is it 3?)

When you stack filters it has the effect of steepening the cutoff slope. To tighten the frequencies that are let through simply patch them up in series, so:

(your input)
|
|
[bp~ 75]
|
[bp~ 75] (-gives 12db/oct)
|
[bp~ 75] (-gives 18db/oct)
|
[bp~ 75] (-gives 24db/oct)
|
[bp~ 75] (-gives 30db/oct)
|
...and so on

hope this helps

S

thanks

it's not exactly what i'm looking for. But we're getting closer

I tried to stack a bunch of lop~ - that works too.

But it seems to me like the gain is alread decreasing BEFORE ( in case of a lop~ ) the sinewaves freq reaches the cutoff frequency.

For example:

90 -> osc~ -> lop~ 100 -> lop~ 100 -> ... ( 8 lop~ ) -> env~
90 -> osc~ -> env~

If i place an numberbox behind each envelope follower, it turn out that the volume of the upper signal is signifficantly lower ( 'round 78db ) than the volume of the lower, dry signal, even though both waves have the same freq. ( 90hz ) and are below the cutoff frequency.

This is of course not, what i want.

When trying the same thing with bp~ ( freq of the osc~ and center freq are both 90hz ), then i notice that even the volume of the center freqency changes. When Q is very low, then it is even amplified. (110db instead of 96db )

So this - sadly - not what i need.

so you want literally a spectral gate? In other words all freqs in the band width 100->150 I want ON, all other freqs outside that band width OFF. No transitional interpolation stuff

Maybe you should start looking at FFT as filters just don't work quite like that..

ah okay - thank you.

well, i had hoped to get around fft, but if that's the only way....

anyway, thanks again to everyone who helped

Unless one of the more knowledgeable members round here knows, you should take a look at FFTease for Pd - it's a bit easier to operate than bare bones Pd fft. I'm pretty sure theres an object for this

http://www.sarc.qub.ac.uk/~elyon/LyonSoftware/MaxMSP/FFTease/

Thank you!

But I think I've alread found a solution in the normal pd-system.
I found this graphic EQ on the forum and i can use it for my purposes. I can controll the gain exactly as I want.

There's just one problem remaining... Can you guys tell me how to read data into a graph ( in my case the graph that contains the gain-info )?

For example, if i wanted the following data to be displayed in the graph, how would I do that?

f(0)=0
... ( inbetween those 0 and 50, f(x) always equals zero )
f(50)=1
...
f(100)=1
f(101)=0
...

Maybe you know what i mean, it's the same type of filter that i described above.
The x-axis is in hz while the y-axis is the gain.

look up the help files for 'arrays'

also, check [tabwrite] , [tabread] etc.

thanks

I'm now doing it with a message box: "gain1 read ./1.txt"

lol, what is that graphic EQ that you found in the forum?

How did you get what you was looking for?