Page 1 of 2
ROLLING off frequencies
Posted: Thu Dec 18, 2008 3:40 am
by bebop
wot does it mean people keep telling me to
cut my sub under 40Hz and roll off at 200Hz i no of corse u need and eq to remove frequencies. but i dont understand the term rolling off.
can some one post me a screen shot of ^^ that about id be very greatful
Posted: Thu Dec 18, 2008 3:49 am
by rendr
That's rolling off on an EQ.
Think of it as the equivalent of a high and low pass for EQ.
The steeper the curve, the stronger the effect, but along with this comes more distortion.
I like to drop things off at 17,000 Hz by 48Db/Oct on my master channel, however I don't bother with the low end because the sub bass is normally a sine wave which has no harmonics to EQ out of it. All the low end filtering should be done on each individual sound, if it needs it. Remember each time you EQ you're distorting the original signal. So use sparingly.
Posted: Thu Dec 18, 2008 9:34 am
by manray
Rendr wrote:Remember each time you EQ you're distorting the original signal. So use sparingly.
Technically true but how much of that is going to be noticeable? And in a Dubstep track?
Personally I do ALOT of high/low passing these days. I've found my tracks are coming out punchier and my sub bass is coming through much stronger. My reasoning is that for example if I've got a clap what's to say there isn't some very low end muddying my mix? I do this on almost every element to some degree.
Posted: Thu Dec 18, 2008 9:37 am
by jackieboi
manray wrote:Rendr wrote:Remember each time you EQ you're distorting the original signal. So use sparingly.
Technically true but how much of that is going to be noticeable? And in a Dubstep track?
Personally I do ALOT of high/low passing these days. I've found my tracks are coming out punchier and my sub bass is coming through much stronger. My reasoning is that for example if I've got a clap what's to say there isn't some very low end muddying my mix? I do this on almost every element to some degree.
Same, i find the 7 band parametric eq in Pro tools absolutely amazing for this, can get things sounding exactly the way i want them and in general my tunes have started sounding a lot cleaner and punchier.
Posted: Thu Dec 18, 2008 9:39 am
by rendr
manray wrote:Rendr wrote:Remember each time you EQ you're distorting the original signal. So use sparingly.
Technically true but how much of that is going to be noticeable? And in a Dubstep track?
No noticeable at all. Just something nice to know for the audiophile / sound engineer. If anything its a positive in any genre (excluding classical). Compress a bassline to distort it's harmonics, then EQ the ones you want to hear.
Posted: Thu Dec 18, 2008 12:48 pm
by macc
Rendr wrote:
No noticeable at all. Just something nice to know for the audiophile / sound engineer. If anything its a positive in any genre (excluding classical). Compress a bassline to distort it's harmonics, then EQ the ones you want to hear.
This post is - I am afraid - utter bollocks. It's perfectly audible, and virtually always negative. It's a completely different thing to the distortion you're talking about. This is phase distortion and not harmonic distortion. A *completely* different thing. And like anything it is perfectly audible when either/both done to a certain degree and you know what to listen for.
Be careful using very steep filters as you may cause more problems than you solve. Particularly on a full mix, you should be very careful.
I've banged on about this recently.... more
here
Sorry if this isn't very clear, posted in a rush. But fire away if I am able to help

Posted: Thu Dec 18, 2008 1:08 pm
by serox
Can one of you please confirm I understand low/high pass with filters please.
I use this sampler with all my sounds ok.
I normally use the lp24 setting with the filter right near the bottom for sub ok, that's right yeh? that means only the frequencies below this are coming through, right?
if I want to high pass sounds like drums I stick it on hp12. If I leave the slider on the filter all the way up wont it let through all frequencies? What I am ideally trying to do is cut out the low frequencies right. But with the filter all the way up I am not allowing everything through at all and only when I start to bring the filter down do I start to actually hear the sound but it still sounds like low stuff is coming through.
Basically I dont get how the high pass works using the filters:/
Posted: Thu Dec 18, 2008 1:47 pm
by b-lam
@serox: you seem to have the basic premise of filters, with highpass only the frequencies above the one you set it at will be let through, and lowpass only the frequencies below will be let through...
filters never really work with this kind of precision though, there will often be some audible lower frequencies with a highpass filter on (which may be what you are hearing). If you want to completely get rid of them try using two filters with the same setting... probably introduces the kind of problems macc is talking about but if you really need to give the sub some space, this seems to be the way to do it.
Posted: Thu Dec 18, 2008 1:53 pm
by serox
Yeh I thought so.
So how come when I set hp12 I have to have the filter all the way down near the bottom to even hear a hihat?
Things dont seem to match up right when it comes to the crossover point. Maybe the sliders are shit on the reason sampler and not very accurate.
Posted: Thu Dec 18, 2008 1:56 pm
by manray
B-LAM wrote:filters never really work with this kind of precision though, there will often be some audible lower frequencies with a highpass filter on (which may be what you are hearing). If you want to completely get rid of them try using two filters with the same setting... probably introduces the kind of problems macc is talking about but if you really need to give the sub some space, this seems to be the way to do it.
Really depends on what the filter/eq is doing and how much reduction they give and how dramatic. You will see figures like 6db/octave etc... which denotes how much it will roll off and how quick.
Posted: Thu Dec 18, 2008 1:56 pm
by serox
If I have everything on hp, whats the point? I am not cutting really anything out.
Posted: Thu Dec 18, 2008 2:03 pm
by macc
With a LP you attenuate everything above the cutoff. If the cutoff is at the top then everything will pass.
With a HP you attenuate everything below the cutoff. If the cutoff is at the top then nothing will pass.
Put a full tune through the different filters and you'll soon understand what's happening

Posted: Thu Dec 18, 2008 2:17 pm
by serox
Macc wrote:With a LP you attenuate everything above the cutoff. If the cutoff is at the top then everything will pass.
With a HP you attenuate everything below the cutoff. If the cutoff is at the top then nothing will pass.
Put a full tune through the different filters and you'll soon understand what's happening

I do understand that bit. I just don't understand why with the filters in the pic I posted I have to have the filter all the way down near the bottom to even hear a hihat. Its like I am attenuating such a small area and it looks like I am running into really low end stuff.
Do most people just leave the HP filter at the same for everything apart from a sub? if so, then what's the point? you are only attenuating the sub freqs.
Posted: Thu Dec 18, 2008 2:45 pm
by macc
Serox wrote:
I do understand that bit. I just don't understand why with the filters in the pic I posted I have to have the filter all the way down near the bottom to even hear a hihat. Its like I am attenuating such a small area and it looks like I am running into really low end stuff.
Do you have any modulation routed to the cutoff? I haven't used that filter in.... 5 or 6 years or something (thank god), but I don't think it was that full range. That is, with a 12dB/oct HP filter I'd still expect to hear a hi hat with some sort of HF content even when set near/at the top.
Perhaps it is being modulated upward from the point where the cutoff knob is by an envelope/other mod source..?
Do most people just leave the HP filter at the same for everything apart from a sub? if so, then what's the point? you are only attenuating the sub freqs.
Attenuating sub frequencies (or more specifically, low end rumble) is what most people here are trying to achieve by rolling off. It's not necessary on absolutely everything, contrary to what you may read, but can often be useful. The cutoff frequency should be set - as with everything - on a case-by case basis

Posted: Thu Dec 18, 2008 2:47 pm
by Sharmaji
filters on synths and samplers are great for broadly-shaping sounds.
use an EQ to solve mix problems; say the synth sounds great by itself, but doesn't cut the way you expect it to when everything else is in. cut out some space from other things, or boost what you need from the synth.
i tend to use very soft curves in my rolloffs; rarely above 12db/octave. more than that and you can get a resonance buildup at the cutoff point; sometimes works great to harden up a sound, usually doesnt. especially when hi-passing kicks.
Posted: Thu Dec 18, 2008 2:54 pm
by serox
I think that filter in Reason is a pile of shit tbh.
For a start its too damn small and it doesn't even have any damn numbers. I am new to make music but its like a kids toy and does not seem to do what it should imo.
I actually hate Reason right now and want to throw it out the window but I cant because its not fucking real.
Posted: Thu Dec 18, 2008 3:25 pm
by manray
Serox wrote:I think that filter in Reason is a pile of shit tbh.
For a start its too damn small and it doesn't even have any damn numbers. I am new to make music but its like a kids toy and does not seem to do what it should imo.
I actually hate Reason right now and want to throw it out the window but I cant because its not fucking real.
Can't stand it myself. You could use the reason MClass EQ to do the same job, might be better than the NN19 built in filter.
Posted: Thu Dec 18, 2008 3:39 pm
by serox
manray wrote:
Can't stand it myself. You could use the reason MClass EQ to do the same job, might be better than the NN19 built in filter.
Yeh I do use it also, at least it has numbers to help!
Posted: Thu Dec 18, 2008 3:40 pm
by jackieboi
Serox wrote:I think that filter in Reason is a pile of shit tbh.
For a start its too damn small and it doesn't even have any damn numbers. I am new to make music but its like a kids toy and does not seem to do what it should imo.
I actually hate Reason right now and want to throw it out the window but I cant because its not fucking real.
Blasphemy!!!
Reasons a quality wee programme once you get to grips with it. I definitely wouldnt use the filter on the sampler though as its pretty basic and the control you have over it is so limited.
Like manray said use the mclass EQ if its eqing your looking to do, essentially all a filter is is an eq with a steep cutoff. If all your using is Reason then the mclass eq will do fine.
Posted: Thu Dec 18, 2008 3:48 pm
by serox
jackieboi wrote:
Like manray said use the mclass EQ if its eqing your looking to do, essentially all a filter is is an eq with a steep cutoff. If all your using is Reason then the mclass eq will do fine.
Yeh I will do.
I am just lazy and hate having to add more shit to the virtual rack.
I should have an EQ on every sound tho really.