From: Dominique Bassal (dominique.bassal@videotron.ca)
Date: Sun Mar 13 2011 - 01:59:33 EST
I never experimented this particular situation, because I control the apparent level with other techniques. And when I need to clean-up tracks, I will not choose a fixed frequency, but go on a track by track basis: the cutoff frequency will vary a lot, sometimes filtering will just worsen things, and sometimes the ripple that comes with abrupt slopes will be helpful. Brainworx even have (another) filter that offers the possibility to exaggerate the ripple, or shift it completely:
That said, I generally prefer using dynamic tools to solve mix problems, like a pre-emphasis filter on the side-chain input of a compressor.
Best
Le 2011-03-12 à 18:35, Eldad Tsabary a écrit :
> Cool
> I'll test more, but I am getting the feeling that cleaning up below 120 may be, with most filters, somewhat costly in dynamic range with and may actually add some boominess due to filter resonance around the cutoff (especially if we do it in multiple tracks). Does this make sense? Is this something you noticed?
> E
>
>
> On 3/12/2011 6:26 PM, Dominique Bassal wrote:
>> You are welcome;
>>
>> Graph have a marketing function in most products...
>>
>> Nugen's SEQ2 offers both worlds : you can choose "good looking" or "realistic" representations of the function. If you choose the latter, you realize that you really can't do what you want with EQs, specially in the low frequencies.
>>
>> The filters specialized in mix tailoring - like Brainworx's - are 6 dB/oct. Very relative cleaning up with that kind of slope...
>>
>> D
>>
>> Le 2011-03-12 à 17:37, Eldad Tsabary a écrit :
>>
>>> Thanks D
>>> Yes I know... I assumed resonance might be the reason, but I used a second order filter (12 dB slope) that at least in its graph seemed linear.
>>> I'll post images later.
>>> E
>>>
>>> On 3/12/2011 5:03 PM, Dominique Bassal wrote:
>>>> Hi
>>>>
>>>> Here are screen caps from PowerCore's DynamicEQ showing very frankly the ripple happening with high Q. Notice that it is covers quite a frequency range. If there is material there, the total peak increase can be significant;
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> This is the reason why this kind of filtering is usually made with soft slopes, like in the second screen cap, which minimizes ripples, but also performs less of a "clean-up", since here you would have to lower the cutoff frequency.
>>>>
>>>> It also explains why high - or low - pass filtering is only performed for mixing clarity purposes, not for RMS gain. For this, parallel compression - also called New-York compression - is the well-known method, although I personally find D-expansion cleaner and more controllable.
>>>>
>>>> Best
>>>>
>>>> Le 2011-03-12 à 14:56, Eldad Tsabary a écrit :
>>>>
>>>>> Hello all,
>>>>> While looking with students on methods of increasing dynamic range of pieces, we EQed individual tracks that have no business in the lower range with a high pass filter (2nd order) at 120 Hz. The idea was that getting rid of rumble from all of the tracks (except bass-range tracks) can both clean the overall mix and reduce measured amplitude peaks of individual tracks without losing actual loudness (thus allowing to bring the entire mix to a louder RMS).
>>>>> This, to my surprise, didn't work at all. In all cases I tried so far, instead of reducing the dB measurement, the signal after processing had a higher dB peak measurement (I used non-realtime EQ in order to use higher quality DSP but also to be able to measure the overall signal).
>>>>>
>>>>> It doesn't make much sense to me because the HPF is supposedly just a passive filter. Using HPF in Pro Tool 8's EQ on a drum overhead track reduced the overall audible loudness and got rid of the bassy sound of the kick. It sounded softer but strangely it measured as 2 dB higher than the original signal.
>>>>>
>>>>> I tried the scientific EQ in Adobe Audition, which is supposedly a well designed low phase filter (same setting - 2nd order, 120 Hz), and it resulted in only a 0.5 dB increase - but still an increase.
>>>>>
>>>>> Does anyone know of this? Anyone has knowledge or ideas about the possible cause of this?
>>>>>
>>>>> The several reasons that I have been thinking of are:
>>>>> 1. quantization error - though it seemed to me waaay too much of an increase
>>>>> 2. some individual transients that were somehow corrupted in the process
>>>>> 3. dc offset
>>>>> 4. phase issue
>>>>>
>>>>> Any insights would be helpful
>>>>> Thanks
>>>>> Eldad
>>
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