ASYMMETRIC Waveforms: What is your go to fix

Howdy All
Most of the time I dont bother unless there is a real loudness issue as this occurs with low rms frequencies

BUT

When it comes to instruments eg Bass…sometimes and depending on DI/io etc this can be significant and more so because its in the kinetic range.

How do you normally deal with asymmetric peaks in the sub 110hz region iin Cubase?

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I’m always willing to learn… What is the ‘kinetic range’ ? :thinking:

Concerning the asymmetric waveforms, could there could be a DC Offset issue involved ? Something that can be checked within the Audio > Statistics window and corrected with the Processes > Remove DC Offset command. But maybe I’m completely off topic, on this one… :blush:

Yeah DC Offset has nothing to do with asymmetry

Kinetic : all audio is theoretically kinetic ie movement of air but essentially I mean air that you feel rather than hear…<100hz or so
Asymmetry has been on my mind lately as I have been doing a lot of study on bass frequency esp as I do a lot of FOH engineering so you really get a chance to feel the mixes.

Seems like the only real tool of substance is RX which has an a great phase tool…just dl and it seems to do the job but not a plugin…would be a great tool for cubase

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I’m curious, what exactly is the problem with the track? Do they sound wrong? I know that bass tracks can be asymmetric, I often notice that when I record them slightly distorted or through a compressor, but it usually isn’t a problem, if they sound right…
Is there low end missing?

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OK; I have looked more closely at the matter, as I didn’t make directly the relation between assymmetry and instrument tones, sorry. According to this source (which indeed makes a clear difference assymmetry/DC Offset) :

… it seems rather normal to have assymmetric waveforms on a broad range of instruments (especially brass ones : trumpets, french horn…), as they are a visual representations of their tone. So, I still don’t get where is the true issue, I admit. And wouldn’t an eventual “correction” of this phenomenon alter the involved instrument tone ?

Beside this, it doesn’t seem to me that a bass (an electric one - Epiphone Korina Explorer, recorded DI on a Hi-Z input of my audio interface) is particularily involved in the issue : here is what I get, after having recorded just few notes in the low portion of its range :

So… :thinking:

You make it sound like asymmetric waveforms are problematic, but they are not. The same sound source may, and very often does, develop both symmetrically and asymmetrically as its dynamics and timbre change in time.

Some effect processors intentionally output asymmetric waveforms by clipping the positive and negative voltage peaks with different shapes. This technique adds both odd and even harmonics to the signal.

In the few decades I’ve been using Cubase, there has not been a single case where I felt the need to correct or redraw a waveform because it was asymmetric. (Static asymmetry such as DC offset is indeed a problem, but that is not the issue you seem to be tackling.)

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Sure…I didnt notice until I did some pretty zoned study…as mentioned in op…if you are mixing FOH even with only 500w rms into subs…you start to notice things.
Its only when you move into understanding the pure physics of sub bass that you realise a lot of things. Is asymmetry a problem nomrally? No, its a natural part of timbre/sound…well as explained…except when moving a lot of air in an unnatural way…you dont want the oxen to fight each other (and other phase tricks)
.
Its all about headroom and unity of phase in that area. …we have limited space in 0dbfs

I didnt want to go into perspectives on what people may/not think is important…but moreso, if others who have covered and understand the physics (in much greater depth than I am up to) , then I was hoping to see their workflow executed in Cubase. Its just another aspect of phase correction…no diff to optimising in the same way as doing a kit.

When moving full excursion in the subwoofer, by NOT having symmetry in the sub bass, you are literally robbing spl from the sub stack. It is actually critical…prob not for horns but for any music (<100hz)played in a PA. You are straining the AC oscillation to one side much like DC offset although a completely diff thing

For anyone interested…this is a simple primer.

Although I only do it for sub bass…the rest doesnt matter and woulnt do it to a whole mix…he just explains it nicely
Cheers

Identical take via 2 diff DI’s (slight gain change to highlight). EVERY instrument, well input source can be different. These were the 2 closest samples; the other asymms get a lot more disparate

OK, but still… They don’t seem asymmetrical to a point that they need a correction. And again, to which point any correction wouldn’t alter the tone of the instrument recorded ?

Those above were the best. If one has a 3db variance, then you have lost 3db of headrom ie doubling of power, often I saw 4-6db so thats a doubling of SPL The tube DI is shown below (40hz)

No ‘TONE’ is harmed because I am only working on <100hz for
EDIT: Kick drums can be far worse

One possible solution could be:

  1. Apply a highpass filter to the subsonic frequency band;
  2. Re-instate the subsonic band by way of synthesis (there are many plug-ins for this on the market).

Lol
Or just rotate the phase and not damage anything which is back where I started. This is not a hard nor uncommon fix these days…we are not talking tone…please; I dont need a diff way to sort it out or going into a whole rave about.

The pic below is the same sample…I just want to be able to do it inside Cubase and not use another package for a fairly simple task

Guys, I appreciate the conversation but its just way outside my op. Question remains, whether someone might think its right or not…

Does anyone on the forum have a workflow within Cubase for sorting out the above prob?

Seriously… FWIW, the low E string of a guitar (played idle and with a ‘regular’ tune) is 82 Hz, which is the one I get on the second fret of my bass third D string : can you really declame that these two have the same tone ? :face_with_monocle:

Good luck…

If you want to reshape the waveform for headroom purposes, limit or clip it while closely watching for distortion. Remember, the waveform as a whole has to stay on the zero axis; otherwise, you’ll create other problems.

Open E on a bass = 41hz

Tone is what is heard including timbre which needs harmonics to be a tone. I think something is going missing in the tramslation…I run a linear phase cross over for this sub part of the bass…you literally only 'hear the fundamental and at that freq…it is felt not hear in reality.

Sorry if that doesnt make sense

Ill leave it there guys…something is missing in these conversations…
That is the whole point of phase rotation…rebalancing the V+ and V-…the RMS does not change …at all.

I do appreciate your efforts to help but its not helping…you are completely missing the point…:frowning:

Please check the pic above with the phase rotation…I wanted to know how others are doing it in Cubase…so far none

Anyway…bedtime in Sydney.

Well what you have looks really good…very clean and pure and you would not have to worry at all in any case

I normally use the iZotope RX phase tool to deal with this.

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Well thats look like where it is headed. +1…spectral layers doesnt seem to have any of these phase tools

I normally also use RX Phase to fix these kinds of issues. However, Acon Acoustica provides a similar tool as well that works equally good for me so far. An advantage over RX is Acoustica’s ARA support so that you can use it inside Cubase as an audio editor in the lower zone, similar to SpecraLayers or Melodyne.