Scope plugins and oversampling

[Music Manic]

Are any of the mastering type plugins using oversampling? Plugins like Optimaster DNA’s compressor, timeworks Master, and PsyQ etc

Is there any device that that allows oversampling with scope too?

Thanks

[valis]

If you're not doing any processing, there's no need to oversample.

OSCs, filters, many of the devices have been upgraded over the years to use oversampling internally. Some change properties as you change samplerates because there either is no oversampling (Vectron if I recall) or others because the OSCs are oversampling at a fixed multiplier of the base samplerate, and one or two even had issues at 96kHz because it ran the oversampling too high (was this addressed?) So it varies by device, but there are certainly devices doing this internally.

I used to know offhand which were which, but I'll defer to GaryB & fr77x2 and others on the specifics.

[Music Manic]

That would be good to know because they’re my go to in the mastering chain and would like to know the specific design.
When pushed hard I hear some distortion in the high end in some. DAS’s Master IT EQ sounds very clean.

[fra77x2]

"When pushed hard"

What do you mean pushed hard?

If you clip the signals you hear the clipping which sounds like distortion....

Equalizers are not limiters. If you "push hard" you get the results of "pushing hard" which is good and nice clipping.

[Music Manic]

"When pushed hard"

What do you mean pushed hard?

If you clip the signals you hear the clipping which sounds like distortion....

Equalizers are not limiters. If you "push hard" you get the results of "pushing hard" which is good and nice clipping.

Well the meters don’t show any clipping but I guess it’s the limiting applied in series with all the plugins. Maybe my setup needs more understanding and control. For instance if I have Timeworx’s compressor-> dNa Mulitband processor to PsyQ things can get messed up very quickly.

[fra77x2]

Try to understand each device's functionality in isolation. Viewing the signal in an oscilloscope and a spectrum analyzer is very helpful.
Recording the signals and observing also helps.

For mastering you don't need "oversampling". Common devices can be used for mastering purposes.

[Spindrift]

I'm not really knowledgeable about what has oversampling or not in Scope.
But it doesn't really matter on any linear processes, such as an EQ without dynamics features.
On non linear processes it does matter in some cases, so they can benefit from internal oversampling.

Basically a non linear process will reshape the waveform, casing new partials to appear in the signal, which can end up above the Nyquist limit. Those partials will cause aliasing, resulting in a non harmonic distortion in the audible spectrum.
An EQ, reverb or delay will not introduce new frequencies, and work fine calculated at audiorate.

Distortion in the high end can happen with some compressors when they are working hard, after all distortion and compression are quite similar in how they work on the waveform. I would say the effect of aliasing introduced when doing non linear processing is pretty much inaudible with most material on most settings. For sure a full track is tough material, so it would be recommendable to use oversampling when compressing/limiting, but the difference will typically be very small in my experience when using plugins that allows you to select oversampling.

Edit: missed non in "On non linear processes it does matter in some cases"

[fra77x2]

Aliasing is meant when I sample a signal with frequencies above the Nyquist rate that "alias" i.e. appear as fake (not in the original signal) frequencies in the opposite side of the spectrum.

By non-linear processes I can distort my signal but I can not create aliasing.

[Music Manic]

Try to understand each device's functionality in isolation. Viewing the signal in an oscilloscope and a spectrum analyzer is very helpful.
Recording the signals and observing also helps.

For mastering you don't need "oversampling". Common devices can be used for mastering purposes.

Yes I will do that. It’s those hi frequencies I need to tame.

[Music Manic]

I'm not really knowledgeable about what has oversampling or not in Scope.
But it doesn't really matter on any linear processes, such as an EQ without dynamics features.
On linear processes it does matter in some cases, so they can benefit from internal oversampling.

Basically a non linear process will reshape the waveform, casing new partials to appear in the signal, which can end up above the Nyquist limit. Those partials will cause aliasing, resulting in a non harmonic distortion in the audible spectrum.
An EQ, reverb or delay will not introduce new frequencies, and work fine calculated at audiorate.

Distortion in the high end can happen with some compressors when they are working hard, after all distortion and compression are quite similar in how they work on the waveform. I would say the effect of aliasing introduced when doing non linear processing is pretty much inaudible with most material on most settings. For sure a full track is tough material, so it would be recommendable to use oversampling when compressing/limiting, but the difference will typically be very small in my experience when using plugins that allows you to select oversampling.

I thought EQing can be non linear too. It’s definitely the compression and limiting that’s doing it plus my misunderstandings.

[garyb]

are you adding gain with an eq?
that should be avoided as much as possible, whether plugins or hardware. many real "mastering" hardware eqs are cut only.

not enough highs? first cut lows.

avoid extra devices. just because you have a lot of plugins doesn't mean you should use all of them. a well-mixed track needs little eq or other processing. i don't mean that you should not use this or that, i'm just pointing out some basic good practices.

[Spindrift]

I thought EQing can be non linear too. It’s definitely the compression and limiting that’s doing it plus my misunderstandings.

Generally they should not add new frequency content to a signal. Typical exceptions are EQ's that also do dynamic processing, or EQ's that will distort when you add a lot of gain. But I guess then the EQ is acting as something else as well as an EQ.

[Spindrift]

Oh, and EQ's can have linear or non linear phase. That is an other issue and has to do with the EQ algo used, and doesn't improve with oversampling.

[valis]

(spindrift gave two responses while typing this, so I am somewhat overlapping but clearly overwriting as well...)

"linear" EQ's mean FFT based, which typically incur a rather large penalty in terms of internal delay. Not an issue in the DAW where PDC compensates, but a problem for realtime tracking & Scope (where we expect no delay in the order of thousands of milliseconds, ie, seconds).

Linear in this discussion is being used however in a different fashion, to mean 'reversible' ie, the changes between source material and the processes being applied can be 'reversed' back to the original signal by applying the inverse of what you did the first time. Nonlinear means 'not reversible' in that there will be changes to the signal that add harmonics that were not present originally, and thus aren't easy reversed back to the original. A truly nonlinear process may also be nonreversible because you'll never get the same result even with the same settings and source material...

And 'distortion' in that sense means *any alteration to the signal* (thus distorting it from it's original form), as well as fra77x2's use of what musicians typically mean by distortion. Nonlinear distortion means you're adding content to the signal that didn't originally exist, and typically (again) is not easily reversible.

EQ's can and often do oversample, for they are not only filters but also applying multiple bands of them, where the overlaps can create phase changes between the two overlapping bands (smearing transients and altering some of the harmonic relationship in the passband). This is normal, and even pleasing to our ears in some cases (or not that noticeable in most cases). But this is why the 'linear eq' types that use FFT functions were originally lauded, however all they really do is trade the overall phase relationship for a 'pre-ring' which again will also be quite noticeable on transient material in isolation, when the process is pushed hard. This isn't super relevant to the stuff we do in Scope again, but it's important as there was a time when these were heralded as some kind of magic that every mastering engineer & producer had to use all the time.

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Spindrift's point about compression coloring the signal is probably more in the right direction. If you're applying multiple series of compressors the idea isn't to probably push them to the point of color (unless you want that of course). Multiband compression also again introduces some phase issues when the bands are pushed in ways that are distinctly different, because again you're basically applying filters (like a crossover network). And of course remember that optimaster already has multiband compression, limiting, expansion etc all internally. So there's little reason to use several multiband compressors in series.

And garyb is correct, if the mix starts with properly chosen sounds (distinct in register and placement), then less eq is required. If your parts are controlled in their dynamics already (synths are, sampled drum loops are), then there's less need to get heavy handed with individual channel and bus compression. And then it's much easier to handle the final mastering steps as well.

Generally speaking, when applying multiple stages of compression you're doing so so that one can handle immediate reactions (problematic singers, levelling out extreme dynamic differences) so that the overall signal is tamed, while the second can handle let's say the more pillowy or longer time based compression to give your rhythm some 'shape'. And when you do this, you would typically apply only the amount of compression across both units that would be appropriate for one unit in isolation, or even less as one hopes you have more control with two in series and can more effectively use each to target whatever problem areas or creative choices you face.

Lastly, I tend to always use Scope to run my live mixes through. I will master offline in software because some of the tools I have only work there and have a fair amount of latency, but I've never had a problem with Scope on my mastering chain. Typically Optimaster or a clean eq, simple compressor and simple limiter are enough.

To this end I find that Timeworx’s compressor is better for me on individual tracks or simpler material, and does indeed give more 'color' with aggressive settings than other tools. Bx & the stock units are good for 'clean' stuff (the stock scope compressor used to cause clicks when pushed VERY aggressively, not sure if it still does that, and that seemed somewhat tempo dependant). So, using each tool for where it does its job best, and using things judiciously, I can't say I've found Scope to be harsh to my ears. Quite the opposite actually...

[Music Manic]

Thanks Valis