Aliasing and Oversampling for DSP Engineers - Sam Fischmann - ADC23

audio.dev/ -- @audiodevcon​
Aliasing and Oversampling for DSP Engineers - Sam Fischmann - ADC 2023
Aliasing distortion and oversampling have become especially popular discussion topics in the wake of widely-available consumer analysis tools such as Plugin Doctor. In response, audio software users have been more vocal about aliasing, in many cases asking audio developers to provide oversampling.
As it turns out, not all oversampling is the same, we face several trade-offs when implementing it, and we don’t always need it. This talk aims to help you understand aliasing distortion, how oversampling addresses it, and some potential downsides of overuse. It also provides guidelines to help you decide when oversampling is necessary, what kind of oversampling to use, and mentions some open-source libraries that give you flexibility to make the right decision for your software.
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Sam Fischmann
Sam is a seasoned developer and composer, with experience spanning Web, embedded, and desktop systems. He founded Musik Hack with Stan Greene to release products that are easy to use without sacrificing quality or creative control. In the process, he learned that not only does he love making audio software, he loves teaching it! You can find him talking with White Sea Studios, Bobby Owsinski, Help me Devvon, or pretty much anybody that wants to have an interesting and engaging conversation.
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Streamed & Edited by Digital Medium Ltd: online.digital-medium.co.uk
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Organized and produced by JUCE: juce.com/
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Special thanks to the ADC23 Team:
Sophie Carus
Derek Heimlich
Andrew Kirk
Bobby Lombardi
Tom Poole
Ralph Richbourg
Jim Roper
Jonathan Roper
Prashant Mishra
#adc #audiodev #dsp #audio

[@Owen-Chiang]

I love your content and energy. Can't wait to see more!

[@MusikHack]

Got questions? Leave them here and I’ll do my best to answer!

[@Manmademadman]

GRRRRRRRREAT Stuff, Sam. Thanks!!

[@TheMasteringProject]

Is this presentation available for download?

[@dat_21]

Are IIR filters are worth it, given the fact that FIR filters can use SIMD very efficiently with good implementation? Latency isn't that much of a problem. 64 tap filter (2x) is like 1.5ms roundtrip and is pretty much negligible, unless there are lots of oversampled plugins in a chain. Also, going past 128 taps for oversampling is way beyond diminishing returns, so might aswell not bother. High order IIRs are prone to numerical issues and are way harder for CPUs, because they include long dependency chains in it's computations. FIRs don't have that problem at all IF implemented correctly. Ah, and yes, min-phase FIRs are possible as well, and their implementation is pretty much identical other than the fact that the kernel must be min-phased. But latency benefits are not all that great. Also, multistage oversampling is kinda not worth it, single stage is simpler to design and performance is pretty much the same if not better.

[@84411234]

I’d like to remind the author that oversampling and upsampling are different concepts