Hi Everyone -
I’m trying to understand what the benefit of using an Apodizing Fast PCM filter is.
My current CD/SACD player lists this filter as an option, and I would like to understand what it does to the sound in simple layman’s terms. I’ve searched on the internet, and as soon as i start reading, the writer uses more technical terms that I just don’t understand.
As always, thanks in advance …
The thing about the filters is the names they use don’t really inspire emotion. The only way to know if you like a filter is from listening to it. Explanations may help but if:
A. You don’t hear a change.
B. You hear a change but don’t like it
C. You think you hear a change and you do like it.
then you know all you really need to know.
On one of my DACs I have seven filters for PCM and three for DSD. I hear zero change with any of the DSD filters and I have two strong favorites for the PCM filters. My current favorite DACs don’t off any filter choices at all and I approve of this.
This may not have helped you, sorry if that is the case.
From a post by a person with a screen name of Rhythmatis on the roonlabs community site:
(I have no opinion myself, and simply assume this to be correct)
"Apodizing filters apply a weighting window to the filter coefficients. Depending on the design, they can cause anywhere from a very small to a large loss of resolution. They also compress the transient energy into a broader but smaller amplitude peak.
You can easily hear this effect by comparing MQA vs non-MQA music files. MQA uses an apodizing filter. It is like a very small dose of compression. The net result is the music will sound perceptively louder because the dynamic range will be reduced and the peaks will be closer to the average."
Jump to the ‘what filter should I use’ section at the bottom. Unfortunately, it is technical but at the end of the day what matters is your preference.
https://addictedtoaudio.com.au/blogs/how-to/how-to-pick-the-best-filter-setting-for-your-dac
That, after all, is where we started.
Let me clear. I do not really know what “microdynamics” are. I’ve been intrigued with high fidelity by almost half a century, but remain innocent of an understanding what an “etched player” might sound like, and what “rigidity” is in regard to sound quality. I do like “gossamer” as a word, but I don’t really understand how it relates to sound reproduction. However, I do have some sympathy with “magic”.
As always, if your equipment has options, play with them and see what you like. But if you want what is clearly the most technically accurate – that is, high fidelity – output from your DAC, choose fast roll-off or sharp-roll-off, and linear phase (or no named phase) rather than minimal phase.
And do not choose NOS or Optimal Transient or Super Slow Roll-off. They are objectively worse, although it seems plenty of people are able to imagine them to be subjectively better.
Ok, my head is officially spinning now
All the filter options are trade-offs. They are all “better” in some way but “worse” in others. An apodizing filter reduces a certain kind of noise called “pre-ringing” but does so at the expense of increased “post-ringing”.
As per the advice above, if you have the option to listen with and without, try both and use the one you like the most in the moment.