alt.hn

6/6/2026 at 6:09:59 PM

Show HN: Resonate – Low-latency, high-resolution spectral analysis

 https://alexandrefrancois.org/Resonate/

by arjf

6/10/2026 at 2:53:11 AM

Nice. To the folks saying "nothing to see here" this appears to be a variation of filter-bank spectral analysis where each band varies in frequency to track "the" in-band sinusoid. Somewhat like a bank of PLLs each with its own tracking bandpass filter. By using IIR filters rather than FFTs you avoid the latency of buffering up a full frame of data before you can run the FFT analysis. I am curious how this handles input containing broadband transients. It might be interesting to use CIC filters rather than an IIR lowpass to get better time selectivity, but maybe that's already been addressed, I didn't read the papers.

by RossBencina

6/10/2026 at 1:34:28 AM

A useful demo for this kind of tool would be a side-by-side on difficult inputs: fast pitch bends, dense chords, and low-SNR recordings. Latency is easy to appreciate visually, but robustness under messy audio is what usually decides whether spectral tools become part of a workflow. Even a small set of repeatable test clips would make the tradeoff much clearer.

by j-river

6/10/2026 at 3:48:41 AM

Slowed down higher pitch example was nice to hear, as this is where often conventional methods are heavily artifacted

by _def

6/9/2026 at 11:24:09 PM

There are some piano tuners I've found who are a bit on the spectrum, who believe they can tune a piano in a way that no digital device can replicate. I'm skeptical, and would like to see how this method holds up against one of these savants.

by jmpman

6/6/2026 at 6:56:31 PM

I have such app for more than 4 years. Your algorithm is not new - it is new for you only :) Here is the app: https://play.google.com/store/apps/details?id=com.bialamusic...

https://apps.apple.com/us/app/chord-detector/id1495811175

by bialamusic

6/7/2026 at 10:48:38 AM

Spectral analysis has indeed been around as a concept for centuries and there have been apps based on the FFT for decades, so definitely nothing new there. What I have implemented however, while based in known concepts and techniques, allows to achieve real-time, low latency and high resolution (both in time and frequency dimensions) performance that I believe are out of reach of established (published) methods. The apps you link are most likely making use of the FFT, which has become widely supported with efficient hardware acceleration and easy to use libraries, because of its central role in ubiquitous DSP applications, e.g. compression. I would be interested in any publications or at least technical descriptions of algorithms/systems that achieve similar performance!

by arjf

6/6/2026 at 8:45:53 PM

Is it the same algorithm or a similar domain? Overlap can exist

by rfgplk

6/7/2026 at 9:25:38 AM

It is more complex than the one described here. The idea is the same but for a working solution many different coefficients are needed and adjusted properly. Resonances are adjusted to have some match to the human perception. It is all time domain as there are no real frequencies in sound.

It is good to see the idea investigated by more people but the man should not try to claim it as his own. We are doing such tings for years and I want this knowledge stays to people so no one should claim it

by bialamusic

6/7/2026 at 12:31:53 PM

Sounds really interesting! Could you share some description of the algorithm used for chord detection? What model of tonality are you using for pitch/chord naming?

by arjf

6/9/2026 at 8:37:17 AM

My email is alex@mlazev.com I will write some details when I have time.

by bialamusic