The goal of a5eq.lv2 is to deliver optimized performance on both AMD64 and ARM64 architectures. By leveraging SIMD instructions, the plugin ensures efficient and reliable operation.
As the author of a5eq.lv2, I welcome feature requests and ideas for improvement.
There are a lot of alternatives out there today, the most popular being either the Cytomic or Zavalishin's SVF implementation. You can also use those to deal with cramping near Nyquist without resorting to oversampling.
Also, why limit to five bands? It's 2024, give me an arbitrary number of bands. Otherwise it's not really more useful than the builtins in any DAW.
I hadn’t fully realized the extent to which EQ cramping is a concern in the audio community, so I’ll definitely dive deeper into mitigation techniques to address it effectively.
Regarding your point about limiting to five bands, I completely agree: there’s no technical reason to impose this restriction, especially given the abundant memory available on modern desktop systems. I’ll explore a more dynamic architecture to allow for arbitrary numbers of bands.
Thanks again for sharing your insights. They’ve given me a lot to think about as I work on improving this project!
Direct form 2nd order filters are a dead end in terms of performance and quality for pro audio. I just wanted to point that out, since this space is very well studied and direct forms have pretty notable disadvantages (stability under modulation, overhead of coefficient computation, poor SIMD optimizations, etc).
Other than that: I found it somewhat confusing that your UI groups parameters by type of control (e.g. all frequencies first) instead of grouping them by EQ:
Low Shelve
Frequency
Gain
Q
Bell 1
Frequency
Gain
Q
Bell 2
Frequency
Gain
Q
Bell 3
Frequency
Gain
Q
High Shelve
Frequency
Gain
Q
Other than that I would just miss High and Lowpass filters. Especially HP filters are a thing that are extremely useful for cleaning up mic rumble and unwanted proximity effect, bonus points for variable steepness (6/12/18/24 db/Oct). In my dialog mixing time there wasn't a single channel without a HP on it (except those who already had it baked in of course).
Since you have a L/R stereo mode maybe an alternative Mid/Side mode could be considered as well.
Another question: do you prevent EQ cramping?
1. Logarithmic plot and spectrum analyzer: This feature is definitely on my roadmap. I agree that having these visual cues is essential for live tuning and precise adjustments.
2. UI grouping: You’re absolutely right about grouping parameters by EQ band rather than by type of control. Your suggested layout makes a lot of sense, and I’ll admit I took a shortcut by organizing the UI the way it is now. I’ll reference this thread in the corresponding GitHub issue to ensure it’s tracked for improvement.
3. High-pass and low-pass filters: I completely agree these are essential additions. I might explore adding them as a separate mode for the EQ. As for slopes, implementation could be a bit trickier since biquads inherently support only 6 and 12 dB/Oct. I’ll add this as a feature request on GitHub so it can be properly tracked and discussed.
4. Mid/Side mode: This is an intriguing suggestion and could offer a lot of creative possibilities. While it’s a bit more complex to implement, I’ll look into how it could fit into the current architecture.
5. EQ cramping prevention: The current design inherently avoids EQ cramping due to the use of the TDF2 transposed structure for biquads. However, I’ll review other topologies to see if there’s room for further optimization.
Thanks again for such thoughtful feedback. It’s input like this that helps me refine and improve my plugins. Also, feel free to jot down any feature requests in Github.