As you may know, there are more and more people putting effort into measurements and EQ profiles for speakers and headphones. A user can then apply that EQ with something like EqualizerAPO.
That's all fine and dandy.... unless you need ASIO and low latency. In that case, 3rd party solutions like that aren't as good anymore. Even with something that supports ASIO, like Voicemeeter, you get a significantly higher latency in the end. (IDK if the situation is any better on macOS.)
So the only solution is some DSP that is integrated with the sound card. Sadly, the vast majority of products out there don't have this functionality. Off top of my head, I know only RME which has this for all I/O and even then it's just a 3-band EQ. Some other sound cards have DSP only for the inputs, but not for the outputs.
Generally, there are two ways to implement it:
1. leave the processing to the host computer and add DSP as a feature of the driver software/mixer — in this case you can either make your own effects or integrate some VST host functionality
2. put the processing on the device itself, with some DSP chip
The first one would be easier to implement, since it's "only software". There are many existing high quality VSTs out there, if you go with that, and in any case, something like an EQ typically uses a negligible amount of CPU.
The second one (with a DSP chip) would give you more control and free you from the potential shenanigans of the host computer, but its also more limiting. And most users would still want a GUI on the computer for adjusting the settings — otherwise you need to add more buttons to the device.
Keep in mind it's not just for an EQ or a compressor. People might use all kinds of effects, like a crossfeed for the headphones and so on.
So I think most users would be happy with option 1, especially if this was an open system where you could share the settings.
In either case, you could also add some basic hardware control, like a DSP switch:
Pressing that would let you cycle through the mixer/DSP presets and each preset would have its own color. (And long press to turn it off.)
But I don't think any hardware buttons are necessary. I think the vast majority of users would set the I/O DSP on the computer and then leave it like that. A button for cycling through presets would be more useful if you wanted to take the device elsewhere, or even use it standalone — in that case you'd need a DSP chip, of course.
To sum up, I can see this as a very attractive feature for the ASR crowd and even more for the music production crowd in general, who can't rely on "external" solutions due to latency requirements. It could be a great way to make your product stand out among all the generic audio interfaces that don't offer anything new.
That's all fine and dandy.... unless you need ASIO and low latency. In that case, 3rd party solutions like that aren't as good anymore. Even with something that supports ASIO, like Voicemeeter, you get a significantly higher latency in the end. (IDK if the situation is any better on macOS.)
So the only solution is some DSP that is integrated with the sound card. Sadly, the vast majority of products out there don't have this functionality. Off top of my head, I know only RME which has this for all I/O and even then it's just a 3-band EQ. Some other sound cards have DSP only for the inputs, but not for the outputs.
Generally, there are two ways to implement it:
1. leave the processing to the host computer and add DSP as a feature of the driver software/mixer — in this case you can either make your own effects or integrate some VST host functionality
2. put the processing on the device itself, with some DSP chip
The first one would be easier to implement, since it's "only software". There are many existing high quality VSTs out there, if you go with that, and in any case, something like an EQ typically uses a negligible amount of CPU.
The second one (with a DSP chip) would give you more control and free you from the potential shenanigans of the host computer, but its also more limiting. And most users would still want a GUI on the computer for adjusting the settings — otherwise you need to add more buttons to the device.
Keep in mind it's not just for an EQ or a compressor. People might use all kinds of effects, like a crossfeed for the headphones and so on.
So I think most users would be happy with option 1, especially if this was an open system where you could share the settings.
In either case, you could also add some basic hardware control, like a DSP switch:
Pressing that would let you cycle through the mixer/DSP presets and each preset would have its own color. (And long press to turn it off.)
But I don't think any hardware buttons are necessary. I think the vast majority of users would set the I/O DSP on the computer and then leave it like that. A button for cycling through presets would be more useful if you wanted to take the device elsewhere, or even use it standalone — in that case you'd need a DSP chip, of course.
To sum up, I can see this as a very attractive feature for the ASR crowd and even more for the music production crowd in general, who can't rely on "external" solutions due to latency requirements. It could be a great way to make your product stand out among all the generic audio interfaces that don't offer anything new.
