Thanks :) I've so far done all the practicing on Sony-WH1000XM3 noise canceling headphones connected to phone (Bluetooth) while putting kids to sleep, traveling in bus etc.

I know I should be practicing on my studio headphones (Sennheiser HD600, I don't right now have a chance for a monitor-based solution).

Can anyone tell from experience how much more profitable it'd be / how harmful it possibly is to do this on non-studio headphones (which aren't too flat, especially low end is heavy): is there a risk I'm constantly fooling out my ears as we speak?

As a dad of two small kids working on the phone whenever I have a chance has been the only way to get exercises done :)

Congratulations!

Keep doing what you're doing.

Congratulations!

Good Job!

To answer your headphones question:

Studio and hifi headphones usually have a different frequency response. Your Sony headphones are bass boosted and lack a lot of higher mids. They have a very different sound profile, that you are getting used to. You can still practice EQing on them, since the differences are relative. If you can detect a 950 Hz boost on one headphone, you can also do that on the other one. And it will obviously matter even less at games like Rebeater, Delay Control or Feedback Eliminator.

The only thing you have to keep in mind is: If you are always listening and practising with the Sony headphones, your ears are getting used to it's sound profile. If you switch to the HD 600 for a mixing job, you'll probably try to match the sound you're used to from your hifi headphones. Which will make your mix boomy (too much bass) and dull (lack of high mids).

Hope this helps!

Thanks guys for the support, this community is a truly supportive one :)

Wolfgang, thanks for sharing your thoughts on my question. I haven't so far gotten all to used to the frequency balance of my Sony headphones (at least to the point where I'd consider the boominess and lack of definition as pleasant qualities). I'll definitely keep your thoughts in mind though: I'll try to do more workout with the studio setup and make sure to use lots of reference tracks when getting more back to mixing tracks again!

congrats!