ATH-M30x

^ this. But frankly, even the m30's or any cheap studio monitors will provide much better sound quality than pretty much any wireless headset out there.

Are the m30xs less bass heavy? I recently bought these and they don't have the most amount of bass I was expecting from closed backs.

Yeah but M50x are over 100$ i think. I believe there is a mid range price option, the AT m30x that could also work. Anyways, if he wants them for monitoring why would he care about being bass boosted? Hes not looking for something super flat to mix on (Thats what I understood from the post)

You're not crazy. It is letting you hear everything that's wrong with your mix. Earbuds have scooped mid frequency response to make it sounds exciting and are not that suitable for mixing. The better the headphone, the flatter the frequency response, the more annoyingly flatter it sounds. I've used the m20x and m30x for mixing and they can be a bit harsh at the high end, so i put in an eq curve correction to flatten the frequencies more and make it more balanced spectrumwise.

I use the ATH-M30X's, they're fantastic.

This is exactly the setup I use, Spark Go to ATH-M30X. Was planning on getting the Spark Neo this week, but there’s no stock here in Hong Kong and I have to order.

I use the ATH M30X for budget reasons but 50s should do the trick for you