If what you are looking for is more referencing without messing with your setup, why don't you try the old and proven Focusrite VRM Box? Cheap and effective in simulating listening scenarios, though you'd have to make do with headphones.

 

I doubt if there is any convenient solution, because it's not only about frequency response. there are more things that can not be measured as easy as it you might think, there is phase response, off axis frequency/transient response, regular transient response, box resonants that behave different on different placement. underlaying ground resistance etc. etc.

Maybe buying a set of Yamaha NS-10 is an option

 

And spend a few years getting used to them and knowing them (with their obnoxious nasality and poor low-end). ;)

Sorry, I had to.

 

Now you're just mean. As if I'm not in enough pain already.