Thoughts on DAC option

I am surprised no one has suggested your source is a weak link.  I am a firm believer in the "garbage in is garbage out" in audio.  

I am not familiar with the Auralic Aries Mini but my internet search suggests it is dated and was never an audiophile component when it was new.

I missed your price point in the discussions, I have an Innuos streamer and love it and the Sense app, but I know their entry products are getting expensive.  

A new or used streamer is where I would look to upgrade your system.  If you can afford an Innuos or something similar I think it would punch the ticket for you.

I am surprised no one has suggested your source is a weak link.  I am a firm believer in the "garbage in is garbage out" in audio.  

Yup. I agree @rikkipuu , once one has heard what a great streamer/player can do there is no going back. 

A new or used streamer is where I would look to upgrade your system.  If you can afford an Innuos or something similar I think it would punch the ticket for you.

He is in New Zealand, he has got to try Antipodes! 

Seriously @OP even if one of their streamers are out of your budget at the moment, you must be curious how it might change the sound you get? I would love to hear your impressions- I may incorrectly assume it must not be hard to demo one if you are in the manufacturer's country? Are you close to a dealer who carries them, or are you able to travel there and demo one in their listening room? 

And I also owned those Transparent Musicwave plus speaker cables a while back, yes, they were very average. 

I'm not sure how I ended up neglecting this thread, a peril of my job I suspect, but I did want to acknowledge the contributions on the use of AI, room treatments and a good quality source.  The latter would need to be second hand, which restricts the ability to demo further.  
To answer your question @mclinnguy I would LOVE to audition an Antipodes!  There is one store in NZ that has a demo version, but attached to equipment that far surpasses my own.  And @rikkipuu I also missed out on an Innuos Zen Mk 3 recently, which is a real shame as I think that would have been the perfect addition to my system. 

The search continues!  All the while in the safe knowledge that any improvements can have limited impacts when the room issues cannot be addressed @mike_in_nc .  The obstacles in room shape alone are significant but arguably the bigger barrier is general household approval as this is our main living area.

I still think the Zen would have been a great option... 

Not a fan of changing a good quality DAC just to roll off the highs in general, unless the DAC is known to have high distortion or other limitations or not operating properly.

Some DACS do provide filters or other adjustments to tailor the sound to preference.  Look for that feature if you do change. 

How are speakers set up relative to listening position?  Less direct line to listening position should accomplish rolling off the highs a bit if that is the only issue.  Are they far enough apart?  Are they toed in to face listening position?  If so change that and see if it helps.

Younger ears will tend to be more sensitive to high frequency issues in general, FWIW.

Are you a Roon user or have any other DSP capabilty in your system?   If not I strongly recommend adding it to provide cost-effective flexibility adjusting the sound as needed rather than having to change otherwise perfectly fine gear.