a resonance in my left ear

@magon ....A good place to start; since you're in SoCA there's undoubtedly audiologists that give you the printouts of your 'interior fq response'....

Mine is in my high end, so difficult to totally erase without wiping out the correction applied.....I consider the remnants as my 'dial tone', throw-back concept that it is.
The Aurender has gotten good comments 'round here, so enjoy.
I like my pc for it's functionality, and I've hammered it to as quiet as possible; eq is mostly handed off to some pro versions with similar traits.  Mostly used for room corrections as noted, 'tweaks' as desired, handed off to active x-overs.....

Was the LA Phil @ the Getty?  If so, I'm jealous...
Like 'live' anything, but it's the audience end response that does me in....a 'dirty white noise', even if from a well-washed and duded up crowd...*L*
Been carrying a noise-canceling headset for just that.....one gets 'looks' but turn away when they observe the absurder.... ;)

Aids have come along way in their functionality and apps....linked to your cell, literally 'tweak-able' on the fly.  I kid that I bought a Mac for my head rather than the shelf....  Like cars, motorcycles, and the like they've gotten their envelope pushed by the stage monitor ear units worn by the players....

Anyway, start with your 'on-board items' and carry on as needed or desired.

Squelch that nasty thang....👍😎
Luck, J

@magon that Bruckner must have been amazing! From what I also understand, having small/narrow ear canals can create amplification issues. When I was little, certain sounds were really loud and they say this is consistent with small canals and then later causes issues. The canals can also start to collapse with age too. I don't know, food for thought if perhaps you have narrow canals

@symphonicsoul Yeah I had a good seat for the Bruckner - slightly back and elevated a little bit (the so-called Terrace at Walt Disney Concert Hall) - actually I bought a fairly cheap ticket and ended up near the side and back of the terrace where the sound is not so good - then a couple came up and said they wanted to trade seats with us because they wanted to sit by the door - so my girlfriend and I got this good seat in the center-front Terrance. LA Phil brass is glorious. And LOUD. I love how Bruckner uses brass. Dvorak, a wonderful composer, but he buries the brass under the strings a lot of the time. By the way I played trombone in college. 

Thanks for tip on small ear canals. Judging by the fit of IEMs that work with me, I do have small ear canals. I'm going to go back to this ENT or maybe find another one and consult on all this stuff. I have an HMO so I'm not sure I can see a different ENT. He was so dismissive of my concerns and really didn't even seem to understand them. Now all these people tell me there are possible explanations. 

The world famous house ear instute is in Los  Angeles in California. One of my many neurotoligist was trained there.they have excellent audiologist as well.good luck.enjoy the music

@magon it's the worst when doctors are dismissive. Interesting that you have small ear canals and thinking that could be in play.

You mentioned the Aurender N100h as not aggravating the issue. I just bought the N150 and got a headache after listening, which went away after I stopped. It's so darn bright and when it hits those frequencies that are bothering me, it's borderline painful. Especially with piano and sax and I know you're having issues with piano notes as well. The sounds stage and separation among instruments is stellar and I'm bummed. Wondering if I should return it and try the N100h instead. Going to try different cables first.

Glad to hear you're a trombonist. I was a horn player and went to Northwestern during the height of the incredible Chicago brass. Was an amazing time to be there. Nothing like hearing Bruckner live.