Help. System sounds thin and bright or harsh

Have you ever gotten good bass from the Harbeths? The specs says they only dip down to about 50hz so not much deep bass will show up. I know it’s a completely different animal but I’m running Martin Logan Impresions with a Parasound A31 and its a beautiful relationship. Very good balance in all octaves and never harsh. Solving your issue through a forum is nearly impossible because whatever scientific recommendation given doesn’t change your ears. Until now you’ve done it all right. I haven’t read all the responses but by now you may have figured out your next move is to keep adjusting speaker placement, properly treat your space, and maybe try other cables. I’ve found cardas to be naturally bright (for my ears in my system) Happy listening.

@ejspain2020 The OP didn't complain about not getting deep bass his issue is "System sounds thin and bright or harsh".

The 50Hz spec is correct but that doesn't account for the room. As an example the 'heartbeat' in Breathe sounds remarkably good from a 50Hz midrange driver - even my local dealer was surprised - (I brought a 1979 MOFI issue in as one of my test records) 

If you want REALLY full, deep bass with the 30.1 / 30.2 you'd need subs as others have mentioned. I use 2 REL T/9x, but turning them off doesn't make my system sound bright/harsh nor does it sound like they are suddenly lacking good bass.

Adding 2 RELs was way less than going up to the 40.2's, which was my calculus but most people buy Harbeth's for it's mid-range performance and their overall range is where most of the music is, depending on what kind of music you listen to.

E.g. an open E on a bass guitar is 41Hz 

@macg19 great points. Hope he gets it figured out. Completely understand how this can be frustrating. I'm about to go down the rabbit whole of adding a new processor so hopefully I don't lose more hair integrating...I'm already bald😉

UPDATE

Thanks all. As i mentioned, looks like it IS the Pass Labs amp.  Powered down all components overnight...turned it on the next morning things were very much improved. THEN, next day, turned everything off EXCEPT for the Pass and things were still way off the next day. Am going to trade out the Pass amp (which Ive had for almost 10 years) for digital mono blocks just to confirm this. Then get the Pass to Reno HIFI or wherever is suggested for an overhaul.  Also thinking if the Pass needs some capacitors replaced it couldnt hurt to send the Parasound jc2 in for a good check up at the same time.  

Silver lining:  In moving the speakers and listening position all around the room in chasing down the sound gremlin (as many suggested) I think I have a perfect starting point for speaker placement once all the gear is up to spec.  The speakers ended up closer to the rear wall and a tad further away from sidewalls with fairly aggressive toe-in. Sounded a lot like I remembered on favorite recordings after the total power down test.

A pair of subs and new front end are still on the wish list.

Some hopeful news...glad you didn't throw the baby out with the bath water:)