New system has fatiguing, harsh high frequency sounds. How to fix?


I just purchased my first audio and home theater system (other than a bluetooth speaker or computer speaker system). I use it for listening to music as well as watching movies. It is a tremendous upgrade and I’m enjoying it. It has clarity and detail that I have never heard before. However, I notice a harshness in the high frequency sounds when listening to music.

I would like my treble to be smooth, sweet, soft, silky and gentle. Right now it is the opposite of that. It is annoying, screechy, metallic and harsh.

I am seeking a solution to that issue. From the little I have been able to find on this subject, it seems that room acoustics might be a big part of my solution. Is that true? If not, what is my next step? An equalizer? I can’t see many options for big changes in speaker placement. At most I can move them a few inches or change the angles.

My listening room is about 11.5 feet by 11.5 feet and square except for the doorway in the back corner which protrudes into the room 18 inches x 44 inches. In the room are a bookcase, couch, end table, media center stand (holding TV, center speaker, receiver, disc player and Roku), computer & computer monitor, my speakers (and rear speaker stands), a ceiling fan and that’s about it... I’m describing the room on the assumption that the room (or its contents) are relevant to the treble problem I’m describing. (However, throwing some thick blankets over my TV and computer monitor, as a test, did not change the issue.)

Here are my home theater components:

  • Computer monitor: WASABI MANGO UHD400 40" 3840X2160
  • TV: LG OLED65C7P 65"
  • Receiver: Sony STRDN1080
  • Disc Player: LG UP875 4K BLU-RAY PLAYER BestBuy SKU 5979504
  • Streaming Box: Roku Ultra streaming player (model 4660)
I mention the monitors (and their size) in case they play a role in reflecting sounds.

Speakers:
  • Front 1: Polk Audio RTi A7 floorstanding speakers
  • Front 2: Polk Audio RTi A5 floorstanding speakers
  • Center Speaker: Klipsch RP-250C Center Channel Speaker
  • Subwoofer 1: Polk Audio PSW125 Subwoofer
  • Subwoofer 2: Klipsch R-112SW Subwoofer 
  • Rear/Surround: Polk Audio RTI A3
Speaker Layout: 5.1 layout with two pair of front speakers and two subwoofers.

The front speakers are on either side of the LG TV on the front wall (and near the room corners. The front speakers are angled in. Minimum distance to wall is 10", but measuring straight/parallel from back of speaker to wall is at least 18". From side of speaker to wall is at least a foot (one side of room has 30 inches). There is only 3" between each RTi A5 and RTi A7 speaker.

The rear speakers are behind the couch at each corner and against the back wall.

One subwoofer is in the back corner. The other is midway on the other wall and angled toward listening area.

For music, I usually prefer listening in 2-channel stereo. The dual pairs of front speakers are awesome. (I initially started out with a 7.1 layout but I prefer this layout now.) The high frequency problem exists even in 2-channel stereo. It also exists if I use only 1 pair of front speakers.

Wiring
All speakers are bi-wired, except the center (and subwoofers), which don’t support it. (Not bi-amp’d, just bi-wired*.)

Speaker wire: Mediabridge 12AWG 4-Conductor Speaker Wire (100 Feet, White) - 99.9% Oxygen Free Copper - ETL Listed & CL2 Rated for In-Wall Use

* https://www.qacoustics.co.uk/blog/2016/06/08/bi-wiring-speakers-exploration-benefits/

Banana Plugs:
  • Mediabridge Banana Plugs - Corrosion-Resistant 24K Gold-Plated Connectors - 12 Pair/24 Banana Plugs (Part# SPC-BP2-12 )
  • Sewell Silverback , 24k Gold Dual Screw Lock Speaker Connector
  • Ocelot Banana Plugs, 24k Gold Plated Connectors, Open Screw Type
BTW, my prior speakers were the Edifier e25 Luna Eclipse. I thought they sounded good and I did not remember them having these harsh high frequency sounds. After listening to my new system for a week, I went back to those for a test and they sounded horrible in comparison. The harsh high frequency sounds are much worse, and every other aspect is worse as well. (That shouldn’t be a surprise given the price ranges being compared, but my incorrect memory had been that they didn’t have this issue.)
lowoverdrive
I would also experiment with hanging a large towel on the front wall, slightly behind, but above the tv ( maybe using painters tape ) to further stop early reflections. 
lowoverdrive- Welcome!  As the responses to the OP amply demonstrate,  if you ask a question like this to 4 audiophiles, you will get 6 or 7 different answers.  You have done a good job of responding and describing the results of your experimentation so far.  Issues like break-in and cabling should not be the source of overwhelmingly harsh high frequencies.  Here are my observations, some of which align with yours:
1.  That is a lot of speaker for a small room.  You are listening in the near-field and that speaker is not designed for that. 
2.  One review I found noted a forward sound with sharp attacks and an edgy sound.  Another review said that could be a bit harsh.  A consumer review said they were for "treble lovers only".  In the near field with modest electronics, that could easily be perceived by someone else as a fatiguing harsh treble.
3.  The speaker is also described as requiring lots of power to open up.  The receiver has been measured to provide only 65 watts/channel at 0.1% distortion.  If that distortion is of the wrong kind, 0.1% can easily be very audible as harshness.  Solid state amps that use feedback to keep the measured distortion low often create that kind of distortion. 
4.  Your small room has two very large glass reflective surfaces (TV and computer monitor).

In sum, you have inadvertently created a sort of positive feedback loop; positive in the sense that all of these factors contribute to the sound quality you described, with an overemphasis on the treble. You found that changing the speakers helped some.  You also noted that the AVR and small speakers are quite adequate for movies, and asked about using the larger speakers with different electronics in a larger room for music.

That is probably the best solution because you probably cannot change enough of the factors that re-inforce each other in that small room.  Modest priced AVRs generally "sound" like they have less than their rated power when playing music and have much of their $$ allocated to digital signal processing, auto-calibration, and the gazillion input and output jacks/plugs/ports on their rear panels.  If you cannot return the large Polk speaker, then I would look for electronics known for a warm or slightly laid back sound (often described as a British sound) and put them in a larger space where the speakers can be well out from the wall behind them and where you can place furniture/pillows, curtains, etc to break up reflections and enhance diffusion of the sound.  If it's just for music, an integrated amplifier might be a good cost-conscious solution.   If you give us a budget and whether you want to buy new or used, we can make specific suggestions. 


Photos: before, during and after:
https://imgur.com/a/o6QzA

Starting point when I posted:
https://imgur.com/VRvxMB2
Dual pairs of large front floorstanding speakers. Treble was harsh and fatiguing.

Testing the A3's
https://imgur.com/EEkVyZK
I sat the smaller A3's on top of the A7's for a quick test. I was not using either floorstanding speaker in this test and the sound was improved. The quick test confirmed I was going in the right direction, just as you guys suggested.


Current home theater setup:
https://imgur.com/j2fGqAq
Sounds the best, but doesn't look as impressive. The various pillows behind the speakers and my extra speaker cables also detract from the appearance. However, after the small tweaks and moving the larger speakers out to open up some space, I don't really have any complaints now, even with sitar or sarangi music. It does not sound harsh or fatiguing. Music sounds very good and movies sound great. The Polk A3's put out a lot of sound. I'm using the Polk Audio CSI A6 center channel speaker now, but I'll have to swap out the TV stand for one with larger shelves to fit this larger center speaker. I'm still using two subwoofers. Movie sound in this small room is just as impressive as with the larger floorstanding speakers.
swampwalker - thank you for that nice summary.

RE: "If you give us a budget and whether you want to buy new or used, we can make specific suggestions. "

That would be awesome. I would like to keep the larger Polk speakers. I like them (build quality and appearance partly). I hope I can repurpose them into a nice music-only system in a larger room.

I describe more details here:

https://forum.audiogon.com/discussions/amp-or-receiver-recommendation-for-polk-audio-rti-a7-floorsta...

In short, my budget is $1000 or so for an integrated amp (or preamp + power amp or whatever is recommended). But I would like to try the dual front speaker setup in the larger room, and that would require more channels.

Since I don't have much experience with audio equipment, I should probably buy new. And I prefer to buy on Amazon because of their generous return policy. I had been anticipating that I would not really know what I wanted/needed until I tried it.

Finally, I do have the option to return one or both pairs of the floorstanding speakers if trying to make a dual front speaker setup work is not a good idea.
OK. HT room sorted I would think. Are you using the room eq of your receiver?
For the music room, I moved to your new thread.