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
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First, I would add sound absorption of some sort, at the first reflection points and on the wall behind the speakers between them.

Second, play with the toe-in and rake of your front speakers.  

Third, consider, as your budget allows, equipment upgrades.
@lowoverdrive A large part of the problem is micro arcing, I have released a new product which you can read about in Member reviews under The new tweak. Problem solved!
@perfectpathtech

A large part of the problem is micro arcing, I have released a new product which you can read about in Member reviews under The new tweak. Problem solved!

What is the link to the reviews? Also, my system sounds pretty good now after implementing the changes recommended in earlier comments. Thanks
What source devices do you hear it with?

With power on switched to that device and nothing playing, with ear to tweeter do you hear any noise or is it dead quiet?

I read in one review that sound quality with that Sony A/V receiver is not as "full" as prior model and "less forgiving of brighter speakers" which could be part of the problem.

I'd check to see if any audible noise is a factor first, eliminate that potential issue with any setup or not  and go from there.
I think perfectpath tech is way out of line recommending that particular product of his in this case.
Everybody run! The moral police just showed up! 🏃🏻‍♂️ 🏃🏻‍♀️ 🏃🏻‍♂️ 🏃🏻‍♀️
If the op wants to smear $300 goo to make his $500 receiver sound better because the vendor recommends it thats his perogative. I’d ask for a money back guarantee first though at least if I were him. Funny how the world has managed to avoid such issues to date without breaking out the new fandangled $300 audiophile goo. Just let us all know how that turns out. 
If noise is heard in tweeter with nothing playing try playing with how the wires are routed. Try to keep power and digital wires in particular as far away from line level analog wires as possible and listen for a difference in noise heard with with goal of keeping it minimal. Avoid wires running parallel and in close proximity to each other for long distances.

 Keeping noise to a minimum helps take the edge of the sound otherwise. Using shielded cables can also help if noise picked up by wires turns out to be an issue in this case. Toe in and equalization may certainly help but minimizing noise if it exists is always a good thing.

Other sources of noise worth isolating from are power transformers in the gear or in nearby household devices in close proximity to wires, flourescent lights, dimmers, nearby computers etc.
I thought it was spelled "micro arching" but I stand corrected…otherwise it could be a small scale podiatry problem. I agree that the goo promotion was surprising with an aura of desperation. Did sales slow down somehow?

I have dimmers all over my house and because I have excellently shielded cables (no biggie) and a few great anti-hum power supplies (my phono preamp, my DAC, and my amplifiers all have DC swatting gizmos, along with an old but working power conditioner for everything) my rig is amazingly humless and clean as a whistle.
"On the other hand, you can build a stunning amp with not many more tools than a screwdriver, a cresent wrench, a soldering iron, and some wire cutters".
you omitted  a 4lb club hammer.lol
It sounds to me that your speakers are just showing up the problems with your source and amp.
You could try another at amp that is better for music together with a dedicated CD or streamer for music.

While it could be the speakers that are the problem I think that changing the above will help the most.
For me the best option would be to have a dedicated system for music.
@iscm
For me the best option would be to have a dedicated system for music.
Already did that. Problem already solved. Thanks.
In the end I gave my surround system to charity, as my music system was just so much better.
The av system was not helped by the fact that films seem to put about 80% of their sound through the center speaker.
It was mostly mono with a few effects and ambience.

I got round this by taking out the centre speaker and reconfiguring, but in the end I just got fed up with it and used my stereo system for everything.
Thats what I do. 2 channel stereo hifih only. No surround.  Never did never will.  I like good sound not sound effects.  
I recently experienced the same sibilance problem on video dialogue when I swapped a new Sony STR-DN1080 into my existing system.  The receiver was the only change I made, so that isolated the problem.  I spoke with Sony technical support and they concluded it's a defective receiver.  So I'm going to return or exchange it.

If anyone is stuck with one of these units, I found I could tame the sibilance to almost tolerable levels by setting the calibration profile to Front Focus, setting the Equalizer treble to -10db on front and center speakers, switching the Sound Field to A.F.D., and turning off the Sound Optimizer and Pure Direct.  

BTW on the same Sony STR-DN1080 receiver, I got perfect non-sibilant vocals on music when I streamed Tidal over Chromecast, and it also gave me jaw-dropping audio quality overall on music.  So the sibilance problem seems to be specific to video sources.  
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First response is my guess too. Got rid of a new Sony receiver (put on CL for free pick up. Gone the next morning.lol.) for that exact same reason. Bought an older Denon model 3803. On the other side is Yamaha rxv777 which is clear has more sparkle, a tad forward sounding and is pretty much the opposite of Denon warm, smooth and slightly laid back sound. The good news is some if the older totl receivers are a MUCH better value than any offerings today. Such as Denon 5800 or Yamaha zx series. 
Good luck
Here is something that I have not seen covered in this blog.  Strings (violins) sound harsh and metallic when playing classical music from my Samsung CD player, or when streaming classical music from my iPhone or MacBook via bluetooth, Airplay or Apple TV to my Yamaha Aventage RX-A2070 AVR.  The speakers are SVS Ultra Towers.  I had the same experience on Klipsch RP-280F towers. But when I listen to classical music from any public TV broadcast, or from any music and/or video app on my TV (Netflix, Amazon, PBS, Apple Music, Pandora, etc.), THE STRINGS SOUND PERFECTLY SOFT, close to what they sound like in a concert hall!  I have the iTunes equalizer settings set to "flat" on my iPhone and MacBook.  The Parametric Equalizer on my AVR is set to YPAO:flat.  Does anyone know why the harshness exists from some sources and not from others?  I am stumped!