Help, my system seem to have slowly gotten " bright"

Since one of your speaker pair sounds good, you have a good setup for debugging this.

My recommendation is to try the different frequency sweep (you can easily find this on Tidal/Qobuz/etc.) and for each frequency write down spl at your listening position.  Do this for both pairs of speakers and see if any significant difference pops up.  If you don't have a SPL meter you can use a free app for your android or ios phone.

I have isolated each speaker and they both some the same. The room hasn’t changed. I am very aware how the placement can have an effect on the sound. I can change the bass sound significantly by just moving them closer to the wall. As I mentioned I have  2 sets of speakers. I have some revel f208’s that are like 7 years old. I later got some revel f228be with is basically the same cabinets with better drivers. I have loved since I got them, they do have a similar sound to the f208’s but just better all around.

So I have just moved the 228,s out and put the 208,s back in and do not hear the excessive brightness present in the others. So I am not sure what to do now.

I did a tone test but couldn’t really notice anything odd.

So, either the tweeters are damaged (but still work ) or the crossover got damaged somehow. Are either of these possable especially the crossover ? What would a marginal crossover sound like ?

I’m assuming you’re noticing brightness on the recordings you have played before and are familiar with. 
So the question is…did anything change in your room? Furniture updates or moving things around? Removing or changing area rug? Removed window treatments? Any changes in wall decor such as paintings, etc.? Changes in power delivery such as adding or removing power conditioner, changing outlets, running dedicated lines?

I am glad it is not a hearing issue.  Now, to diagnose the problem.  Put on something that is a mono recording which exhibits the problem.  Use a balance control, or disconnect one speaker to listem to one channel at a time.  Is the problem the same for both channels?  If there is a difference, try switching the left and right cables to the speakers.  If the problem stays the same, it is the speakers that are at fault.  If it switches channels, it is something upstream of the speakers.  You can move progressivel upstream doing this kind of switching to isolate which component is at fault.  If you have problems in both channels that is about the same, it would be an odd sort of failure, particularly if it is the speakers at fault—it would mean identical damage that is short of taking out the tweeters entirely.

The fact that you’ve had multiple tweeter failures suggest that you are over driving your speakers or that something like your amp is defective and maybe sending a lot of ultrasonic energy to the tweeter and damaging it.

For reference if anyone’s interested i notice this on molly tuttle and golden highways album city of gold. Very good bluegrass album from someone " flying under the Radar " for lack of a better term. Other stuff too but I have been playing that alot lately.

Its the same sound one hears when someone is public speaking too close to the microphone and you hear that shhhh kinda sound.

I did swap the f208’s back in and they don’t have the shrill like the f228be’s do.

The tweeter has to be damaged, they used to outclass the f208’s 

I really need to sell some stuff but am glad I have it all right now.

You're on the right path.  You have to take your time and continue to experiment until you get it figured out.  That's the only way.  Happy listening.  

I had a hearing test 1 month ago at a ear nose throat doc. I get one every  work anyway. Some upper frequency loss but its been that way for some time.

My system

source is a sony hap-zeis hd player that was around starting in 2014 or 

so. No longer made, 7 years old.

preamps, parasound jc2 and also a backert rhumba extreme 1.3

amps  parasound a-21 and a jc5.

speakers revel f228be and also have some f208 also.

transparent audio speaker cables.

AQ red river xlr, 2 sets. 

I have never conciderd the tweeters could be cooked. 

They have failed 3 times on the f208's. Dont know why to this day.

One time at a semi moderate volume. I was there when it happened. Didnt hear anything odd and then suddenly they sounded dead. Is it possable the beryllium

tweeters dont just work or not work like the others that blew ? Like maybe they can be damaged and still make sound? 

Anyway i will get some sort of tone testing cd or whatever and try it out.

FWIW my car stereo and my headphones at work dont sound like this. 

Try some good recording to see if the result is the same.listen to your friend system to see if your ears will react the same like your system.My friend has a dirty tweeter on his B&W speakers  when the tech clean them ? Problem solve. He went to audiologist twice. Ears ok.

Were the speakers previously toed in more?  With some speakers this can make a huge difference.

Ironically, age related hearing loss can produce this. If we lose certain frequencies, others become more noticeable. So loss of highs can result in upper mids sounding prominent, especially in the sibilance range. Just another joy of aging.

We can only guess without knowing the whole setup. Could this be an outside issue with your electrical, something introducing a lot of noise in your house or neighborhood?

Op’s ears became more natural sound mode from un-natural Hi-Fi ear mode. Many people (almost women, non-audiophiles) are always in natural sound mode and they hear un-natural Hi-Fi sounds as bright and noisy.

All Hi-Fi systems sound like a left speaker in below video. Alex/WTA

Do you have a tube preamp?  Could the coupling caps be going bad?

Again, I would recommend having your ears checked.  What you describe might be the start of hyperacusis, an ear condition.  

If it is an equipment issue, my bet is on the speakers.  But, it would be extremely unlikely that both speakers have the same degradation, and to the same degree, so listen to each one alone to determine if there are differences between the two.  If they sound the same, the problem is probably elsewhere.

@rhg3 has a great suggestion.  Listen to one frequency at a time.  If you have a way to play youtube through your system, test frequencies are available on youtube.

As for hearing suggestions, your change is in the opposite direction of normal hearing degradation.  You lose high frequencies as you get older.  Many expensive speakers teen to be a bit bright because the target market is older people with losses in the highs.  I guess it isn't impossible for hearing loss to be in the low frequencies.

As for my suggestion on bass, realize that you will turn it up until the bass sounds right.  If you have lost bass, then you will turn up the volume until the bass sounds right and you will have turned up the high frequencies so high they seem bright.  It isn't whether you have decent bass, it is whether you have a balance between bass and treble.

Jerry

you have gotten older get your hearing checked before you do anything you might regret

If you didn't make any changes to the gear, placement, etc. maybe it's your hearing.

My 1st thoughts were it has something to do with the speakers. Did you move or adjust your speakers recently? Move any of the surrounding furniture? I recently had issues with fatigue after messing with my speaker placement. That was an eye opening experience for me. 

As far as equipment goes since you ruled out the amp/preamp I would wonder if the power supply of your source is going bad. Or perhaps some other capacitors as others have mentioned. 

On a side note..does adding more bass actually make a speaker sound less "bright" or fatiguing? 

Obviously my thoughts on what could be causing your sudden "brightness" are just guesses. Please share when/if you figure out what the cause is. 

The reason is especially if you have some older gear is the capacitors are starting. To dry out ,with that you willl start losing detail brightness comes with thst.

the vast majority of speakers come with stock lower quality capacitors and resistors .you mentioned nothing on your speakers ,having rebuilding Loudspeaker Xovers for years ,that’s  a place where most companies skimp in lower quality capacitors like Solen ,and resistors .

Can you confirm that it is the system at fault?  Do others hear the problem as well?  Do you also hear this problem when you visit audio stores?  I am wondering if you might be developing a hearing problem. 

Could be the speakers themselves.

Since you ruled the amp and preamp. Maybe the tweeters are somehow damaged. You would not expect Revels of that level to be the problem but again it’s possible.

OP   "my system seem " bright"

Find how much bright your system sounds.

While your audio system playing your favorite music, say "hello" in low voice and listen your voice and music.  Alex/WTA

Have you tried a test cd to that goes through the frequency range, left and right?

Revel f228be a couple of years old. 

It would be very helpful to know all of your components and the venue would not hurt. Irdeally you could put some photos in a virtual system (under your user ID) so we could make a real assessment.

All this was in the last few months. It still seems to be decent bass but the highs are just rough. 

What speakers are you using, and how old are they?

Often "bright" is actually a lack of bass.  Make sure you consider the possibility of bass reduction over the years as you cogitate about this.