Stand alone tweeter?

Dear all,
I think my speaker’s HF sounds too harsh, I have tried all possible acoustics treatment that I can afford and repositioning it, however it still sounds harsh.

I am not good in DIYing, and the dealer said that the tweeter is ok, and for now my budget doesn’t allow me to buy new speakers.

I understand that there are stand alone super tweeter, but is there any stand alone tweeter?

What is considered best to produce smooth HF?

Thanks alot in advance for any advice