Transforming harsh, boomy frequencies into something more pleasant?

I need advice in making a tone I made sound less harsh and easy on the ears. Try and imagine if this was a stock sound on a synthesizer. How would it be mixed differently? Do I need to use some type of special compression? The waveform itself may need to be looked at to determine what's best.

Things I've tried
- looking at it on an EQ. If I were to add a highpass filter, I think it just eliminates the main tones I'm hearing and doesn't actually fix the problem.
-Trying general compression and setting a threshold to where the signal is coming from, setting the attack and release various amounts.

Maybe the frequency bandwidth of each of those tones is too wide?

sounds like feedback. do you have a spectral compressor? if not you might be able to ring it out with some specific EQ bands after experimenting. 

there's stuff like Oeksound "soothe 2" and similar plug ins made for this kind of thing but you may be able to sort it out w/some experimenting w/eq and compression

Possibly resonance taming might be your best bet:

https://www.tbproaudio.de/products/dseq (my personal choice)

or

https://www.hornetplugins.com/plugins/hornet-sleek/

https://www.voxengo.com/product/teote/ (unfortunately the man is screwed at the moment with digital payments being blocked in his country)

Thanks both of you - spectral compressors really look like they way to go here, or using a combo of that and other effects/EQ. I'm trying it out with Robbert van der Helm Releases Spectral Compressor. I'm also trying TDR Nova as a dynamic EQ. 

Yeah, Sooth2 is the way forward.
Also, if the verb that I hear is on a bus then make sure get that under control as well.