Sound from the speakers of my MBPro with Touch Bar degrading

I have a 15-inch MacBook Pro with Touch bar.

When I play loud music or watch a movie in which there's a noisy action scene for instance, the speakers' sound quality suddenly degrades. Sound continues to be played but as if there was no treble at all. The only "fix" I've found is to plug headphones, wait till the system output gets changed to the headphones, and plug them out again. This seems to reinit the built-in speakers to good, full-spectrum quality, but not for long — sound quickly degrades again under the same conditions.

Is there anything I can do about this?

UPDATE: almost 3 months later, multiple updates down the road and upgrade to high sierra, I am sad to report that the issue still persist. I will probably have to return to the apple store to RMA my macbook...

I'm sorry I would comment on your post instead posting an answer but new account requires me to have enough rep....

I have the exact same issue with my macbook pro 2017 15" with touchbar.

I found that it happens only after going over around 85% volume. No matter which software provokes it.

Plugging and unplugging headphones work for me too. Also killing coreaudiod solves the issue but requires apps that were using the sound drivers to be restarted.

This is a real pain to manage.

I hope this is a software issue as it seems to have started right after Sierra was updated on July 27 2017.

This is happening to me as well, under the same circumstances. Rebooting my computer allows me to listen to loud audio again, but only for about 10-15 minutes before the sound degrades again.