Xbox 360, tinny sound

[KierenGG]

Just turned on my Xbox and the sound quality has gone up st creak.
The sound is fuzzy / tinny and seems to have lost any bass.
All the wires etc are connected correctly and plugged in properly but nothing helps.

It did this once before ages ago (could have been xbox that was RROD replaced) which went after a while but I don't know how to fix it.
Please help!
Google gives fk all help

[Xenocide]

Could it be the telly is shagged? Try it with another one.

[KierenGG]

TV sound is fine for normally channels

[KierenGG]

20 minutes later back to normal

[boomboompow]

Had this happen once years ago, fixed itself and has never reoccurred