Resolve playback audio clear on headphones, but not speakers

When I playback a clip in the resolve timeline, the audio seems unclear and almost muffled.

I'm on windows 11, high spec new laptop.

- resolve timeline + laptop speakers = muffled
- resolve timeline + laptop speakers + multiple files/formats = muffled
- windows media player + laptop speakers = clear
- resolve timeline + Bluetooth headphones = clear
- rendered output = clear

I've tried

- multiple settings, too many to document
- another PC with same MP3 file = clear
- asking in this forum (see below)
- changing timeline framerate (muffled)
- removing the video, so it's just audio (muffled)

I feel it's either a setting issue, or a driver issue, but i'm open to any advice.

Can someone please direct me to how I can set up a different audio driver from the "Realtek High Definition Audio (SST) one I'm using at present, just as a test?

https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=193590&p=1006597#p1006597

I've just found the issue in my windows settings.

settings>system>sound>All sound devices>Properties> Speakers Realtek(R) Audio>audio enhancements = off.

This seemed to work.

That would be the correct setting to use. You need to be able to hear the audio without any enhancement.