We’re going to need more information on your setup and what you’ve tried or not.

https://makemusic.zendesk.com/hc/en-us/community/posts/215729367-General-Discussion-House-Rules 

It’s possible that you may need to update to 27.3 but that’s also a knee-jerk reaction so let’s see if we can spot something obvious first.

Robert,

MM really needs to revisit the sound playback. Forever it has been a source of complaint. Number one is always, volume too low especially the percussion. I have JBL powered studio monitors  and have them about maxed out for Finale but it will blow your ears off if you use any other program like Audacity or Youtube for instance. They must be turned down a lot!

I think your Speedy will use the last dynamic you entered for some reason. So, if it was a p the sound will be low. I did not notice this in earlier versions like 25.5 but it seems so in 27.3 but perhaps I just don't remember.