I use DisplayPort audio as my main output, and it seems there is a slight delay between the sink being started and me actually hearing anything (the audio isn't delayed I just miss the start). I've managed to mostly fix it by disabling suspend on idle, so now once I've played some audio once its fine.
However when I reboot I then miss the first bit of audio again. I have no idea what I need to do to fix this. If I try to manually enable the sink with with pacmd suspend 0 I still get the same issue. The only potential fix I can think of is to set a KDE startup command for pacmd play-file and point it to a very short silent audio file. Does anyone have any better ideas?
Edit:
I forgot to mention, when suspend on idle is enabled there is an audible pop every time the audio starts and suspends. With suspend on idle disabled I still hear this pop on login (and the first time audio is played) which suggests something is happening when I log in
Edit 2:
Apparently it still does it every time the audio stream switches to a different app, however if I start the second one playing before I pause the first it starts straight away
Are you sure your speakers aren't powering down after a delay without input? You might be able to solve this issue and the popping with better speakers.
I have noticed this too on pipewire. Everytime a new audio stream starts , even from a paused state, there is a small delay before it is heard. Not a syncing problem as the audio is synced, but a delayed start. I thought it might have something do with the sound bar I had routed the audio through. Based on your experience, seems not.
I did experience the same delay when using HDMI port instead of DisplayPort too (IIRC). So it might be something else not related to port.
Initially, I used HDMI -> Soundbar -> Monitor. The soundbar handles the sound and forwards the video signal to the monitor. Right now, it's the same, except it is using display port for Laptop to Soundbar connection. Hope I understood the question correctly.
If you ever figure out the delay, please do update with a solution.