I also tried jconvolver in the past, but often hit issues when combined with pipewire. Pipewire’s native virtual surround support just works when configured correctly.
You can change the default sink to go to the virtual surround device this way:
<span style="color:#323232;">pactl list short sinks # get sink name
</span><span style="color:#323232;">pactl set-default-sink <set default sink>
</span>
There will be a way to set the default in the pipewire config files (~/.config/pipewire/pipewire.conf.d/*), too.
I use “catia” when I want to do manual audio routing, and I guess similar is possible with pavucontrol.