I have an older Panasonic monitor (no tuner or speakers). If I hook this up to a Roku soundbar with an HDMI cable (there is no ARC on the monitor) will the sound come out of the soundbar and the picture on the monitor?
Haven't tried it but in theory should work.
One possible issue is an older monitor may not implement latest HDMI standards (part of which includes copy protection), so some video might not play.
No, for anything connected to the monitor to have audio come out the streambar you have to have an audio out of the monitor and connected to an audio in on the streambar. Streambar's only audio inputs are HDMI-arc and optical.
I do use a streambar as my computer speakers, with the help of analog to digital converter. There's 3.5 mm phono cable out of the computer onto the converter, optical out to the streambar, works great. The computer and streambar are connected to the monitor by 2-1 HDMI switch.
@Tivoburkee, I took the OP's question to mean will the Roku's channels sound come out of the Streambar, not something else connected to the monitor. It should, shouldn't it?
Yes, if the source of programs is the streambar, sound stays with streambar and video to the monitor. But nothing else connected to the monitor will be heard via the streambar not without the hdmi-arc or optical.