Is it okay two ultrasonic subs in Bluetooth. My concern is regarding the noise of the speaker diminishing the sub effects.
If they have a high enough dynamic range and they use a recent enough BT version you should be fine. Usually BT only generates white noise when it’s not playing anything. And even if it does, the ultras should be louder than that. Do test in FrequenSee obviously.
In frequsee app I see peaks at the higher ranges is. Above audible range. How do I asses if it’s recent enough by? I bought it a couple of years ago.
If you see the peaks at 17-20kHz, you’re good. No need to worry about anything else.
There used to be some compression and cutting off with the earlier BT protocols, but anything above v4 should be good. Which means post-2010.