The tape out has no volume control in the signal path, so you wouldn't be able to control the output to the sub.
You could do this, but you would have to adjust the sub's volume from the sub itself to match the main speakers. I guess, if you happen to listen to the exact same volume level and setting each time, you would be okay. Otherwise, you're going to spend a lot of time readjusting the sub's volume.
You could do this, but you would have to adjust the sub's volume from the sub itself to match the main speakers. I guess, if you happen to listen to the exact same volume level and setting each time, you would be okay. Otherwise, you're going to spend a lot of time readjusting the sub's volume.