The Temblor T10 is designed for recording studios, where it’s an advantage to be able to A/B-compare a mix with and without the subwoofer. To make these comparisons quick and easy, the T10 includes a momentary footswitch that bypasses the subwoofer, highpass filter, and Sub Out, allowing the audio source signal to pass directly through the T10 to the full-range studio monitors.
The Temblor T8 is designed for entry-level personal studios, gaming, and home theaters, where the subwoofer will probably be in use constantly. For these applications, implementing a bypass circuit and footswitch would add cost without providing a compelling advantage.
