One of the benefits of in-ceiling speakers is how easily they disappear into a room. Unfortunately, the sound coming from the back of the speaker doesn’t disappear and can distract those in the rooms above the speakers. MartinLogan offers back boxes, or enclosures, for Motion CI In-ceiling speakers. For these situations where sound control is desired, these retrofittable back boxes are the perfect solution. They offer 20dB of noise reduction into adjacent areas and offer the perfect solution to achieve consistent performance where ceiling cavity sizes may vary throughout an installation. Please note that the volume of air in the retrofit enclosure is smaller than that of your ceiling, and bass extension will be reduced. If sound control is not necessary for your unique installation, we recommend not using the back box so the speaker can take advantage of the larger airspace in your ceiling cavity.