This ceiling speaker with backcan can be used for for a commercial application. It has built in 70v transformer but also has 8 ohms setting so you can use for your regular 8 ohms application. It is very easy to remove the grill to adjust the 70v setting. The one piece grill covers the complete speaker for better custom looks. Sophisticated crossover delivers better bass, clarity and clean highs.
For a retrofit installation, no construction bracket is needed.