Sub-No Lost Space: Powered Car Subwoofer. Subwoofer Fits Inside Spare Tire Seamlessly (Goes on top of spare tire so you can leave your spare tire in place). Hidden In Spare Tire – Takes up No Trunk Space. Installation location: The Car Subwoofer Audio can also be mounted in trunk or under seat but we recommend mounting it in your spare tire. Bass boost, low pass crossover filter, and phase control. Fast heat dissipation: This under-seat powered car/truck subwoofer is with multiple cooling holes on both sides to insure heat dissipation and prevent the speaker from burning. Service: We are responsible for the product and believe in the quality of the product. Professional functions and high reliability bring you a different experience and ensure the satisfaction of every customer. If you have any questions about our products, we will answer them at any time. Perfect sound quality experience: Super clean sound that is musical and will not fatigue your ears. When this is mounted in your spare tire, the sound transmits cleanly and evenly throughout the vehicle without any vibrations or unwanted noises.