Philharmonic Concert Bass drums offer unprecedented bass response. The 6 ply African Mahogany shells provide a natural resonance unlike any other shell material. These highly responsive shells have a naturally low, rich frequency response that is ideal for use in concert settings. Fully rounded bearing edges reinforce the low frequency response of the heads and will hold up to many years of high end performance and professional quality sound. Tuning is fast and easy with Pearl's exclusive Silent Tensioning Lug System. Each oversized t-handle lug and claw is insulated at every contact point with itself and the shell to assure that there is no rattle possible from the drum. 8mm thick tuning rods have coarse threads so that quick adjustments can be made to adjust for temperature and humidity in the hall. 100% maple hoops provide durability and even tuning. Each bass drum has 2 acoustically located air vents to allow the drum to breath for superior response and projection. PBA bass drums come with Remo NuSkyn Heads and are available in Matte Walnut Lacquer finish.