Andy Davis preaches a verse by verse expository sermon on Revelation 8. The main subject of the sermon is the final seal and the beginning of the sounding of the trumpets.

The Fifth and Sixth Trumpets: Satan's Hordes Unleashed (Revelation Sermon 16 of 49)

This Podcast from Two Journeys Ministry includes sermons, lectures, and classes from Dr. Andrew M. Davis, the senior pastor of the First Baptist Church of Durham. 

Two Journeys exists to help Christians make progress in the two journeys of the Christian life, the internal journey of sanctification and the external journey of gospel advancement. We do this by exporting biblical teaching for the good of Christ’s Church and for the glory of God.