What a contrast between the 6th and 7th trumpets. The 6th is on earth, it seems the 7th is a view of what is going on in heaven -- at least 11:15-19.
References to the covenant are in: Matthew 26:28; Mark 14:24; Luke 22:20; 1 Corinthians 11:25; 2 Corinthians 3:6 & 14; Hebrews 7:22, 9:15-20. Note especially Hebrews 8:7-13, which is likely to be developed much more completely during the new era.