Reporting question for Speaker - Peavey, 15", Black Widow 1505-8 DT BW, 700W, 8Ω

Product:
Speaker - Peavey, 15", Black Widow 1505-8 DT BW, 700W, 8Ω

Question:
what is the difference with a 1505 DT and a 1508 DT Black Widow speaker?