CREATE TABLE table_1601027_2 (driver_matched_db VARCHAR, headphone_class VARCHAR)

Name the driver matched db for joseph grado signature
SELECT driver_matched_db FROM table_1601027_2 WHERE headphone_class = "Joseph Grado Signature"
SELECT "driver_matched_db" FROM "table_1601027_2" WHERE "Joseph Grado Signature" = "headphone_class"