headphone model         headphone class sensitivity (db)  impedance (ohms) driver - matched db    construction earpads                             termination  succeeded by
0            sr40                 unknown              100                32             unknown         plastic    foam  1 / 8 (3.5 mm) plug with 1 / 4 adaptor        igrado
1           sr325                prestige               98                32                0.05  aluminum alloy   bowls                     1 / 4 (6.5 mm) plug        sr325i
2          hp1000  joseph grado signature          unknown                40             unknown  aluminum alloy   flats                     1 / 4 (6.5 mm) plug  no successor
3           sr100                prestige          unknown                32             unknown         plastic   flats                     1 / 4 (6.5 mm) plug         sr125
4           sr200                prestige          unknown                32             unknown         plastic   flats                     1 / 4 (6.5 mm) plug         sr225
5           sr300                prestige          unknown                32             unknown         plastic   flats                     1 / 4 (6.5 mm) plug         sr325

Table as JSON:
{"headphone model":{"0":"sr40","1":"sr325","2":"hp1000","3":"sr100","4":"sr200","5":"sr300"},"headphone class":{"0":"unknown","1":"prestige","2":"joseph grado signature","3":"prestige","4":"prestige","5":"prestige"},"sensitivity (db)":{"0":"100","1":"98","2":"unknown","3":"unknown","4":"unknown","5":"unknown"},"impedance (ohms)":{"0":32,"1":32,"2":40,"3":32,"4":32,"5":32},"driver - matched db":{"0":"unknown","1":"0.05","2":"unknown","3":"unknown","4":"unknown","5":"unknown"},"construction":{"0":"plastic","1":"aluminum alloy","2":"aluminum alloy","3":"plastic","4":"plastic","5":"plastic"},"earpads":{"0":"foam","1":"bowls","2":"flats","3":"flats","4":"flats","5":"flats"},"termination":{"0":"1 \/ 8 (3.5 mm) plug with 1 \/ 4 adaptor","1":"1 \/ 4 (6.5 mm) plug","2":"1 \/ 4 (6.5 mm) plug","3":"1 \/ 4 (6.5 mm) plug","4":"1 \/ 4 (6.5 mm) plug","5":"1 \/ 4 (6.5 mm) plug"},"succeeded by":{"0":"igrado","1":"sr325i","2":"no successor","3":"sr125","4":"sr225","5":"sr325"}}