One should generally ignore the manufacturers’ specifications when choosing headphones, especially frequency-response numbers as there is no standard testing methodology for headphone frequency response and many vendors tend to exaggerate the specs for marketing purposes. Given that the specs published are accurate, these numbers do not actually tell you how that particular set of headphones actually sounds. Instead of relying on the specs, it would be best to rely on your own ears. Or, if you can’t test out the headphones personally, read reviews from a trusted source who has tested it out.