The helmet is similar in all respects to the HD448 on the form, only the design changes slightly for the silver part. Mostly brands rename their helmets and slightly change the design but do not improve the sound part. On the HD449, there has been a small improvement in sound, the bass effect on the HD448 were well in their place not too far forward as many nomadic headphones. But the serious slightly lacked consistency and when we put too technical pieces coming down low, the headset was hard to follow. So a good point with this lightweight bass enhancement and severe (slightly forward, but it is reasonable and does not fall into the boom-boom). If not for the rest of the sound part this headset remains a UFO, a rendering excellent for any type of music with a very nice midrange (on the upper midrange), a very good clarity, an air remains acute at all tiring and precise enough, which allows to make out details microphones on certain instruments that we hear on some not much more expensive helmets. The signature is not neutral, but almost, for it is he who it closest to neutrality in nomadic helmets in the room rate. 5 stars for a very good value for money, and sound that amazes and out of the usual standards.