HD-665 : Good Passive Isolation and acceptable sound quality.

I live in a noisy avenue and I wanted a isolating headphone to practice piano and also to focus only in my music when producing.

The closed-back design of this headphone prevents the audio to leak and cuts off the external audio by a fair amount, just like when I use earplugs to sleep.

Once I put the headphones on, without music I already can't listen the street noise. A dialogue with somebody one meter away from me is already 50% to 70% eliminated.

With music in the minimum volume of my Macbook I can forget about the world's sounds. It really isolates.

Sound quality: I replaced my broken AKG K 240 Studio with a Superlux HD-668 B. They sound nearly the same. Using the HD-668B as a reference, the Superlux HD-665 sounds less clear in the highs (I can't tell whether I'm listening to a 128k MP3 or 192k MP3, in which the HD-668B is instantly recognizable). I made the comparison with an EQ and the highs start to fall from 1K  about 6db/octave. You also lose loads of reverb because of the highs removal. The mix sounds ?boxy?. There is more stereo separation than in the open-back headphone and therefore you can't have a very good stereo image. The HD-665 has loads of bass, as expected, having in mind this is a drummer/bass player headphone and they are responsible for the rhythm section and should play in sync.

The comfort: The HD-668 B weights 251g and the HD-665 372g. This 121g can be wearing if you want to use it for long hours. The headband is in rubber and has a self-adjusting mechanism. It feels a bit tight for me. The ear pad is in synthetic leather and is not replaceable. There is also the issue of the pressure in the ears caused by the isolating format. In my case, I only use it two hours/day so I adapted well to it.

The build quality is good and seems to be a durable headphone. My other Superlux, the HD-668B is with me for about 2 years already and no problems so far.

This headphone is indicated for drummers to play with a group. I think it does the job really well for that purpose.

I recommend it if you want to have control of external noise, track instruments or play with a band. For mixing or mastering I would recommend other models. For listening to music it is pleasant depending in your style, such as hip-hop or electronic, but at the same time, the heavy weight and the pressure can be uncomfortable for a long period listening.