Performance

Judging the performance of headphones is always a hard task because there are no benchmarks that you can perform. What I have tried to do is find out what I like in a pair of headphones and then measure all other headphones in comparison to that. My reference headphones are the Sennheiser HD595 which use an open back design. Normally when I get a pair of headphones for review I hook them up to my Creative X-FI XtremeMusic, but since this card only features USB connectivity I had to test it with the on-cord sound card. This does of course make it harder to compare it to the other headsets that I have had for review.

Listening Experience

To start off with I fired up Windows Media Player 11 to listen to some music with the ZM-RS6F USB. In this test I try listening to a large variety of music and I have my own little volume level test where I basically go through the same piece of music at different volume levels and listen for audio distortion, of course this is a very rough test which means that I only use it to test if there are any faults in the headset.

At first the music sounded a little muffled so I opened up the configuration utility provided on the CD to see if I could tweak the audio settings a bit. Now normally if surround headphones sound a little muffled it's because the "center" speakers aren't on pair with the rest volume wise, and this turned out to also be the case with these headphones. I actually had to boost the volume level of the center speak to near maximum in order to make these headphones perform while listening to music. Of course this is just my opinion of how a pair of headphones should sound, but I can definitely recommend that you play around with the volume levels if you have a surround headset because chances are that you can get way better performance just by altering the individual volume levels.

The listening experience was O.k., but definitely not near the quality one can achieve with a X-FI and a decent pair of, i.e. Sennheiser or Technics headphones. One of the things that troubled me the most was a strange sound lag that appeared each time the on-cord sound card began to play music. It sounded like a small audio "lag" or scratch. At first I thought it had something to do with the USB-subsystem controller in Windows, but after disabling all Windows USB power saving features the "lag" was still there.

Movies

Since the ZM-RS6F is a surround sound headset I decided to test it by watching a movie. The surround effects was quite nice and all, but the headset lacked a little bass in order to make the effects more believable. Overall the experience was pleasant, but it's clear that the sound lacks a little finesse in order to be able to compete with some of the other high end headsets that I have had.

CounterStrike:Source

Playing Counter Strike:Source with the Zalman surround sound was a positive surprise. Counter Strike:Source supports native 5.1 surround sound and therefore performance coupled with any 5.1 capable solution is bound to give you an experience out of the ordinary. I found that it was quite easy to hear from where the enemies where coming although the sound still sounded a bit muffled and wasn't as clear as I was used to coming from a Creative X-Fi based solution.

Again the bass didn't seem to be up to the job. Explosions and other effect simply sounded weak compared to other headsets. Now whether this is due to the C-Media sound card or the headset itself is unknown.

Comfort

These headphones are quite comfortable to wear because they have some big and soft pads placed at strategic places. Even though it's quite heavy it's still comfortable to wear, however, due to the fact that the vents on both ear cups are so small there is no real "airflow" through the cups. This makes it hard for heat to escape and makes your ears heat up gradually. Of course this isn't a major problem, but it's worth noticing because there are a lot of alternatives out there with open back designs that are way more comfortable to wear over an extended period of time.

One of the comfort aspects that I like about Zalman's design is that they press against your head in a way that makes them stick, but doesn't collapse your ears. This balance between pressure and comfort is a hard one to get right, but I think that Zalman are quite close with the ZM-RS6F USB.

Durability

The ZM-RS6F USB seems to be a really durable construction. I tried bending the plastic parts to near breaking point, but they just popped right back into shape. Even the joints seem to be constructed in a way that makes them less prone to breaking by overbending them.

By looking inside the ear cups it seems that the audio drives are well protected within the plastic shell, no wires dangling in front of the drives or loose internal parts which is good.