I tested the Zalman ZM-RS6F headphones in two steps. First, I determined the audio characteristics of the device with the help of an audio analyzer. The second step implies a subjective evaluation of the sound quality in certain test compositions. A Creative Audigy 2 ZS audio card was the audio source in the tests.
When the test audio signal was synchronously outputted onto three speakers, the maximum sound pressure level was 118.7dB; when onto one speaker – it was 117.1dB. The highest values of the sound pressure fall onto the range of low frequencies. This value is always lower for middle and high frequencies. These values of sound pressure are too high and may easily harm your ears after a long exposure. When the test audio-track was being reproduced, the resonance ports were emitting a powerful stream of air as if there was a fan in the caps. For note: the pain threshold of the human ear is 120dB (after that the sound will harm your ears).
To pick up the frequency characteristic, we send an evenly-saturated signal, the so-called “pink noise”, to the headphones. The data were gathered with the help of a special calibrated microphone and a Euradio PRO600S spectrum-analyzer.
This diagram allows evaluating the misbalance of the frequency characteristic and estimating the real range of frequencies as reproduced by the headphones. The screenshot above illustrates the point that our model does reproduce low and middle frequencies, but has some slumps in the area of high frequencies. The irregularity of the frequency chracteristic is very high there.
The Zalman ZM-RS6F was poor during aural tests: a muddy stereo-panorama, “cut-down” high frequencies, timbral misbalance, and a handful of other negative factors. Although these headphones are truly multi-channel, I would prefer standard stereophonic headphones to them. Moreover, you can purchase much better “ears” for their money.