The preamplifier

The preamplifier

The AVPro, Kinyo and Tekuni headphones come with a preamplifier, which gathers simultaneously the connections and amplifies the sound card signal. They integrate two headphones outputs (7 or 9 pins Din formats, required for surround sound). They also have analogical outputs to connect a 5.1 speaker system. So it is possible to also use your headphones or speaker set without plugging or unplugging any cables. Most of the preamplifiers have an average quality and it is necessary to adjust simultaneously the preamplifier and the sound card volume to an ideal setting. The Zalman Theatre 6 is the only one sold where the preamplifier is optional. The ZM-RSA price is $75, which in addition to the price of the headphones, brings the package to $130, while the Kinyo KY-100 costs $50, headphone and preamplifiers included. Of course it is possible to foresee the quality differences of the headphones with such a price gap.


What is the benefit of a preamplifier? It is indispensable if your sound card doesn´t provide the accurate voltage to the mini-jack output. If you plug your headphones directly into the analogical output of your sound card, the only amplification will come from the sound card. Of the sound cards that don´t require a preamplifier are the Audigy line of products; the Audigy 2, Audigy 2 ZS, and the Audigy LS. They provide a maximum 2V, which is quite good. The SBLive 5.1 also has adequate voltage, but some of the OEM products don´t. With a little less punch, the Terratec cards DMX 6Fire 24/96, Aureon 5.1 Sky and 7.1 Space also provide the necessary electrical output.

This isn’t the case for the Hercules Fortissimo III 7.1 and Digifire 7.1 sound cards, which only provide a maximum of 1V. The XP Game Theatre is, however, adequately equipped. As for the integrated chipsets, they generally provide low voltage and require a preamplifier to offer enough sound. This problem also goes with the out of date NVIDIA APU. Some motherboards have extremely low voltage at the mini-jack output level.



The main disadvantage of preamplifiers is that it is just more hardware between the headphones and sound card. With a headphone + preamplifier pack at $60 it is possible to imagine the poor quality of audio components included in the preamplifier.

In order to have a clear and objective test procedure, we tested each preamplifier with the RightMark Audio Analyser 5.3. The first test was directly at the Audigy 2 sound card analogical output, then with the preamplifier between the Audigy 2 and the reference card. Being that the Kinyo KY-100, Tekuni CAM-6c and AVPRO PDVD-9208 have similar components and sound quality, we used only the results of the CAM-6c for simplicity.

All tests were made in 16 bits/ 44.1 KHz with the RMAA 5.3



From the results we can see that the Tekuni, Kinyo and AVPRO headphone preamplifiers are far from ideal in terms of amplification and sound reproduction. This result, however, should take into consideration that the ZM-RSA amplifier was used at 80% maximum volume, which corresponded to the optimum sound for the Audigy 2 sound card. The other pre-amplifiers don´t stand such high voltage and reach extreme saturation. Therefore, we adjusted the volume to 55% in order to use the preamplifier correctly. But even when weighing these results, the Kinyo, Tekuni and AVPro preamplifiers it is apparent that they largely distort sound and ruin all quality improvement obtained with the Audigy 2. In short, using these preamplifiers we might as well have used an entry level integrated chipset instead of the Audigy 2. The ZM-RSA also affects performance but not as much.

Even before testing the headphones, the low quality of the amplifiers was already apparent. This is even more unfortunate, because they are indispensable for headphone use. First, because if your sound card or your chipset doesn’t provide the accurate voltage, and second because the Tekuni, Kinyo et AVPro headphones have a 7 or 9 pins Dyn Type plug which can´t be directly connected to a sound card. The Dyn to mini-jack adapter delivered with the headphone only allows stereo and not 5.1 functions. Only the Zalman and the Gainward initially have an adequate plug-in (3 cable with a mini-jack) directly connectable to the sound card.

AVPRO PDVD-9208

AVPRO PDVD-9208

The AVPRO PDVD-9208 is the smallest headset of this test. Before its dismantling, we doubted that it actually contained four speakers. But it does, even if the components are smaller than those used by the competition. Like all Cosonic headphones the PDVD-9208 has four speakers. The vibrating subwoofer is 30 mm wide, the front speaker 40mm wide, the center and surround are two smaller 23 mm wide speakers. The PDVD-9208 has a cabled remote control which allows separate adjustment for the bass, center, front and surround volumes. The general volume control is located on the preamplifier.



Like the KY-100 and CAM-6c, the PDVD-9208 comes with an external preamplifier fed by an adapter. This preamplifier can also be powered via a USB port located at the back. It is vertically shaped pod, and provides the possibility to use a headphone via the two 9-pin Din connector or a 5.1 speaker set thanks to analogical outputs. It also includes a volume control knob and on/off switch. The preamplifier has an auxiliary mini jack stereo input and a front side switch allowing 5.1 or the auxiliary input use. The PDVD-9208 has the Dolby Digital and DTS logos on the packaging thanks to WinDVD 5.0 and Intervideo WinRip software included with the headphones.
Comfort:
At 160g, the PDVD-9208 is by far the lightest headphone of this test. The central joint is a simple metal stripe with a thin leather band. This stripe rests lightly on top of the head, and the earpieces mainly support (and create) the weight of the headphones. Their weight is easily forgotten, but their small size is a little bothersome in that they lean on your ears and don’t cover them. After a while, the weight was felt on our ears, and even though the PDVD-9208 is lighter than its competitors it is not a comfortable headphone.

Overall sound reproduction:
Like most of the headphones of this comparative test the PDVD-9208 doesn´t have an extraordinary sound reproduction. Sound is generally quite flat. It’s difficult to see its advantages compared to regular headphones such as the Sennheiser HD-212, which are half the cost. Bass output is weak. Treble is flat and lacks accuracy. Mediums are unremarkable. Nothing really stands apart here. The PDVD-9208 sound does, however, saturate less than the CAM-6c and the KY-100. It is important not to set levels too high with the remote control and remain below 70% of the maximum sound card level (with an Audigy 2).

Sound reproduction in games:
The positioning provided by the PDVD-9208 is similar to those provided by Cosonic headphones. The central voice has a better space position and seems less close than with the KY-100. But there again the positioning isn´t as clear as with 5.1 speakers.

Sound reproduction with video DVD:
Tests with different Video DVD showed that the PDVD-9208 has good results with 5.1 sound tracks. The positioning is accurate and immersion effects are better reproduced compared to a regular headphone used without specific algorithm. The poor sound quality, however, doesn´t help the viewer to literally dive into movie.

Gainward SoundXplosion 5.1

Gainward SoundXplosion 5.1

The SoundXplosion 5.1 is a first for Gainward. The manufacturer is better known for graphic and external / internal sound cards like the Music2Go. This headphone doesn’t come with a preamplifier so you will need a powerful sound card. You choose to buy the Zalman ZM-RSA preamplifier. Gainward sells the SoundXplosion 5.1 with a 2 meter mini-jack extension. The overall length is 4 meters, a good distance for movie viewing. The plug-in is a three strand mini-jack cable plugged directly into the sound card.



Located inside each earpiece are three small 30 mm Gold-Shine SP3006 speakers and a fourth 40mm speaker located in the body. This speaker, dedicated to bass frequencies, produces 100 mw and 4 ohms. The three other speakers provide, respectively; the central voice, the right or left front voice and the right or left surround voice. Each speaker has its own bandwidth: 50Hz to 400 Hz for the subwoofer, 250 Hz to 17 KHz for the frontal and surround, and 180 Hz to 14 KHz for the central. The frequency limit seems to be controlled by the headphones and doesn´t require any specific settings on the motherboard. It is not possible to adjust the volume from the headphones. All settings are made from the sound card drivers. This configuration isn´t handy, especially for games.

Comfort:

At 250 grams, the SoundXplosion is one the lightweights of this comparative test. It is possible to feel the difference compared to the CAM-6c and the ZM-RS6F juggernaut. The central joint is made of two flexible bars and a partly fleece-lined hanging plastic band. The slight pressure on top of the head is comfortable even after a while. The head adaptability is automatic and doesn´t require any settings. The earpieces are fleece-lined and don´t produce excessive pressure on the ears. The material around the earpieces is made of imitation leather and can become uncomfortable in a short period of time and heats up more than the foam rubber used for the CAM-6c. The SoundXplosion, however, has good place in the comfort category thanks to reduced weight.

Overall sound reproduction:
Used with stereo sources, the SoundXplosion provided good sound, but not always as good as standard headphones in this price range. Treble had average results with good clarity and average accuracy. The reproduction of medium was a little bit better and the overall sound tessitura is clear-cut and pleasant even if at times a bit sharp for some types of music. Bass was quite sharp but had a lack of depth. Musical instrument repartition was good, sufficiently sustained, even if the result is far from a Sennheiser HD570.

We noticed one thing true for all the headphone in this test. At higher volumes, a large part of the sound isn´t contained in the headphones. These headphones aren´t open but the use of large speakers and some material doesn´t provide sufficient sound isolation.

Sound reproduction in games:
The use of a 4.1 or 5.1 speaker set is sometime hazardous for games as it requires a specific position of the elements for true enjoyment. With 5.1 headphones this problem is inexistent as the speakers are always in the same position and a few millimetres away from your ears. The result is quite impressive as sound effects are well reproduced. It is possible to hear the difference between the central and front voices and notice the activation of surround speakers. The RightMark 3D Sound tests confirm this vertical and horizontal sound positioning efficiency.

Sound reproduction with video DVD:
More than with games it is with the video DVDs that 5.1 headphones stood out. Indeed the contribution of the central voice is essential. Some effects, however, weren´t well perceived like the transition between fronts and surround speakers which lacked progressiveness. Sound effect going from the front to the rear will be better reproduced with 5.1 speakers.

Kinyo KY-100

Kinyo KY-100

The Kinyo KY-100 uses the same components as the Tekuni CAM-6c. They both use 30 and 40 mm speakers manufactured by Cosonic. Both headphones are manufactured by Cosonic and then re-branded with the name Kinyo or Tekuni. The resemblance goes even further with the CAM-6c as the preamplifier is identical to the one provided by Tekuni except for the cabled remote control which controls all elements separately. The preamplifier, however, has a general volume control versus a simple switch on/off for the CAM-6c. Settings are less detailed with the KY-100 but their well thought volume control on the preamplifier is a real advantage.


Inside the earpiece, the KY-100 is similar to the CAM-6c except that the four speakers are cast in one piece and the vibrating bass speaker with close to the others instead of being in the earpiece body. Vibrating effects, however, due to the bass are as bad with the KY-100 as with the CAM-6c.

Comfort:
With a slightly lighter weight than the CAM-6c, the KY-100 is one of the heavyweights of this test. It was, however, possible to wear these headphones easier than the CAM-6c. The single and well stuffed central joint leans on the top of the head and supports most of the weigh. The earpieces absorb the rest of the weight by leaning around your ears. The earpieces are made of stuffed imitation leather and quickly warm up with skin contact. Altogether, despite its weight, the KY-100 isn´t the least comfortable headphone of this test.

Overall sound reproduction:
Like the CAM-6c preamplifier, the KY-100’s has significant weaknesses. The sound card volume cannot exceed 55%. Beyond this limit sound is messy and saturation reached its peak. With adjustment it was possible to find a good level for games but not for music. Bass was mediocre, vibrating more than it really transmited sound. Mediums were more or less good and quite noticeable. Treble, however, was ultra-flat and saturated quickly when going up in frequency. Like with the CAM-6c it was possible to notice a persistent blowing sound.

Sound reproduction in games:
The sound spatialization provided by the KY-100 was rather interesting and had a good restitution. Like with the CAM-6c sound coming out from the central voice seemed really close. This effect was quite disconcerting at the beginning. Otherwise, the restitution of surround effects was good and the positioning of 3D sound accurate even if transitions were quite difficult to follow.

Sound reproduction with video DVD:
Like with the CAM-6c, the KY-100 has some trouble with a sound positioning which doesn´t always quite match up with the listening position. It is difficult to keep the subtleties of a moving sound going from the front to the rear or the vice versa. A central voice positioned in an abnormal position can also be quite disturbing.

Tekuni CAM-6c

Tekuni CAM-6c

The Tekuni CAM-6c is a complete headphone as comes with a preamplifier and microphone. This microphone will please gamers using a communication system for team playing. The micro quality is good and is plugged directly to sound card micro input. The preamplifier has two headphone outputs, so you can connect a second headphone set, (if you find the rare Din 7 plug plug-in headphones without preamplifier). The preamplifier has three mini-jack inputs for the sound card connection and for a direct 5.1 speaker set connection. It is, therefore, possible to alternately switch with ease from headphone to speaker set. Cables connecting the headphone to the preamplifier are three meters long. The preamplifier requires, like the others in this test, a separate electrical power supply via an adapter (included with the preamplifier).


In the CAM-6c earpieces, we find three speakers, one 40mm for frontal sound and two 30 mm for surround and center. These speakers are made by Cosonic and are also in the Kinyo Ky-100. Bass frequencies are produced by a fourth vibrating speaker. To activate this particularity you need to deactivate the bass redirection on the sound card. After 30 seconds this result was frankly mediocre and not interesting. The earpiece serves in shaking and compressing your ears a little more. This feeling isn´t agreeable or realistic. The CAM-6c has a cabled remote control located on the cables of the headphone. This remote control is quite odd as it doesn’t have a general volume control, but three different controls for front, centre and surround. This configuration allows some specific settings but it is almost useless if you want to raise or lower the general volume control. The remote control also has a DVD-CD switch. The DVD function activates the 5.1 mode and the CD function activates the stereo mode. Tekuni provides a Din-mini jack adapter (only for stereo) to connect the headphones to something other than the preamplifier.

Comfort:
Just looking at the CAM-6c is enough to guess that this headphone won´t be the most comfortable of this test. It is the heaviest at 350 g. This weight quickly becomes tiring for the neck. The CAM-6c is annoyingly present on your head. The central joint supports all the weight. Even if the earpieces have a nice design they don´t stick to your ears due to an over sized central joint. This is too bad as their stuffing is comfortable and could have partly supported the headphone weight. The central joint is made of two metal stripes with a partly stuffed leather band. It is possible to twist the metal stripes to tighten the headphone´s earpieces.

Overall sound reproduction:
In use with the preamplifier the CAM-6c is disappointing, to say the least. First it is imperative to lower the maximum volume of the sound card to 55%. Beyond this limit sound is messy and saturation is reaches a peak. It is normal for a preamplifier to use a low signal as its role is to amplify. However something was wrong here as the maximum volume produced by the preamplifier doesn´t blow your ears. After the sound card, it is necessary to adjust the settings by remote control. With the best adjustments, sound remains of poor quality. Bass was mediocre and vibrates more than it really emits sound. Treble was average, losing their clarity in higher frequencies and saturating quickly. Mediums are a little better and are well reproduced. It was possible to notice a persistent blowing sound.

Sound reproduction in games:
Even if the sound provided by the CAM-6c was not of high quality, the 5.1 and sound spatialization effects were good. The central voice appears very close to the user. It is as if someone was talking to you right in front of your face. This sound effect is disconcerting with games like Far cry using 5.1 sound effects. The voice separation is good and it is possible to easily locate the origin of the sound source.

Sound reproduction in video DVD:
Like with games the position of the central voice is quite disturbing at the beginning. The normal position of the central voice is on top or below the screen and comes from the characters. With the CAM-6c sound seems to come from a closer source. Sound from the surround speakers has a treble predominance. And finally, like most of the headphones of this test, transition between front and surround speakers have a lack of gradation.

Zalman ZM-RS6F

Zalman ZM-RS6F

The ZM-RS6F comes without preamplifier, but can be used with the ZM-RSA (see above tests). We mainly tested this headphone connected directly to the sound card, but it is also possible to use it with the ZM-RSA, the best preamplifier of this test ($75). The Zalman headphones were originally manufactured by MM Gear under the M500FL name. It has a characteristic shape due to the design of the central joint and the arrangement of the speakers in the earpiece. The three speakers are horizontally positioned as you can see on the picture below. Their position is logical with the front speaker in the middle, the centre speaker in front and the surround speaker at the back.

A fourth speaker dedicated to bass is missing, so the bass frequencies are integrally retransmitted via the three 40 mm wide speakers. It means that the bass redirection has to be deactivated from the sound card. So with this headphone the ".1" isn’t accurate. The ZM-RS6F is a 5.0 and not a 5.1 headphone.


If you don´t have a preamplifier all the adjustments have to be made from the sound card. The ZM-RS6F doesn´t have any controls. This configuration isn´t practical especially when gaming. The cable connecting the headphone to the computer is three meters long. This is sufficient for most applications. All connections are the mini-jack type and it is possible to connect them anywhere without an adapter.

Comfort:
The ZM-RS6F just after the CAM-6c and the KY-100, is the heaviest headphone of this test at 320 g (without the cables). The design is, however, better as the weight partitioned between the head and ears. It is still difficult to forget that you are wearing headphones, but with the right settings the pressure around your ears and on your head isn´t tiring. However the weight is an inconvenient compared to the Gainward SoundXplosion 5.1, for example. The earpiece’s design is good and isn’t faulted with excessive heating. Still the pressure around your ears can be a bit much.

Overall sound reproduction:
Like most of the headphones tested the ZM-RS6F didn´t have an extraordinary sound. Used with stereo sources, it doesn´t provide the same sound quality that standard headphones of the same price range provide like the Sennheiser HD-212 or the Altec Lansing AHS512 at half the price. Treble was unremarkable and below the SoundXplosion 5.1 level, but still above the three others tested. More specifically it was flat and had a lack of clarity in the highest frequencies. Sound could have been more polished and accurate. This is particularly obvious when listening to classical music. Mediums were correct with a taut and dry sound. Bass was far too weak, had a lack of tightness and are not present enough.

Sound reproduction in games:
Thanks to the taut and present mediums, the ZM-RS6F gave a good impression in games. The horizontal positioning of the speakers seemed to work with 3D sound. The front or rear sound position worked, even if transitions still have a lack of subtlety due to the close positioning of the speakers.

Sound reproduction with video DVD:
The ZM-RS6F had good results with 5.1 sound track movies. The restitution of effects on sound positions is good and the positions clearly identifiable. However, sound transitions between two positions(an object going from the front to the back) is still abrupt and lacked of subtlety. This doesn´t happen with speaker sets as sounds progressively fade away in the front reappear in the back with surround speakers.

5.1 Headphones Vs Stereo Headphones

5.1 headphones for computers don´t provide great sound quality and they don´t stand comparison with standard classic stereo headphones like the HD-212 costing approximately $50. Sound is flat and saturation becomes obvious with small increases in volume. Putting the qualitative aspects aside, we will now review 5.1 function and see if there is any advantage to the presence of several speakers for the user.

Indeed stereo headphones are at least as efficient as a 5.1 speaker set in reproducing sound ambiance. This is especially true for games. It is due to the excellent stereo effects of headphones and a perfectible stereo image for computer speakers. And all 3D sound standards like DirectSound 3D and EAX have been designed to designate a 3D positioning with stereo systems. Algorithms used when activating the "headphone" parameters are tried and true and provide a simple but efficient sound ambiance with a correct 3D positioning.

We have made a few comparative tests withRightMark 3DSound in order to compare a quite good 5.1 headphone (the Zalman ZM-RS6F) to a stereo headphone of comparable price (Sennheiser HD-212).

For this test we used a Creative labs Audigy 2 sound card with the following parameters:

- 5.1 ZM-RS6F headphone: sound card parameters and Windows XP on 5.1 mode
- HD-212 stereo headphone: sound card parameters and Windows XP on headphone mode

The results were quite disturbing as it is difficult to decide during the first hearing the best sound positioning between the two of them. The ZM-RS6F provides a better sound spatialization and the feeling of surrounding sound is noticeable more significant. However the HD-212 had excellent results, mainly with positioning accuracy of sound sources in motion. The sound restitution of a stereo headphone is better when rotating around an object than with a 5.1 headphone. Transitions made by algorithms and used with DS3D and EAX are more subtle and progressive than with a 5.1 headphone and the 5.1 activated mode. Technically, 3D sound restitution is better with stereo headphones than with 5.1 headphones. If you add to the equation the better sound quality of stereo headphones, the result seems quite obvious.

If 5.1 headphones don´t bring any vital improvements to games, what about for movies? Indeed, in that area, the EAX or the DirectSound 3D won’t be of any help to the stereo headphone (except for the Creative Labs CMSS 3D which is an EAX component). We have compared the results of the ZM-RS6F connected in 5.1 and using the Audigy 2 5.1 decoding and the results of the HD-212 connected in stereo, using else the headphone sound card mode or else the Dolby Headphone technology integrated to Power DVD and WinDVD software in full version.

Dolby Headphones use a technology developed dedicated to headphones. This technology emulates surround sound on simple stereo headphones. For that, Dolby Headphones use a specific algorithm allowing virtual sound spatialization. It is included via software modules in the main DVD applications like Power DVD or WinDVD. It should be selected in the audio parameters to work correctly. It is then possible to access several configuration types emulating different spatialization: DH1 Small Room, DH2 Conference Room, DH3 Movie Theatre Model. Below the pictures of the Power DVD dedicated software solution.


The CMSS 3D is an owner technology integrated to Creative Labs sound cards. It uses the EAX routines and the DirectSound 3D to emulate a 4.1, sound from any stereo sound sources. It is very efficient but differs from the Dolby Headphone by using stereo sources and not 5.1 sources like the Dolby Headphone.


Here the 5.1 headphones give a rather convincing result due to the immersion impression provided by the numerous headphone elements and even if it lacks of precision with the positioning effects. The stereo headphone combined with the Dolby Headphone technology provides a smaller image but is able to relatively a have good effect restitution. It has to be noted that Dolby Headphone isn´t very good at providing sound located only at the back of the listening position. The Creative Labs CMSS 3D is a little bit more comfortable with this type of effects. The result is more than convincing and is close to the result provided by the 5.1 headphone. And once again if the qualitative aspects are added, we realise that is more appreciable to watch a movie with stereo headphones and the Dolby Headphones technology than with a 5.1 headphone.

Conclusion

In a nutshell…

We weren’t really impressed by any of the 5.1 headphones. The 5.1 system corresponds to 3 or 4 elements of the headphone, but is not always satisfactory for watching movies, playing games or listening to music. Sound quality is clearly not good with 5.1 headphones. And tests with DS3D and movies showed that it was possible to have a correct surround sound with simple stereo headphones.

Under these conditions it is difficult to recommend any of these 5.1 headphones. We will just single out two of the better ones, the Gainward SoundXplosion 5.1 and the Zalman ZM-RS6F. They provide a less mediocre sound quality than the others and have correct positioning. They are directly compatible with 5.1 sound cards plug-in, and avoid the use of preamplifiers, which for the other units were a fatal flaw and we cannot recommend at all.