Pioneer Digital Wireless Surround Headphones SE-DIR800C

by | Jan 23, 2006 | Component Reviews | 0 comments

Pioneer Digital Wireless Surround Headphones SE-DIR800C

SRP: $399

Decoder functions – Dolby Digital, Dolby Pro Logic II, DTS, PCM (44.1K & 48K)
Dolby Headphone Modes (DH) – DH1, DH2, DH3, Off
Pro Logic II Modes – Auto, Movie, Music, Off
Secondary carrier frequency – 3.75MHz
Transmission distance – 8m to the front
Distortion – 1% or less at 1K
Audio inputs – optical digital, coaxial digital (RCA), analog (RCA)
Power source – DC 9V from supplied AC wallwart
Dimensions – 209mm W x 50mm H x 104mm D
Weight: 520g

Frequency range – 12Hz-22kHz
Power source – 2 rechargeable or standard AA batteries
Weight: 250g without batteries

AC power adaptor (9V)
2 rechargeable batteries
Coaxial digital cable (1.5m)
Vertical stand
Manual & warranty card

Laying the Virtual Groundwork

While it is not possible to get in a wireless headphone the high level of reproduction possible with the best wired headphones plus a dedicated headphone amp, there are some fairly listenable ones available, and they are very useful for watching video privately while others occasionally pass between you and the screen, and/or for late night listening or viewing. (Or worse yet, somebody walking in front of the screen late at night and not seeing your phone cord!) I reviewed the Amphony wireless phones some time ago and continue to use them for such purposes; they now have an updated audiophile model said to be improved fidelity.

Unfortunately, when viewing many feature film or music DVDs, or the increasing number of network and cable programs with 5.1 soundtracks, the standard headphone user has to switch to the two-channel option or hear only the L & R fontal channels – losing the feed on the center and surrounds completely.  I’ve experienced the frustration of watching, say, half of an action movie with a really dynamic surround soundtrack – such as “T2” – and then suddenly it’s “all sound off” time (since my HT viewing area is open to the rest of the house), and I’m forced to don boring stereo headphones for the rest of the movie.

Some years ago the Australian spatial sound specialists Lake DSP demonstrated at CES the prototype of what eventually became Dolby Headphone. The idea was to replicate the effect of five virtual speakers surrounding the listener when wearing headphones fed a 5.1 signal and processed by the special circuitry.  The room had five small speakers arrayed in the usual fashion and the listener was urged to put the headphones being fed the processed signal on and off – comparing the sound to that heard directly from the speakers. The comparison was very close indeed.

I don’t have any facts to back this up, but my feeling is that in order to easily manufacture the chip with what is now known as Dolby Headphone or DH, some corners in Lake’s design had to be rounded off. Because both listening to the circuit currently being included in several audio components, as well as the processed DH tracks being featured on a few music discs such as the new Monster Cable hi-res albums, I find the effect frankly underwhelming.  In fact I find it similar to Headroom’s long-offered process which is designed to fill in some of the sonic image between one’s ears when wearing standard headphones.  I find in common with many other listeners I  prefer the improved fidelity with the Headroom circuit off, in spite of the rather unnatural clumping of each stereo channel right at each ear instead of being spread out. (The fact is stereo recordings are simply not created for headphone listening – they are for loudspeaker listening.  Only true binaural recordings are designed for headphone listening. Everyone running around with their iPods etc. are not only listening to music with its soul extracted due to the MP3-type squeeze, but also music originally recorded only for playback on speakers – not on headphones!)

I later heard a similar spatial headphone circuit demo by the Smythe brothers who were instrumental in the original development of the DTS codec.  Theirs was not just impressive – it was jaw-droppingly accurate.  There was absolutely no difference to be heard between putting on the phones and talking them off to listen to the speakers in the demo room!  I don’t know what happened to this technology and would be very curious why it isn’t being implemented by the industry.

Auditioning the Pioneer Phones

I hooked up and compared the three different inputs possible with the surround phones.  I discovered that feeding the digital inputs from the digital output jacks on my Sunfire AV preamp I could only access a stereo signal, since the preamp had its own Dolby and DTS decoders built in.  In order to get an encoded DD or DTS signal into the Pioneer transmitter I had to connect an optical digital cable from the output of my Integra 10.5 universal player. 

It was a disappointment to find that there was no discrete virtual speaker processing of the six-channel hi-res signals from SACDs or DVD-As – only imposing the Dolby Headphone circuit onto the two-channel hi-res option to create a sort of pseudo-virtual-surround speaker configuration in the headphones.  The best virtual speaker display comes from feeding the Pioneer transmitter either a DTS 5.1 or Dolby 5.1 encoded signal and letting it do the decoding before it processes the signals for the headphones.

The better the two-channel signal fed the transmitter to process with Dolby Headphone, the better will be the resulting virtual speaker effect on the phones. The 96K Classic Records DAADs work very well, after selecting a mixdown to 48K for acceptance by the transmitter.  Standard CDs with below average sonics sounded least good on the Pioneer, as if the processing exaggerated some of the sonic inconsistencies. The four different settings for DH are as follows:  The Off position gives you a straight-thru stereo signal without any processing at all.  DH1 is the driest sound – a small room with almost no reverb; DH2 is the default setting – an average listening room; and DH3 is the reverb of a small movie theater environment.  I found the highest reverb setting to be more realistic than any of the “boingerizer” settings on most  AV preamps and receivers, but it still sounded artificial on most sources.

There is a standard headphone jack on the front of the transmitter so that a second set of phones may be plugged in simultaneously and adjusted with a separate level control on the unit. So both headphone listeners would get whatever processing was selected – though one would be wireless and the other wired.  The transmitter uses an infrared signal to the wireless phones rather than the 2.4 GHz signal of the Amphony phones (the same as Wi-Fi/Airport uses).  I found that while the Pioneer had a narrower and smaller range than the Ambiphons, it was free of the often loud noises and squeals when moving around in the room.  It just went silent when moving too far to one side of the transmitter or too far away in the room.

The headphones themselves have a well-designed headband system and large 40mm-diameter diaphragms.  However, I didn’t find them as comfortable as either my Amphonys or my Grado and AKG wired phones. I listened to a variety of music recordings and watched portions of several films on DVD with DTS and Dolby 5.1 tracks.  Since I could feed the Amphony transmitter an analog signal and the Pioneer a digital signal from either my preamp or my universal player, I could have both wireless phones at hand and switch back and forth between them.

What I found was that there were never effects of sounds occurring behind with the  surround phones. There was a more open and natural acoustic, especially in outdoor scenes in movies. But there was one scene around beehives in a Japanese 5.1 film in which some of the bees seemed to circle my head when using the Amphonys, but with the Pioneer I heard no such effect. In general even with DVDs I preferred the better fidelity of the Amphonys vs. the overly-processed sound of the surround phones.  It would seem that at the least the dialog track would be more centered out from you and in front with the surround phones, but I found the dialog on most films more pleasant to hear even though it was inside my skull without the virtual processing.

With strictly music sources the somewhat strident and thinner sonics of the surround phones offered a stronger contrast to the smoother and more musical sound of the standard Amphonys. It sometimes struck me as similar to the difference between a poor solid state amp and a good tubed amp.  While the transmitter options offer a variety of subtle adjustments to the virtual speaker effects on the phones, they all seem to suffer from similar EQ inconsistencies – even when the Off position on Dolby Headphone is selected. I recall reviewing an early Sony virtual surround wireless headphone system some years back – well before Dolby Headphone.  It suffered from the same overly-processed sonics.  Another reviewer highly recommended the Pioneers as abouts the best wireless phones – never mind the virtual surround feature.  I beg to differ. I surmise that some listeners will be so captivated by the semi-successful feeling of listening to a surround system via headphones that they will be willing to ignore the fidelity compromises.  If having this option interests you the phones should at least be tried out at a dealers.

– John Sunier

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