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Gefen EXT-WHDMI wireless HDMI extender review: Gefen EXT-WHDMI wireless HDMI extender

Gefen EXT-WHDMI wireless HDMI extender

David Katzmaier Editorial Director -- Personal Tech
David reviews TVs and leads the Personal Tech team at CNET, covering mobile, software, computing, streaming and home entertainment. We provide helpful, expert reviews, advice and videos on what gadget or service to buy and how to get the most out of it.
Expertise A 20-year CNET veteran, David has been reviewing TVs since the days of CRT, rear-projection and plasma. Prior to CNET he worked at Sound & Vision magazine and eTown.com. He is known to two people on Twitter as the Cormac McCarthy of consumer electronics. Credentials
  • Although still awaiting his Oscar for Best Picture Reviewer, David does hold certifications from the Imaging Science Foundation and the National Institutes of Standards and Technology on display calibration and evaluation.
David Katzmaier
10 min read


Gefen EXT-WHDMI wireless HDMI extender

The Good

Stable reception with full HD resolution and generally very good quality; supports 1080p/24 high-definition video; two HDMI and one component-video input with analog audio; solid build quality.

The Bad

Expensive; minor false contouring; cannot support 1080p/60 video; no remote for manually switching between sources; limited to a 30-foot range; some gaming lag.

The Bottom Line

The professional-grade Gefen EXT-WHDMI may not quite match the quality of an actual HDMI cable, but its solid transmissions make it a viable candidate when wireless HDMI is the best option.

In 2008 we gave the Best of CES award to the Belkin FlyWire, the first mainstream wireless HDMI system that was promised to go to market. After numerous delays that system still is not available, but the idea is still going strong. CES 2009 saw multiple manufacturers, including Panasonic and LG, announce wireless video transmission capability built into their HDTVs, where a separate transmitter beams audio and video information from a variety of components to a display that only needs a power cord.

The Gefen EXT-WHDMI is one of the first commercially available wireless HDMI systems that will work with any TV and any components. While expensive, it lets users who want a custom installation skip the cost of running wires from source components to a wall-mounted flat-panel HDTV or ceiling-mounted projector. Its 30-foot range isn't really designed to blast signals from one side of the house to the other, or outside, but within the same room it works basically as advertised. No, the video quality isn't quite up to that of a regular HDMI cable, and in some areas fell short of the other current wireless HDMI system, Sony's DMX-WL1, but it's still pretty darn good and, with its exceedingly stable signal, finally represents a viable alternative to long, expensive cable runs. In addition, unlike the Sony, the Gefen's capability to handle 1080p/24 video heightens its appeal to videophiles.

One important note: With these kinds of systems more than usual, we recommend buying from a vendor that offers a solid return policy in case it doesn't work in your installation.

The Gefen EXT-WHDMI consists of two similar-looking boxes, one slightly larger than the other, each about the size of a stack of five Blu-ray Discs. The larger of the two boxes is the transmitter, which has a single stubby antenna jutting from its rear; the smaller is the receiver, with two such antennas. Both boxes are fan-cooled, but the fan noise wasn't audible under normal viewing conditions, and certainly quieter than a PlayStation 3 or Xbox 360, for example.

The front panel of the receiver is sparse, with just three LEDs to indicate power, a live link to the transmitter, and the presence of transmitted video.

Each compact metal box is quite solidly built, as befits a company like Gefen that produces gear intended mainly for professional use. They're rounded on the edges and incorporate mirror-finish front panels with a few LED indicators and, in the case of the transmitter, a single button to select between input sources.

The front panel of the transmitter includes indicators for various sources and a button to select between them.

Unlike Sony with its DMX-WL1, Gefen does not offer a remote control to switch between sources and there's no way to integrate a universal remote that we could discern. If you want to switch between input sources on the EXT-WHDMI, you'll have to get up and press the input switch button on the box.

Gefen includes an Auto input switch mode, which ideally causes the receiver to automatically switch to the active HDMI input when you power up the connected HDMI device. Once we got the hang of turning on and off the two HDMI sources the automatic HDMI switching worked relatively well, but there were some hiccups.

We connected a PS3 and a DirecTV HR20 satellite box via HDMI, and we could never get the Gefen to switch back to the satellite box without turning off the PS3. On the other hand, every time we were watching the satellite and powered on the PS3, the Gefen would switch inputs, as if it was giving priority to the PS3. This behavior occurred regardless of which of the two HDMI inputs the devices were connected to, and we suspect other HDMI devices might give different results.

Also, despite the user manual's claim that we could activate the component-video source by turning off both HDMI sources, that never happened. To watch the component-video source, our only option was to use the front-panel switch to manually select it.

One way to get around the whole input switching issue is to connect an HDMI switcher or an audiovisual receiver with HDMI switching to one input of the Gefen's transmitter.

The Gefen EXT-WHDMI system uses ultra-wideband wireless technology developed by a company called TZero. According to TZero, the technology is superior to other methods like 60GHz and Wi-Fi used by other wireless HDMI developers because it's more stable and less subject to interference. The version 1.0 UWB system used by Gefen has a stated range of 30 feet, which TZero characterizes as conservative.

Gefen's system is compatible with video signals up to 1080p/30, including 1080p/24, 1080i, 720p, 480p, and standard-definition 480i. That's better than the Sony, which maxes out at 1080i and can't do any variety of 1080p. Unfortunately, the Gefen still isn't compatible with 1080p/60 signals, which are quite common among Blu-ray players, game consoles and upconverting DVD players.

Since 1080p/60 is not supported by the Gefen, you should set your device to 1080i mode, then engage the 1080p/24 option. With the PS3 and Panasonic DMP-BD35 we used for testing, those settings allowed 1080p/24 video to reach the Gefen and the display, yet also allowed the menus and other non-film content to display in 1080i. With those settings we didn't miss not having a 1080p/60 output resolution, but they're only valid on TVs that can accept and display 1080p/24. If your display doesn't support 1080p/24, you'll have to disable that output option on your source device and stick to 1080i.

Around back of the transmitter are the two HDMI ports, the component-video port, an analog audio input, and a provision for an IR blaster (not included).

The transmitter has three inputs: two HDMI and one component video, and all of the supported resolutions work via both HDMI and component. There's also a separate stereo analog audio input on the transmitter that has a corresponding output on the receiver. Unfortunately, stereo audio on the transmitter can't be piped into the HDMI output on the receiver; you'll need to connect the audio output separately. However, the provision of an analog audio connection lets you connect both component-video and legacy DVI devices that require a separate audio connection. In that vein we'd have liked to see a provision for optical or coaxial digital surround sound audio, like the Sony has, but it's not available.

An HDMI output and an analog audio output, plus a port for an IR blaster, comprise the receiver's back panel.

The Gefen also lacks the included IR blasters found on the Sony. Both the transmitter and receiver have IR blaster and receiver jacks, but for some reason the company didn't include the blasters.

Two HDMI cables are included in the box, but no IR blasters are included.

The EXT-WHDMI works with HDMI CEC, a protocol for sending commands over HDMI. To use it, you point your remote control at the display, which sends the commands over the Gefen's wireless connection back to the source device. Both the TV and the source device must be HDMI CEC compatible.

In our testing, this feature worked as advertised. We were able to control our Panasonic Blu-ray player using both a Sony and a Samsung TV over the Gefen by simply pointing the remote at the TVs and having the player respond. Of course, your results will vary depending on which devices you have connected.

Overall the video quality of the EXT-WHDMI was very good. All of the pop and detail of 1080i and 1080p video was in evidence, and the advantage of being able to transmit 1080p/24, with its inherently smoother and more filmlike motion compared with 1080i (when seen on compatible displays) should be a boon for videophiles. Speaking of smoothness in moving video, the Gefen appeared to maintain the source's frame rate without introducing any of the stutter or dropped frames we experienced on the Acoustic Research HDP100.

The Gefen isn't quite as good as using a standard HDMI cable, however, and in at least one key video quality aspect we tested--false contouring--it also fell a bit short of the Sony DMX-WL1. With program material, as opposed to test patterns, we give the video quality nod to the Sony, despite its inability to handle 1080p. But the Gefen scores higher in Performance overall, thanks to its more stable signal and still-solid video quality.

We compared the three (Gefen, Sony, and standard HDMI cable) using the Panasonic TH-65VX100U as our reference display with a variety of sources: PlayStation 3, Panasonic DMP-BD35, and DirecTV HR20 satellite box. We'll restrict most of our video-quality discussions to the highest-quality source, Baraka on Blu-ray delivered via the PS3.

Our setup placed the Sony and the Gefen transmitters and receivers next to one another in the same room, with about 20 feet of distance and line-of-sight between transmitters and receivers. There was anywhere from 4 to 10 active Wi-Fi networks in the area during testing, according to our laptop PC.

The major weakness we could discern with the Gefen was false contouring, which appeared as subtle lines of gradation in nearly flat fields and fine transitions that wasn't visible in the images conveyed by the Sony or by regular HDMI cable. During the beginning of Chapter 8 of Baraka, for example, we saw evidence of faint contours in the water beneath the ascending flock of birds, and also a very faint pattern that almost looked mottled in the brownish lake. Contours were even more obvious in the background graphics of the PS3, and again neither of the two comparable methods showed these contours. It's worth mentioning that this kind of contouring was infrequent and subtle when it did occur in Baraka and other sources we watched.

At times, the image delivered by the Gefen also appeared just a bit noisier than via the cable or the Sony wireless transmitter. The beginning of Chapter 10, for example, includes a very slow pan over a Brazilian shantytown, and there was a bit more noise in the bricks of the buildings and the green of the hillside when we watched the Gefen. We doubt the difference would be visible outside of side-by-side comparisons, however, and the noise test material from the HQV Blu-ray Disc looked basically the same between all three of the HDMI transmission methods.

There were also a few areas where the Gefen beat the Sony. We noticed minor edge enhancement around text on the Sony that wasn't visible on the Gefen, and in test patterns it was even more obvious. Thin lines on the Sony, such as the graphics around some menu elements on Blu-ray Discs, also showed slight shimmering on the Sony whereas the Gefen was completely stable. Numerous test patterns also looked significantly better on the Gefen, especially resolution--the Gefen was perfect, while the Sony broke up, flickered, or lost definition in the highest-detail areas.

In fact, a couple of the toughest patterns on the Digital Video Essentials--HD Basics test Blu-ray (Luminance and Chroma Zone Plate) would "break" the Sony's communication, forcing us to cycle its receiver's power before we could continue watching. The Gefen didn't look as good as the HDMI cable on those patterns, but its communication remained stable. For the techies out there, it did appear as if the Gefen was truncating chroma (color) resolution, but again the difference was quite difficult to spot outside of test patterns.

During one pattern, a jaggies test from HQV, the Gefen stuttered quite a bit about half the time--the other half remaining smooth--while the Sony did not. We don't consider this a huge failure since we couldn't duplicate it with other material.

We made these comparisons with the Sony in 1080i mode, since it doesn't support 1080p. When we switched to 1080p/24 the Gefen worked fine, delivering the smoother video without that subtle hitching motion seen on film sources displayed at 1080i, for example in the pan over the buildings in Chapter 12 of Baraka. Again, you'll need to connect a compatible display and to pay pretty close attention to appreciate the 1080p/24 difference, so the Gefen's capability to handle that format is probably an advantage only videophiles will care about.

Between the two wireless systems, the Sony evinced significantly less delay than the Gefen, which becomes especially important to video gamers. When watching via the Gefen and flipping around to various items in the PS3 menu, for instance, we experienced maybe a third- to a half-second delay between pressing the key on our controller and seeing the result on the screen. The delay on the Sony DMX-WL1 was much shorter--enough so that less-twitchy gamers might not notice--and, of course, we experienced no delay at all with the HDMI cable.

According to Gefen's user manual, the system can transmit two-channel PCM and multichannel Dolby Digital and DTS soundtracks, but it couldn't do the latter in our testing. It failed to transmit a Dolby Digital soundtrack that passed with no problems via a standard HDMI cable. We don't consider this a huge deal, however, since most installations won't require multichannel audio on the receiving end.

Finally we moved the Gefen into another room about 30 feet away and through a door. The image appeared but was broken up and essentially unwatchable. On the other hand, in our original configuration, the transmission remained stable regardless of whether we walked between the transmitter and receiver, placed components in front of the antennas, or stashed the receiver behind the TV. In general, the Gefen was quite stable overall as long as we kept within the 30-foot range.


Gefen EXT-WHDMI wireless HDMI extender

Score Breakdown

Design 7Features 7Performance 7