Essential Install | OneAV Brand Spotlight
Enter PXLDRIVE: The In-Zone
Uncompressed 18G Solution
PXLDRIVE is a signal recovery method that I have put over
two years engineering, refi ning and perfecting effort into.
The product is a detachable dongle placed at the display
end of an HDMI link with the ability to revive uncompressed
HDMI signals up to the maximum 18Gbps bitrate over
new or pre-existing passive long reach HDMI cables.
If we look at the retrofi tting application (cables already
residing in the wall), it is clear the industry requires an
effective detachable active implementation to resurrect
these cables. PXLDRIVE is robust, interoperable and
supports long reach cables that can be thin and
convenient to pull in new install scenarios due to its 18G
gain curve implementation. It’s an interconnect solution
that acts like it is a 1m cable regardless of its actual
length, say up to 20m (all low-speed features, all high-
speed formats, including 18G), yes, 100% uncompressed.
The product works by using an adaptive equaliser and
re-timer block to maximise its effectiveness. Each block
is critical to ensure the maximum throughput of an 18G
signal can be restored to achieve 4K60 8bit 4:4:4 and 4K60
12bit 4:2:2 delivery. It has achieved the fi rst long reach THX
Certifi ed 4K Interconnect distinction using what I call a ‘bit-
in, bit-out’ methodology, get a bit, regenerate a bit, clean
the bit, send the bit. There is no digital processing or native
bit manipulation and no need for fi rmware updates.
So How Does It Work?
Pixelgen has
taken the issue
of completely
uncompressed 4K
and HDR signals
head-on
PXLDRIVE uses an adaptive equalizer device that adjusts
frequency dependent gain automatically depending
on the amount of loss detected. The adaptive equalizer
block operates by applying the appropriate gain for any
given loss (also known as attenuation). The benefi t of an
adaptive EQ is that it can detect cable length based on
a simulated model of what a cable looks like regarding
attenuation (or loss) and can apply the inverse gain.
Conversely, the majority of native HDMI 18Gbps
recovery methods use fi xed equalisation.
This strategy sets a typically
high gain state permanently
for the frequencies required
to be regenerated. In the
case of active cables, the
length is known, therefore a
pre-determined gain setting
is applied. Unfortunately,
this is not enough to guarantee reliability as there is
no retiming function post-EQ (as there is limited PCB
real estate inside the cable head itself). These ‘EQ-only’
techniques can be susceptible to confl icting EQ states
between the active cable’s EQ and the display’s EQ. Fixed
EQ extender products are not an acceptable solution for
retrofi tting 18G applications for this reason.
To stress the importance of adaptive equalisation, we
evaluated 20 random passive long reach HDMI cables
connected to PXLDRIVE in comparison to a common 18G
extender utilising fi xed equalisation. We used four readily
available HDMI 18G capable UHD sources and a single
18G 4K60 4:4:4 capable HDMI display. So, PXLDRIVE’s
auto-adaptive solution could; A) recover more short cables
regardless of gauge, B) recover more mid-range cables
with more 18G source types and C) still resurrect the
longer HDMI cables!
An interesting revelation occurred to me during
testing. I was always in the mind that all random HDMI
cables buried away out there had high loss, but this is not
the case – remember most cable manufacturers were just
going thicker to reach in the 1080p days! With PXLDRIVE,
shorter, mid-range and long HDMI cables regar