To quote my learned colleague Mr Duncan, "Oh dear."Oh dear, oh dear, oh dear..."

Y'see, this isn't going to please the 'digits is digits' brigade one little bit, and will almost inevitably stir up a hornet's nest of slanging from those who say they know the facts but have never tried – but here goes...

I've just changed the HDMI cables in my system, and the difference it has made is simply jaw-dropping.

I don't just mean subtly better; I'm talking real "Huh? What happened there???" stuff.

I'd read about The Chord Company's new HDMI Active Silver Plus cable, and seen some online comments from another reviewer I trust and respect, but who's not exactly known for getting too excited about things AV.

I'd also noted with interest the knee-jerk reaction of one of our forum posters to our original news story: "20m-£450  0.75m£95 what a rip off no respect for the customer i will go else where".

So I gave the new cable a whirl.

And all I can say to bluerobbo22 is "Don't knock it if you haven't tried it."

The cables had sat in their box since they arrived early last week, as I'd been chained to the office desk all week covering various staff holidays. It was only yesterday, when even watching the cricket through my fingers became too much to bear, that I hauled out the system and started swapping.

Out with the cable from receiver to TV, the one from Sky+ HD box to the receiver, and the one connecting the Blu-ray Disc player; and in their place one 1.5m run of Chord Active HDMI, and two 3m lengths.

Plugged up, black end to the source, filter network bumps teased through narrow gaps behind the system, and then I sat back to have a look and a listen.

Amazing! Everything on the Sky HD channels looked sharper, brighter, better defined. Colours were less garish - and we're talking on a calibrated TV here - and even the text of the on-screen graphics was crisper, and easier to take in at a glance.

And the sound gains were, if anything, even greater. Whether with music from SACD, carried in DSD to the receiver – yes, I tried it with the Oppo as well as the BD machine - or movie soundtracks, the overall effect is of less clutter in the sound, greater intelligibility, and simply more precision.

The science bitSo how's it done? The secret, Chord says, is the use of "a high frequency filter on all lengths. [This] reduces the intra/inter channel skew between the four pairs of TDMS signals."

Now given that the transmission minimised differential signaling used in HDMI cables is already using that differential signaling to reduce EMI, and a twisted pair configuration to reduce noise, you may not think the filter network has much to do.

But clearly it works, and with obvious results. I spent the next hour switching cables back and forth, including swapping the Active for the otherwise similar standard Silver Plus, while my wife tapped her toes, looked at her watch and made "We need to go shopping" noises – but even she was soon commenting on the visual and audible gains.

And not just on BD discs: we were amazed how much more the new cables made of the stunningly shot Rick Stein's Far Eastern Odyssey, which we have stacked up on the Sky Planner at the moment, and found ourselves watching several Discovery documentaries, just relishing the picture quality.

And, as regular readers will know, we were doing all this on a Fujitsu 50in display that's virtually an antique, at least in the accelerated timescale of TV product cycles.

More after the break

Now, if only Chord could have done something to pep up the England performance before the Aussies gave us a total drubbing up in Leeds...