There is a long and detailed test done by Clint DeBoer of Audioholics on long HDMI cables. His conclusion? For up to 10 meters any HDMI cable will suffice if you are looking at just 720p/1080i or at 1080p at 8 bits. If you want Deep Colour, or TrueHD, you have to be a little more careful. For lengths longer than 10m, it is not just the cable, but a combination of cable, the projector (or TV), and the bit rate (or bandwidth being sent) that come into play. Please read the following article carefully:
Long HDMI Cable Bench Tests - Monster Cable Shootout — Reviews and News from Audioholics
I quote Clint's conclusions:
Your take-away from all this should be the following:
* At lengths less than 4 meters you can just about use silly string (OK, not really) and get HDMI to pass at any current resolution. At less than 3 meters you'll even extend that to 12-bit color and possibly the next crazy idea HDMI Licensing decides to throw at consumers. Don't spend a lot on these cables and if you want to save money you won't let anyone at a big box store talk you into buying from them.
* At long lengths (over 10 meters) you really need to pay attention to the manufacturer if you don't want to risk running into potential problems with 1080p and future formats such as Deep Color. With that said, just about any cable at or under 10 meters will pass 720p/1080i and nearly everyone will pass 1080p at 8-bit color as well.
* If you have an existing HDMI cable and are running into problems, we'd suggest at least attempting the insertion of an active component at the sink (display) side. This is going to be far cheaper than ripping out your walls and re-running new cables - and likely just as effective.
* HDMI has proven to be a moving target and there is no telling what crazy (likely unnecessary) format they will try to push down the cable next. Due to this, it's always good to "overbuild" your cable install, especially if it's a longer distance and going to end up behind drywall.
* If you're not prone to upgraditis and think 1080p will be your maximum resolution for the life of your install, don't sweat it...
There are going to be exceptions to all these "rules" but in the end I'd have to say that I really thought I'd see more differences in the real-world performances of longer-length cables. Since we're all basically pinned at 8-bit 1080p, I didn't. It's likely you won't either. So all those people saying "buy any cable you want, it doesn't matter" are, for the most part, correct - at least until manufacturers advance to 12-bit software and signal transmission. Where they are not accurate is in assuming HDMI (since it is digital) is either "on" or "off" (it either works or doesn??t). HDMI signals can be partially corrupted as you saw above. The other area in which they are off concerns the future. If and when 12-bit "Deep Color" video truly comes to market (as more than just a listed spec) individual cable situations can (and likely will) change. For this reason take all of the above measurements and principles into account and make sure you build your installation wisely.
I would also suggest you to look at DAC's HDMI cable sold by Designer Audio (Designer Audio - Products
) I have been using this for some time and am very happy with it. I am not
using the length you are specifying. In addition they are 1.3 certified. If you live in Mumbai, go across to Designer Audio shop and ask questions and maybe a guarantee on 15m lengths. If they have a 15m piece lying around, get a test done at 1080p.
If you live elsewhere, call them on the phone and talk to them. Find out if they are ready to take back the cable if it does not work at those lengths.
Since HDMI is an evolving standard, there are certain risks, and one cannot guarantee that a particular cable will or will not work. At the same time, I am sure you can get a good cable at much less than 18K.