Re: THX Certified sound systems and rate..contribute urself.
Then you probably need to go back to one.
THX labs never revealed what specs they look for or what tests they do.
It's on the THX website, mate. You really need to learn how to read instead of just writing. There are multiple specs, so a THX (desktop MM) product is very different from a THX (Home theatre) product, or a THX certified movie theatre. The specs are not public domain, and therefore not available to non-certified installers or manufacturers. I have a copy in front of me, but obviously I am not sharing as it is under NDA and not to me for that matter
As a manufacturer, one may choose to exceed the spec by putting more money into the product and not send it for certification. The decision on certification rests with the manufacturer.
In short, If I find two audio products, one with THX certificate and one without THX, I would definitely go for the one with THX.
The Kraft 400 power amplifier costs 30,000 Euros, it is not THX certified, but I guess a Denon POA-A1 for 2,000 Euro is better because it has THX2 certificate? Really, sometimes use proper logic.
FWIW, I personally own audio equipment exceeding the cost of 30 Logitech Z5500 sets - and am on my 8th high-end system now (think 1L+ each time, and 3L+ for my current set). And I've learnt only one thing, and that is that badges and certificates don't mean anything, product quality has got only to do with market niches, cost and profit ratios and nothing else. So if two equally priced products differ only in the certification, it is a possibility that the one without the certificate would have more money put into the parts and bits because they didn't actually have to pay Georgey boy. Or that both are skimming your pockets. There is no way to tell unless you do a bit of research and put in some listening time
And the Logitechs do sound like ass. That is pretty much the consensus on this and pretty much all other forums, unless you happen to be the type who thinks a one-note bass boom is bass, or that a sibilant and over-pronounced top end is 'clear'. It sounds like crap, and is not that well-built either.
Badges are for fools who can't make judgements. Someday you need to join a marketing organisation (I was in the marketing industry for a long time) and see how they disguise truths in the ZPTOs and THXs. It's all the same - create acronyms and confuse the crap out of the consumer. Once you open up a MX5021 for modding or listen to a Z5500 with a decent system and some decent music you (should) will see and hear for yourself.
You're welcome to believe what you want, but it's not gospel truth. Someday you'll realise that there is much more to products than text on a webpage. When you do, go for some high-end auditions in your city and you will hear the truth. Bangalore has many excellent setups, start looking for a way to listen to them.
Good luck.