THX ultra amps?

[Jeffo19]

I am looking at 2 power amps strictly for 2 channel audio, the RB 1070 or RB 981, and the RB 1080 or RB 991. For some reason the RB 991 and RB 1080 have a THX badge on them, but the others don't. Why is this? Is the 1080 designed more for Home theater and not as much for 2 channel music. Does this have any effect on it being a 2 channel audiophile amp? I can get a good deal on either amp, but I am just not sure of the THX, and also if 200 watts will be overdriving my speakers!

[Sim reality]

THX ultra is a set of minimum standards set THX tests equipment to... The manufacturer has to pay for the test to be performed and the licensing of the use of the trademark...

This was great more then a decade ago when it was actually useful because electronics manufacturers had not achieved the level of performance they have now... But today THX testing for separates is a little like a car manufacturer advertising consumer reports rollover ratings for a sports car...

As for 200 watts... It actually better to have "too much" power then not enough... Speakers are usually damaged when the amps clip which produces a DC current on the coils and overheats the coils... While in theory it's possible to "overdrive" speakers you would have to be doing something "stupid" like plugging the speakers or amp into the wrong socket and sending a bad pulse to the speakers... Or sending really loud test tones... Or just in general trying to ruin your hearing...

[Jeffo19]

So it is basically a sort of quality control test. I just find it odd that this is done on the RB 1080, but not the RB 1070?
Also, why would the speaker manufacturers put power handling, or recommended amp power for their speakers, and tell you to not exceed the rating(25-130W) are what my Kefs are rated at for their recommended power. Someone told me that while it is true what you said about having more power, but also that you shold stay within the recommended watt range for the speakers used, or the drivers can be pushed to hard, causing excess cone excursion.
I would think this would be true with a 130W amp as well as a 200W amp depending on high you use your volumn level.

[Sim reality]

I think it's the time range that Rotel released the amps... It almost seems at some point the marketing people at Rotel decided that they did not need to THX certify their amps (IE: none of the Digital amps and I think the RB-1090 are THX certified)... But that is just conjecture...

The problem is that the peak power ratings for speakers are frequency specific and usually based on the amount of heat dissipated which is difficult to express as a single number... (IE: in a traditional speaker the low frequencies suck up a lot more power then the high frequencies)...

I would admit if you are sending low frequencies to bookshelf speakers you might have a problem (if you don't use common sense)... But with floor standing or using a cutoff frequencies with a sub should keep you out of trouble...

You should also be able to hear when the speakers are getting over driven pretty easily (it sounds like the whole speaker is buzzing) and as long as you don't smell anything there shouldn't be any damage done...

If you are trying to design the system to be idiot proof you should probably go with an integrated solution instead of outboard amps...

[Joey_V]

I think it's the time range that Rotel released the amps... It almost seems at some point the marketing people at Rotel decided that they did not need to THX certify their amps (IE: none of the Digital amps and I think the RB-1090 are THX certified)... But that is just conjecture...

1090 is thx certified btw.

[chinets]

Rotel 5 channel amp x 200 Watts which is the 1095 is THX certified for sure!!!

[Marlboroman]

Here is what Rotel technical support has to say on the issue:

"Rotel does not certify new product with THX anymore. The units that they did pay to have certified will continue to have the THX certification placed on them.

Most THX amplifier specs ensure that power amplifiers (whether "stand alone" components or receiver amplifier sections) meet sensible, though we feel, minimal performance standards. These standards cover continuous power output, headroom (the ability to handle a very strong signal without distorting it), and long-term reliability. These are all reasonable goals. The original and very demanding THX standards did a reasonable job in assuring consumers that they were getting the performance they needed for good home theater. In fact, Rotel adopted these original high performance goals and participated in the THX certification process. During that time, our products met or surpassed their criteria and we branded our products with their logo.

Recently, however, we have noticed that the current plethora of THX standards (different levels of required performance for different types of products) has confused the market place.

In addition, we feel very strongly that THX certification adds no real value - and certainly no performance advantage - to amplifiers that are properly designed in the first place. When coupled with the confusion caused by different levels of THX certification, the inherent costs of running a product past THX's engineers often reduces a product's perceived and real value by raising its price. That's why Rotel stopped using the THX certification process several years ago.

Our dedication to making high-performance amplifiers has not diminished since then. In fact, many of Rotel's current (though non-certified) amplifiers outperform older certified models. The reason for this is our strict adherence to a philosophy called "Balanced Design Concept" that results in careful and continuous evaluation of every part used in our products and the positive performance synergies that result.

For proof, we don't offer another logo on our front panels. Instead, we proudly place the Rotel name there and offer a wide range of independent evaluations and product reviews by an international roster of perceptive and demanding critics. You can read those reviews on our web site (www.rotel.com) or in many magazines and specialty web sites dedicated to the best in audio and video performance.

In summary, we believe that THX has, in fact, provided a real service to our industry. And we thank them for doing so. But our customers deserve the benefits of our most stringent efforts to provide the best performance at the most reasonable cost. In this area, we do not feel that their interests are best served by adding certification costs to products that already meet - and exceed - those standards."

[Pez]

That statement from Rotel pretty much sums up my feeling on the THX certification. Being THX certified might be of some use but I see it as more as a marketing tool when placed on high end components.

[nash]

When a Lincoln mid-range sedan has THX certification, you know it's not worth the paper it's printed on

[Pez]

When a Lincoln mid-range sedan has THX certification, you know it's not worth the paper it's printed on

Thats why I only buy cars with a Bose system.

[apodaca]

There is a great write up at audioholics.com about THX certification - you will undertand the power of the dark side once you read it.