Originally Posted by DIYHomeTheater
My speakers are THX Ultra2 certified. I don't precisely recall the reason why a preamp should be certified so as well, but recall reading that it should be to reproduce 'reference levels' or something similar.
(****I will preface my comments by stating this is for informational purposes only, that one can achieve stellar performance *without* THX certification, and that THX certification is not required to have an excellent sounding HT. I am not recommending THX to you, nor do I want your thread to devolve into a debate about the relative merits of THX certification, which can certainly happen very quickly on this forum.)
With the above preface, if one is using THX certified speakers, one could consider THX certification of the receiver or pre/pro for several reasons:1. To be certain of having the capability to achieve "Reference Level"
in the specifically sized room, and at the specific listening distances described in the THX spec. For THX Ultra2, that means 85 dB average levels with 20 dB of headroom:http://www.thx.com/consumer/thx-tech...ference-level/
in a room of 3,000 cubic feet and at a listening distance of 12 feet.http://www.thx.com/consumer/home-ent...ce-categories/
Your room is bigger than that, and your listening distances will be greater than that, so THX RL may not quite be achievable in your system. However, RL is *very* loud, and few people can listen at full RL for extended periods. I usually listen at -6 to -8 dB below RL.2. To be able to mate THX speakers and subs with the THX crossover.
The speakers, subs and the crossover work as a system. When the "system" is design from the start to work together, the ideal crossover can be achieved. The THX crossover is designed specifically to work with the roll-off characteristics of THX speakers. The result is the ideal Linkwitz-Riley, dual 4th order crossover, which is free from phase shift. Many non-THX receivers use the same crossover points and slopes as the THX crossover. However, it is not *required* in a non-THX receiver/pre/pro.3. To be able to use the THX processing modes.
Some people find benefit in the THX processing modes:http://www.thx.com/consumer/thx-tech...iver-features/
These processing modes are only available in THX certified receivers or pre/pros.
THX is a certification process which enables the consumer to be assured that the product carrying the certification meets a specific set of performance criteria, and that any THX certified product will work with any other THX certified product to achieve the prescribed levels of performance. Whether it has value to any one consumer is up to that consumer.
Again, it is certainly *possible*
to put together a non-THX system that performs as well or better than a THX system. It's just up to the consumer to ensure everything works together as required.