Appendix b - thx information – Bryston SP1.7PRECISION User Manual
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APPENDIX B - THX INFORMATION
Below is a summary of issues and information related to the proprietary and patented THX processing incorpo-
rated used in the SP1. The available space cannot include all the available information on this topic. Therefore,
if you want more information or wish to research the topic in more detail please use the THX website at
WWW.THX.COM.
When you choose the THX option for surround decoding modes within the SP1.7, by pressing the THX button
on the front panel or the remote, an additional “post-processing” method is activated. The additional signal pro-
cessing used in this mode is the result of extensive research, testing and refinement by the technical and engi-
neering staff at LucasFilm, Ltd. All movie soundtracks regardless of their original encoding format (Dolby
Digital, Dolby Pro-Logic, DTS, Stereo or Mono) can benefit from THX post-processing.
NOTE: THX is only available with movie modes PLII Film, NEO:6 Cinema, Pro Logic, Dolby Digital, and
DTS as per THX licensing agreements.
The THX mode would not normally be activated for music or movies that were made specifically for television
or other broadcast shows such as sports programming. The THX processing, designed to compensate for large
room mixing environments is not required for these programs because they are normally mixed/post-produced in
small room environments, as opposed to the large room environments normally used for theatrical motion pic-
ture mixing/post-production.
The SP1’s THX mode adds additional DSP post-processing to either the Dolby or DTS processing already in
place to help create a more precise match between the sound produced within a commercial motion picture the-
ater and the sound produced in your residential ‘theater’.
THX’s research shows that this is necessary because, all of the multi-channel film sound formats were originally
designed and spectrally balanced for use within large commercial movie theaters. Moreover, the specially
equipped and designed theater used by the sound mixing professionals to produce the final theatrical audio track
on any film (called a ‘dubbing stage’) is also considerably larger than your ‘home theater’ since it was created to
replicate the environment of a typical commercial cinema space, not your home theater space.
It is in those “dubbing stages” that the dialogue, sound effects and music are all individually recorded and
mixed to a six (5.1) or four channel(Pro- Logic) soundtrack for release in commercial movie theaters. This is the
same soundtrack that is later released on videotape and DVD for playback in a Home Theatre system.
During their research, the THX engineers identified the fundamental tonal and spatial errors created when
Theatre environment film sound tracks are reproduced in residential spaces.
The SP1.7, contains special processing designed by THX to correct those errors and restore the appropriate tonal
and spatial balance to a movie soundtrack, so that you can hear what the film’s producer/director intended.
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