Why is THX important
12/Oct/2010 04:52 Filed in:
Industry News
THX® Certified Program
THX product certification categories are based ondelivering the best cinematic experience to specific room sizes.
- THX Ultra2 Certified - larger home theaters, 3,000 cubic feet in size, with a viewing distance of 12 feet or greater from the screen
- THX Select2 Certified - medium home theater, up to 2,000 cubic feet in size, with a 10-12 foot viewing distance from the screen
- THX I/S Plus System - Certified Systems (AV Receiver + Speaker Bundle): powered to fill a small home theater or dorm room where the viewing distance from the screen is 6-8 feet
Accurately translating the cinema experience to the home is not easy. Movies are created in large mixing studios for playback in large, powerful cinema auditoriums. When played back in the home, however, movie soundtracks don’t always deliver the same impact.
With a THX Certified AV receiver, cinema volume and fidelity is recreated in the living room. This performance is achieved through strict laboratory testing, a THX Reference Level design and THX DSP technology.
Performance Benefits- 2,000 Bench Tests: THX testing delivers accurate and powerful audio performance.
- THX Reference Level: Designed to recreate the movie industry SPL setting, 85dB with 20dB of headroom. By turning the volume dial to “0” on a THX Certified receiver, you will experience the exact volume level used by the sound designer – with the same level of sound fidelity.
- THX Loudness Plus: Automatically rebalances the surround level and restores bass and treble as the volume is lowered, allowing you to hear critical sound details and effects at any volume level.
THX Receiver & Standalone Power Amp Tests
- Load Testing Voltage, Multi-channel and Single Channel, Continuous and Burst - single channel tests ensure that all channels have equal capability. Continuous and burst multichannel tests ensure that the product has a heavy duty power supply that is capable of accurate playback of the most demanding program material
- Load Testing Current, Peak Current Capability - tests the ability of the amplifier to deliver high current on demand
- Noise - must have low noise performance, with no audible hiss from the speakers
- THD+N, Modulation Distortion, Difference Frequency Distortion - ensures clean undistorted performance
- Output Impedance - tests to make sure the frequency response of the amplifier is not affected by the speaker load. In the newer switching designs, a mechanism must be in place for the amplifier to automatically correct for the load
- Accurate Frequency Response - is essential for reproducing the source material accurately
- Hum - ensures that the level of AC Power line hum is not audible
- Crosstalk - checks for any cross channel information leakage
- Stability with a Capacitive Load - makes sure the product is stable with difficult speaker loads
- Fan Noise - fan noise and other audible noise can be annoying in scenes with low dialogue, THX maintains specific rules for fan operating noise
- Electrical Tests Measured on Every Output include: Gain, Input sensitivity Overload restore time, Phase response DC offset at the output, Polarity Transient time/propagation, Transient output Transient recovery
THX Certified Blu-ray Player Tests- De-interlacing: Bob, Weave – ensures images are de-interlaced properly, free of artifacts
- Motion Conversion – evaluates how action sequences in movies affects de-interlacing performance
- Cadence – ensures proper frame rate conversions
- Jaggies – checks lines or borders at low horizontal or vertical angles to ensure smoothness
- Contouring – evaluates areas of changing contrast to minimize blocking
- Overscan – no overscan or cropping is present with HD content
- White Level – white levels are achieved correctly without clipping
- Black Level – lower black levels are accurately portrayed without crushing
- Video Integrity – accurately reproduces primary and secondary colors
- Scaling – delivers clean visuals from a variety of resolutions without adding artifacts
- Horizontal Blanking – active video line and pixels are in the correct locations
- Audio Decoding – accurate decoding of surround formats
Tags: THX, Home Theater
