User manual JBL SYN3-H

[. . . ] You will hear in your home, exactly what the director and sound engineer heard in the recording studio. The system will reproduce the audio flawlessly and without distortion. CINEMA/MUSIC SWITCHING: The Synthesis Three main speakers (S3M) utilize different combinations of transducers that are specifically chosen for playing cinema or music. Via an electronic relay, the speaker mode can be switched, depending on whether the surround processor is in the music or cinema mode. [. . . ] If you have purchased the Synthesis Three Home Media System, which utilizes the S3M speakers for the left and right channels, it is necessary to connect the five pin din cable (included) to each speaker. This cable is essential to the system, for it allows the speakers to switch from the music mode to the cinema mode. Plug one end into the five pin din jack (located above the speaker terminals) and the other end into the jack located on the power sequencer labeled "Speaker 1". Do the same for the second speaker. FINE TUNING YOUR AUDIO SYSTEM ACOUSTICAL PROBLEMS IN LISTENING ROOMS The Home THX Audio System addresses many of the problems common to high quality reproduction of music or soundtracks in a home environment. For example, the dispersion pattern of the front LCR speakers minimizes the effects of floor and ceiling reflections. Still, there are many variables which are beyond the control of a manufacturer. Room reflections create spurious false images and "comb filter" interference effects which alter the tonality of the system while degrading the localization of specific sounds. Larger rooms sustain echoes which degrade dialog intelligibility and detail. All rooms have standing waves which emphasize certain frequencies at the expense of others, based on the dimensions of the room. Other concerns include environmental noise, which is often greater than people realize. Although they might become accustomed to its presence and "tune it out, " it still reduces the perceived low-level resolution of the system. Sounds tend to bounce back and forth between the parallel wall many times before they die out, causing a characteristic bright, "zingy" sound and interfering with the intended tonal balance and acoustic nature of the soundtrack. No clear reflections should be heard at any point in the room--especially not near the primary seating area. Listen for a "flutter echo" of the hand clap (a rapidly-repeating percussive sound, indicative of the sound bouncing between two parallel walls). Again, the best home theatres are fairly "dead" acoustically. This allows the program material and the playback system to create the environment, rather than having the room's native acoustic signature color everything. The solution for slap echoes is usually a combination of absorption and diffusion. Specifically, placing absorptive material behind the front speakers (heavy drapes, fiberglass, dense foam) and diffusion in the rear of the room (bookcases, irregularlyshaped furniture, etc. ) will deliver the greatest benefits. This will effectively suppress the slap echoes while at the same time providing a diffusive surface in the rear for the surround speakers. This enhances the enveloping characteristic of the surrounds even further. In those relatively rare cases where you have the luxury of building the home theatre room from scratch, consider using non-parallel surfaces in the construction of the room. A difference of as little as 6° will break up the slap echoes very effectively. [. . . ] Rooms having equal dimensions are the worst, since the standing waves in all directions reinforce one another. Room dimensions which are even multiples of one another are also to be avoided where possible. STANDING WAVE SOLUTIONS: SPEAKER PLACEMENT Speaker placement also has an effect on standing waves and their audibility. In particular, placement of any speaker (including subwoofers) where two walls and the floor meet will tend to stimulate all of the available standing waves, causing the most irregular response. [. . . ]