Instruction Manual Model 372 PBM THX High Performance THX Powered Subwoofer System ® Atlantic Technology® I NNOVATIVE H OME T HEATER 343 Vanderbilt Avenue Norwood, MA 02062 (781) 762-6300 Model 372 PBM THX MODEL 372 PBM THX Atlantic Technology® High Performance THX Powered Subwoofer System Congratulations on your purchase of an Atlantic Technology 372 PBM THX powered subwoofer. With proper care, your new subwoofer will provide many years of trouble-free, high quality reproduction. The 372 PBM is fully THX certified to provide very high output levels and a wide dynamic range with smooth in-room response down to 20 Hz, with a peak SPL of 108 dB. The subwoofer also features a proprietary class G linear amplifier conservatively rated at 275 watts rms. This amplifier, coupled with a massive 15" high-excursion woofer will deliver very high output levels with minimum distortion. Your Atlantic Technology powered subwoofer will easily integrate with virtually all other brands of loudspeakers on the market. All inputs and outputs, both line level and high (speaker) level, are designed for optimum signal integrity. The premium quality gold plated connectors and all controls are clearly labeled and versatile in operation. The amplifier has more than ample power and headroom to supply a high fidelity foundation to any audio or home theater system. Lucasfilm Home THX George Lucas and Lucasfilm, creators of the Star Wars saga, originated and perfected Home THX, a strict set of standards and guidelines for home theaters, enabling you to reproduce the full sound of the finest theaters in your home. When properly followed, these guidelines address and correct the problems encountered when a film soundtrack is played back in the smaller environment of the home. The Home THX system adapts a soundtrack mixed and equalized to play back in a large theater to reproduce naturally when you experience the film at home. It is important to realize that THX is not a recording process or a special decoding system. All motion pictures will be reproduced as they were heard in the film studio dubbing stage through the Home THX system, no matter what surround decoding system is used. Whether you are using Dolby Digital® (AC-3®), DTS® Dolby Pro Logic® or any other system, Home THX , , will make the experience more natural and lifelike. With the lights down, your intimate home theater environment is transformed into the large acoustic space of a real theater. It's really quite startling how "big" your room will sound when the lights are off and the visual cues of your room size are absent. Features Your Atlantic Technology 372 PBM THX powered subwoofer was engineered using the latest technology and finest components available. q q q q High excursion 15" driver in a sealed acoustic suspension cabinet Class "G" linear power amplifier conservatively rated at 275 watts RMS Discrete, high current output devices Working frequency range from 20 Hz to full bypass, (approximately 500 Hz) 2 Model 372 PBM THX Atlantic Technology® q Adjustable low-pass filter from 55 Hz to full bypass The slope of this low-pass filter is 18 dB/octave. This allows for flexible integration with most any brand or type of speaker on the market. A subsonic filter is also incorporated to filter out inaudible frequencies that can rob amplifier power. Two line inputs, two line thruputs, and an 80 Hz line level output The thruputs allow daisy-chaining of multiple subwoofers, or can act as a return path back to the processor. The high-pass outputs send the audio signal, minus the bass frequencies below 80Hz, back to your amplifier and main speakers. Phase inverter toggle switch (0/180 degrees) Allows matching with many systems whose output may be inverse phased. Front panel variable volume control with THX bypass position Automatic standby operation The 7-10 minute turn-off delay features a front panel indicator and a defeat switch. IEC AC power socket Unit comes supplied with a detachable power cord. Heavy duty rocker type power switch Design and construction meets all UL/CSA European safety requirements q q q q q q q Connection The Atlantic Technology 372 PBM THX Powered Subwoofer is simple to hook up, offering several connection methods for maximum flexibility. Study the system diagrams starting on page 5. Once you have found the example which most closely matches your system, hook up your subwoofer(s) as shown in that diagram. Low-Level Connection For simplicity, we suggest using the low-level (RCA style jacks) subwoofer line out or preamp outputs if your receiver/amplifier has them. Simply connect your subwoofer with high quality shielded cables as shown in the diagrams. High-Level Connection Alternately, you may use the high-level (speaker) inputs. Make sure to match the type and gauge speaker wire used to connect your main speakers. We recommend that you connect your new 372 PBM THX Powered Subwoofer(s) using high quality wire of 16 gauge or larger. There are many respected manufacturers in the audio industry that specialize in speaker wire and interconnect cables suitable for your new system. We recommend that you consult your local audio/video specialist for more specific information. Warning: To prevent risk of electrical shock or damage to your equipment, always unplug all component AC cords before proceeding with speaker and component connections! The last step in wiring your system is plugging in the AC cords! 3 Model 372 PBM THX Atlantic Technology® Figure 1: Amplifier panel and controls for Model 372 PBM THX 4 Model 372 PBM THX Atlantic Technology® Receiver/Amplifier/Processor Example 1: Subwoofer Line Out/ Low Level In This is the most commonly used system connection for systems with surround sound receivers/ processors. Sub Woofer Out HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Single Sub Woofer Optional Second Sub Woofer Example 2: Preamp Line Out/Low Level In for 1 Subwoofer This arrangement is for owners of stereo receivers/ amplifiers with Preamp outputs. If your receiver/ amplifier uses jumper links between the Pre-out and Main In, then you must remove them and use option 1 or 2. If your receiver/ amplifier uses a switch instead of connectors, then use option 3. Receiver/Amplifier/Processor Single Sub Woofer Option 1 L R Pre Out HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Main In Y-adapters Option 2 L R Pre Out HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Main In Option 3 L R Pre Amp Internal External Pre Out HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Main In 5 Model 372 PBM THX Atlantic Technology® Receiver/Amplifier/Processor Example 3: Preamp Line Out/Low Level In for 2 Subwoofers Note that the L/MONO input is used on both subwoofers. Instead of Y-adapters, you may also use the THRU outputs to connect back to the Main Inputs as shown in Option 2 of Example 2. Y-adapters L R Pre Out Main In HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Left Sub Woofer Right Sub Woofer Example 4: Preamp Line Out/Low Level In using Hi-Pass Out for 1 Subwoofer The line level HiPass outputs send audio signals above the Lo-Pass filter setting to the main L and R power amplifier inputs. This keeps the low frequencies out of the left and right front speakers, allowing the subwoofers to reproduce the bass frequencies. Receiver/Amplifier/Processor Pre Out L R Main In SUBWOOFER LO-PASS 80 55 100 140 EXT FILTER THX HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Sub Woofer Note: These outputs are primarily intended for use in a two channel satellite/subwoofer system where the left and right speakers are small and not designed to reproduce bass. It is also useful when your receiver/ amplifier/processor does not internally incorporate a low pass filter. 6 Model 372 PBM THX Atlantic Technology® Receiver/Amplifier Example 5: Speaker Out/ High Level In for 1 Subwoofer This is the most common method for connecting a subwoofer to a system without a dedicated subwoofer line out or Preamp outputs. Main Speakers Left Right HI PASS OUT LOW LEVEL IN THRU L/MONO RIGHT L/MONO HI LEVEL INPUT RIGHT Left Front Speaker Sub Woofer Right Front Speaker Example 6: Speaker Out/ High Level In for 2 Subwoofers This is the most common method for connecting 2 subwoofers to a system without a dedicated subwoofer line out or Preamp outputs. Note that the L/MONO High Level input is used on both left and right subwoofers. Main Speakers Receiver/Amplifier Left Right HI PASS OUT LOW LEVEL IN THRU L/MONO RIGHT HI PASS OUT LOW LEVEL IN THRU L/MONO RIGHT L/MONO HI LEVEL INPUT RIGHT L/MONO HI LEVEL INPUT RIGHT Left Front Speaker Left Sub Woofer Right Sub Woofer Right Front Speaker 7 Model 372 PBM THX Atlantic Technology® Option 1 THX Receiver/Amplifier/Processor THX Example: THX Subwoofer Out/Low Level In Option 1 is the most commonly used method of connecting two subwoofers to a THX system. You may also use a Yadapter as shown in Option 2. Option 2 THX Receiver/Amplifier/Processor THX Sub Woofer Out THX Sub Woofer Out Y-adapter HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT HI PASS OUT LOW LEVEL THRU IN L/MONO RIGHT Single Sub Woofer Optional Second Sub Woofer Single Sub Woofer Optional Second Sub Woofer Note: The front panel level control and the rear panel subwoofer lo-pass control must be in the THX position for proper THX operation. You can connect your 372 PBM THX by using a variety of connectors, or by removing 1/2" of insulation from each wire end, twisting the strands of wire together, placing the wire through one of the post holes and screwing down the nut tightly. We recommend that you check your local electrical codes to make sure you are not using an improper connector. It is important to observe polarity while making speaker connections: red (+) terminals on the amplifier to red (+) on the speaker, black (-) on the amplifier to black (-) on the speaker. Look carefully at the wires you are using and note that one of the wires in each pair is marked by either a different color, printing, ridges, or a thread intertwined with the wire strands. By convention, the marked wire is connected to the red (+) terminal. Figure 2: Speaker Wiring Terminals Power Connection Connect the power cord to an AC outlet only after making all other connections to the subwoofer. This will avoid any chance of accidentally activating the subwoofer while wiring. The AC cord should be plugged into its own wall outlet or into a quality power strip. Avoid using a switched outlet on the rear panel of another component. The subwoofer can draw more current than these outlets can provide and performance will suffer. Once the subwoofer is hooked up and the power switch is turned on, leave it on. The automatic on/off circuitry will only activate the subwoofer in the presence of an audio signal from your audio/video system. After 7-10 minutes with no signal detected from the rest of the system, the amplifier will shut itself off and go into standby mode. When an audio signal is present, the power LED will glow green. Power consumption in the standby mode is negligible. 8 Model 372 PBM THX Atlantic Technology® Changing the Fuse To change the fuse, remove the power cord, insert a screwdriver tip into the notch in the side of the fuseholder, and pry it out. Replace with the correct value fuse and push back into place. Fuse values are marked adjacent to the IEC AC socket. Insert screwdriver tip here Figure 3: The fuse is located next to the IEC AC socket Placement and Operation The Model 372 PBM THX Powered Subwoofer should be placed in the front of the room, close to a corner (Figure 4). Every room has its own unique sound, and flexibility in the exact placement of the subwoofer is always desirable. In general, the closer the woofer is placed to a corner, the more bass response you will hear. However, in many rooms, corner placement can produce too much bass and the subwoofer will work best well away from the corner. Experiment to find the best position in your room. Refer back to the wiring diagrams starting on page 5 for the correct wiring scheme for your particular setup. Then proceed with listening. Figure 4: Typical arrangement for a single subwoofer in a home theater. Start here Less Bass More Bass 9 Model 372 PBM THX Atlantic Technology® Subwoofer Tuning--Using the Variable Level Control Start your listening with the high-pass filter set at 80Hz, the phase switch set to normal, and the front panel variable level control (Figure 5) set to minimum, just above the Fixed THX clickstop position. Play some music that you know has good bass content, and turn the level control up until you just start to hear the subwoofer working. Now, from your normal liste ...