DESCENT i TM u s e r ’ s m a n u a l
Serial Number ___________________________________ Record your serial numbers here for easy reference. You will need this information when filling out your warranty registration. Descent i’s serial number is located near the bottom of the backplate and also on the shipping container.
Thank you—to you the MartinLogan owner, for loving what we do, and for making it possible for us to do what we love.
CONTENTS & INTRODUCTION Contents & Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 Installation in Brief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Controls and Connections . . . . . . . . . . . . . . . . . . . . . . . 6 Accessing the Control Panel Control Panel Rear Connection Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2-Channel Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Multi-Channel Mode . . . . . . . . . . . . . . . . . . . .
INSTALLATION We know you are eager to hear your new MartinLogan subwoofer, so this section is provided to allow fast and easy set up. Once you have your subwoofer operational, please take the time to read, in depth, the rest of the information in this manual. It will give you perspective on how to attain the greatest possible performance from this most exacting woofer system.
CONTROLS AND CONNECTIONS Accessing the Control Panel The control panel is located behind the inset metal plate located on top of the subwoofer. To access the control panel, gently press the area above the MartinLogan logo. When the spring releases gently pull the metal plate away from the subwoofer. Control Panel Level Setting the level too high will cause the bass to seem bloated and is the single most common cause of bad sounding subwoofers.
configuration of your listening environment, the placement of the unit, and your seating arrangement. Due to the way bass sound waves develop in different rooms, there is no rule of thumb for setting phase. For instance, if your room has a peak at the subwoofer crossover area, you may wish to set the phase so the actual acoustic outputs of the subwoofer and main speakers are out of phase. Experiment, try different settings and be patient.
Rear Connection Panel Sub Out For systems utilizing multiple subwoofers. Connect Sub Out to the LFE Input or Right In / Left In on additional sub(s). Status Light The Descent i is equipped with a multi-color LED to indicate the current status of the woofers. The following list explains the meaning of the different colors: Right Out / Left Out Should only be used if connecting this sub between a pre-amp and amplifier. Connect to the Left In/Right In on the amplifier.
WARNING! Turn the Master Power switch Off and unplug it before making or breaking any signal connections! 2-Channel Mode This setup is recommended if your subwoofer will be used in a 2-channel only system. When a signal is connected to the subwoofers Left In/Right In, the Low Pass Filter control is active. Signal Connection (see figure 4): 1 Connect the left out/right out from your preamp/receiver to the Left In/Right In of the subwoofer. Use quality RCA interconnects.
Multi-Channel Mode This setup is recommended if you will use your subwoofer in a dedicated home theater or multi-channel system. When a signal is connected to the subwoofer’s LFE In, the Low Pass Filter control is NOT active. Your processor handles most of the bass management. Signal Connection (see figure 6—RCA shown): 1 Connect the LFE out of the processor to the LFE In. Use either an RCA or an XLR interconnect.
2-Channel/Multi-Channel Mode This setup is recommended if your subwoofer will be used in both 2-channel mode and as a LFE channel in a multi-channel system. By following this setup, you will allow your processor to handle most of the bass management while running in multi-channel mode, and relinquish control of the low pass filter to the subwoofer when running in a 2-channel mode. Signal Connection (see figure 8): 1 Connect the left and right out of your preamplifier to the subwoofer’s Left In / Right In.
2-Channel Mode Using Speaker Level Inputs This setup is recommended if your subwoofer will be used in a 2-channel only system with full-range front loudspeakers. When a signal is connected to the subwoofer’s Left In/Right In subwoofer’s Low Pass Filter control is active. Signal Connection (see figure 10): 1 Connect the left and right outputs of your amplifier to the subwoofer’s high-level Speaker Level In (Left In/Right In) binding posts. Use quality speaker cable.
2-Channel Mode With 2-Channel Output This setup is recommended if your subwoofer will be used in a 2-channel only system. Signal Connection (see figure 11): 1 Connect the left out/right out from your preamplifier to the Left In/Right In of the subwoofer. Use quality RCA interconnects. 2 Connect the Left Out/Right Out of your subwoofer to the left in/right in of your amplifier. Use quality RCA interconnects. Recommended Control Settings: 1 Set the controls as recommended on page 9. 2.
Sub Out—Using Multiple Subwoofers Using Sub Out offers an easy way to implement multiple subwoofers in your audio/video system. Note: Additional subwoofers must run as either dedicated 2-channel (stereo) or multi-channel (LFE) subwoofers, but not both. Signal Connection: 1 Connect the first subwoofer to your system using one of the five modes previously described. 2 Connect the Sub Out of the first subwoofer to either the LFE In or the Right (or Left) In of the next subwoofer. Use quality RCA interconnects.
WARNING! The power cord should not be installed, removed, or left detached from the subwoofer while the other end is connected to an AC power source. The IEC cord should be firmly inserted into the AC power receptacle on the rear connection panel of the subwoofer, then to any convenient AC wall outlet. Directly adjacent to the AC power receptacle on the rear connection panel of the subwoofer is a master power switch.
PLACEMENT Listening Position Generally, subwoofers have the most output when placed in the corner of a room. However, this can also exaggerate the subwoofers output making blending difficult. We recommend starting by placing the subwoofer in a corner. It should be placed in such a way that there are 2 inches between the grill and the wall. This will avoid blocking the output of any woofers.
ROOM ACOUSTICS Your Room Terminology This is an area that requires both a little background to understand and some time and experimentation to attain the best performance from your system. Standing Waves Sound coming from a subwoofer bounces around in a room until a pattern emerges—this is called a standing wave. Typically, this is only a problem with frequencies below 100Hz. When this happens different parts of your room experience either an excess or a lack of bass.
Solid Footing After living and experimenting with your subwoofer, you may want to use ETC (energy transfer coupler) spikes supplied with the subwoofer (see figure 18). With the use of these spikes, the subwoofer will become more firmly planted on the floor and, consequently, bass will tighten and imaging will become more coherent and detailed. It is best not to implement the spikes, however, until you are secure in the positioning, as the spikes can damage the floor if the speaker is moved.
HOME THEATER It had long been the practice of stereo buffs to connect their television to the stereo system. The advantage was the use of the larger speakers and more powerful amplifier of the stereo system. Even though the sound was greatly improved, it was still mono and limited by the broadcast signal. In the late 1970's and early ‘80's two new home movie formats became widely available to the public: VCR and laser disc. At the same time video screen sizes began increasing.
MARTINLOGAN EXCLUSIVES BalancedForce™ For Cleaner Bass Resulting from an equal and opposite reaction to the cone's movement, strong bass causes all traditional subwoofer enclosures to generate acoustic vibrations. You feel this by touching the cabinet. Although the "physics" of this phenomenon actually cause a subwoofer cabinet to resonate or even dance, most subwoofer designers apply weight or mass to the cabinet to minimize such disturbances, but still leave one by product—"smeared bass".
FREQUENTLY ASKED QUESTIONS & TROUBLESHOOTING Frequently Asked Questions Troubleshooting How do I clean my subwoofer? Use a dust free cloth or a soft brush to clean your subwoofer. We recommend a specialty cloth (available through the Xtatic shop at www.martinlogan.com) that cleans better than anything else we have tried. No Output • Check that all your system components are turned on. • Check that the master power switch adjacent to the AC receptacle is set to 'On'.
DIMENSIONAL DRAWINGS Plan View (Top) Front Elevation Back Elevation 22 Dimensional Drawings Side Elevation
GENERAL INFORMATION Specifications* System Frequency Response 18–120 Hz ± 3 dB. Anechoic through the LFE effects input. Low Pass Filter Frequencies 30, 35, 45, 55, 65, 80Hz High Pass Filter Frequencies Bypass, 40Hz, 70Hz Phase 0°, 90°, 180°, 270° 25Hz & 50Hz Level ±10dB Power On, Auto, Standby Components 3 × 10” (25.4cm) high-excursion, aluminum cone with extended throw driver assembly, sealed non-resonant asymmetrical chamber format Amplifiers 3 × 250W (at < 0.
GLOSSARY OF AUDIO TERMS AC. Abbreviation for alternating current. DC. Abbreviation for direct current. Active crossover. Uses active devices (transistors, IC’s, tubes) and some form of power supply to operate. Diffraction. The breaking up of a sound wave caused by some type of mechanical interference such as a cabinet edge, grill frame or other similar object. Amplitude. The extreme range of a signal. Usually measured from the average to the extreme. Diaphragm.
Inductance. The property of an electrical circuit by which a varying current in it produces a varying magnetic field that introduces voltages in the same circuit or in a nearby circuit. It is measured in henrys. Inductor. A device designed primarily to introduce inductance into an electrical circuit. Sometimes called a choke or coil. Linearity. The extent to which any signal handling process is accomplished without amplitude distortion. Midrange. The middle frequencies where the ear is the most sensitive.
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WARNING! Do not use your Descent i loudspeakers outside of the country of original sale—voltage requirements vary by country. Improper voltage can cause damage that will be potentially expensive to repair. The Descent i is shipped to authorized MartinLogan distributors with the correct power supply for use in the country of intended sale. A list of authorized distributors can be accessed at www.martinlogan.com or by emailing info@martinlogan.com.
