Grotto 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. Grotto 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 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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 Grotto, 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 Controls Level Setting the level too high will cause the bass to seem bloated and is the single most common cause of bad sounding subwoofers. A rule of thumb is that the subwoofer should not draw attention to itself, but should simply make the system’s low end seem more extended and accurate. Phase Control The phase control is entirely dependent on the size and configuration of your listening environment, the placement of the unit, and your seating arrangement.
Connections 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. The High Pass: Out control filters the output from these connections. Status Light The Grotto 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: No color: No power. The subwoofer is not plugged in, or the fuse has blown.
2-Channel Mode WARNING! Turn the Master Power switch Off and unplug it before making or breaking any signal connections! 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 5): 1 Connect the LFE out of the processor to the LFE In. WARNING! Based on the performance of most processors, it is recommended that MartinLogan center and effects type speakers (i.e.
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 6): 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 7): 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 8): 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.
AC Power Connection 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 Your room is actually a component and an important part of your system. This component is a large variable and can dramatically add to or subtract from a great sonic experience. Resonant Cavities. Small alcoves or closet type areas in your room can be chambers that create their own "standing waves" and can drum their own "one note" sounds. All sound is composed of waves.
Home Theater It had long been the practice of stereo buffs to connect their television to a 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 1980’s two new home movie formats became widely available to the public: VCR and laser disc. By 1985, both formats had developed into very high quality audio/video sources.
MartinLogan Exclusives Servo-Controlled Dynamic Drivers All dynamic drivers generate distortion caused by spider and surround nonlinearities as well as voice coil inductive disturbances and variant motor strength during massive woofer excursions. These challenges plague all subwoofer designers. The result? Induced harmonic and intermodulated distortions causing dramatic disturbances at high excursions. This occurs significantly in almost all non-servo-controlled subwoofers.
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 20 Dimensional Drawings Side Elevation
General Information Specifications* System Frequency Response 22–120 Hz ± 3 dB. Anechoic through the LFE effects input. Low Pass Filter Frequencies 30, 35, 45, 55, 65, 80Hz High Pass Filter Frequencies 70Hz Phase 0°, 90°, 180°, 270° 25Hz Level ±10dB Power On, Auto, Standby Components 10 ” (25.4cm) high-excursion, aluminum cone with extended throw driver assembly, sealed non-resonant asymmetrical chamber format Amplifier 300W (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. Arc.
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.
WARNING! Do not use your Grotto 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 Grotto 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. ® Lawrence, Kansas, USA tel 785.749.0133 fax 785.749.
