MartinLogan GROTTO, User Manual

Page 1: ...TM G R O T T O TM u s e r s m a n u a l M A R T I N L O G A N the loudspeaker technology company ...

Page 2: ...t Equal Sub Out Using Multiple Grottos 11 AC Power Connection 12 Replacing the Fuse Break In Placement 13 Listening Position Installing the Grotto in a Cabinet Ask Your Dealer Enjoy Yourself Room Acoustics 14 Your Room Terminology Solid Footing 15 Home Theater 16 Grotto Advantages 17 Servo Controlled Dynamic Drivers Low Pass Filters Maximize Blending 25Hz Level Control Frequently Asked Questions T...

Page 3: ...Signal Connection Use the best cables you can High quality cables avail able from your specialty dealer are recommended and will give you superior performance Attach your preamplifier processor outputs through cables to the signal input area located on the Grotto s rear panel Please see the Connections and Control Settings section pages 6 12 of this manual for more details If you plan to connect y...

Page 4: ...s used to drive the output stage with precision and extremely high efficiency Low pass filtering and phase control have been designed to make integrating the Grotto subwoofer with MartinLogan and non MartinLogan prod ucts both seamless and simple The materials in your new Grotto subwoofer are of the highest quality and will provide years of enduring enjoy ment and deepening respect The cabinetry i...

Page 5: ...iment try dif ferent settings and be patient 25Hz Level Knob The 25Hz Level knob significantly adjusts the level between 20 and 30Hz by 12dB This is an area where peaks and dips of different amplitudes often manifest in real environments This setting is dependent on room size and construction system configuration and personal preference Auto On Standby Power Switch The Auto On Standby switch contr...

Page 6: ...erconnects If your preamplifier only has one set of out puts you may need to obtain Y adapters from your dealer Recommended Control Settings see figure 3 1 Set the 25Hz Level control to 0 2 Set the low pass filter switch to the closest option equal to 70 of your loudspeakers lowest frequency response 3 While playing music with bass content turn the level con trol up until the music has deep extend...

Page 7: ...tion Recommended Control Settings see figure 5 1 Set the 25Hz Level control to 0 2 Use the bass management section of your processor s speaker level setup option to set the subwoofer level at an appropriate level Follow the instructions in your proces sor manual to fine tune the subwoofer level 3 If your processor offers the option to setup crossovers for a subwoofer we recommend that you start wi...

Page 8: ...bass content turn the level control up until the music has deep extended bass that is not overwhelming 5 Try the phase control in different settings until the best blending is obtained If you are augmenting MartinLogan loudspeakers we suggest you start with the phase set at 90 0 if you are using Script loudspeakers 6 If you have completed steps 1 5 and still have weak or boomy bass adjust the 25Hz...

Page 9: ...our Grotto to the speakers Recommended Control Settings see figure 9 1 Set the 25Hz Level control to 0 2 Set the low pass filter switch to the closest option equal to 70 of your loudspeakers lowest frequency response 3 While playing music with bass content turn the level con trol up until the music has deep extended bass being careful to avoid levels that become overwhelming 4 Try the phase contro...

Page 10: ...ifier to the left and right inputs of the Grotto using quality RCA interconnects 2 Connect the left and right outputs of your Grotto to the left and right inputs of your amplifier using quality RCA interconnects Recommended Control Settings see figure 3 1 Set the controls as recommended on page 6 Figure 10 Signal connection for 2 channel mode with 2 channel output 2 Channel Mode With 2 Channel Out...

Page 11: ...rs see figure 12 3 Repeat step 2 for each additional Grotto subwoofer in the chain using the same input for every connection Recommended Control Settings 1 Adjust the control settings of the first subwoofer using the recommended control settings from the connection method used to connect the master Grotto with your audio system 2 Adjust the control settings of each additional subwoofer using the r...

Page 12: ...sale be certain that AC power supplied in any subse quent location is suitable before connecting and operating the subwoofer Substantially impaired performance or severe damage may occur to the Grotto subwoofer if operation is attempted from an incorrect AC power source If the fuse in your Grotto should require changing turn your Grotto off and unplug it before removing the fuse Replace the bad fu...

Page 13: ...ealer Your MartinLogan dealer can suggest many options for optimal subwoofer placement They also have many tools at their disposal such as experience familiarity with the associated equipment and even sound analysis equipment which may make the task of determining optimal subwoofer placement easier Enjoy Yourself The Grotto is a very refined subwoofer and will benefit from care in setup With the a...

Page 14: ...your room experience either an excess or a lack of bass Some people believe that having a room without parallel walls will eliminate this effect The truth is that non parallel walls only generate different standing wave patterns than those that occur in rectangular rooms Average rooms tend to have very strong standing waves in the frequencies below 30Hz For this reason the Grotto features an adjus...

Page 15: ... audio equipment racks speakers etc Spike Installation Instructions 1 Carefully remove the grill cloths from your Grotto 2 Carefully lay the Grotto on its side to gain access to the bottom 3 Remove existing feet or spikes Thread new spikes into holes and screw them in all of the way 4 Tighten jam nut snugly by hand Do not over tighten the nut 5 Right the subwoofer Caution Make sure your hands and ...

Page 16: ...ur stereo playback then they should be of very high quality and able to play loud over 102 dB and reproduce bass below 80 Hz Center Channel Many experts believe this to be the most important speaker in a home theater system as almost all of the dialogue and a large portion of the front speaker information is repro duced by the center channel It is important that the same manufacturer of the front ...

Page 17: ...namic driver technologies The Grotto s low pass filters achieve extremely precise cross over points in both amplitude and time domain resulting in seamless blending with both MartinLogan and non MartinLogan products By tailoring custom filters to the main speaker roll off characteristics minimum group delay results in cohesive integration and musical results 25Hz Level Control The Grotto 25Hz leve...

Page 18: ...ore It s a good idea to disconnect all of your audio video components during stormy weather No Output Check that all your system components are turned on Check that the power switch on the Grotto is set to either Auto or On Check your wires and connections Check all interconnecting cables Make sure the level control is not turned down Turn off and unplug the Grotto and check the fuse near the AC p...

Page 19: ...r convenience MartinLogan also offers online warranty registration at www martinlogan com MartinLogan may not honor warranty service claims unless we have a completed Warranty Registration card on file If you did not receive a Certificate of Registration with your new Grotto subwoofer you cannot be assured of having received a new unit If this is the case please contact your authorized MartinLogan...

Page 20: ... difference in decibels between two sounds is ten times the Base 10 logarithm of the ratio of their power levels DC Abbreviation for direct current 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 Diaphragm A thin flexible membrane or cone that vibrates in response to electrical signals to produce ...

Page 21: ...e of the RMS sound pressure Resistance That property of a conductor by which it opposes the flow of electric current resulting in the generation of heat in the conducting material usually expressed in ohms Resistor A device used in a circuit to provide resistance Resonance The effect produced when the natural vibra tion frequency of a body is greatly amplified by reinforcing vibrations at the same...

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Page 24: ...01 Delaware Street Lawrence Kansas 66046 USA tel 785 749 0133 fax 785 749 5320 www martinlogan com M A R T I N L O G A N the loudspeaker technology company 2003 MartinLogan All rights reserved Rev 052103 ...