Abbingdon Music Research LS-77 owner manual Precautions, Running-In

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Precautions

This component has been tested and found to comply with the limits set out in the EMC Directive using a connection cable shorter than 3 metres.

Running-In

AMR estimates that the LS-77 may take between 300-500 operating hoursat fairly high sound pressure levels for all of the internal components to be fully-broken in. Hence, please anticipate the sonic performance of the LS-77 to settle only after it has been used for this approximate length of time.

We recommend the following procedure to speed upthe "burn in" for the LS-77:

Place the speakers face to face with faceplates almost touching and connect normally to the Amplifier. In conjunction with an out of phase mono signal this will cancel most noise. A heavy blanket may be thrown over the speakers to cancel more noise.

Play the “Pink Noise Out Of Phase” track (Track 4) from AMR’s System Test CD (included with the speakers) on repeat. Raise the volume as high as sensible (but quite high), the out of phase nature will cancel a lot of noise, so be careful when raising levels not to overload the Amplifier.

Using AMR’s AM-77 & CD-77 the maximum level recommended for burn in is -10db, the minimum level -16db. When using -16db a minimum of 120 Hours burn in should be applied, with -12…-10db level setting on the AM- 77 this can be shortened to 72 Hours. This will take the LS-77’s through the phase where the performance changes quite dramatically.

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Contents LS-77 Reference Class Professional Monitor Loudspeakers Page Page Precautions Running-InContents Page Unpacking Front Panel of the LS-77Please check that all contents are present Component Overview LS-77 Front FasciaContact with the chassis Connecting the loudspeakers SetupUsing AMRs OptiLink Speakon Cable Speaker R Speaker L Using Binding Posts Speaker Cable Stereo Amplifier Interconnect Cable Multi-channel set up Connecting the amplifierChoice of loudspeaker cable Symmetry and room modes PositioningDistance between the loudspeakers Distance to the loudspeakers Distance to back and side wallsLevelling/Speaker Support Loudspeaker Toe-in Room and furniture influenceCare & Maintainance Care and maintenanceRunning-in the loudspeakers Power rating LS- 77 Technical Features Troubleshooting Troubleshooting GuideSpecifications Specifications TableAppendix a Adjustment of tonal balan ce HF Level Placement Suggestions HF Level R1 Placement Appendix B Abbingdon Acoustic Setup Regime Page ~100″/254cm ~115 ″/290cm Page Page Appendix C Biamplifying the LS-77 LS-77 Speaker R Speaker L Speaker Cable Appendix D The AMR Active System AM-77 Control Center Edition CCESetting up the AMR Active System Line Level ConnectionSpeaker Connection Scenario Testing and Troubleshooting the AMR Active System AMR Active System Configuration Diagram LS-77 Speaker LAppendix E LS-77 in OptiArray configurations Introducing AMRs OptiArray scalable acoustic systemPage AMR recommends the following OptiArray Setups Epsilon/Zeta Iota/Zappa Omicron/Sigma Epsilon/Zeta System wiring Appendix G Acoustics Background In formation AcousticsGood acoustics Reverberation timePage Diffusers Absorption or Diffusion ?Absorbers Membrane absorbersStanding Waves Porous absorbersRoom modes