Abbingdon Music Research LS-77 owner manual

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1,0,0(25Hz)

2,0,0(50Hz)

3,0,0(75Hz)

4,0,0(100Hz)

0,0,1(62Hz)

6.7m

Undesirable Listening Positions

1,0,0(25Hz)

2,0,0(50Hz)

3,0,0(75Hz)

4,0,0(100Hz)

0,0,1(62Hz)

2.8m

6.7m

Desirable Listening Positions

2.8m

How does the standing waves influence the sound field? - The curve expresses the area of the room where the actual frequency is audible. At the minima the frequency is represented at a much lower level (sometimes -40 dB compared to the maximum). If the room has the same dimensions as length, width, and even height it is very problematic to obtain an even sound distribution.

How to prohibit standing waves - Parallel walls in the room should be prevented if possible. Then the strongest modes are suppressed. This obviously requires purpose built rooms. When placing the speakers it is important that as few modes as possible are excited. This is why the speakers should not be placed in a maximum of a standing wave, nor should the listener be located in a maximum or minimum of a standing wave.

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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