Abbingdon Music Research LS-77 owner manual Room modes

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wave. Or one whole wavelength - or 1½, 2, 2½ and so on. This phenomenon is called standing waves. Actually the sound wave is not standing. But it is experienced like that because the sound pressure maxima and minima are positioned in fixed places in the room.

G 6 Room modes

These special frequencies are also called room modes. Standing waves between parallel walls are called axial modes. Other modes exist. For instance tangential and radial modes. Normally the axial modes are the strongest.

The standing waves are characterized by having a maximum sound pressure at the boundaries of the room. Depending on the frequency there are one or more dips across the room. In a box shaped room the frequencies can be calculated as follows:

Where:

f = frequency in Hz; c = speed of sound (approx. 340 m/s or 1130 ft/s); l = length of the room; b = width of the room; h = height of the room; n = integer from 0 and up

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Contents LS-77 Reference Class Professional Monitor Loudspeakers Page Page Running-In PrecautionsContents Page Front Panel of the LS-77 UnpackingPlease check that all contents are present LS-77 Front Fascia Component OverviewContact with the chassis Setup Connecting the loudspeakersUsing AMRs OptiLink Speakon Cable Speaker R Speaker L Using Binding Posts Speaker Cable Stereo Amplifier Interconnect Cable Connecting the amplifier Multi-channel set upChoice of loudspeaker cable Positioning Symmetry and room modesDistance between the loudspeakers Distance to back and side walls Distance to the loudspeakersLevelling/Speaker Support Room and furniture influence Loudspeaker Toe-inCare and maintenance Care & MaintainanceRunning-in the loudspeakers Power rating LS- 77 Technical Features Troubleshooting Guide TroubleshootingSpecifications Table SpecificationsAppendix 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 AM-77 Control Center Edition CCE Appendix D The AMR Active SystemLine Level Connection Setting up the AMR Active SystemSpeaker Connection Scenario Testing and Troubleshooting the AMR Active System LS-77 Speaker L AMR Active System Configuration DiagramIntroducing AMRs OptiArray scalable acoustic system Appendix E LS-77 in OptiArray configurationsPage AMR recommends the following OptiArray Setups Epsilon/Zeta Iota/Zappa Omicron/Sigma Epsilon/Zeta System wiring Reverberation time Appendix G Acoustics Background In formationAcoustics Good acousticsPage Membrane absorbers DiffusersAbsorption or Diffusion ? AbsorbersPorous absorbers Standing WavesRoom modes