Loudspeaker Test. Report

Transcription

1 Loudspeaker Test Report Manufacturer: System Sensor Type: Recessed wall mount Model: SPW For: System Sensor Report No.: R1843/LS/SPW Prepared By: C.Nicolaides B.Sc July 29 AMS Acoustics, London

2 1. Object 2. Scope 1.1 The object of this Report is to present measurements of the acoustic performance of the SPW device. 2.1 The following characteristics were measured On-axis (reference axis) frequency response Polar response Impedance Applied voltage On-axis 3 rd octave band sound pressure level from which the following are calculated: (i) Directivity Index [db], tabulated and graphical (ii) Directivity factor, Q (iii) Effective octave and wide band (1Hz to 1kHz) impedance (iv) Octave band Sensitivity 1m, 1W/oct] (v) Wide band Sensitivity: 1m, 1W 1m, 1W 1m, 1W Speech 1m, 1W (vi) Acoustic Power 1W], tabulated and graphical (vii) Octave band Power Apportionment [%] (viii) Impedance bode plot (ix) Expected maximum Sound pressure level 1m] (assuming no compression) (x) Frequency response chart (xi) Polar response charts.

3 3. Method 4. Results 5. Notes 3.1 The device was mounted in Free Space as shown in figure 1 - Mounting Method C. 3.2 The measurements were made in an anechoic chamber. 3.3 Measurements were made as detailed in AMS Test Method document No. IR/1a/LS/Meth. 3.4 All measurements were made in general accordance with BS EN 6268: Part 5: The On-axis 3 rd octave frequency response of the device is shown graphically. 4.2 The Impedance bode plot of the device is shown graphically. 4.3 Polar plots of the device are shown graphically. 4.4 Tabulated values of Directivity index, Directivity factor, Sensitivity, Acoustic Power, Power Apportionment, Impedance and Maximum SPL are shown in the Summary data sheet. 4.5 The Directivity Index has been calculated using Gerzon equal angle, weighted area method. 5.1 Sensitivity The octave band sensitivity is produced in its useful form for calculations. It should be noted that the octave band sensitivity is given as 1m, 1W/Oct. To determine the output when only the overall power is known, then only the overall dba or dblin values should be used. For more detailed information, refer to AMS Acoustics Data Sheet Loudspeaker Sensitivity Interpretation of Results. 5.2 Polar Plots For convenience, each polar plot has been normalized to db. For this reason, caution is advised when comparison of levels between octave bands are made. The reference axis frequency response should be used for comparison purposes.

4 6. Engineers Notes & Observations The reference point is located at the centre of the loudspeaker driver, in line with the baffle board. The reference axis is normal to the grille, in line with the reference point. The impedance does not fall to below 8% of the rated impedance within the frequency range 89Hz to 11.2kHz.

5 Loudspeaker Information Manufacturer : System Sensor Model Code : SPW Type : Recessed wall mount Colour : White Serial No. : NM Batch No. : NM Other Markings : NM Backbox : As supplied Grille : As supplied Weight (grams) : 58 Depth (mm) : 23 mm Width (mm) : 128 mm Height (mm) : 15 mm Special Features : None. Internal Details Driver Types/Sizes : NM Driver Serial No.(s) : NM Driver Markings : NM Damping Material : NM Available Tappings : 7.7V:.25W,.5W, 1W, 2W Electrical Details Resonant Frequency(s) : See impedance plot Cross-Over Frequency(s) : NA Nominal Impedance (ohms): 25 Inductance : NM Capacitance : NM NM = Not Measured, NA = Not Applicable

6 Manufacturer : System Sensor Model Code : SPW Mounting : HalfSphere Transformer Tapping : 2W Effective Impedance : 2733 Measurement Distance : 1.4m Reference Axis Located at : degrees Frequency (Hz) Parameter k 2k 4k 8k db dba Axial Q Directivity Index (db on Axis) Sensitivity 1m, 1W/Oct) m, 1W)25Hz-4kHz m, 1W)Speech Shape Acoustic Power 1W) Apportioned Power (%) Effective Impedance (Ohms) Expected maximum SPL 1m) Test Signal: Pink noise(1hz-1khz, 3rd octave bands) Directivity Index db k 2k 4k 8k Frequency, Hz Acoustic Pow er 1W k 2k 4k 8k Frequency, Hz

7 SPW Band Limited Frequency Response (Normalised to db) 5-5 Relative Level, db IEC 3rd-Octave Frequency, Hz Impedance Bode Plot Impedance, ohms Phase Angle, degs Frequency, Hz

8 SPW Left & Bottom Hz Right & Top Horizontal Vertical Hz Hz kHz kHz kHz kHz A-Weight

9 SPW Wide Band Frequency Response Note: The wide band frequency response is derived using MLS methods and does not necessarily relate to the sensitivity values given in the summary table. Signed: Countersigned:

10 Loudspeaker Mounting Methods Backbox Driver & Grille Mounting Method A Loudspeaker Mounted in a Reflective Baffle Mounting Method B Loudspeaker Mounted in an Absorbent Baffle Mounting Method C Loudspeaker Mounted on a Reflective Baffle Mounting Method B Loudspeaker Mounted on an Absorbent Baffle Mounting Method E Loudspeaker not Attached to any Surface and Radiation Unaffected by nearby Reflecting Surfaces