Sonic Series acoustic louvre SL4-60
The Sonic Series acoustic louvre SL4-60 is a 600mm deep acoustic louvre designed to provide controlled airborne sound reduction while maintaining airflow performance. Specify where acoustic attenuation is the primary design constraint and system depth allows for a deeper louvre configuration.
Engineered to balance acoustic attenuation, airflow performance and weather protection,the SL4-60 provides the highest airborne sound reduction of any acoustic louvre in the Sonic Series range. With a Weighted Sound Reduction Index of Rw 33, it exceeds the acoustic performance of comparable chevron blade configurations while maintaining Class 1 airflow performance and a 35% free open area.

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Product name:
AcousTech Sonic Series acoustic louvre SL4-60
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Weighted Sound Reduction Index (Rw):
Rw 33 (C −1, Ctr −4) assessed to AS 1191-2002, rated to AS/NZS ISO 717.1
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Insertion loss:
27dB (C −1, Ctr −4)
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Free open area (FOA):
35%
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Effective flow area (EFA):
0.29m² (1000 × 1000mm reference specimen)
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Discharge coefficient (Cd):
0.83
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Airflow classification:
Class 1 to AS 4740
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Rain penetration class:
Class C (overall) / Class A (0 m/s)
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Fire rating:
Manufactured from non-combustible materials
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Test standards:
AS/NZS ISO 717.1 | AS 4740
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Typical test specimen:
1000 × 1000mm
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Customisation:
Available in standard module sizes or engineered to project-specific dimensions.

| Frequency (Hz)-1/3 Octave |
Noise Reduction | |
|---|---|---|
| 1/3 Octave | 1/1 Octave | |
| 100 | 18 | 20 |
| 125 | 20 | |
| 160 | 22 | |
| 200 | 26 | 27 |
| 250 | 27 | |
| 315 | 28 | |
| 400 | 29 | 30 |
| 500 | 30 | |
| 630 | 32 | |
| 800 | 31 | 32 |
| 1000 | 31 | |
| 1250 | 34 | |
| 1600 | 35 | 35 |
| 2000 | 35 | |
| 2500 | 36 | |
| 3150 | 37 | 36 |
| 4000 | 36 | |
| 5000 | 36 | |

| Face Velocity (m/s) |
Throat Velocity (m/s) |
Pressure Drop (Pa) | Cd (-) |
|---|---|---|---|
| 0.5 | 2.3 | 4.5 | 0.83 |
| 1 | 4.5 | 18 | 0.83 |
| 1.5 | 6.8 | 41 | 0.83 |
| 2 | 9.1 | 74 | 0.82 |
| 2.5 | 11.4 | 113 | 0.83 |
| 3 | 13.6 | 164 | 0.83 |
| FOA | Cd | EFA | Performance Level |
|---|---|---|---|
| 35% | 0.83 | 0.29 | Class 1 |
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Penetration rate

Core Velocity
(m/s)Penetration
Rate (L/h.m2)Effectiveness Rain
Penetration
Class0 0.0 1.000 A 0.5 1.0 0.986 B 1 4.2 0.944 C 1.5 4.7 0.938 C 2 5.2 0.931 C 2.5 5.2 0.931 C 3 5.7 0.924 C 3.5 6.3 0.917 C
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Download
Sonic Series acoustic louvre SL4-60 datasheet PDF
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Download
AcousTech Sonic Series acoustic louvre - Information pack PDF
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Download
AcousTech Sonic Series acoustic louvre SL4-60 line drawing PDF
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AcousTech Sonic Series acoustic louvre SL4-60 - DWG DWG
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AcousTech Sonic Series acoustic louvre SL4-60 - RFA RFA