d&b audiotechnik 24S/24S-D Loudspeaker

General Information

This document is Manual Version 1.3 en, dated 06/2025, with document number D2624.EN .01. Copyright © 2025 by d&b audiotechnik GmbH & Co. KG. All rights reserved.

Keep this document with the product or in a safe place for future reference. When reselling this product, hand over this document to the new owner.

Contact Information:

d&b audiotechnik GmbH & Co. KG
Eugen-Adolff-Str. 134, D-71522 Backnang, Germany
T +49-7191-9669-0, F +49-7191-95 00 00
docadmin@dbaudio.com, www.dbaudio.com

1 Safety Precautions

Potential risk of personal injury: Never stand in the immediate vicinity of loudspeakers driven at a high level. Professional loudspeaker systems can cause sound pressure levels detrimental to human health. Seemingly non-critical sound levels (from approx. 95 dB SPL) can cause hearing damage if people are exposed to it over a long period.

When setting up loudspeakers or stands, ensure they are on a firm surface. If stacking systems, use straps to secure them against movement.

Only use accessories tested and approved by d&b for assembly and mobile deployment. Refer to specific "Mounting instructions" or "Flying system and Rigging manuals" for correct application and maximum load capacity.

Ensure all additional hardware, fixings, and fasteners used for installation or mobile deployment are of appropriate size and load safety factor, following manufacturers' instructions and relevant safety guidelines.

Regularly check loudspeaker housings and accessories for signs of wear and tear, and replace them when necessary. Regularly check all load-bearing bolts in the mounting devices.

Potential risk of material damage: Loudspeakers produce a static magnetic field. Keep loudspeakers away from equipment and objects that may be impaired or damaged by an external magnetic field. A distance of 0.5 m (1.5 ft) from magnetic data carriers (floppy disks, audio/video tapes, bank cards) is generally sufficient; a distance of over 1 m (3 ft) may be necessary for computer and video monitors.

2 24S/24S-D Loudspeaker

2.1 Product Description

The 24S and 24S-D are high-performance 2-way loudspeakers featuring two 12" neodymium LF drivers in a bass-reflex enclosure and different HF sections for various installed sound applications. Both models are lightweight passive designs utilizing a 1.4" exit neodymium driver and large horns for accurate pattern control. They offer rotatable dispersion characteristics of (h x v) 75° x 45° (24S) or 110° x 45° (24S-D).

The two 12" LF drivers are positioned in a dipolar arrangement, providing exceptional vertical dispersion control even at lower frequencies. Specially designed ports with optimized flow characteristics offer improved, efficient low-frequency reproduction.

With a frequency response extending from 55 Hz to over 18 kHz, the cabinets can be used as full-range systems or supplemented by subwoofers from the xS- or xA-Series.

The enclosures are constructed from marine plywood with an impact-resistant paint finish. The fronts are protected by a rigid metal grill backed by acoustically transparent foam. The cabinets are Ball Impact Resistant according to DIN 18032-3.

Rigging Components

The top, bottom, side, and rear panels of the cabinets are equipped with M10 threaded inserts for connecting various rigging accessories:

• Z5553 Flying bracket 24S
• Z5554 Horizontal bracket 24S
• Z5384 VP Flying adapter
• Z5551 VP Flying adapter link

Rigging examples: 24S/24S-D flown with Z5553 Flying bracket 24S; 24S/24S-D ceiling mounted with Z5554 Horizontal bracket 24S; 24S/24S-D array with Z5384 VP Flying adapter/Z5551 VP Flying adapter link.

2.2 Connections

The cabinets are fitted with an NL4 M connector (pin assignment 1+/1-) and a two-pole screw terminal block (ST). Pin equivalents for applicable connector options are listed below:

Fixed Cable Connection

The 24S and 24S-D loudspeakers include a cover plate [1] and a rubber grommet feed-through [2]. These can be used to hide the connector panel for indoor operation. For unprotected outdoor operation, the connector panel must be covered using both items to achieve an IP rating of IP34.

To install the fixed cable connection:

1. Remove the knockout opening in the cover plate [1] and attach the rubber grommet [2].
2. Insert the connection cable through the rubber grommet.
3. Undo the four screws of the connector panel.
4. Connect the cable wires to the screw terminal, observing correct polarity.
5. Push the cover plate towards the connector panel until it fits into place.
6. Fix the cover plate and connector panel using all screws.

Illustration showing the steps for installing a fixed cable connection.

NL4 Cable Connection with Cover Plate

The NL4 connector socket is recessed, allowing the use of the cover plate [1] with an NL4 cable connector. Neutrik NL4FC type connectors are recommended.

Installation follows the same procedure as the fixed cable connection.

WR Option (Weather Resistance)

NOTICE! The WR option enables loudspeaker operation in changing ambient conditions but is not intended for permanent, unprotected outdoor use. Provide additional cover for the loudspeakers and aim them horizontally or with a downward tilt.

WR cabinets feature a black PCP (Polyurea Cabinet Protection) finish for impact and weather resistance. They include a recessed connector panel with a Faston type connector (2 x 6.3 mm, female). A cover plate for single or dual PG cable glands (PG13.5 for 6-12 mm cable diameters) is provided.

To install the fixed connection cable (WR option):

1. Insert the connection cable through the PG screwing and connect the male connector to the female connector.
2. Push the cover plate towards the connector panel until it fits into place.
3. Fix the cover plate to the connector panel using the four countersunk screws.

Illustration showing Faston type connectors and the WR option connection.

2.3 Operation

NOTICE! Only operate d&b loudspeakers with a correctly configured d&b amplifier to avoid damaging loudspeaker components.

Recommended d&b Amplifiers: 40D, 30D.

Controller setups for d&b amplifiers are available in Dual Channel and/or Mix TOP/SUB mode.

2.3.1 Controller Settings

The functions CUT, HFA, and CPL can be selected for acoustic adjustment.

CUT Mode: Reduces the low-frequency level. The cabinets are configured for use with actively driven d&b subwoofers.

HFA Mode (High Frequency Attenuation): Rolls off the HF response for a natural, balanced frequency response when used in near-field or delay applications. Attenuation begins gradually at 1 kHz, dropping by approximately 3 dB at 10 kHz, mimicking the frequency response decline experienced when listening from a distance in a reverberant room.

CPL Function: Compensates for coupling effects between the cabinet and close boundary surfaces. CPL begins gradually around 1 kHz, with maximum attenuation below 400 Hz. The CPL function can be set to dB attenuation values between 0 and -9 for balanced frequency response. Positive CPL values provide an adjustable low-frequency boost (0 to +5 dB) at around 65 Hz, usable in full-range mode without subwoofers.

Graphs showing frequency response correction in HFA mode and CPL function.

2.4 Dispersion Characteristics

The following graphs illustrate the dispersion angle over frequency for a single cabinet, using lines of equal sound pressure (isobars) at -6 dB and -12 dB.

Isobar diagrams for the 24S in vertical and horizontal setups.

Isobar diagrams for the 24S in horizontal setup with horn rotated and vertical setup.

Isobar diagrams for the 24S-D in vertical and horizontal setups.

Isobar diagrams for the 24S-D in horizontal setup with horn rotated and vertical setup.

Altering the HF Horn Dispersion

By default, the HF horn is fitted to provide the nominal horizontal dispersion for upright cabinet use. A white label on the horn flange indicates this, visible through the front grill.

The HF horn can be rotated by 90°.

Tools required: Torx wrench (#TX20).

1. Undo the torx screws on the top and bottom panels of the cabinet and remove the front grill.
2. Undo the screws holding the horn flange and rotate the horn.
3. Refit the horn: Ensure the gasket is in place, refit the horn, and tighten screws clockwise until they fit precisely into the countersunk holes.
4. Refit the front grill.

Illustration showing how to alter the HF dispersion.

2.5 Technical Specifications

System Data

• Frequency response (-5 dB standard): 55 Hz - 18 kHz
• Frequency response (-5 dB CUT mode): 90 Hz - 18 kHz
• Frequency response (-10 dB standard, IEC60268): 49 Hz - 20 kHz
• Frequency response (-10 dB CUT mode, IEC60268): 63 Hz - 20 kHz
• Max. sound pressure (1 m, free field):
• 24S with 30D/D20: 138 dB
• 24S with 40D/D40/D80: 138 dB
• 24S-D with 30D/D20: 137 dB
• 24S-D with 40D/D40/D80: 137 dB
• (SPLmax peak, pink noise test signal with crest factor of 4)

Loudspeaker Data

• Nominal impedance: 4 ohms
• Power handling capacity (RMS/peak 10 ms): 500/2000 W
• Nominal dispersion angle (horizontal) 24S: 75°
• Nominal dispersion angle (horizontal) 24S-D: 110°
• Nominal dispersion angle (vertical): 45°
• Components: 2 x 12" driver with neodymium magnet, 1.4" exit compression driver on rotatable CD horn
• Passive crossover network
• Connections: 1 x NL4 M, 1 x screw terminal (ST - up to 4 mm²/AWG 11)
• WR option: Faston type connector (2 x 6.3 mm)
• Pin assignment: NL4 M: 1+/1-
• WR option: Brown: (+) / Blue: (-)
• Weight: 33 kg (73 lb)

Graphs showing 24S and 24S-D frequency response in standard and CUT modes.

Cabinet dimensions in mm [inch] for 24S/24S-D.

3 Manufacturer's Declarations

3.1 Conformity of Loudspeakers

This declaration applies to:

• d&b Z1610 24S loudspeaker
• d&b Z1611 24S-D loudspeaker

by d&b audiotechnik GmbH & Co. KG. All product variants are included, provided they correspond to the original technical version and have not been subject to any later design or electromechanical modifications.

d&b audiotechnik declares that these products are in conformity with the provisions of the respective directives, including all applicable amendments. Detailed and applicable declarations are available on request and can be ordered from d&b or downloaded from the d&b website at www.dbaudio.com.

3.2 WEEE Declaration (Disposal)

Electrical and electronic equipment must be disposed of separately from normal waste at the end of its operational lifetime.

Please dispose of this product according to the respective national regulations or contractual agreements. For questions concerning disposal, contact d&b audiotechnik.

WEEE-Reg.-Nr. DE: 13421928