RL 901K

3-way-coaxial-loudspeaker with cardioid characteristic in bass range

The RL 901K has been designed for both the professional user at medium-size to large audio, video and film studios and for the discerning music enthusiast.

(shown veneer: american cherry nature)

RL 901K

The RL 901K has been designed for both the professional user at medium-size to large audio, video and film studios and for the discerning music enthusiast.

By the radiating characteristic within the frequency range from 30 through 250 Hz the reflections on the back walls of listening rooms can be minimized. The transfer characteristic can be matched to the acoustical conditions of the reproduction room as well as to the set-up situation by a low-frequent infinitely variable adaptation within two adjustable frequency ranges.

The unit for the medium and high-frequency range is combined in a coaxial manner with a long-throw 16-inch bass system and is provided with a directivity index, which supplements in an excellent way that of the bass system. The total directivity index of the monitor was optimized for middle through larger listening distances between 2 and 4 metres. The whole system is superior by excellent localization behaviour. The high-power long-throw bass system is driven in a compact cabinet so that optimum impulse behaviour can be reached. Moreover, with a series of constructional measures we have provided that convincing lowest values of non-linear distortions and colorations could be reached.

The three-channel MOSFET power amplifier with electronic crossover is integrated within the back wall of the cabinet and can be swing out for service purposes. An intermittent LED lighting signals when the overload limit is reached. After crossing of the maximum level the output level will be reduced by 20 dB to avoid any overloading of the components.

A variety of special stands and racks is available as accessories. According fixing elements have been integrated into the loudspeaker cabinet.


active 3-way-monitor for listening distances between 2 and 4 m

Maximum SPL
from 100 Hz ... 6 kHz

116 ... 122 dB / r = 1 m (3.3 ft)


25 Hz ... 20 kHz ± 3 dB

Acoustic output level / PE = - 14 dBu

89 dB / r = 1 m (3.3 ft)

Directivity index
from 200 Hz ... 10 kHz

increasing from 5 to 10 dB

Inherent noise sound level

≤ 7 dB (A) / r = 1 m (3.3 ft)

Total harmonic distortion
measured at 96 dB / r = 1 m (3.3 ft)
from 100 Hz ... 10 kHz

≤ - 44 dB

Nominal Input level

+ 6 dBu adjustable

Input impedance

≥ 10 kOhm RC balanced

Electronic Crossover frequencies

550 Hz and 2.8 kHz

Nominal output power MOSFET-amplifier

180 Watt / 4 Ohm
100 Watt / 4 Ohm
100 Watt / 4 Ohm

Input Connector


Loudspeaker systems

400 mm (16") cone
Mid-range unit
125 mm (5") cone
25 mm (1") dome

Operation and Clipping indicator

LED on front side

Power requirements

230 Volt ~ ± 10 %, 50 Hz ... 60 Hz
115 Volt ~ ± 10 %, 50 Hz ... 60 Hz (optional)
100 Volt ~ ± 10 %, 50 Hz ... 60 Hz (optional)

Power consumption

35 VA at standby
max. 300 VA at full load

Mains Connection

IEC power connector

Dimensions (H x W x D)

550 x 500 x 430 mm (21.6 x 19.7 x 17 in)


48 kg (105.6 lbs)

Temperature requirements

for use
+ 15°C ... + 35°C (59°F ... 95°F)
for storage
- 25°C ... + 45°C (- 13°F ... 113°F)
45 ... 75 %

Design of the Cabinet

MDF-wood in ash black veneered; optional different veneers or colors
with holding device; optional without holding device
with handles; optional without handles

Floor bracket stand RL901K

  • Loudspeaker rotable mounted
  • Deliverable heights (Top edge loudspeaker): 1310 mm (51.6 in), 1425 mm (56.1 in), 1565 mm (61.6 in) and 1775 mm (69.9 in)
  • Base panel (W x D): 620 mm x 550 mm (24.4 in x 21.7 in)
  • Base panel and stabilisation panel veneered
  • Racks black powder-coated

Pedestal RL901K

  • Integrated cable duct in the pedestal
  • Height (Top edge loudspeaker): approx. 1200 mm (47.2 in)
  • Base panel (W x D): 500 mm x 430 mm (19.7 in x 16.9 in)
  • Pedestal veneered

Wall bracket RL901K

  • 18° tilting und 25° rotable
  • Wall bracket black powder-coated

Ceiling bracket RL901K

  • Loudspeaker rotable mounted
  • Standard height between adapter plate and bracket: 300 mm
  • other length available
  • Ceiling bracket black powder-coated

Standard veneer ash black (RAL9005), optional veneers and optional colours

We offer our loudspeakers in standard veneer ash black (RAL9005) or for an additional charge in different optional veneers respectively optional colours. This website provides an overview on the optional veneer and lacquer styles. We are pleased to check if your desired individual veneer and colour can be realised.

Important information about deviations from sample pattern

Wood is a natural product. Even the most thorough manufacturing can result in deviations in colour or structure and is no cause for complaint.
Images are represented differently on every screen and hence not colour-proof.