RL 901K

RL901K V1
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
    Mid-range unit

400 mm (16") cone
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
    for storage

+ 15°C ... + 35°C (59°F ... 95°F)
- 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
RL 901K Free field frequency response
RL 901K Total harmonic distortions
RL 901K Directional characteristic
RL 901K Gabelständer
Floor bracket stand
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
RL 901K Standfuss
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
RL 901K Wandhalterung
Wall bracket
18° tilting und 25° rotable
Wall bracket black powder-coated
RL 901K Deckenhalterung
Ceiling bracket
Loudspeaker rotable mounted
Standard height between adapter plate and bracket: 300 mm
other length available
Ceiling bracket black powder-coated
Brochure and Documentation
Instructions for installation and use
Comparison of the operation sound level curves of the loudspeakers RL 901 and RL 901K
Installation instructions for floor bracket stand models RL 901K - RL 903
Technical drawings
Technical drawing to the loudspeaker
Technical drawing to the floor bracket stand with details of the standard heights
Technical drawing to the pedestal
Test reports
Offprint to the RL 901K from Produktion Partner 5/2002
Test report to the RL 901K, RL 903K and BASIS 4K
Report to the RL 901K from LINE UP 3/2006