The Klein + Hummel O 300 is a monitor which draws upon all of Klein + Hummel's years of experience in monitor design, which has been fine-tuned through extensive computer simulations and countless listening tests. It is indeed unique in its class, for it does in fact deliver superlative sound absent of colorations, precise bass response, picture-perfect dispersion patterns, and a stunningly real soundstage with remarkable image focus and depth.
The advantages of the three-way system
To authentically re-create the sound captured in a recording-particularly a recording of the human voice-an active three-way system was chosen. In comparison with two-way monitors, the 300 offers clear advantages that have been discussed in detail earlier in this catalog. The sophisticated three-way design employed in the O 300 makes this loudspeaker system extremely precise and revealing of detail, and it enables the mixing engineer to make critical judgments with supreme confidence.
Exact localization and extraordinary sense of space
By utilising a dense, new, extremely low-resonance material called LRIM, we were able to mould the waveguides required for optimal dispersion directly into the baffle. The elliptical shape of the high-frequency horn makes the dispersion angle in the vertical plane more narrow thus reducing the amount of early reflections off the console surface which would otherwise interfere with the direct sound from the speakers (comb-filter effects), thereby improving spatial definition. At the same time, the effective horizontal listening area is made wider, giving the recording engineer greater freedom of movement in front of the console. The use of LRIM has also made it possible to align the acoustic centers of the two drivers exactly on one plane, parallel to the baffle, thereby preventing time and phase coherency problems at the crossover frequencies. This allows the individual drivers to work together perfectly to produce a precisely detailed soundstage.
Superb sonic qualities
For a loudspeaker system to achieve extremely flat frequency response and create an authentic reproduction of the original sound, its components need to be of very high quality, carefully manufactured, and selected for their compatibility with one another.
The 8Â¼" (210 mm) cone woofer is made of a special lightweight polypropylene material that has excellent self-damping properties. Its long-excursion voice coil enables this driver to produce very low frequencies at high sound pressure levels with practically no distortion. In contrast to common bass-reflex systems, which tend to blur the low end, the acoustic suspension system of the O 300 D delivers tight, articulate bass which is strikingly clear, detailed, and natural, particularly in transients.
The midrange is handled by a treated fabric dome with a dia-phragm/voice coil of 3" (76 mm) in diameter. Since its mass is much lower than that of cone drivers, it has the advantage of being able to achieve superior impulse response and extremely uniform amplitude response. As a result, midrange reproduction is impressively true-to-life, especially with the human voice.
The high-frequency driver is equipped with a titanium/fabric dome that combines the transparency of a titanium dome with the low distortion of a fabric dome. This driver has been finely matched to its elliptical waveguide, ensuring exceptional directivity.
All three drivers are magnetically shielded, allowing you to place the speakers directly next to video monitors or computers.
The O 300 includes very flexible room-matching circuitry to alter the amplitude response of the monitor as needed, depending on speaker placement, in multiple steps and in three critically relevant frequency ranges. This flexibility can be instrumental in turning less than ideal room acoustics into a favorable listening environment.
Each of the three drivers in the O 300 is powered by a high-performance amplifier that is exactly matched to the driver's technical requirements and which embodies Klein + Hummel's long years of audio experience. Precisely tuned electronic crossovers help provide proverbial operational reliability and high amplifier output with minimal distortion.
The monitor is equipped with effective protection circuitry designed to allow impulse peaks through and to respond with limiting only when a voice coil is in danger of thermal overload or a power amplifier runs the risk of overheating. Activation of the limiter is indicated by blinking of the illuminated K + H logo.
Future-proof digital input
The O 300 is equipped with switchable inputs for analog signals and digital signals in both AES/EBU and S/P-DIF formats. The D/A converter incorporates the latests technology, has a wide dynamic range, 24-bit resolution, and accomodates sampling rates from 32 to 96 kHz.
The analog input of the O 300 is tranformer-balanced and floating, utilising a superior quality transformer that, even at high volume levels and the lowest frequencies, helps achieve extremely low distortion.
The input sensitivity of +6 dBu allows you to connect all standard studio signal sources.
Unique: separate inputs for external processing
A special connector included as standard equipment on the back of the O 300 D gives you direct access to each of the three power amplifiers. This unique feature enables you to use an external digital controller Pro C 28 to modify the response to compensate for amplitude and phase anomalies resulting from the monitor's placement in the room or the particular acoustic conditions of the studio. While this type of acoustical optimization will require the appropriate experience and equipment, it is certainly more economical than a structural renovation of the studio.
Solid MDF enclosure, award-winning design
The monitor stands out not only for its sound but also for its attractive, modern design, and in fact received an international design award in 1998. The sides of the cabinet are constructed of low-resonance MDF wood, and the front baffle is moulded of dense LRIM. The cabinet is available in either a charcoal-gray enamel finish or a rugged dark-gray nylon-fiber nap. The attractive metal grille is the final touch.
Sophisticated 3-way system
The most important frequency spectrum lies in the ideal broadcast zone of the loudspeaker
Extremely low-distortion reproduction
Exceptionally neutral sound stage from 40 Hz to 20 kHz
No standing waves in enclosure
No partial coloration
No comb-filter effect
Unconventional enclosure concept
Very compact enclosure constructed of advanced materials
Avoidance of resonance via combination of MDF and LRIM (Low Resonance Integral Moulding)
Very accurate bass reproduction via sealed enclosure
Precision centers of loudspeaker are on one plane
Homogenous baffle with no diffraction or fastening elements and with excellent self-damping properties
Extremely wide effective listening area for main monitor via horizontal installation
Numerous installation possibilities
Optional baffle cover/grill
Dispersion is horizontally wide
Increased freedom of movement at mixing console
Vertically narrow sound dispersion reducing early reflections off console surface
Perfect dispersion pattern
Integrated electronic limiter for each driver
Active crossover equalizer with 24 dB/oct.
AF-input equipped with minimal distortion input circuit
Power and overload/limiter-display integrated into Klein + Hummel logo
3 x 4 room-matching circuitry for different placement options
-3 dB free field frequency response 35 Hz - 24 kHz, Â± 3 dB
Pass band free field frequency response 40 Hz - 20 kHz, Â± 2 dB
Self generated noise level at 10 cm < 20 dB(A)
THD < 0,5% at 1 m distance from 95 dB SPL (> 100 Hz)
Max. SPL in half space at 3% THD in 1m 112.8 db SPL
Max. SPL averaged between 100 Hz and 6 kHz
Woofer amplifier, cont. output power (THD < 0.1%) 150 W
Woofer amplifier, peak output power 250 W
Midrange amplifier, cont. output power (THD < 0.1%) 65 W
Midrange amplifier, peak output power 75 W
Tweeter amplifier, cont. output power (THD < 0.1%) 65 W
Tweeter amplifier, peak output power 110 W
Controller design Analog, acive
Crossover - Frequency 650 Hz / 3.3 kHz
Crossover - Slope 24 dB/oct
Equalization - Bass 0; -3; -6; -9 dB
Equalization - Mid +2; 0; -2; -4 dB
Equalization - High +2; +1; 0; -1 dB
Protection circuitry Limiter: low, mid, high
Subsonic filter: frequency/slope 30 Hz; 6 dB/oct
Impedance, bal. floating XLR, 14 kOhms, optional
Input sensitivity +6 dBu
Max. input level +20 dBu (7.8 Vrms)
Gain Control 0 ... - 28 dB
CMRR > 60 dB @ 15 kHz
Displays, indicators - power on K + H logo "red"
Displays, indicators - limit / clip K + H logo "blinking"
Mains 230 V; 120 V; 100 V AC
Power consumption - idle 18 W
Power consumption - full output AC; DC 240 W
Cabinet surface Painted
Color standard Anthracite (RAL 7021), silver (RAL 9006)
Special (add-on price) On request
Baffle cover Optional removable metal grille
Drivers Magnetically shielded
Woofer 210 mm (8")
Midrange 76 mm (3")
Tweeter 25 mm (1")
Mounting points 2 x M8 on sides, rear panel bracket
Height x width x depth 253 x 383 x 290 mm (10" x 15.1" x 11.4")
Net volume internal 18.3 liters
Weight 14 kg (30.8 lbs)
1x O 300
1x Power cord
1x Operation manual