Koss CM-1030 loudspeakers

 

 

The Koss CM/1030 represents the culmination of theory, technology and engineering experience in loudspeaker design. First, Koss engineers set the parameters for frequency response, efficiency and cabinet size. From these initial specifications, the Koss Theory developed specific design characteristics that include a 10-inch woofer, a mass aligned dual port system,, a parallel midrange system, and both a tweeter and treble tweeter that feature a unique acoustic transformer. And to mesh the system into an unbelievably beautiful entity, the CM/1030 uses a quasi second-orede crossover network. Once you've heard the Koss CM/1030 , we think you'll agree that no 4 bandpass system available today even comes close in performance.

 

Although much has been attributed to the speed and efficiency of the modern computer, there is little that any computer can accomplish without first having the specific scientific equations and data necessary to achieve specified goals. In the case of the new Koss CM loudspeaker systems, the modern computer allowed Koss engineers to perform the massive and complex audio engineering calculations required in using network synthesis to establish the engineering parameters for all CM systems.

Nevertheless, whereas the computer may have simplified the workload, it was still the genius of electrical and audio engineers and even, in the case of the cabinet designs, the brilliance of structural engineers, that made this remarkable new generation of loudspeaker systems possible.

 

Specifications

Bandpass Response (to typify the normal listening room situation):

Low Frequency ;  3 dB down point 29 Hz

High Frequency :  3 dB down point 19 kHz

Overall System Response :  6 dB down point 26 Hz to 19,5 kHz

Polar Response:  -3 dB (at 8 kHz);  -6 dB (at 10 kHz)

Intermodulation Distortion Products:  less than 0,1%

Reference Sensitivity:  94 dB SPL

Recommended Amplified Power Rating (8 ohm):  15 watts/channel (minimum); 200 watts/channel (maximum)

Impedance:  5 Ω (nominal), 4 Ω (minimum)

Input Power Overload Protection:  Fused 3 AG 3 A

Dimensions (W x D x H):  16-1/2" x 14-1/2" x 38-7/8"

Weight:  74 lbs

Zenith MC-7050 receiver

Zenith's top-of-the-line stereo receiver, model MC7050, is a tuner/amplifier unit offering 40 watts of RMS power per channel minimum into 8 ohms, over a bandwidth of 20 to 20,000 Hz. The Total Harmonic Distortion is put at 0,2percent or less. A loudness compensation switch automatically increases low and high frequencies for richer sound at low volume levels, while high and low filters eliminate frequency noise at both ends of the sound spectrum. The tuner section  has tuned RF on FM, a ceramic filter to eliminate noise and alternate stations interference, a MOS FET integrated circuit to "Lock In" FM stations and a phase-locked loop MPX integrated circuit to maintain precise phasing of pilot and subcarrier signals on FM for low distortion and good stereo separation. Other features include; tape monitor; tape dubbing; 41-position detent volume control; 11-position detent bass and treble controls; center detent balance control; A/B/A+B speaker selector; FM mute; headphone and microphone jacks; flywheel tuning ; separate tuning and signal strength meters.

Specifications

Power Amp Section

Continuous Power Output:  40 watts pef channel (min. RMS at 8 Ω, from 20 -20,000 Hz, no more than 0,2% Total Harmonic Distortion)

Total Harmonic Distortion (20 Hz to 20 kHz from Aux)

Continuous Rated Power Output :  no more than 0,2%

1 watt per Channel Output

8 Ω :  no more than 0,08%

Intermodulation Distortion (50 Hz : 7,000 Hz = 4: 1, from Aux)

Continuous Rated Power Output:  no more than 0,2%

1 watt per Channel Power Output

8 Ω :  0,05%

Damping Factor (20 Hz - 20 kHz, 8 Ω):  40

Input Sensitivity/Impedance:

Phono 1, 2 :  2,5 mV/50 k Ω

Mic :  2,5 mV/50 k Ω

Aux :  150 mV/50 k Ω

Tape Play :  150 mV/50 k Ω

Phono Overload Level (T.H.D. 0,1%)

Phono :  125 mV 91 kHz)

Output Level/Impedance

Tape Rec :  150 mV

Headphone : low impedance

Frequency Response:

Phono (RIAA equalization) :  30 Hz - 15,000 Hz ±1 dB

Aux, Tape Play :  20 Hz - 20,000 Hz ±1 dB

Tone Controls

Bass :  ±10 dB at 100 Hz

Treble :  ±10 dB at 10 kHz

Filters

High :  -9 dB at 10 kHz

Low :  -6 dB at 100 Hz

Loudness Contour (Vol. Control set at approx. 40 dB position) :  +10 dB at 100 Hz; +5 dB at 10 kHz

Hum and Noise (IHF, short-circuited, A network, Rated Power):

Phono :  75 dB

Aux, Tape Play :  85 dB

FM Section

Usable Sensitivity

Mono : 10,3 dBf (1,8 µV)

Stereo :  19,0 dBf (4,9 µV)

50 dB Quieting Sensitivity

Mono :  14,8 dBf (3,0 µV)

Stereo :  37,3 dBf (40 µV)

Signal-to-Noise Ratio

Mono :  70 dB

Stereo :  65 dB

Distortion at 65 dBf 100 Hz 1 kHz

Mono :  0,1%

Stereo :  0,3%

Frequency Response:  30 Hz - 15 kh ( +0,6 dB -2,0 dB)

Capture Ratio:  1,0 dB

Alternate Channel Selectivity:  70 dB

Spurious Response Ratio:  75 dB

Image response Ratio:  65 dB

IF response ratio:  90 dB

AM Suppression Ratio:  60 dB

Muting Threshold:  19,2 dBf (5,0 µV)

Stereo Separation

At 1 kHz :  45 dB

IHF :  35 dB

Subcarrier product ratio:  60 dB

SCA Rejection Ratio:  65 dB

Antenna Input:  300 Ω (balanced), 75 Ω (unbalanced)

AM Section

Sensitivity

IHF Ferrite Antenna :  200 µV/m

IHF External Antenna :  15 µV

Selectivity:  40 dB

Signal-to-Noise Ratio :  50 dB

Image Response Ratio:  45 dB

IF Response Ratio:  40 dB

Antenna:  Built-in Ferrite loopstick Antenna

Semiconductors:  45 transitors; 27 Diodes; 5 ICs; 1 FET

General section

Power Requirements:  120 V 60 Hz

Power Consumption:  280watts

Dimensions (W x H x D):  19,27" x 14,96" x 5,51"

Weight:  27,5 lbs

Monitor Audio R700MD loudspeakers

The R700MD is a classic case of producing a big, dynamic sound from a small enclosure. It utilizes Monitor Audio's unique metal-dome tweeter technology with an advanced polypropylene bass driver. These two drivers have been specially designed to naturally compliment each other, thus minimum cross over elements are required, ensuring maximum efficiency and minimum distortion. The cabinet also incorporates a port at the rear to reinforce the bass response. The cabinet is internally braced and damped with both bituminous pads and acoustic foam with the front baffle made of medite. The result is a very rigid, dead anclosure. The crossover elements are hardwired and hotglued to their housing to further reduce the effects of vibration.

The size and finish of the R700MD elegantly understates the impressive sound that it is capable of achieving. Cabinet construction and woofer design ensure good bass response whilst the unique tweeter produces a sweetness of high-end detail.

Specifications:

System Type:  2-way, stands designed,  Reflex

Frequency Range:  40 Hz - 20 kHz

Frequency Response:  55 Hz - 20 kHz ±3 dB

Impedance:  8 Ω

Sensitivity:  89 dB

Recommended AAMp. Power:  20 - 100 watts

Dimensions (H x W x D):  350 x 216 x 252 mm

Weight:  6,6 kg

Finish:  Walnut, Oak, Black

Mordaunt-Short MS300 loudspeakers

Unparallelled musical involvement

Like the MS100, the MS300 also employs "pseudo-active" drive but, by using a secondary bass unit and a larger cabinet, it achieves a significant increase in dynamic range and bass extension - adding authority too the vitality of its musical performance. The highly informative character of both the MS100 and MS300 demands use with top quality drive equipment, careful setting up and, preferably, frame stand mounting.

POSITEC Total Overload Protection System

POSITEC is an entirely new, automatic, low cost, protection system, pioneered and optimised by Mordaunt-Short and now fitted to all MS loudspeakers, safeguarding them against accidental overload and equipment malfunctions, in use with amplifiers rated up to 300 watts per channel.

Inaudible during normal use, POSITEC shuts down any drive unit at risk from overload - resetting automatically afterwards.

Specifications

Drive Units:

Low Frequency :  2 x 165 mm cone (MSB165B) Bass

High Frequency :  1 x 12 mm synthetic dome tweeter

Sensitivity:  89 dB at 1W/1m

Max. SPL :  112,5 dB peak

Amp. Recommand:  25-300 watts per channel

Dimensions (H x W x D):  540 x 225 x 245 mm

Finishes:  light Oak or Walnut selected Wood Veneer