Справочное Руководство для Crown studio reference i

Page 29

Studio Reference 

IIIII & II

  Professional Studio Amplifiers

Crown specifications are guaranteed for three years.

In an effort to provide you with as much information as possible about the high power-producing capabilities of your amplifier,
we have created the following power matrices.

Minimum Guaranteed Power Specifications

Crown’s minimum power specifications represent the absolute smallest amount of output power you can expect from your
amplifier when it is driven to full output under the given conditions. Some spaces in each matrix may be left blank because the
same guarantee is not provided for those conditions—however, your amplifier will perform well under all conditions listed in
each matrix.

When measuring power, 0.1% THD appears to be the industry standard for distortion. Two of the maximum average power
specifications shown in each minimum power matrix are measured at 0.1% THD so you can easily compare Crown specifications
to those of other manufacturers. But this high level of distortion actually allows for some clipping which is undesirable. Because
of this, a maximum average power specification at 0.05% THD is included in each minimum power matrix which represents non-
clipped conditions. Also, power at 0.02% THD is provided in the preceding specifications. Although most manufacturers do not
give power specifications at 0.05% or 0.02% THD, we encourage them to provide these specifications so you will have a more
realistic representation of the way amplifiers should be used in the real world—without a clipped output signal.

Many manufacturers publish power specs with a tolerance of ±1 dB or worse. This means their amplifier can deviate more than
20% in output! A 100 watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturers qualify
their specs by saying they are “typical,” “subject to manufacturing tolerances,” “single channel driven” or that they are specified
with “fuses bypassed.” Each of these statements effectively removes any performance guarantee. In fact, some manufacturers
use these tactics to generate large power numbers, and they don’t even print a disclaimer. We take a different approach at
Crown—our amplifiers are 

guaranteed to meet or exceed their specifications for three years. Further, because our published

8

Studio Reference I – 

(both channels

driven)

(balanced output)

16

4

FTC Continuous Average

0.1% THD + Noise

(See note 4)

1 kHz

20Hz-20kHz

750

1,490

785

1,575

1,565

Maximum Average

Load (Ohms)

1 kHz

0.1% THD+N

(See note 1)

0.1% THD+N

(See note 2)

1,190

800

2,375

1,595

2,350

1,580

20Hz-20kHz

1,075

760

2,150

1,535

4

2

8

8

16

4

715

1,440

750

1,515

1,490

1,095

750

2,200

1,515

2,185

1,500

970

725

1,985

1,440

0.05% THD+N

(See note 3)

1 kHz

1,170

790

2,335

1,580

2,320

1,565

1,075

745

2,160

1,495

2,175

1,480

4

2

8

(balanced output)

(both channels

driven)

8

16

4

795

1,595

820

1,660

1,640

1,255

825

2,505

1,660

2,485

1,655

1,135

820

2,280

1,610

1,255

815

2,460

1,645

2,475

1,640

4

2

8

(balanced output)

(both channels

driven)

Fig. 6.1  Studio Reference 

I Minimum Power Matrix

specs are set below our “in-house” mea-
surements, you can expect 

every Crown

amplifier to 

exceed its published minimum

power specs. We believe you should get
what you pay for.

Minimum Power Notes:
All minimum power specifications are based on
0.5% regulated AC mains with THD of less than
1.0% and an ambient room temperature of 70° F
(21° C). Standard EIA power (RS-490) is not shown
here because it is identical to FTC Continuous
Average Power.

1. A 1 kHz sine wave is presented to the ampli-

fier and the output monitored for nonlinear dis-
tortion. The level is increased until THD
reaches 0.1%. At this point, average power
per channel is reported.

2. A sine wave is presented to the amplifier over

the range from 20 Hz to 20 kHz and the output
monitored for nonlinear distortion. The level at
each frequency is increased until THD reaches
0.1%. At this point, average power per chan-
nel is reported.

3. A 1 kHz sine wave is presented to the ampli-

fier and the output monitored for nonlinear dis-
tortion. The level is increased until THD
reaches 0.05%. At this point, average power
per channel is reported.

4. Continuous power in the context of Federal

Trade Commission testing is understood to be
a minimum of five minutes of operation. Har-
monic distortion is measured as the RMS sum
total and given as a percentage of the funda-
mental output voltage. This applies for all watt-
ages greater than 0.25 watts.