Crown Audio STUDIO AMPLIFIER owner manual Minimum Guaranteed Power Specifications, Page

Studio Reference I & 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

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

Studio Reference I – Minimum Guaranteed Power (Watts)

Mains		(Ohms)	Maximum Average			FTC Continuous Average
	Stereo/Mono		0.1% THD+N	0.1% THD+N	0.05% THD+N	0.1% THD + Noise
	Mode		(See note 1)	(See note 2)	(See note 3)	(See note 4)
AC		Load
			1 kHz	20Hz-20kHz	1 kHz	1 kHz	20Hz-20kHz
	Stereo	4	1,190	1,075	1,170
	(both channels
Hz		8	800	760	790	785	750
	driven)
60	Bridge-Mono	8	2,375	2,150	2,335
VAC,
	(balanced output)	16	1,595	1,535	1,580	1,575	1,490
120	Parallel-Mono	2	2,350		2,320
		4	1,580		1,565	1,565
	Stereo	4	1,095	970	1,075
	(both channels
Hz		8	750	725	745	750	715
	driven)
50	Bridge-Mono	8	2,200	1,985	2,160
VAC,
	(balanced output)	16	1,515	1,440	1,495	1,515	1,440
100	Parallel-Mono	2	2,185		2,175
		4	1,500		1,480	1,490
	Stereo	4	1,255	1,135	1,255
	(both channels
Hz		8	825	820	815	820	795
	driven)
50	Bridge-Mono	8	2,505	2,280	2,460
VAC,
	(balanced output)	16	1,660	1,610	1,645	1,660	1,595
240	Parallel-Mono	2	2,485		2,475
		4	1,655		1,640	1,640

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.

Fig. 6.1 Studio Reference I Minimum Power Matrix

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