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XLS 202/402 Exact Watts RMS


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#1 Stevep

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Posted 06 June 2006 - 10:57 AM

Purchased two XLS 202 and two XLS 402 for home stereo. I need to know the exact watts RMS for these amps. The Crown website shows one rating, then the box that the amps are shipped in say another. I checked several forums etc., but cannot seem to get a exact number for the amps.... help, have not purchased speakers yet since I'm not exactly sure of RMS ratings....... I realize it is not that important to be exact and more is better for headroom, but I would really like to know........ Thanks

#2 DGlass

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Posted 06 June 2006 - 01:09 PM

The reason there are two ratings is the new XLS Dseries has had an overhall and redesign so the power specs have improved.

Original XLS series models
202 145w/ch 8-0hms, 200w/ch 4-ohms, 250w/ch 2-ohms
402 260w/ch 8-0hms, 400w/ch 4-ohms, 570w/ch 2-ohms
602 370w/ch 8-0hms, 600w/ch 4-ohms, 640w/ch 2-ohms

XLS Dseries
202D 200w/ch 8-0hms, 300w/ch 4-ohms, 330w/ch 2-ohms
402D 300w/ch 8-0hms, 450w/ch 4-ohms, 570w/ch 2-ohms
602D 380w/ch 8-0hms, 600w/ch 4-ohms, 840w/ch 2-ohms
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#3 crackers8199

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Posted 06 June 2006 - 05:20 PM

I read that the rating on these amps is only at 1KHz, and that you should look for ratings at 20Hz - 20KHz...where do I find these or how are they calculated?

#4 DGlass

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Posted 08 June 2006 - 09:12 AM

QUOTE(crackers8199 @ Jun 6 2006, 05:20 PM)
I read that the rating on these amps is only at 1KHz, and that you should look for ratings at 20Hz - 20KHz...where do I find these or how are they calculated?
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Exact Wattage RMS is relative to the testing proceedure being used. There are two standards for amplifier output ratings the FTC and EIA ratings standards.
The FTC standard was established by the Federal Trade Commission and requires that a manufacturer’s stated power ratings must meet the advertised frequency range (usually 20 Hz to 20 kHz) at the rated THD (Total Harmonic Distortion) with both channels driven.
The EIA rating, established by The Electronic Industries Association, is the power output of a single channel driven at typically 1 kHz with 1% THD clipping. The EIA standard will typically be 10 to 20% higher than the FTC ratings.
We go one step further than the EIA ratings and drive both channels as we feel the fairest, most honest, and most revealing rating method is the obvious one: to specify power with all channels fully driven, as this is a more real world scenario. When fewer channels are being tested, the more power the ones that aren’t being used can deliver. This can artificially increase the apparent power output. By testing with both channels driven we are decreasing the the 10-20% difference  between the two power rating methods when only one channel driven.
What does a 10-20% power difference mean in reality? For an average person to hear a difference in loudness/level, you would need to double the power output of an amp to the speakers. You can hear the difference between 200 and 400 watts, a 3 dB increase or doubling of power, but you won’t hear a difference between 200 watts and 240 watts as small difference in output power are not discernable to the human ear.
To put it in a nut shell we basically provide a more conservative power spec of the EIA standard because we test with both channels driven during our tests not just one.  smile.gif