Si realmente dan los mismos vatios reales en banco de pruebas (no te fíes de lo que los fabricantes declaran) van a dar exactamente la misma potencia. Pura física. la diferencia de potencia implica diferencia en el SPLmax que podremos alcanzar con una misma caja que soporte la potencia del que más; no implica en sí mayor calidad de sonido).
cvasit odos los A/V del mecado gama baja (típicos de yamaha; pioneer; denon, etc) dan con todos los canales excitados a 8 OPhmios unos 30/35W; en estéreio suelen dar más de 60W. Los modelos de series "medias" ya suelen entregar con todos mlos canales excitados de 45/80W (dependiendo del modelo); y en estéreo muchos oscilan enrte 90W/140W reales). Esas potencias que comento se dan a 0dB cvuando el sistema está calibrado para que 0dB sea su máxima potebcia (potencia que bajará a la mitad cada vez que reduzcamos el volumen 3dB). Un diferencia que puede llevar a engaño por efecto placebo (desconocimiento del aficionado) entre la potencia de dos amplificadores, es que no utilicen el mismo tipo de distribución de la misma en el potenciómetro (pudiendo dar en algunos casos mismas potencias reañes a recorridos diferentesde potenciómetro... cuando a tope darían exactamente la misma potencia).
Por ejemplo:
- un A/V Marantz SR8002 (2000$ cuando se analizó) da esta potencia máxima real en banco de pruebas según los canales excitados:
Marantz SR8002 A/V Receiver Measurements | Sound & VisionThis graph shows that the SR8002’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 174.1 watts and 1% distortion at 187.4 watts. Clearly, the distortion level is very flat across all power outputs until it gets to about 155 watts. Into 4 ohms, the amplifier reaches 0.1% distortion at 231.9 watts and 1% distortion at 271.5 watts.
With five channels driven continuously into 8-ohm loads, the receiver reaches 0.1% distortion at 119.0 watts and 1% distortion at 133.8 watts. With all channels driven continuously into 8-ohm loads, it reaches 0.1% distortion at 109.1 watts and 1% distortion at 117.7 watts. The power specs do not specify the number of channels driven, but at 125Wpc into 8 ohms with less than 0.08% THD, they are not far off the mark.
Aquí la potencia real de un yamaha 775 (850$ cuando se analizó) en el mismo banco de pruebas según los canales que tengamos excitados:
Audio: The graph shows the RX-V775WA’s left channel, from Audio1 input to speaker output with two channels driving 8-ohm loads. Measurements for THD+noise, crosstalk, signal-to-noise ratio, and analog/digital frequency response were all within expected performance parameters.
0.1% THD 1.0% THD
2 Channels Continuously Driven, 8 ohm loads 122.8 watts 147.5 watts
2 Channels Continuously Driven, 4 ohm loads 149.7 watts 181.9 watts
5 Channels Continuously Driven, 8 ohm loads 38.2 watts 55.2 watts
7 Channels Continuously Driven, 8 ohm loads 32.2 watts 41.3 watts
http://www.soundandvision.com/conten...ver-test-bench
Aquí un A/V Arcam (6000$ cuando se analizó) donde puedes ver la potencia máxima a misma THD dependiendo de los canales excitados con el mismo banco de pruebas:
http://www.soundandvision.com/conten...ver-test-bench0.1% THD 1.0% THD
2 Channels Continuously Driven, 8 ohm loads: 132.0 watts 163.9 watts
5 Channels Continuously Driven, 8 ohm loads: 93.8 watts 124.7 watts
7 Channels Continuously Driven, 8 ohm loads: 86.1 watts 106.6 watts
Analog frequency response in Stereo Direct mode:
–0.04 dB at 10 Hz
–0.01 dB at 20 Hz
+0.04 dB at 20 kHz
–2.75 dB at 50 kHz
Analog frequency response with signal processing:
–0.51 dB at 10 Hz
–0.14 dB at 20 Hz
–0.17 dB at 20 kHz
–13.18 dB at 50 kHz
-Aquí un Denon AVR-E400 (599$ cuando se analizó) que da esta potencia según canales excitados por el mismo banco de pruebas:
Audio: This graph shows the AVR-E400’s left channel, from CD input to speaker output with two channels driving 8-ohm loads.
0.1% THD 1.0% THD
2 Channels, 8 Ohms 103.0 watts 116.5 watts
2 Channels, 4 Ohms 93.3 watts 166.4 watts
5 Channels, 8 Ohms 70.0 watts 84.7 watts
7 Channels, 8 Ohms 62.3 watts 69.5 watts
Analog frequency response in Pure Direct mode:
–0.05 dB at 10 Hz
–0.00 dB at 20 Hz
+0.01 dB at 20 kHz
–2.80 dB at 50 kHz.
Analog frequency response with signal processing:
–0.33 dB at 10 Hz
–0.10 dB at 20 Hz
–0.19 dB at 20 kHz
–15.92 dB at 50 kHz.
There was no multichannel input to measure. THD+N from the CD input to the speaker output was less than 0.011% at 1 kHz when driving 2.83 volts into an 8-ohm load. Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –75.20 dB left to right and –78.06 dB right to left. The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –109.43 dBrA.
From the Dolby Digital input to the loudspeaker output, the left channel measures –0.01 dB at 20 Hz and –0.14 dB at 20 kHz. The center channel measures –0.01 dB at 20 Hz and –0.15 dB at 20 kHz, and the left surround channel measures –0.02 dB at 20 Hz and –0.07 dB at 20 kHz. From the Dolby Digital input to the line-level output, the LFE channel is +0.01 dB at 20 Hz when referenced to the level at 40 Hz and reaches the upper 3-dB down point at 109 Hz and the upper 6-dB down point at 116 Hz.—MJP
En dicho banco de pruebas puedes encontrar la potencia real comparativa entre muchos amplificadores a igualdad de THD y canales excitados (es decir, la potencia real que dan en idénticas condiciones)
Un saludete



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