sean5340 Posted February 5, 2015 Share Posted February 5, 2015 I realize the wrms looks better with only two channels driven. I s there a way to figure wrms with all channels driven? Power Output All Channels 125 W (6 ohms, 1 kHz, 0.7%, 2 channels driven) Front L/R 110 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC) 125 W + 125 W (6 ohms, 1 kHz, 0.7%, 2 channels driven, FTC) Center 110 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC) 125 W (6 ohms, 1 kHz, 0.7%, 2 channels driven, FTC) Surround L/R 110 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC) 125 W + 125 W (6 ohms, 1 kHz, 0.7%, 2 channels driven, FTC) Surround Back L/R 110 W (8 ohms, 20 Hz-20 kHz, 0.08%, 2 channels driven, FTC) 125 W + 125 W (6 ohms, 1 kHz, 0.7%, 2 channels driven, FTC) Dynamic Power 250 W (3 ohms, 1 ch) 220 W (4 ohms, 1 ch) 130 W (8 ohms, 1 ch) Quote Link to comment Share on other sites More sharing options...
ricktate Posted February 5, 2015 Share Posted February 5, 2015 The better companies post all channels driven but if it only says 100 for 2 channels you can bet it will be a lot less with 4 channels driven. Rick Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 5, 2015 Share Posted February 5, 2015 (edited) What receiver are you talking about? Normally you can find a bench test somewhere on line. EDIT specs Edited February 5, 2015 by CECAA850 Quote Link to comment Share on other sites More sharing options...
JJkizak Posted February 5, 2015 Share Posted February 5, 2015 You have to have taken a course in "Political Discourse" to understand how they come up to the stated power levels. I just use another AVR to drive the front speakers to get enough balls to get to 98 DB SPL. JJK Quote Link to comment Share on other sites More sharing options...
wvu80 Posted February 5, 2015 Share Posted February 5, 2015 I always thought it was simple math when calculating for an AVR with a single power supply. If you have 100 into 2 channels, then you have 50 into 4 channels. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted February 5, 2015 Share Posted February 5, 2015 (edited) Here is an interesting fact: For example, to sound as loud as a 1 kHz tone at 70 dB SPL, a 40 Hz tone must be at 90 dB. That extra 20 dB is 100 times the power! So if your speakers only need 1 W to produce that 70 dB, 1 kHz tone, then a 40 Hz tone requires 100 W to sound as loud. Wow! What other useless piece of info can I throw out there that adds nothing to what the OP ask? Edited February 5, 2015 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
artto Posted February 5, 2015 Share Posted February 5, 2015 (edited) Mags like Sound & Vision often test the receivers with all channels driven & at different impedance. Just taking the quoted watts per channel and multiplying or dividing it by the number of channels WILL NOT (in most cases) give you an accurate idea of the REAL power output capability per channel. One of the spec's I now look at is "Total Power" / "Maximum Output". Often the manufacturer will rate the power output at say, 125watts RMS/channel, but the Total/Maximum power output is limited to 630 watts, which is equivalent to only 90 watts per channel (7 channels) or 126 watts (5 channels). The Total/Maximum power output is allowed to fluctuate and be distributed among the channels as needed. It is "assumed" that full rated power will never be required at all channels simultaneously, but if it is, the Total/Maximum power output is what you will be limited to at the specified distortion and bandwidth. The other thing to watch out for is how the power was measured. Pioneer for instance often quotes power output at 1KHz, not full bandwidth, or they'll quote very low THD, like 0.003%, but that occurs only at 1KHz, one channel driven, well below the quoted rated power output. Another issue I've come across recently (since I'm in the market for a new A/V receiver) is 4K compatibility, currently not a big issue, but eventually it will be - that's the direction the world is moving. The issue is High-bandwidth Digital Copyright Protection (HDCP). Currently there are only two brands producing receivers that are HDCP2.2 compliant, Sony & Onkyo. If the receiver is not HDCP2.2 compliant it may not allow pass-thru or upscaling to 4k Ultra High Definition from the source. http://www.crutchfield.com/learn/what-you-need-to-know-about-hdcp-2-2.html Edited February 5, 2015 by artto Quote Link to comment Share on other sites More sharing options...
willland Posted February 5, 2015 Share Posted February 5, 2015 I always thought it was simple math when calculating for an AVR with a single power supply. If you have 100 into 2 channels, then you have 50 into 4 channels. That is really not the case because power supplies are not created equal. Bill Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 5, 2015 Share Posted February 5, 2015 (edited) When in doubt, look at the weight of the unit. I know this has been brought up before, but what about the listed amps on the back where the power plugs in. The UL listed amps. Take this 9 channel amp (Onkyo/Integra DTA-70.1) with a listed power output of 150 W/Ch at 8 Ω 20 Hz-20 kHz, 0.05%; 2 Channels driven, FTC. When the UL listed amps on the back is 11.7 amps. 11.7 x 120 = 1404 watts in MAX. 1404 divided by 9 channels is 156 watts per channel. That extra 6 watts could be overhead... In summary, amps on back of unit times 120 volts = total watts it can sustain (non-burst). Have I missed something here?? Edited February 5, 2015 by mustang guy 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 5, 2015 Share Posted February 5, 2015 (edited) Here are the Onkyo/Integra DTR-70.6 Flagship Receiver specs. weight 57 lbs Power Output (8 Ω, 20 Hz-20 kHz, FTC) 135W /Channel (8 Ω) Rated 10.7 amps on back so 120 volts times 10.7 amps = 1284 total watts max available. 1284 watts total divided by 11 possible channels = 116 watts per channel Edited February 5, 2015 by mustang guy Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 5, 2015 Share Posted February 5, 2015 In summary, amps on back of unit times 120 volts = total watts it can sustain (non-burst). Have I missed something here?? Are you assuming 100% efficiency? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 5, 2015 Share Posted February 5, 2015 When in doubt, look at the weight of the unit. That doesn't work like it used to. Quote Link to comment Share on other sites More sharing options...
sean5340 Posted February 5, 2015 Author Share Posted February 5, 2015 The unit I have in question is an Onkyo NR717. The specs listed in the OP is for this unit. Quote Link to comment Share on other sites More sharing options...
Max2 Posted February 5, 2015 Share Posted February 5, 2015 What receiver are you talking about? Normally you can find a bench test somewhere on line. If you're talking about your 3490, it measured 116 wpc with 7 channels driven. Have you got a link for this bench test? Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 5, 2015 Share Posted February 5, 2015 (edited) The unit I have in question is an Onkyo NR717. The specs listed in the OP is for this unit. 6.8 amps on back times 120 volts = 816 watts total available 816 watts divided by 7 channels = 116 watts per channel sustained max not including overhead and efficiency. I'd say the 110 watts is the one for all driven... Edited February 5, 2015 by mustang guy Quote Link to comment Share on other sites More sharing options...
artto Posted February 5, 2015 Share Posted February 5, 2015 When in doubt, look at the weight of the unit. I know this has been brought up before, but what about the listed amps on the back where the power plugs in. The UL listed amps. Take this 9 channel amp (Onkyo/Integra DTA-70.1) with a listed power output of 150 W/Ch at 8 Ω 20 Hz-20 kHz, 0.05%; 2 Channels driven, FTC. When the UL listed amps on the back is 11.7 amps. 11.7 x 120 = 1404 watts in MAX. 1404 divided by 9 channels is 156 watts per channel. That extra 6 watts could be overhead... In summary, amps on back of unit times 120 volts = total watts it can sustain (non-burst). Have I missed something here?? "Have I missed something here??" Yes. Just like the volume control on an amplifier has nothing to do with the actual power output (it's all relative), the same goes for how much current it's drawing. The word "volume" control is a misnomer. It's actually a "gain" control. As the loudness of the sound goes up or down the "gain" stays the same, but the loudness (output) level changes with the input level. An amplifier can easily put out more power than it's designed/rated for, or draw more current than it's rated for. The question then becomes how much, and for for how long, before audible distortion or failure occurs. And that depends on the design and quality of the amplifier. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 5, 2015 Share Posted February 5, 2015 What receiver are you talking about? Normally you can find a bench test somewhere on line. If you're talking about your 3490, it measured 116 wpc with 7 channels driven. Have you got a link for this bench test? I went to find it and can't. I copied and pasted what he had and found a 7 channel receiver. When I did it this time it came up with a 2 channel. I'll try to figure out what I did wrong. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 5, 2015 Share Posted February 5, 2015 The unit I have in question is an Onkyo NR717. The specs listed in the OP is for this unit. Disregard my post with specs then, I screwed up somewhere. I'll delete it now. Quote Link to comment Share on other sites More sharing options...
Max2 Posted February 5, 2015 Share Posted February 5, 2015 What receiver are you talking about? Normally you can find a bench test somewhere on line. If you're talking about your 3490, it measured 116 wpc with 7 channels driven. Have you got a link for this bench test? I went to find it and can't. I copied and pasted what he had and found a 7 channel receiver. When I did it this time it came up with a 2 channel. I'll try to figure out what I did wrong. No sweat. Those numbers would be the most impressive I have seen come out of an HK AVR. Heck, even the Denon and Onk flagships take a pretty good hit once you go from 5 channels to 7. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 5, 2015 Share Posted February 5, 2015 When in doubt, look at the weight of the unit. I know this has been brought up before, but what about the listed amps on the back where the power plugs in. The UL listed amps. Take this 9 channel amp (Onkyo/Integra DTA-70.1) with a listed power output of 150 W/Ch at 8 Ω 20 Hz-20 kHz, 0.05%; 2 Channels driven, FTC. When the UL listed amps on the back is 11.7 amps. 11.7 x 120 = 1404 watts in MAX. 1404 divided by 9 channels is 156 watts per channel. That extra 6 watts could be overhead... In summary, amps on back of unit times 120 volts = total watts it can sustain (non-burst). Have I missed something here?? "Have I missed something here??" Yes. Just like the volume control on an amplifier has nothing to do with the actual power output (it's all relative), the same goes for how much current it's drawing. The word "volume" control is a misnomer. It's actually a "gain" control. As the loudness of the sound goes up or down the "gain" stays the same, but the loudness (output) level changes with the input level. An amplifier can easily put out more power than it's designed/rated for, or draw more current than it's rated for. The question then becomes how much, and for for how long, before audible distortion or failure occurs. And that depends on the design and quality of the amplifier. OK. But still, how can you have a sustained amount of output greater than the total input once the caps are discharged? Quote Link to comment Share on other sites More sharing options...
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