AVR Power Output Comparison

[fuzz092888]

I would hazard a guess that for receiver type power the variation is somewhere in the 15-25% range. At least for the few I've seen that list both, that's usually approximately the disparity between 1khz and 20-20.

 

[Steve81]

ADTG, don't listen to him, he is just being funny/tricky. /// Pyrrho's point/math is still valid.

I do have that ugly tendency Actually I wasn't trying to address Pyrrho's post (I didn't read it till now ), just showing how a receiver can run out of gas quicker than anticipated running 5 channels versus 2.

 

[Steve81]

Are those people claiming that it can't put out any power into 5 channels at once (not even 1 watt per channel?), or are they not smart enough to be able to measure it, or is there something else going on?

Taking a wild guess, it's possible they weren't able to get a repeatable result.

 

[PENG]

So do you think HTM screwed up with the Yamaha 473 going into protection mode in 5 CH? Or the 573 getting only 25 WPC in 5Ch?

Not screwed up, they may just did not bother to tell us the details. I am quite sure the AVR can deliver more than 25X5, probably at least 40X5 but protection mode might have gotten a little aggressive when it sensed something had got to be wrong for all 5 channels to be outputting 25W at the same time. Just my educated gues, but if I were the design engineer, I would definitely consider that kind of intelligent algorithm.

 

[PENG]

I do have that ugly tendency Actually I wasn't trying to address Pyrrho's post (I didn't read it till now ), just showing how a receiver can run out of gas quicker than anticipated running 5 channels versus 2.

Understood, and I must admit, your math is highly creative to the point it is also convincing at first glance, are you an accountant?

 

[Steve81]

are you an accountant?

It's like you have some sort of insight into my secret identity

 

[Steve81]

if I were the design engineer, I would definitely consider that kind of intelligent algorithm.

Ditto. I'd imagine it helps with warranty claims/reliability if you can't abuse the thing too badly.

 

[Steve81]

generally, how much more wattage does one get when fudging from a 20-20khz rating to a 1khz rating?

I don't know that it's possible to generalize, but a graph like this might give you some ideas.

 

[mike c]

I don't know that it's possible to generalize, but a graph like this might give you some ideas.

hmmm, can you break that down "like i'm a 5 year old"

 

[Steve81]

hmmm, can you break that down "like i'm a 5 year old"

I'll do my best The above graph represents a sweep by frequency for two fixed drive levels into 8 ohms, i.e. 5V (3.125W @ 8 ohms) and 20V (50W @ 8 ohms). This is a bit different from a continuous full power bandwidth test as run here at AH in that you're basically looking at how much distortion you'd get with pure tones at 3W and 50W respectively into 8 ohms, i.e. 50W @ 20kHz yields about 0.3% THD+N. While obviously not a real world scenario, it still gives a starting point as to how an amplifier performs across its full operating bandwidth.

With respect to the CFP-BW test, I'm not 100% sure of how its structured (and it may well vary between how its run here vs by manufacturers such as Onkyo), but my educated guess is that its running something similar to pink noise in that the signal has equal power from octave to octave. As 5kHz-20kHz represents only two octaves, its effect on the final number will be mitigated a bit from what you see in that graph. The effect of that top end rise may be further cut depending on the bandwidth chosen to measure distortion. If you're cutting things off at 20kHz, then harmonic distortion for content beyond 10kHz doesn't enter into the equation at all.

With any luck, all this makes some sense at 3:30 in the morning and I'm not just a rambling loon.

 

[ichigo]

It's worth noting that hometheater.com measures their receivers at 1KHz. They've done full range tests before on a few of their receivers. Their Marantz SR9600 review for example showed 133 watts per channel in the ACD test at 1KHz, but only 61 WPC when they ran the same test at 20Hz. Low bass is brutal on amplifiers.

Audioholics also used to run full sweeps.

Their numbers for example are:

Yamaha RX-Z11 20-20KHz: 172 W x 2 @ 8 ohms | 256 W x 2 @ 4 ohms.
Denon 5308CI 20-20KHz: 150 W x 2 @ 8 ohms | 220 W x 2 @ 4 ohms

This is much lower than Hometheater.com's rating's which are about 25-35% higher.

 

[PENG]

Ditto. I'd imagine it helps with warranty claims/reliability if you can't abuse the thing too badly.

Kidding aside, I thank you for bringing up an excellent point. We can play with numbers just for fun, but at the end of the day there are things that may not be what it seems to be on surface. In your example, it does show that 100WX5 is not necessarily exactly the same as 500WX1 for the power supply (an exaggerated example just to make a point, not a practical one at all). That's why some of us go to engineering school, but not all of those who went, has your kind of insight and thoughful nature to clearly grasp the basic concepts.

 

[PENG]

It's worth noting that hometheater.com measures their receivers at 1KHz. They've done full range tests before on a few of their receivers. Their Marantz SR9600 review for example showed 133 watts per channel in the ACD test at 1KHz, but only 61 WPC when they ran the same test at 20Hz. Low bass is brutal on amplifiers.

Where did you see that? I read that HTM review must have missed that point. By the way, HTM typically provide their numbers for 0.1% and 1% THD+N. I would compare the 0.1% numbers with AH's and see if they get closer. In any case even 25% isn't too bad consider the measurements are taken in different labs, lots of little things can add up to result in their kind of variance.

 

[ichigo]

Where did you see that? I read that HTM review must have missed that point. By the way, HTM typically provide their numbers for 0.1% and 1% THD+N. I would compare the 0.1% numbers with AH's and see if they get closer. In any case even 25% isn't too bad consider the measurements are taken in different labs, lots of little things can add up to result in their kind of variance.

Driving seven channels into 8Ω, the Marantz delivered 61Wpc at 20Hz and 133Wpc at 1kHz (to the nearest watt) before clipping (1% THD+noise).

The Marantz SR9600 THX Ultra 2 AV Surround Receiver Measurements | Home Theater

 

[mike c]

I'll do my best The above graph represents a sweep by frequency for two fixed drive levels into 8 ohms, i.e. 5V (3.125W @ 8 ohms) and 20V (50W @ 8 ohms). This is a bit different from a continuous full power bandwidth test as run here at AH in that you're basically looking at how much distortion you'd get with pure tones at 3W and 50W respectively into 8 ohms, i.e. 50W @ 20kHz yields about 0.3% THD+N. While obviously not a real world scenario, it still gives a starting point as to how an amplifier performs across its full operating bandwidth.

With respect to the CFP-BW test, I'm not 100% sure of how its structured (and it may well vary between how its run here vs by manufacturers such as Onkyo), but my educated guess is that its running something similar to pink noise in that the signal has equal power from octave to octave. As 5kHz-20kHz represents only two octaves, its effect on the final number will be mitigated a bit from what you see in that graph. The effect of that top end rise may be further cut depending on the bandwidth chosen to measure distortion. If you're cutting things off at 20kHz, then harmonic distortion for content beyond 10kHz doesn't enter into the equation at all.

With any luck, all this makes some sense at 3:30 in the morning and I'm not just a rambling loon.

if that was your explanation to a 5yo. i don't know how you explain to EE's.

 

[Steve81]

if that was your explanation to a 5yo. i don't know how you explain to EE's.

Alright let me try again

The pretty yellow line shows how many cooties there will be by frequency with ~3 watts of output from the black shiny box. The red line is the same except at 50 watts.

 

[Steve81]

A little more to chew on:

Price	Make/Model	8 Ohm, 2 Ch	4 Ohm, 2 Ch	8 Ohm, 5 Ch
$9,000	Classe CT-5300	434.8	190*	322.1
$8,095	Bryston 9B SST2	151.3	245.5	148.7
$7,500	Denon POA-A1HDCI	197.2	318	188.2
$5,899	Earthquake Cinenova Grande	374.4	564.7	329.6
$5,699	ADA PTM-8150	187.7	268.5	138.8**
$5,000	Anthem Statement P5	400	642	383
$3,995	Cary Model 7.125	158.6	313.1	148.5
$3,295	Butler TDB 5150	250.5	393.7	227.2**
$2,999	NAD M25	259.5	484.6	230.7**
$2,800	Sherbourn PA-7-350	488.3	746.9	356.3
$2,799	Rotel RMB-1575	319.9	510	317.9
$2,500	Parasound 5250	325.6	546	298.1
$2,499	Rotem RMB-1077	133	257	118.0**
$2,499	Audiocontrol Savoy	255.3	413.8	178.4**
$2,399	Marantz MM8077	150.3	241.8	125.4
$2,299	Arcam P1000	237	359	173**
$2,000	Emotiva MPS-1	187	280	175**
$1,999	Anthem MCA50	232.3	378.1	222.8
$1,800	Integra DTA-70.1	177.7	266.7	137.7
$1,599	Outlaw Model 7500	342.3	492.8	301.1
$1,200	Marantz MM7055	152.8	236.4	117.8
$1,199	Rotel RMB-1085	114.8	218.4	114.8
$999	Outlaw Model 7125	189	269	142**
* Limiter Engaged
**7/8 Channels Driven

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This covers Home Theater's amps back to 2005. Pricing is as of the review date.

 

[AcuDefTechGuy]

For $1600, I think the Outlaw 7500 is the best bang for the buck in terms of output.

 

[PENG]

For $1600, I think the Outlaw 7500 is the best bang for the buck in terms of output.

I think you are right, but I hope it has two or more smaller transformers than one big one. Normally the bigger they are, the louder they hum, everything else being equal of course. Probably won't be a factor for you though if you know what I mean..

 

[Bryceo]

:0 I like what I see but where's Bose?