whats my real wpc?

Donny

Big Damn Hero
I have a pioneer vsx d307 pro logic reciever and I'm sure it's rated 100wpc just like everyother black box I haven't bothered to look up specs but after ready a post awhile back about power consuption to find true wattage er something so 210watt cons= wha? 30wpc???? I wouldn't be surprised cause I only get 3rd the way up the volume before it starts sounding bad but it could be accoustics I'm hearing and not the reciever I can hear the windows chim in. so plz give me your ideas
 
bluebook stats,

PIONEER RCV, VSX-D307
Description: 2-CHANNEL, DOLBY PRO LOGIC
Manufacture Years: 1998 - Current
Additional Information:
Power: 100wpc
Retail
MSRP: $200.00
 
Donny said:
I have a pioneer vsx d307 pro logic reciever and I'm sure it's rated 100wpc just like everyother black box I haven't bothered to look up specs but after ready a post awhile back about power consuption to find true wattage er something so 210watt cons= wha? 30wpc???? I wouldn't be surprised cause I only get 3rd the way up the volume before it starts sounding bad but it could be accoustics I'm hearing and not the reciever I can hear the windows chim in. so plz give me your ideas


I wished McIntosh would restart their 'Amplifier Clinic' program. That would be a great way to learn how much power your receiver actually has. I had a similar Pioneer pro-logic unit (absolute junk, BTW) that seemed pretty anemic for '100 watts' Probably more like 30 watts the way McIntosh would measure it. LOL

'100 wpc' doesn't mean much unless we learn the frequency response of the rating, and the distortion level at rated power. Also, we'd need to know if the spec is watts RMS, peak watts, etc.
 
I think it's probably "Sparkomatic Car Stereo Watts".
 
The biggest reason that home theatre receivers have suspect power ratings is that they are not required to rate them with all channels driven simultaneously. This is similar to the problem with ratings of early hi-fi gear when there were no standards and 40W amps could be rated as high as 300W by stretching the rating methodology to the point of being ridiculous. It got so bad that in the early 70's, a standard was developed by the FTC for stereo amplifiers that required ratings in RMS into 8 ohms, at a specified distortion level with both channels driven full bandwidth. These regulations do not apply to mutichannel amplifiers so we are back to the bad old days of manufacturers using whatever makes their amp look best. If you think that this situation is bad, it is insignificant compared to what is going on in the auto sound industry. There you can find manufacturers advertising 5000 W amplifiers that can be driven off of a standard 12 volt car battery.
 
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Well, if you want to have fun...

... put dummy loads on (all) channels, inject a 1000 Hz sine wave into one input channel (or all of 'em, if you're feeling mean), attach an oscilloscope across the appropriate output, and crank up the gain 'til you see the output waveform clip. Measure the ACV at or just below clipping and do the math.

This isn't nearly as demanding as the FTC power rules for home stereo equipment (which required a 60-min 'warm up' at 1/3 of rated power IIRC... even in the ol' days, some amps would shut down from overheating during the preconditioning).

Note: Don't hold me responsible if the amp fries during this test! :)

EDIT: Looked for the original FTC regulation of 1974. Didn't find it, but I DID find some interesting info on the proposed 2000 update of the regulation:
http://www.ftc.gov/opa/2000/12/amprule.htm

Not sure what the current regulation is, though
 
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I use total wattage comsumption divided by 5, or to be conservative, 6, for 2 channel, so for 5 channel HT you could divide by 2.5, then divide again by 5.

210 max wattage consumption divided by 2.5 = 84 watts avail, 1 channel driven, divided by 2, 42 wpc in stereo with both channels driven, or divided by 5, 17 wpc in 5 channel surround with all channels driven.

This is of course just a rule of thumb and not meant to be definitive. 42 real wpc is adequate for most stereo systems IMO. It looks like their 100 wpc rating "can be considered" correct with one channel driven, and if you work from there it comes out to 20 wpc.

And with HT it's a bit different, consider: if a car blows up (yay!) the sound will probably start in the center channel, then move to the mains then to the rears. How often will all 5 channels be called upon to drive peak levels simultaneously? Still, it probably happens occasionally.

Don, that probably works out to 100,000 wpc PMPO! :D

Pete
 
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Think one of the mags tested a 100 wpc HT receiver in the past and it was something crappy like 33 wpc. Thats disgusting !
 
All Channels driven 20-20K

Some reviews I have read about power oputput on typical 5.1 receivers are about 21wpc all channels driven at 20-20K. . . At 1K one channel driven = 100watts. . .

You stil;l see true numbers but you have to read the specs carefully. Usually is states output at 1K = 100 watts at .1% THD or some such. . . When you find a higher line HT receiver like my Pioneer ELITE VSX-45TX it states "All Channels driven at 20-20K" = 100watts

Some really confuse the issue by giving you stereo readings or 2 channels driven and then they bafflegab the rest of the description.

However when you see the stated specs at "All Channels Driven" you can depend on the number be it at 6ohms and 1% distortion or whatever. . .

This is from my model;
Surround Power 110 W x 7 (20HZ - 20kHZ @ 8 ohm, 0.09% THD
Stereo Power 110 W x 2 (20HZ - 20kHZ @ 8 ohm, 0.09% THD

At least it gives you output for all channels and in my case I believe it as I run difficult full range speakers that will shut down mostr HT receivers.
 
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twintwelve1484 said:
I think it's probably "Sparkomatic Car Stereo Watts".

VSX-D307
A/V Receivers
M.S.R.P. $275.00

33452vsx-d307.jpg




Amplifier Features

* Stereo: 100 watts per channel, 40 Hz to 20 kHz, 0.9% THD at 8 ohm
* Surround: Front: 100 watts x 2, Rear: 100 watts x 1, Center: 100 watts x 1


In Stereo, It's probably more like 50-60 watts per channel, 20-20khz, at 0.1% thd.

In Surround.... LOL - that's when Twintwelve's 'Sparkomatic' watts kick in! haha
 
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I have a VSX-D309, which I use for the surround system in my one living room. It is rated at 60wpc x 5, and actually I think it does a better job than some of these receivers with somewhat overblown numbers. Use Utah WD-90s upfront which are fairly efficient, a Sony center channel, and some old Design Acoustics speakers are surrounds. Has no problem driving this stuff to good listening levels for the room (but I don't generally use this setup for anything but HT or maybe an occasional football game on the radio). My take on this... if you buy a model like this from a reasonable company (no HT in a box crap) it will perform decently (no frills, just does what it is supposed to do), you don't care greatly about its supposed power output so you still get a decent receiver nothing special. If you buy a TOTL receiver you are looking for quality and willing to pay for it so you get something in return for your money.

The worst bet is to try to buy the most specs at the cheapest price, get a flashy looking box, lots of lights and a lack of performance to back it up. The above mentioned Pioneer weighs more than some of the "700 watt total power" units from some other manufacturers.
 
thx guys I know the numbers are so over rated now it's hard to tell 42 wpc does seem close to the truth maybe less I don't push it for fear of clipping and it gets annoy the neighbors loud already but I won't be happy till I get call the law loud. o guys plz be nice compairing it to sparkomatic was uncalled for
 
I only get 3rd the way up the volume before it starts sounding bad but it could be accoustics I'm hearing and not the reciever I can hear the windows chim in

Could very well be acoustics. It could also be that the speakers you have hooked up are a difficult load to drive for the Pioneer.

Even if the real output is only 30 WPC, you can still get pretty loud with a speaker rated at 90db or more.

My 2 cents. ;)
 
Clevanator said:


* Stereo: 100 watts per channel, 40 Hz to 20 kHz, 0.9% THD at 8 ohm
* Surround: Front: 100 watts x 2, Rear: 100 watts x 1, Center: 100 watts x 1

"In Stereo, It's probably more like 50-60 watts per channel, 20-20khz, at 0.1% thd."

All channels driven at rated bandwidth it is more likely around 25-30wpc and you can hear 0.9% . . . need to be lower than around 0.5%
 
gyusher said:
"In Stereo, It's probably more like 50-60 watts per channel, 20-20khz, at 0.1% thd."

All channels driven at rated bandwidth it is more likely around 25-30wpc and you can hear 0.9% . . . need to be lower than around 0.5%


Interesting! So the power curve isn't as 'steep' as I might have guessed? i.e, distortion doesn't rise more quickly with increased power? I would have inferred that distortion remained relatively 'flat' until nearing the clipping point, where it rises sharply.

I've never tested output, so I'll obviously defer to those who have. But I did get a warm fuzzy feeling looking at the specs printed on top of my Mac...

Stereo - 0.1% Maximum Harmonic Distortion at any power level from 250 milliwatts to 200 watts per channel from 20 Hz to 20,000 Hz both channels operating

and

Stereo - 200 watts minimum sine wave continuous average power output, per channel, both channels operating into 1 ohm, 2 ohm, 4 ohm, or 8 ohm load impedance from 20 Hz to 20,000 Hz

:)
 
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