Watts = Quality

[hoongern]

PMPO ratings are extremely unreliable
I've got some computer speakers which rated as the following

1. 5W RMS - 1200W PMPO
2. 20W RMS - 600W PMPO

the pmpo for 5w is higher for that 20w?
what i hate is that for some speakers (most?), even when they put pmpo ratings, they don't even show the RMS rating

Even RMS ratings can also be misleading... My friends 5W tube amp sounds better than my 250W RMS amp, for goodness sake...

 

[navin]

Take a 10W+10W RMS into 8 ohm amplifier....Double this for PMPO = 160W....Generally PMPO = 8 times the RMS rating.

if a sony sysmte is advertised as 7000W PMPO then 7000/16 = 437W rms/ch. that also looks a bit much. i dont think it put out more than 20W rms/ch. 7000/20 = 350. wow! how do the marketing guys justify this. after all there must be some minimum standards.

 

[5th element]

after all there must be some minimum standards.

Obviously not!

Also what surprises me is the amount of people that do buy these computer speakers, you can pay obsurd amounts for these little crappy boxes. Little do ppl realise that you can buy a "proper" 20-30 watts RMS hifi amp and a "proper" set of mini speakers for the same or less. Infact you could get quite a nice little set up.

Sony TAFE230 - 40 watts RMS whathifi recommended £50 at hyperfi.

Then a choice of either Whafedale diamond 8.1's or Mission 771's
for £50 again at hyperfi. Id prefer the missions as they would look better next to the computer.

But for £100 you get hifi that would cost £300 RRP, and sound leaps and bounds above 20000000000000 PMPO computers.

And the bonus with the amplifier, it can act as your monitor stand!

 

[SimontY]

Sony TAFE230 - 40 watts RMS whathifi recommended £50 at hyperfi.

Come on mate, we all know Hyperfi don't actually stock any of these products!!!

They're even worse than Richer Sounds...

I do agree with what you're saying though. But for gaming I'd say you can't beat a Videologic Crossfire 4.1 setup - has a real amp with good PSU, and a deep-sounding punchy sub - ****es on any ordinary pc speakers - and they don't claim silly watts, hehe.

 

[Matttcattt]

other than for exagerated wattage ratings, what is the point of a "Peak Music Power Output" rating? what else are you going to use computer speakers for?

are they saying that their speakers cant handle HT or sine waves? why do these need to be rated seperatly?

not only do they exagerate max power ratings, but now they make up a new rating, to confuse people further.

 

[Timn8ter]

Well, this is amazing. I haven't seen the PMPO spec here. I don't think the US marketing folks have caught on to that one yet. I've seen Total Music Power but it doesn't hit the exaggerations you're talking about.

 

[AudioFreak]

PMPO is all over the place here, I have often seen 'boom boxes' and multi channel mini systems that would struggle to put out 100W between all channels when going full throttle ratted at 3000W - 4000W PMPO.

 

[ooheadsoo]

Look at any head unit power rating or car audio driver - they're all pmpo.

 

[lucpes]

Check out this funny article by Rod Elliott:

http://sound.westhost.com/power.htm

Also, the 7000W rating ought to be referred as WLS*


*When Lightning Strikes

 

[5th element]

Just had another thought Pmpo PEAK, noone states how long this peak is sustainable for! Hmmmmm 0.0000000000001seconds i bet.

We have bought two things from hyperfi! with no problems at all, a pair of mission speakers and a pioneer tape deck.

 

[SimontY]

Just had another thought Pmpo PEAK, noone states how long this peak is sustainable for! Hmmmmm 0.0000000000001seconds i bet.

We have bought two things from hyperfi! with no problems at all, a pair of mission speakers and a pioneer tape deck.

Heh, ok. Truth is, my experiences were from quite a few years ago, although one does read of places like Hyperfi not stocking more than a few of each item, as they are ex-dem or some dodgy seconds or something. But it's all good, who cares about a little scratch, if the price is halved?!?

The speakers I now use on my home PC are from them, just got anything after they didn't really have any of the models I wanted. They were my first 'hi-fi' speakers - Tangent Monitor 6, I'm on my 4th set now, last 2 DIY

 

[5th element]

Well your on the rite track now! DIY ALL THE WAY!!!

 

[Karoliina]

Hi,

Watts don't mean quality. In Finland, there are number of brands of lo-fi speakers (mostly muldimedia) speakers marketed with PMPO watts that are not real watts. Some system made of plastic and size of a postcard has 3500 W PMPO. With small printing there reads somewhere, that in RMS it means 0.5 W... I have always wondered what those PMPO watts mean. Imaginary marketing watts or what?

Anyway, I personally run my subwoofer with 1.2 kW
(continuous 8 ohm) PA power amplifier (real watts). The 18 inch Fane sub is barely adequate to our home theater in terms of SPL
(of course this is quite relative, there are many home theaters
out there with subs that are quite much jokes if compared to ours).

When I was building it, people
claimed that I would need only 1 watts or so to run such "huge
driver" that has efficiency of 100 dB/1W, but I knew that lots of
power was needed and I was right - you know what, 18 inch
is not so huge.
The power is needed to compensate the needed equalization. The subwoofer wouldn't be a subwoofer without equalization and the driver is not optimally efficient at 20 Hz because the box is
tuned so that it covers the area between 20 Hz and 80 Hz that
means that I had to sacrifice 11 dB of the efficiency. With my experience, I need to drive the sub
with very high power, near to clipping level of the amp to get
sufficient volume level to the home theater. The excursion
becomes problem with hundreds of watts and it causes audible
distortion. The driver in the next sub project will have definately
more displacement with less distortion.
And the next amplifier will have even more power.
I have calculated that for example
Adire Audio Tumult needs to be driven
with a 1.6 kW amp to get all the benefit of its huge displacement
capacity.

Anyway, however,
my next LCR speakers will be optimized towards efficiency,
because with mid and high frequencies, using hundreds or
thousands of watts is not an option because of the increase
of the distortion.

Best Wishes,
Karoliina

 

[Timn8ter]

This may be an explanation of PMPO.

http://en.wikipedia.org/wiki/PMPO

 

[nicksmurf]

I remember talking about this in another thread somewere else. The US government used to have some law. I guess it coincided with weight and measurment laws. It was how to properly mearsure the output of an audio amplifier. I think they scraped it a long time ago though. I have to look it up but I think on some OLD equipment they used to say something more or less like "measured by federal standards".

Now of days it sounds like whatever committie in congress is in charge of weight and measurments should check out this issue.

 

[Jay]

PMPO ratings are extremely unreliable
I've got some computer speakers which rated as the following

1. 5W RMS - 1200W PMPO
2. 20W RMS - 600W PMPO

the pmpo for 5w is higher for that 20w?
what i hate is that for some speakers (most?), even when they put pmpo ratings, they don't even show the RMS rating

Even RMS ratings can also be misleading... My friends 5W tube amp sounds better than my 250W RMS amp, for goodness sake...

Of course ratings can be misleading, especially if no standard is ever used for the quantification. Even for RMS we need to know the detailed condition of measurements.

Wattage is about electricity, not sound. It is decible which people usually think of when looking at the numbers.

Take your 100W amp and feed it with a speaker as big as a house. 100W is not loud.

Compare a 5W 300B and a 250W of Class-B Darlington amplifier, both using Lowther fullrange speaker. The 300B will sound better. No wonder.

Compare your friend's 5W and your 250W using a Grand Utopia speaker, sit 1m from the speaker and listen. You probably won't know which one is louder. But then go out and listen from a distance. Your neighbours may think that your 5W is very cheap. That is where low wattage amps do not qualify. Most people just use high wattage systems simply to impress neighbours.

 

[jomor]

Most of the buyers dont even know what a sound is!! Watts sell, and thats a fact, all over the world. The most classic example are car audio head units. 4x50Watts ( with just a 10A fuse )

A conversation I had recently

- What brand are your car speakers?

Me: - Vifa (D26NC-05-06, P17)

- How many watts are they

- Huh? Ehm, I m not sure, I think they re about 60w rms

- How much did you pay for them?

- About 250€ including the crossovers, designed for the specific drivers.

- Ha! I gave just 75€ for my 200watt Kenwoods


- Do they sound better?

- They 're Kenwoods!



i didnt bother to explain

 

[5th element]

We sit here laughing, pitying or whatever all these ppl, There Kenwoods!. But at the end of the day if they are happy then its not a problem. Although its still good they are there as its some nice entertainment for us folk.

 

[megajocke]

PMPO power is calculated by taking the peak power and multiplying it with the ratio between sales people and engineers squared. Or possibly cubed if it is computer-speakers I have a pair of "160W" computer speakers... the driver is a 2" or something like that...

 

[5th element]

Nah PMPO = profit margin potential optomizer.