Inflated PMPO figures

[pimpom]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?
E.g., an amp with a true 20-watt output may be rated at more than
1000 watts PMPO. (Please, let's not get sidetracked into how
there's no such thing as RMS power - call it continuous power or
whatever).

I'm old enough to remember when IHF music power was often cited
with some justification. At least you could actually get that
amount of power output for a fleeting moment at very high THD
levels. But multiple-kW ratings are now claimed for a music
system using a few TDA2030 ICs. Even large reputable companies do
it, so I find it hard to believe that they just grab some random
figures out of thin air. Do they have some way of working out
those figures, no matter how specious their reasoning might be? I
was out of touch with the audio field for a long time, so I guess
I missed something when the trend started.

 

[Kevin Aylward]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?

Number out of a hat, praying to donald duck, throwing a dice....

E.g., an amp with a true 20-watt output may be rated at more than
1000 watts PMPO. (Please, let's not get sidetracked into how
there's no such thing as RMS power - call it continuous power or
whatever).

I'm old enough to remember when IHF music power was often cited
with some justification. At least you could actually get that
amount of power output for a fleeting moment at very high THD
levels. But multiple-kW ratings are now claimed for a music
system using a few TDA2030 ICs.

Oh..

The dat sheet says 14W, which is average contineous power. I diont see that
it can give out more than around 25w contineous due to its 3.5A current
limit.

Even large reputable companies do
it, so I find it hard to believe that they just grab some random
figures out of thin air.

I dont. They did that with the space shuttle. Like 1:50, so try 1:200, too
low, try 1:1000, to low, tray 1:100,000 ok, we can go with that...

Do they have some way of working out
those figures,

Yeah, mulitply by the number of fairies that they thought someone may have
seen, last Tuesday.

Kevin Aylward

www.kevinaylward.co.uk

 

[Eeyore]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?

They don't. It's exclusive to the car audio market and maybe also
computer type audio.

Long ago the FTC (in the USA) introduced a rule that prevented hi-fi
manufacturers from doing any such thing.

In Europe, IEC ratings are used.

Graham

 

[Eeyore]

They don't. It's exclusive to the car audio market and maybe also
computer type audio.

Long ago the FTC (in the USA) introduced a rule that prevented hi-fi
manufacturers from doing any such thing.

p.s. it's called 'the Amplifier Rule'.

Graham

 

[PhattyMo]

p.s. it's called 'the Amplifier Rule'.

Graham

I always thought it was called "Ohms Law". *shrug*

 

[Eeyore]

John, what's up with you ? The OP didn't indicate where he lives so 'in the
USA' was merely clarification. He may never have heard of them. There is a
whole world outside your borders you know.


I don't understand what you mean.


They are somewhat different actually because they're International, not
single nation. In fact UL is now patterning after IEC. See UL1950 and
IEC950 (may be 60950 by now) for example.

I think it's interesting to note that even though you play at
subscribing to the EU,

You mean me personally ? I think it has some very good bits and some very
bad bits and the bad bits seem to be getting worse at a rate of knots now.

I would gladly now consider re-joining EFTA (see wiki) which would give all
the trade benefits without all the compulsory social and generally insane
shit. Did you know the majority of British Law (I think maybe as much as
60%) is now made in Brussels ? The Commission produces 'Directives', which
in the UK are executed as 'Orders in Coucil' which may not be debated in
Parliament.

you refuse to subscribe to the Euro as your currency base.

Am I wrong?

If only they'd called the Euro 'The Pound' it expect it would have
happened. But that was disallowed. No existing currency name was allowed.

Also remember The Pound was a highly rated currency in its own right, as
opposed to say the Italian Lira.

It was like the same silly idea about a 'genuine' Euro power socket. The
most popular, the Schuko type and the most safe, The British '13 Amp' are
both ruled out. So it'll probably never happen.

Graham

 

[pimpom]

Number out of a hat, praying to donald duck, throwing a
dice....


Oh..

The dat sheet says 14W, which is average contineous power. I
diont see that it can give out more than around 25w contineous
due to its 3.5A current limit.


I dont. They did that with the space shuttle. Like 1:50, so try
1:200, too low, try 1:1000, to low, tray 1:100,000 ok, we can
go with that...


Yeah, mulitply by the number of fairies that they thought
someone may have seen, last Tuesday.

OK. So they do grab those figures out of thin air. I was
wondering if there was some way of producing those figures, no
matter how false and contrived the math might be.

As an example, the amplified speakers I'm using for my computer
is a Kobian SW-1480 (reasonable sound for a USD20 equivalent
price tag). It's a 2.1 set using a TDA2030 for each of the woofer
and two satellites (4 ohms each), running from a common power
supply which is very close to the TDA2030's max rating of +/-18V
at idle. Even if the full 36V is squared and divided by 4ohms (an
absurd and totally irrelevant 'formula'), the total for all three
amps still falls short of 1000W. Yet the PMPO is claimed to be,
as the model number suggests, 1480W!! What really surprises me is
that similarly absurd figures are touted even by giant
multinational companies.

 

[Eeyore]

As an example, the amplified speakers I'm using for my computer
is a Kobian SW-1480 (reasonable sound for a USD20 equivalent
price tag). It's a 2.1 set using a TDA2030 for each of the woofer
and two satellites (4 ohms each), running from a common power
supply which is very close to the TDA2030's max rating of +/-18V
at idle. Even if the full 36V is squared and divided by 4ohms (an
absurd and totally irrelevant 'formula'), the total for all three
amps still falls short of 1000W. Yet the PMPO is claimed to be,
as the model number suggests, 1480W!! What really surprises me is
that similarly absurd figures are touted even by giant
multinational companies.

For some bizarre reason the US FTC considered this market under 'the
Amplifier Rule' and exempted it !

You'll probably find some obscure reasoning on their site.

Graham

 

[Richard The Dreaded Libertarian]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?
E.g., an amp with a true 20-watt output may be rated at more than
1000 watts PMPO.

They run it through the same model that the Warmingists use to get their
figures. ;-)

Cheers!
Rich

 

[Eeyore]

They run it through the same model that the Warmingists use to get their
figures. ;-)

LOL ! There is actually a 'sort of' defintion of pimpo but you don't want to
hear it because it's stupid. It can be varied to suit the marketing guys too
of course.

Graham

 

[YD]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?
E.g., an amp with a true 20-watt output may be rated at more than
1000 watts PMPO. (Please, let's not get sidetracked into how
there's no such thing as RMS power - call it continuous power or
whatever).

I'm old enough to remember when IHF music power was often cited
with some justification. At least you could actually get that
amount of power output for a fleeting moment at very high THD
levels. But multiple-kW ratings are now claimed for a music
system using a few TDA2030 ICs. Even large reputable companies do
it, so I find it hard to believe that they just grab some random
figures out of thin air. Do they have some way of working out
those figures, no matter how specious their reasoning might be? I
was out of touch with the audio field for a long time, so I guess
I missed something when the trend started.

At the local computer store I recently walked by a couple of shoe-box
sized speakers claming 25,000 W. Got some funny looks as I couldn't
resist laughing out rather loudly (much less than 25 kW, though).

- YD.

 

[Mark Zenier]

How do some manufacturers of audio amps arrive at the
ridiculously high PMPO ratings they give for their products?

According to a sidebar in an Elektor Electronics a couple of years ago,
it was based on how much power the amplifier could output for a one
millisecond pulse, or one cycle of 1000 hz (or something stupid like
that). So it boiled down to the energy stored in the power supply filter
capacitors, multiplied by 1000. Watts = Joules/Second.

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)

 

[Richard The Dreaded Libertarian]

Nice retort. Nice, indeed!

Thanks!

Your commentary has recently become much more incisive.

Has your life changed in any way you'd like to share?

Not especially - Maybe I've abandoned all hope lately, given the two
candidates we have for "president".

It used to be "would you rather be hung or shot?" Nowadays it's "Would
you rather be disemboweled or boiled in oil?"

Thanks,
Rich

 

[[email protected]]

Thanks!





Not especially - Maybe I've abandoned all hope lately, given the two
candidates we have for "president".

It used to be "would you rather be hung or shot?" Nowadays it's "Would
you rather be disemboweled or boiled in oil?"

Thanks,
Rich

Look on the bright side. Some countries allow a third term for
president.

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

Can you imagine a third term for you know who...?

heh

Michael

 

[Eeyore]

---
Although it's not explicitly stated, it's probably something like giving
the Chinks a break by letting them sell stuff here which doesn't quite
measure up to what they claim.

Pretty much the same as the license we allow you which doesn't say:
"Instead of just one, you should have bought two Jaguars so you'll have
one to drive while the other one's in the shop.

You can blame that on Ford then. Fix or repair daily isn't it ?

Graham

 

[David L. Jones]

Look on the bright side. Some countries allow a third term for
president.

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

Can you imagine a third term for you know who...?

I can kinda-sorta understand how Bush weaseled his way in the first
time, even though he didn't actually get a majority vote. But who on
earth voted for him a second time around?

Hard to understand you Yanks!

Dave.

 

[Eeyore]

---
Hardly.

What you can blame on Ford is the invention of the assembly line. How
you use it to endlessly replicate errors is your own affair.

My father had several Jags and had minimal problem with them. I think he
positively adored his 3.8 Mk II (in metallic 'golden sand').

Graham

 

[Rich Grise]

John Fields wrote:

You can blame that on Ford then. Fix or repair daily isn't it ?

Nah, Fords are great! Just keep oil in them, and they'll run forever. They
are kind of notorious for using oil, however ("Uh, fill up the oil and
check the gas...").

Cheers!
Rich

 

[Rich Grise]

ISTM that nowadays it's "hanged", even though "hung" is what your
plastic surgeon recommends.

Heh. ;-) Actually, I knew that, I just wanted to go for the colloquial
form of the expression, more amenable to Joe Six-pack. ;-)

Cheers!
Rich

 

[Eeyore]

Nah, Fords are great! Just keep oil in them, and they'll run forever. They
are kind of notorious for using oil, however ("Uh, fill up the oil and
check the gas...").

I think you're confusing them with Toyota ! ;~)

Oh, except Toyotas don't use oil.

Graham