"Arfa Daily" wrote in message
...

"Bob Mannix" wrote in message
...
"Dave" wrote in message
...
Hi all.
I'm sorry if this seems OT but I hope someone can still help.
Anyone know how to convert EIAJ into RMS values?
Say if you have an amplifier stating as having 230W EIAJ power, any idea
what that might be in RMS?
I've tried Googling but nothing of sense comes up.
Cheers in advance.
Wavey Dave

It depends on the voltage range, I guess, as it's defined as follows:

Maximum EIAJ standard test output power: average of RMS output voltage
squared divided by load impedance.

Don't know what the test conditions are for this though. Probably safe to
say roughly the same as RMS power depending on how you drive it.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)


Who on earth comes up with this stuff ? I'm sure it must have made some
sense to the person at the time, but dear me, average of RMS ? Squared ?
Divided by load impedance ? Should it also have "multiplied by the outside
air temperature and divided by the number of channels cubed, minus the
number you first thought of" in there as well ... ?


Well, why I'm not sure, but calculating power as voltage squared over
impedance is perfectly reasonable and no cause to bring in the air
temperature! It's some sort of average that takes into account the dynamic
voltage range of the system. Not that I care, but someone might.

As to the loudness of speakers, efficient speakers are loud and low quality,
high quality speakers are inefficient and quieter (generally speaking) so
you make your choice. Notting Hill Carnival sound system, go for efficiency
and b*gg*r the fidelity, you want to rattle windows, Self absorbed, anally
retentive, solo, esoteric hi-fi listening, low efficiency speakers and big
amps ;o) !


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

In article ,
Bob Mannix wrote:
As to the loudness of speakers, efficient speakers are loud and low
quality, high quality speakers are inefficient and quieter (generally
speaking) so you make your choice.

Indeed. Recently re-heard some Lowther super efficient speakers mounted in
horn loaded cabinets. Driven off tiny amps. And they sounded horrid -
extremely coloured sound. Might be worthwhile where power was a problem,
though.

--
*Sticks and stones may break my bones but whips and chains excite me*

Dave Plowman London SW
To e-mail, change noise into sound.

Bob Mannix wrote:
"Arfa Daily" wrote in message
...
"Bob Mannix" wrote in message
...
"Dave" wrote in message
...
Hi all.
I'm sorry if this seems OT but I hope someone can still help.
Anyone know how to convert EIAJ into RMS values?
Say if you have an amplifier stating as having 230W EIAJ power, any idea
what that might be in RMS?
I've tried Googling but nothing of sense comes up.
Cheers in advance.
Wavey Dave
It depends on the voltage range, I guess, as it's defined as follows:

Maximum EIAJ standard test output power: average of RMS output voltage
squared divided by load impedance.

Don't know what the test conditions are for this though. Probably safe to
say roughly the same as RMS power depending on how you drive it.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)


Who on earth comes up with this stuff ? I'm sure it must have made some
sense to the person at the time, but dear me, average of RMS ? Squared ?
Divided by load impedance ? Should it also have "multiplied by the outside
air temperature and divided by the number of channels cubed, minus the
number you first thought of" in there as well ... ?


Well, why I'm not sure, but calculating power as voltage squared over
impedance is perfectly reasonable and no cause to bring in the air
temperature! It's some sort of average that takes into account the dynamic
voltage range of the system. Not that I care, but someone might.

As to the loudness of speakers, efficient speakers are loud and low quality, \
Not necssarily.

high quality speakers are inefficient and quieter (generally speaking) so
you make your choice. Notting Hill Carnival sound system, go for efficiency
and b*gg*r the fidelity, you want to rattle windows, Self absorbed, anally
retentive, solo, esoteric hi-fi listening, low efficiency speakers and big
amps ;o) !


Best speakers we used in my time making rigs, were JBL horn copies by
DAS About 110dB/watt.

Those and bullet horn tweeters covered about 800Hz upwards very very
well. superb low distortion a but the frequency response had a few
little peaks in it.

IIRC we used 8 or 12 inch units at around 92-95dB/watt - massive magnets
on em.

And twin 15" or a single 18" unit to go up to 200hz or so in reflex
cabs. Us of lighweigght foam composite cones and BIG magnets gets a very
decent efficiency out of even those.

What you are thinking of is crappo hifi. Its easy enough to take a
poorly damped speaker and strangle it to get a flattish reponse, and
people want '100W speakers' not 'speakers capable of doing 120db SPL'.
It sounds ok, its just chap. My DAS studio monitors were massively more
efficient. Sadly they have decoiled and need a recone..after 25 yars..



Or if its loud you want, cheap magnet, ultra thin paper cone, a
celestion! and into a box..and hey folks, its the Vox AC30!! a very good
soundboard for an electric guitar, with multiple interesting resonances
and fed from a ovrdriven 100 ohm impedance valve amp with all negative
feedback removed for gain!. You cant get better than that ;-)

Loud, for 30watts..

In article ,
The Natural Philosopher wrote:
Those and bullet horn tweeters covered about 800Hz upwards very very
well. superb low distortion a but the frequency response had a few
little peaks in it.

As do all horns. That's why they're useless for true Hi-Fi.

--
*I used to have an open mind but my brains kept falling out *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
The Natural Philosopher wrote:
Those and bullet horn tweeters covered about 800Hz upwards very very
well. superb low distortion a but the frequency response had a few
little peaks in it.

As do all horns. That's why they're useless for true Hi-Fi.


Well, its a tradeoff. Between sensitivity and flat response. And wide
bandwith..

Remember we were only spanning IIRC about two octaves with each unit.

Tweeters came in around 4k, mid horns 1k-4k, lower mid 250hz-1k Bass
units 50-250hz More or less.

I don't think I have ever hard better high power clarity than from those
horns. Quad ESL'S. yes, but at abysmal power output.

You have to pay real money though. The knock off plastic copies are rubbish.

And decide whether its low intermidulation you want, or a razor flat
frequency response. Since any room you put stuff in and any hall you
recrd in buggers up the frequency response I don't count it as a huge
problem. But rooms don't distort ..loudspeakers do. It jut makes the
recording dull.

OK if there is a major and high peak or notch, you can hear it, but not
a minor rippling across the band.

Iv always liked top quality horns, but I have never hard them much
outsid what we were doing..not in the hifi stores anyway.