Energy and frequency

[Music Man]

Why is it that lower frequencies are known to blow audio speakers seeing
that higher
frequencies produce more energy RMS?
What actually blows the amplifiers?

Thanks

 

[Lord Garth]

"Music Man" <j.michael@cwcom.net> wrote in message
news:428c0ec7$0$326$cc9e4d1f@news.dial.pipex.com...

Why is it that lower frequencies are known to blow audio speakers seeing
that higher
frequencies produce more energy RMS?
What actually blows the amplifiers?

DC has a pretty low frequency...like zero.

"blowing" an amp can occur for many reasons. Components can age and fail
or they can be over stressed electrically, mechanically or thermally. These
stresses can cause the components or their connections to open or short.
You've ask a very broad question there.

A speaker can be blown from the failure of the mechanical suspension of the
cone or the
coil can become shorted or open.

 

[Ban]

Music Man wrote:

Why is it that lower frequencies are known to blow audio speakers
seeing that higher
frequencies produce more energy RMS?
What actually blows the amplifiers?

Thanks

What you mean is that higher frequencies require less excursion for the same
sound pressure level than bass. When the max. excursion is reached the voice
coil bumps against the pole plate in the back gets deformed and eventually
destroyed.
It is also true that higher frequencies contain more energy in normal music
and voice material. With music the maximum is around 800Hz.
Amplifiers are blown by short circuits or very low impedance loads if they
do not have a current limiter built in. They are also blown by
overtemperature, which can be created with too high a level, too high
ambient temperatures and poor cooling(i.e. covering the cooling fins).
--
ciao Ban
Bordighera, Italy

 

[Bob Masta]

On Thu, 19 May 2005 04:57:58 +0100, "Music Man" <j.michael@cwcom.net>
wrote:

Why is it that lower frequencies are known to blow audio speakers seeing
that higher
frequencies produce more energy RMS?
What actually blows the amplifiers?

Thanks

First of all, your ears are less sensitive to low
frequencies (they are most sensitive around
1k-4k, falling off above and below that). And
since many folks like gut-thumping bass,
there can be a lot of watts involved before
your ears complain.

But second of all, your statement isn't
always the case. In pro sound systems
(nightclubs, etc) which are cranked up a
lot, it's often the tweeters that give out
first. This typically happens from overdriving
the amp so that it clips. The signal that is
causing the clipping is typically low frequency
(those gut-thumping bass lines) but the
clipping distortion is much higher and goes
to the tweeters. Since tweeters are typically
rated for much lower power than the woofers
in a system (due to normal hearing sensitivity),
they can't handle the power due to clipping
and blow out.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

 

[Jamie]

Music Man wrote:

Why is it that lower frequencies are known to blow audio speakers seeing
that higher
frequencies produce more energy RMS?
What actually blows the amplifiers?

Thanks


distortion is the speakers worse enemy.

distortion can hold a speaker cone at a flat setting
position due to the amp flat topping from saturation.
this effect causes heating in the coil and cone
deformity.

complex audio requires a good size Amp (not to be used
at distortion levels) to transfer all of the multiple
sounds to the speakers with out depreciation of any instrument
being heard.

And many amps are not designed to be used at full power of 100%
duty cycle especially with out proper ventilation and heat sinking.