Slam
 

On Thu, 02 Oct 2003 19:56:27 +0100, Laurence Payne
wrote:


Any really good amplifier will be able to handle full power
more-or-less continuously - certainly for several minutes - without a
problem.

And wouldn't object to being asked to deliver considerably more if
momentarily demanded? You seem to be arguing against transient
headroom :-)

Anyone who knows anything about amps *does* argue against 'transient
headroom', which is just another word for a cheap power supply. Take a
£15,000 Krell amp, for instance. This will deliver close to a kilowatt
into an 8 ohm load forever, with virtually *no* 'transient headroom'.
You think this makes it lacking in 'slam'?
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Slam
 

In article , The Old
Fogey wrote:
Can anyone define 'Slam' in the context of audio power amps?

First, some other people's "definitions" in the general sense (I will
come to the amplifier context) from the only two audio glossaries I can
find online and some related material.

* A Stereophile magazine glossary defines slam as "British for impact."
(July 1993)

* The GoodSound! Glossary: "Slam: An audio reviewers description of
a systems ability to portray bass notes with visceral impact and
weight."

* B&W: "bass attack."

The general context for most uses of "slam" is of visceral impact (in
the listener) created by an audio system. As such I guess the sensation
to be caused by pressure waves with a large change in pressure across
a small distance. So I assume it is generated by a system's ability
to accelerate air. That is, in response to a transient input of large
amplitude the loudspeaker cones must respond rapidly to create the
pressure wave.

The loudspeaker will have a large role in this (e.g. low cone mass will
probably help). As for cables, B&W say "Too much cable impedance and
you begin to lose bass attack or "slam"."

As for the amplifier I assume its role in "slam" is to cause the bass
driver cones to accelerate rapidly in response to a good transient input
of large magnitude. I do not know how to express this. Especialy as
the article which I thought did got an unexplained "**Nope" in response
which I don't understand as I thought that article was spot on in the
amplifier context.

"Slam" is an effect I have never actually felt in the concert hall even
with big bass percussion so it may only be an artificial effect which
occurs in "small" listening rooms. It happens in mine on all kinds
of music. Perhaps it is an effect which gets created at large rock
concerts but I only listen to rock at home.

It is certainly used as reviewer jargon and as a marketing term. The
differences of opinion here belie statements to the effect that it is
a well understood term.

--
John Phillips

Slam
 

In article , The Old
Fogey wrote:
Can anyone define 'Slam' in the context of audio power amps?

First, some other people's "definitions" in the general sense (I will
come to the amplifier context) from the only two audio glossaries I can
find online and some related material.

* A Stereophile magazine glossary defines slam as "British for impact."
(July 1993)

* The GoodSound! Glossary: "Slam: An audio reviewers description of
a systems ability to portray bass notes with visceral impact and
weight."

* B&W: "bass attack."

The general context for most uses of "slam" is of visceral impact (in
the listener) created by an audio system. As such I guess the sensation
to be caused by pressure waves with a large change in pressure across
a small distance. So I assume it is generated by a system's ability
to accelerate air. That is, in response to a transient input of large
amplitude the loudspeaker cones must respond rapidly to create the
pressure wave.

The loudspeaker will have a large role in this (e.g. low cone mass will
probably help). As for cables, B&W say "Too much cable impedance and
you begin to lose bass attack or "slam"."

As for the amplifier I assume its role in "slam" is to cause the bass
driver cones to accelerate rapidly in response to a good transient input
of large magnitude. I do not know how to express this. Especialy as
the article which I thought did got an unexplained "**Nope" in response
which I don't understand as I thought that article was spot on in the
amplifier context.

"Slam" is an effect I have never actually felt in the concert hall even
with big bass percussion so it may only be an artificial effect which
occurs in "small" listening rooms. It happens in mine on all kinds
of music. Perhaps it is an effect which gets created at large rock
concerts but I only listen to rock at home.

It is certainly used as reviewer jargon and as a marketing term. The
differences of opinion here belie statements to the effect that it is
a well understood term.

--
John Phillips

Slam
 

On 02 Oct 2003 21:26:32 GMT
ohawker (Andy Evans) wrote:



You've been staying up late watching those Open University science
programmes - don't think you're the only one awake at 4.45am watching
reconstructions of trebuchets hurling silicone loads........

sili*cone* ?

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

Slam
 

On 02 Oct 2003 21:26:32 GMT
ohawker (Andy Evans) wrote:



You've been staying up late watching those Open University science
programmes - don't think you're the only one awake at 4.45am watching
reconstructions of trebuchets hurling silicone loads........

sili*cone* ?

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

Slam
 

At last, someone's brought some sense to this debate. Well done that man.
This also explains why some bigger, heavier amplifiers are capable of
expressing 'atmosphere' better than their smaller cousins, since when
launched from a trebuchet they will see more of it. The same applies to
speakers, bringing a new insight into why bigger speakers displace more air
than smaller ones.

However, given the fractious nature of some of this group's denizens, I see
a new area of potential conflict arising: in an energy-equivalent test
(cyrus/trebuchet against heavy amp dropped from a chair), which gives the
most realistic slam?

I think this thread has some way to run yet...

Tony
....especially if amplifiers start to fall around the contributors...


"Stewart" wrote in message
...
Some amps do have more SLAM! I can personally vouch for this and
demonstrate
it! and it can be measured accurately and scientifically with a db Meter
and
a seismograph.

If you take a big Krell or McIntosh and throw it on the ground it will
produce allot of slam, but if you take a wee Cyrus and throw it on the
ground the same way it produces way less slam. this can easily be
measured.
On the other hand, if you take a Cyrus and launch it from a trebuchet it
can
produce more slam than the krell dropped from head height.

Slam is what happens when two objects collide. It's to do with velocity x
mass / d (density of arrival surface) = s (slam) = energy expelled during
impact

I recommend the trebuchet method for launching if you want to test out
your
own equipment. subs are the most fun.

Stew.



"Tim S Kemp" wrote in message
. ..

"The Old Fogey" wrote in message
om...
Can anyone define 'Slam' in the context of audio power amps?

The ability to deal with sudden short lived transient sounds -
preferably
without affecting the rest of the output of the amp. Normally acheived
with
good PSU design and big power reserves and capable of transient output
well
beyond the units continuous ratings.

Slam
 

At last, someone's brought some sense to this debate. Well done that man.
This also explains why some bigger, heavier amplifiers are capable of
expressing 'atmosphere' better than their smaller cousins, since when
launched from a trebuchet they will see more of it. The same applies to
speakers, bringing a new insight into why bigger speakers displace more air
than smaller ones.

However, given the fractious nature of some of this group's denizens, I see
a new area of potential conflict arising: in an energy-equivalent test
(cyrus/trebuchet against heavy amp dropped from a chair), which gives the
most realistic slam?

I think this thread has some way to run yet...

Tony
....especially if amplifiers start to fall around the contributors...


"Stewart" wrote in message
...
Some amps do have more SLAM! I can personally vouch for this and
demonstrate
it! and it can be measured accurately and scientifically with a db Meter
and
a seismograph.

If you take a big Krell or McIntosh and throw it on the ground it will
produce allot of slam, but if you take a wee Cyrus and throw it on the
ground the same way it produces way less slam. this can easily be
measured.
On the other hand, if you take a Cyrus and launch it from a trebuchet it
can
produce more slam than the krell dropped from head height.

Slam is what happens when two objects collide. It's to do with velocity x
mass / d (density of arrival surface) = s (slam) = energy expelled during
impact

I recommend the trebuchet method for launching if you want to test out
your
own equipment. subs are the most fun.

Stew.



"Tim S Kemp" wrote in message
. ..

"The Old Fogey" wrote in message
om...
Can anyone define 'Slam' in the context of audio power amps?

The ability to deal with sudden short lived transient sounds -
preferably
without affecting the rest of the output of the amp. Normally acheived
with
good PSU design and big power reserves and capable of transient output
well
beyond the units continuous ratings.

Slam
 

"John Phillips" wrote in message
...

"Slam" is an effect I have never actually felt in the concert hall
even
with big bass percussion so it may only be an artificial effect
which
occurs in "small" listening rooms. It happens in mine on all kinds
of music. Perhaps it is an effect which gets created at large rock
concerts but I only listen to rock at home.

Sit on the floor in front of a kick drum when someone kicks it hard...
That's slam :-) You can get the same kick drum effect just in front
of a loud PA at a gig

Slam
 

"John Phillips" wrote in message
...

"Slam" is an effect I have never actually felt in the concert hall
even
with big bass percussion so it may only be an artificial effect
which
occurs in "small" listening rooms. It happens in mine on all kinds
of music. Perhaps it is an effect which gets created at large rock
concerts but I only listen to rock at home.

Sit on the floor in front of a kick drum when someone kicks it hard...
That's slam :-) You can get the same kick drum effect just in front
of a loud PA at a gig

Slam
 

I did fortuitously come across some useful technical information in the
International Extremely Academic Journal of Engineering Vol xviii(34) Jan (345)
iii

Why you should use a SET amplifier.
"As everybody knows, high power amplifiers use larger electrons to achieve this
high power. The bigger electrons don't start or stop as fast as normal
electrons resulting in much heavier, less nimble Watts. So high power
amplifiers can never have the finesse of low power amplifiers. High
sensitivity speakers only work with the smaller electrons (the smallest are
produced by tube amplifiers). Thus if you use a high power amplifier with
sensitive speakers you need a transformer that slims down the electrons and
makes them swifter. Such transformers are available from Jenny Craig Audio
Inc., Phen-Fenophile Corp. and the US Nuclear Agency."
PS. Don't forget to elevate the amplifiers above the speakers, so the signal
can flow easier.

The SATRI principle
Q. Does anyone possess any information about amplifiers using the SATRI
principle?
A. Of course! Jean-Paul Satri was a famous French philosopher who invented
boredom. He wrote the hit song sung by Janis Joplin : "freedom's just another
word for nothing". He and his friend Genet built amplifiers out of abandoned
bidets found behind brothels. Many Pacific Rim restaurants use his menu
stylings. Sorry, no other info available.


=== Andy Evans ===
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