A contrabassoon has gut feeling. A 64 ft organ pipe has gut feeling, as in subsonics causing your insides to start moving. But neither has slam. A kettle drum has slam in spades, but a fundamental around 150Hz. So it seems its transient rise time (and therefore total bandwidth) that is a primary source of slam.
Either that or Slam is just not quantifiable as too subjective.
Stereophile's definition of slam (or impact) seems as good as any.
A quality of concussive force, as from a deep, strong bass attack, which produces a brief sensation of visceral pressure.
Ways to increase "slam
I agree with the recent posts that "slam" or improved transient response by an amp is due to its midrange qualities, not the bass. For better bass, amp makers increase the size of power transformers add a lot of capacitance to reduce the sag that occurs when the energy demand is highest. However, to improve the transient response, the voltage regulators already mentioned are important, but so is low ESR in the power supply section, especially the power capacitors.
I have a Hafler P7000 amp and it seemed a little soft to me in the lower midrange, so I added a single 50 uf 300 volt blackgate capacitor to each bank of 2800 uf ~80 volt capacitors already there. This improved the transient response of the amp noticably, solely because the tiny blackgates could produce the needed electrons faster than the much larger ones.
Other important characteristics of an amp which improves transient response is lower distortion (due to the feedback) and better components in series with the signal. Poor quality resistors and capacitors in the signal path will all kill the transient response of the amp.
It seems that an amp which is better at transient response and lower distortion would reproduce a square wave better than others.
Retsel
I agree with the recent posts that "slam" or improved transient response by an amp is due to its midrange qualities, not the bass. For better bass, amp makers increase the size of power transformers add a lot of capacitance to reduce the sag that occurs when the energy demand is highest. However, to improve the transient response, the voltage regulators already mentioned are important, but so is low ESR in the power supply section, especially the power capacitors.
I have a Hafler P7000 amp and it seemed a little soft to me in the lower midrange, so I added a single 50 uf 300 volt blackgate capacitor to each bank of 2800 uf ~80 volt capacitors already there. This improved the transient response of the amp noticably, solely because the tiny blackgates could produce the needed electrons faster than the much larger ones.
Other important characteristics of an amp which improves transient response is lower distortion (due to the feedback) and better components in series with the signal. Poor quality resistors and capacitors in the signal path will all kill the transient response of the amp.
It seems that an amp which is better at transient response and lower distortion would reproduce a square wave better than others.
Retsel
Vasquo, perfect question, thx... and I'll second rayma's post...
For me this definition implies several things....
First, that we are listening at a pretty high SPL to begin with if we are looking for 'slam'.
So how an amp sounds at low level for 'slamming bass' is pretty much immaterial and a bit of a logical contradiction, no matter how efficient the sub(s). Likewise, how much headroom the amp has at low level doesn't matter....
And at any kind of drive level capable of producing a visceral 'slam', the voltage headroom needed to keep from clipping gets pretty dang high pretty dang fast. 12db headroom minimum, 18db mo' better
.Hey, here's another definition for 'slam'....
....it's when you're at the edge of running out of gear or gas
(Gear & gas for the whole slam-impulse bandwidth, that is...)
In case anyone is interested here are some measurements for the macro reference from when it was first released. Crown Macro Reference power amplifier Measurements | Stereophile.com. Only thing I can infer from them is that is will happily deliver lots of power without problem for hours on end.
Interesting remark which MIGHT take us back to the damping factor of these crowns, which is - if I understood correctly - achieved to a great extent by the large amount of feedback applied.
shame that marketing kills even a very objective company. 'incredible energy storage'?
The flywheels at JET are closer to incredible at 400MW each Power supply and flywheels | EFDA
ah well. back to reality
The flywheels at JET are closer to incredible at 400MW each Power supply and flywheels | EFDA
ah well. back to reality
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It was a very impressive set up the last time I saw it. My father helped build JET over the course of many years so I got to see a lot of it, mostly before the huge concrete doors were closed (radioactivity is generated by the machine).
Agree. But we can forget about the miking/recording/mixing technique for once.
I know my CDs well, so does my friend who has come to the same conclusion on the particularity of the Crown SR.
The particular slam (or "beat" or "bass attack" or "bass kick" or "oompf" or whatever we can call it) is just there, and it's a result of the amp. Honnest.
Yeah, they realised back in the mid 80s that the design would never scale as not enough cobolt in the world to turn into radioactive waste. It must have been scary the first time the plasma short caused the whole torus to jump. Now THAT is power.
Shame fusion is STILL 20 years away and might always remain so bar that big yellow ball in the sky.
I would prefer not to comment on the rest of the audio spectrum produced by the amp as it might distract from the main question. It's really the bass realism and punch/slam which is easily noticeable.
when you say bass realism and punch, can you give some examples (tracks would be really good). It would be interesting to analyse the frequency response of what you consider 'bass' and the crest factor.
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