I'd characterize "slam" as the same subjective artifact as "punch" but at a freq. range just BELOW what "punch" provides.
"punch" = about 70-300 Hz.
"slam" = about 40-70 Hz.
Both are air compression artifacts, and both are derived from the driver eff. as it relates to current and waveform onset relative to driver Mms and air compression abbreviating initial decay (ie. fast drive/pulse and artificially fast initial stop - driven with lot's of current relative to a typical impedance curve).
This is typified by a high eff. high force/Bl driver in a moderate volume (relative to the driver's Vas) sealed box with the overall driver Mms and actual bandwidth dictating the freq. range of "punch" to "slam".
Tip: you can usually get a bit more "slam" with just an Impedance compensation circuit at Fb (resonance in-box) where the amplifier can "dump" current at those lower freq.s. Of course with an open baffle it's just Fs (resonance in free-air). (..this is with a common "voltage"/low output impedance amplifier, and it works better with amp's that have larger power supplies.)
"punch" = about 70-300 Hz.
"slam" = about 40-70 Hz.
Both are air compression artifacts, and both are derived from the driver eff. as it relates to current and waveform onset relative to driver Mms and air compression abbreviating initial decay (ie. fast drive/pulse and artificially fast initial stop - driven with lot's of current relative to a typical impedance curve).
This is typified by a high eff. high force/Bl driver in a moderate volume (relative to the driver's Vas) sealed box with the overall driver Mms and actual bandwidth dictating the freq. range of "punch" to "slam".
Tip: you can usually get a bit more "slam" with just an Impedance compensation circuit at Fb (resonance in-box) where the amplifier can "dump" current at those lower freq.s. Of course with an open baffle it's just Fs (resonance in free-air). (..this is with a common "voltage"/low output impedance amplifier, and it works better with amp's that have larger power supplies.)
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Fair enough. What must people mean is that "hit you in the chest" sound sensation. That's usually done with sealed or horn loaded woofers, big ones.
I've had OB speakers that played easily down into the mid 20s, verified measurement. But they did not slam. Plenty of low end, but it was different, clean, almost not noticeable - even with 21" woofers. That was a strange sensation, to have all that low end, but no thump. It's not a sound most of us are used to.
If slam is on the recording then I want it reproduced. If it is produced independently by the speakers then I don't want it.
It's difficult to know this when you haven't found it yet. It's difficult to find it when you go looking for it. It will happen eventually if you do everything else properly.
It's difficult to know this when you haven't found it yet. It's difficult to find it when you go looking for it. It will happen eventually if you do everything else properly.
Interesting. This make me wonder what's different about dipole bass.
Is chest slam more of an indoor system phenomena? Ive had it with many indoor systems but I cant recollect it with outdoor concerts despite good bass SPL from bass bins (out of the near-field).
Could chest slam be more of a gross room pressurisation phenomena from a box speaker then a passing pressure wave launched from a dipole? The kind of box sub pressure that causes ceiling tiles to dance and windows to flap should also cause the chest with its internal air space to also get compressed and vibrate.
Cool! Have you heard "punch" or "slam" from OB? If so more more punch than slam?
Your observation is neatly backed up by this experiment of resonance of the human chest cavity, with peaks around 60Hz and 120Hz:
The actual values with different folk may range markedly from that experiment as they only used three subjects all about the same weight.
Your ranges are more sensible to cover the different chest sizes primary resonance and harmonics.
Any hints to find something that is hidden? Are there some tracks that can be recommended to more easily produce chest slam?
The way I'm talking about you don't produce it, it's a part of the sound of the instrument and it's on the recording. Slam is often subtle.. when your system is capable the enjoyment is in the quality, not the quantity. It is found on many recordings and can be enjoyed even when there isn't any actual slam.
Get close enough to the sub stacks and you will! I've worked with rigs in stadiums and hockey rinks that are insane. But maybe not a scary as some crazy car systems.
For sure. I remember standing in front of a row of EAW 850 subs during sound check when my buddies at front of house decided to screw with me. I thought my insides would turn to jelly and my heat would explode. Seriously frightening.
Get close enough to the sub stacks and you will! I've worked with rigs in stadiums and hockey rinks that are insane. But maybe not a scary as some crazy car systems.
For sure. I remember standing in front of a row of EAW 850 subs during sound check when my buddies at front of house decided to screw with me. I thought my insides would turn to jelly and my heat would explode. Seriously frightening.
Yep Ive felt slam outdoors in the near field of sub stacks exiting the mosh too. But back a bit outdoors I dont remember it.
I think high SPL bass is potentially deaf inducing stuff. The SPLs can be very high without causing immediate warning pain like in the midrange. Besides the slam thing is fun. Maybe John Entwhistle's story can save some of us:
Entwistle the legendry bass player of The Who was typically blunt about the formidable racket he made. “I just wanted to be louder than anyone else,” he once said. “I really got irritated when people could turn up their guitar amps and play louder than me.” Not that there was ever much chance of that happening. Famously, his bass rig grew to be so towering and such a sprawl that among Who insiders it was known as Little Manhattan. He became so deaf he had to rely on lip reading to understand speech and towards the end of his life played by feeling the rush of air from his giant amp stacks.
So maybe dipole bass and lack of slam is a bonus?
(..or the drums.)
Yup.
It's definitely proximity-dependent (and spl, though I don't think it's a linear relationship between the two).
It's subjective. You almost certainly will not achieve the exact quality the track was produced with, and even then - most aren't trying to do that with their systems, rather the listener typically want's something closer to what they feel is "live".
One thing it usually affects is set-back/depth of those reproduced sound-sources. More air-compression typically "moves" those virtual instruments further forward into the mix. THAT can be annoying with ex. a *drum-kit "on top of a singer" (..and it's something that OB's are VASTLY better at: keeping virtual instrument set-back, than sealed/ported designs).
*well, unless the singer is playing drums ..err, Genesis/Collins, ZZTop? (..though probably not even then because I doubt many tracks would be mixed that way.)
Modes (peaks above the average) sound quite different - much longer sustain/droning/booming.
Sure. More "punch" and not much "slam". My HT has both OB upper-bass/lower-mid. front channels and subwoofer. The subwoofer drivers were specifically chosen for the very high Qe (week motors) to get more pressure down low w/ less eq. - BUT such drivers have both a comparatively slow rise-time and very sloppy decay": they "drone" (and distort). The front channels however have some pro 10" drivers with a Qe around .6 and an IB sensitivity at 150 Hz around 93db - and they do provide some "punch" though not a lot.
For "punch" and "slam" as well as more subjectively "apparent" bass level, I use bass shakers (2) in the seats.
So drums might be a model for real acoustic U-frame dipole slam? If so maybe drum kick might be best reproduced by a dipole rather then a box. An OB with a driver big enough and powerful enough to smash out the impulse?
Whats your thoughts about having an OB under a chair or right behind the back rest for close proximity <90Hz slam?
..drums aren't dipoles. The closest loudspeaker "analog" would be a sealed bipole bass/subwoofer (and with a very small amount of time-delay on one of the two woofers).
My HT sub is a floor loaded OB with a digital (Receiver) crossover at 100 Hz (..but it's also got a large Inductor in series to "flatten-out" the response above 35 Hz). (..it's powered by a 700 watt amp.) I should have gotten at least 4 of those drivers for more "headroom", but I only have two 15"s.
It doesn't have any substantive "slam" (or "punch" considering it's range of operation), but it is a platform for my second row of recliners - and it really shakes the floor of that platform (which is a neat effect, even if it's rarely noticed because of having your feet off the floor/platform when reclined).
The front "exit" (basically an "H-frame") is within 2 feet of the front listeners with the seats reclined normally, and the rear "exit" is within 3 feet of the rear listeners with their seats reclined normally. (The platform itself is around 8 inches high and about 10 feet wide by 6 feet long.)
Proximity is extremely important with an OB sub (even one like mine that isn't designed for "slam" or "punch").
I can turn-off the sub and the only reduction is apparent "hall sound", or that lower freq. soundstage expansion. Speaking of that: it doesn't sound like an HT, rather it sounds like a large movie theater (and the difference is very noticeable when compared to monopole sealed/ported designs). I can also watch movies/shows (LOUD) at night while other family members are sleeping a few rooms away (..and without doors that have exterior-grade seals). (..I've recently been binging Marvel and Star Wars shows on Disney + late at night: Marvel - Jessica Jones/Daredevil/LukeCage/IronFist/Loki; Star Wars: The Mandalorian/The Book of Bobafet.)
My HT sub is a floor loaded OB with a digital (Receiver) crossover at 100 Hz (..but it's also got a large Inductor in series to "flatten-out" the response above 35 Hz). (..it's powered by a 700 watt amp.) I should have gotten at least 4 of those drivers for more "headroom", but I only have two 15"s.
It doesn't have any substantive "slam" (or "punch" considering it's range of operation), but it is a platform for my second row of recliners - and it really shakes the floor of that platform (which is a neat effect, even if it's rarely noticed because of having your feet off the floor/platform when reclined).
The front "exit" (basically an "H-frame") is within 2 feet of the front listeners with the seats reclined normally, and the rear "exit" is within 3 feet of the rear listeners with their seats reclined normally. (The platform itself is around 8 inches high and about 10 feet wide by 6 feet long.)
Proximity is extremely important with an OB sub (even one like mine that isn't designed for "slam" or "punch").
I can turn-off the sub and the only reduction is apparent "hall sound", or that lower freq. soundstage expansion. Speaking of that: it doesn't sound like an HT, rather it sounds like a large movie theater (and the difference is very noticeable when compared to monopole sealed/ported designs). I can also watch movies/shows (LOUD) at night while other family members are sleeping a few rooms away (..and without doors that have exterior-grade seals). (..I've recently been binging Marvel and Star Wars shows on Disney + late at night: Marvel - Jessica Jones/Daredevil/LukeCage/IronFist/Loki; Star Wars: The Mandalorian/The Book of Bobafet.)
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That's a very fun thing with good, clean LF output.
It can make your listening space seem much larger - and different from recording to recording.Yeah it is cool - especially with good atmospheric mixing. (..Alien Covenant had some spectacular/"massive" audio scenes, even if the movie was "blah" and messed-up the Alien/Predator universe.)
Really the weirdest/coolest thing about the system is that I can turn off the sub, with only the front channels and their 100 Hz high-pass and the addition of the bass shakers make it sound like the system has full bass extension. It's just crazy what the body interprets physically to turn the result into apparent sound (though there is some sound, but it's much lower in level than the average).
Still, at least with music I'd take the low freq. soundstage over the bass shaker's physical presentation (..if I had to choose between the two), this is despite the fact that I prefer 70'-90's pop & rock. I really like that "visual" aspect to music-listening. On the other hand (though not in-opposite) IF it was just through headphones: the bass shakers I'd qualify as an absolute "MUST HAVE". 😊
Really the weirdest/coolest thing about the system is that I can turn off the sub, with only the front channels and their 100 Hz high-pass and the addition of the bass shakers make it sound like the system has full bass extension. It's just crazy what the body interprets physically to turn the result into apparent sound (though there is some sound, but it's much lower in level than the average).
Still, at least with music I'd take the low freq. soundstage over the bass shaker's physical presentation (..if I had to choose between the two), this is despite the fact that I prefer 70'-90's pop & rock. I really like that "visual" aspect to music-listening. On the other hand (though not in-opposite) IF it was just through headphones: the bass shakers I'd qualify as an absolute "MUST HAVE". 😊
I do not know for the SLAM of comming 'copters in Platoon movie but for the upper punch, drums we more often talk with rock and pop, what is sure is you must have the good harmonics till the treble, to have this feeling of fastness/dryness like a whiplash effect but with more impact. I noticed by changing just a 0,1 uf film cap by another in a LR24 Bessel... with one I have the "punch"...not with the other !
I surmise the power response, group delay and curve targett to enter in the equation...not only the way the upper bass is loaded.
I surmise the power response, group delay and curve targett to enter in the equation...not only the way the upper bass is loaded.
For those who think there is little to no tactile bass in most recordings ie in the 20-40 Hz region, just look at a spectrum analysis of instruments like a piano, acoustic double bass and even a marimba. I think most of us audiophile guys are turned off by bloated, exaggerated and sloppy bass, but there is alot of very low frequency energy and transients in acoustic music. The telarc version of Stravinsky's Rite of Spring is an absolute blast to play on a high end system that delivers true full range low end into the 20 Hz area. I'm not talking about EQing it to get down that low. I'm talking about LF reproduction from inherently linear bass that goes that low and well dampened without any electronic help. 99% of what I've heard people call full range high end bass isn't that at all.
Once you've heard a decent sealed or horn loaded system that can play the 32 ft low C pipe on an organ unattenuated, you'll know what I'm talking about. You can hear 16.3 Hz with your body being part of the experience. Call it slam, punch, whatever. A kick drum wave form is nothing but a short burst of a very low frequency sine wave. I haven't heard any decent sounding kick drum through a PA system yet, with only one exception. A traditionally recorded and processed kick drum is just a fake sound once it goes through EQ and horrible flabby PA subs.
Closest I've come to decent PA concert bass was at a Genesis gig 1986 in Munich, Germany. I was a tech that oversaw banks and banks of Crown Macros running close to 100 sub cabs. The bass was the tightest and lowest I've ever heard in large scale. Drum kits sounded incredible as did the moog Taurus pedal and Tony Banks synths. The kick drum was in a whole different league and the fundamental attack sounded (fealt) like a sledgehammer hitting a large old oak tree. Never heard anything like it ever again. The lack of distortion and compression was simply unbelievable.
Once you've heard a decent sealed or horn loaded system that can play the 32 ft low C pipe on an organ unattenuated, you'll know what I'm talking about. You can hear 16.3 Hz with your body being part of the experience. Call it slam, punch, whatever. A kick drum wave form is nothing but a short burst of a very low frequency sine wave. I haven't heard any decent sounding kick drum through a PA system yet, with only one exception. A traditionally recorded and processed kick drum is just a fake sound once it goes through EQ and horrible flabby PA subs.
Closest I've come to decent PA concert bass was at a Genesis gig 1986 in Munich, Germany. I was a tech that oversaw banks and banks of Crown Macros running close to 100 sub cabs. The bass was the tightest and lowest I've ever heard in large scale. Drum kits sounded incredible as did the moog Taurus pedal and Tony Banks synths. The kick drum was in a whole different league and the fundamental attack sounded (fealt) like a sledgehammer hitting a large old oak tree. Never heard anything like it ever again. The lack of distortion and compression was simply unbelievable.
Nothing worse IMHO than detached sounding upper and lower bass lacking coherence. That two part type of bass where the lower mids and low end sound like separate events is just awful.
What recording is that from? I've tracked alot of acoustic bass and can tell you there is life down below the fundamental 41 Hz E, despite in theory the instruments lack of output. Its in the attack of the notes and shows up as gross phase shifts when high passed above 20 Hz. Yes, there's rumble if the player isn't that skilled or if there's bleed from outside sources getting in, but if its an isolated recording, there's no need for a high pass beyond 20 Hz.