Until somebody shows me FR of their sub-sonic home speakers, I remain skeptical of their claims. Yes, there are systems that do go down low. I'm not saying it can't be done.
Likewise skeptical until I see an RTA of organ or any other recording with subsonic content that is loud enough to be heard on a system with a sane house curve.
A sure sign of loose rumours is when somebody ignorantly says "my system does down to 15 Hz..." because if you want anybody to believe you know what you are talking about, you'd have to say "down XdB at 15 Hz...."... which means you actually measured it.*
There is also the question of just what is booming subsonically? Can you discern the note or is it just some hotspot resonance of muddy provenance?**
B.
* not sure where you'd buy a calibrated mic that goes that low. Does that mean these claims are suspicious?
**Sure is nice to follow the PBS/Burns Vietnam War series.Wonderful bass, eh. A treat.
Likewise skeptical until I see an RTA of organ or any other recording with subsonic content that is loud enough to be heard on a system with a sane house curve.
A sure sign of loose rumours is when somebody ignorantly says "my system does down to 15 Hz..." because if you want anybody to believe you know what you are talking about, you'd have to say "down XdB at 15 Hz...."... which means you actually measured it.*
There is also the question of just what is booming subsonically? Can you discern the note or is it just some hotspot resonance of muddy provenance?**
B.
* not sure where you'd buy a calibrated mic that goes that low. Does that mean these claims are suspicious?
**Sure is nice to follow the PBS/Burns Vietnam War series.Wonderful bass, eh. A treat.
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If you look over the lists of movies that I provided and actually analyze them (as the people at avs did) you will see that the single digit frequencies are certainly not a mistake. The Hulk Punch scene, the F'ing Irene helicopter scene, the Star Trek warp scene, the Pod Emergence and Lightning scenes from War of the Worlds, the Planet Explosion scene in the Douglas Adams movie, these are not mistakes. The bass is there on purpose, it's not rubbish that should have been eliminated. It was put there intentionally and it very much enhances the movie if you can reproduce it. People aren't buying 16 or 32 18 inch drivers just for fun, there's a purpose to the madness.
I wonder how much fundamental is in the lowest piano notes relative to the harmonics. I suspect the vast majority of the power is in the harmonics, and that's surely the way we recognize the pitch of such low notes. The fundamental of the lowest half octave could be totally filtered out without being noticed as missing.
Bass guitars have traditionally had four strings tuned the same as the orchestral string bass or "doghouse." The lowest note is E at 40 Hz, and this seems to be where the better (midsize or so) "mid-fi" speakers start rolling off. This will do bass guitar and (supposedly) bass drum, and I suspect a lot of commercial recording engineers and mastering engineers add a 40Hz high pass with the argument that there's nothing musical below that, and any signal there will just take away available power from higher frequencies. I seem to remember that (using 40Hz highpass on every track) as mixing advice from a while back. I'd like to see some stats, but I suspect a lot of pop music CDs have virtually no signal below 40Hz.
But 5-string bass guitars are becoming more popular (I see people playing them live and I can hear/"feel" the extra lower notes) - the low string is the B a musical fourth below the E, and it's at about 30Hz. It's a whole step above that 27.5Hz low A on a piano. It's getting to where "mid-fi" isn't good enough for modern pop music anymore.
Yes, I know that and have commented on it earlier in this thread. Certainly you read my comments on that.
But I do hear many recording with rubbish down there that I'm sure the engineers never heard, or they would not have left it there. A subsonic filter can do a world of good if you are mixing on speakers with no bass. Failing that, the end user may need the VLF filter.
I showed 2 measurements in post #3. And the guy with the ported system did measure, he can do somewhere around 140 db across the spectrum.
The lists I linked to show Spectrum Labs measurements of the frequency response vs time. I also posted this from data-bass forum I think.
The guy that posted that sells sealed subs for exactly this purpose, his listening room is plenty loud to feel this bass. And his son has thousands of dollars of measurement equipment.
Nobody is saying that, in fact there's been a LOT of conversation here about how loud it needs to be to make it worth bothering.
As someone else mentioned previously, these scenes were measured. First the signal was measured, then the output at the listening position was measured and the signal out matched the signal in very well. These guys have fully featured dsp, it's not a crap shoot where nobody knows what they are doing.
ALL the modern mics are calibrated down to 20 hz. But if you want better you can get mics calibrated down to 5 hz from Cross Spectrum Labs like I did.
Listen, Ben, literally every single point in your post has already been discussed extensively. If you can't bother to read the data that is literally being spoon fed in this thread there's not much anyone can do to help. It's not like you have to go out and research on your own, all the data has been linked to or at least mentioned.
Yes of course, there's a lot of older stuff and even some newer stuff that was just not produced properly. Those defectives don't make the lists of bass content to search out like I posted links to. Especially live acoustic stuff is bad for this. If you have one guy tapping his toe on the stage it could be a disaster without a high pass filter to block that garbage.
See attached.
Not a particularly impressive system, 2x12" on one side and a single 21" that's doing a good impression of a side table at the other.
The main speakers go down to about 50Hz, so the subs are only covering the VLF.
Chris
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I specifically didn't mention that one because it could be argued that that one is either a mistake or if not a mistake, just overtly gratuitous since it does not correspond to anything happening in the movie at that point and there's nothing else like it through the rest of the movie. I'm not sure how much it does to enhance the movie, other than for the pure basshead freaks that are amused by such things. (Like me.) I'm not sure Pano would appreciate it as much as the others I listed which do actually enhance the scene.
Speaking of movie references, the most unexpected low bass I've encountered was toward the end of "Jay and Silent Bob Strike Back," where Mark Hamill's character, Cocknocker (yes, that Mark Hamill), deploys his rather unique superpower. 
The resulting concussive sound effect was enough to rattle the door knocker on the outside of my front door at a frequency low enough to convince me for a few seconds that someone was actually out there knocking, albeit rather nervously. Didn't get around to looking at the spectrum before returning the rental, but it had to be down around 10 Hz or so. Guess I'll have to try that one again sometime.
[EDIT] Hey, look! Who knew you could say "cocknocker" around here! Wheee!
The resulting concussive sound effect was enough to rattle the door knocker on the outside of my front door at a frequency low enough to convince me for a few seconds that someone was actually out there knocking, albeit rather nervously. Didn't get around to looking at the spectrum before returning the rental, but it had to be down around 10 Hz or so. Guess I'll have to try that one again sometime.
[EDIT] Hey, look! Who knew you could say "cocknocker" around here! Wheee!
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I'm good with 110db at 30hz or so. I just wanted to say "cocknocker"
Not a bad name for a subwoofer.
Here is bottom D on two grand pianos and the FFT. The audio samples are attached.
I forget the context of it now, but I remember reading years ago that if you played Bach's Toccata and Fugue via a tiny 6 transistor AM radio to a musician who had never before heard the piece, they would be able to correctly transcribe the lower organ pedals. In other the words the harmonics had all the audible clues of the fundamental.
The fundamental on these piano samples is 36.7Hz
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Thanks Mooly. People tend to forget that much of the energy in a note isn't in the fundamental, but in its harmonics. Your graphs show that well.
A few years back I was at a meeting of the Acoustical Society at which both Tom Danley and Don Keele were presenters. There was also a presentation by a voice teacher who showed us the harmonic content of different voices and singing styles. Most of the voice energy was in the 2nd and 3rd harmonics, not the fundamental.
A few years back I was at a meeting of the Acoustical Society at which both Tom Danley and Don Keele were presenters. There was also a presentation by a voice teacher who showed us the harmonic content of different voices and singing styles. Most of the voice energy was in the 2nd and 3rd harmonics, not the fundamental.
Explains why the Frugel-Horn Lites do so well. They ar edefinitly not doing the fundamental but are good at the 2nd & 3rd.
dave
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