Purpose of flat response below 20Hz - Why does it matter? - Page 8

Me.

In fact, it's a requirement.

What system are you using for sub duties, just so I know from what position you and SL (actually, you do realize how silly it sounds for you to include him in your whole ashamed/laughing nonsense) would be laughing?

Bosso

Actually, it's you who is arguing. I posted data and facts. You've admitted to not having ever confirmed ULF content in any source that you've heard and approve of and you've posted your in-room response to show that you can't experience it if you did confirm it.

That would make your argument the contrary opinion, and a very weak one at that.

Your bad, indeed.

Bosso

Please do and then ask him how its really a sacrifice in theory. No difference in physics, just seems to be a semantic swinging pendulum here....what ever suits your purpose.


Now I would love to have > 110dB at 10Hz with < 2000Watts (maybe I will with a DIY rotrary design) but there is no free lunch in high end HT so 8000Watts is needed. It costs $$$ but that is it, when $$$ isnt a huge issue how is it remotely a sacrifice?

Conclusion sacrifice for you, not for me and Bosso.

Do you even have a custom HT room?

The sharks are in the water Bosso. Enjoy it my friend

You and Bosso are simply awesome, that is all.

How stupid of me to assume people on this forum have limited funds.

Maybe someday I can build a cost-no-object system, proclaim nothing is a constraint because I have bottomless pockets, and be as awesome as you and Bozo.

It's not so much about funds, per se. It's about room size, room interaction, sub placement, listening position measurements, and from a fiscal standpoint DIY skills (and equipment and knowledge needed to build). Also, it's about what exactly you can do. I can easily afford a badass IB setup, but I'm not going to do it in this house since we're moving soon. You can get all the output you need for "relatively" cheap. You just have to make concessions elsewhere...whether it's time, effort, or placement of sub(s).

I never said that I hate your subs (or any other system designs). I was just stating the obvious. Those are rather large subwoofers.

I am kind of disappointed that you are afraid to push them when you suspect that there may be higher level ULF below tune. Why not high pass those speakers at the proper frequency to protect those drivers?

Data and facts are useless without competent interpretation.

So far I've seen a ton of hand-waiving and little desire to apply data in a competent and reasonable fashion.

I've asked you repeatedly what the musical relevance of the ULF content of the Sting track was: did it correspond to something in the music or was it simply outside noise?

You've not bothered to answer. Can you not competently correlate a graph to music?


This is the same Penn that dared to call me "elitist," right?

Sounds like several folks here aren't using Monster cables.

Well, its not a good thing ofcoarse. But, as far as sacrifices go its a small one, dontyouthink?

Amplifier power is cheap, doesnt need to be replaced for years, doesnt take up any space and is easy to buy.

But it's a start. You have any?


Beats nothing, which is what you've brought to the thread.


This is simple, but you seem to be having a hard time with it. It means nothing to you because you can't reproduce it.

I have competently correlated hundreds of graphs with my positions hundreds of times. Use a search engine.

In the meanwhile, the thread isn't about you. As I've suggested, please start another 'why <20 Hz DOESN'T matter" thread and stop jacking this one.

Bosso

So, you and SL will have a good laugh because I spent too much money on my amplifier?

Actually, yesterday I e-mailed SL and asked him how to figure out how much amplifier equals "tons of power".

You were right. He indeed had a good laugh.

Bosso

WOW! You are even more awesome than you were yesterday! Can you top that?

What is the point of posts like this? Is it common here?

No, though I did ask both you and Sahak94 in this thread about how to take my own data using files encoded in Apple Lossless on a machine running OSX, and got no reply from her/him and no useful reply from you. (Your "watch your woofers" wasn't useful, because mine are concealed from view.)


You may have taken the first step, showing the presence of ULF in one piece of music. But you haven't done the one thing that would make your position have merit beyond the world of special effects bombast*. That is, you've not made any showing whatsoever that the ULF signal that you have shown to merely exist in one commercial music recording is intentional by pointing out how it correlates with the music.

If you can successfully do that, you will have basically won me (at least, possibly others but I can't speak for others) over to your position, because you will have demonstrated with competent data (already taken) and convincing interpretation (the missing step right now) that you are correct.

Blind testing as convinced me before that my preconceived notions about the importance of Q in closed box subs was wrong, and your ideas were better. The same could very well be true here. Yet here you continue to refuse to take the obvious step required to do that, even though you've taken the measurements and therefore must have the track. Why?

Given your reluctance to do something that should take at the very most five minutes and five seconds (the length of the track in question), a reasonable person can infer that you know the ULF content on that particular track is more likely than not simply a mistake, and its presence does not actually bolster your position one bit.

*Wrt special effects, the debate is not whether the signals exist, but what the nature of "high fidelity" is as to the re-showing of entirely fake events. Obviously, given that movie theaters can't produce ULF, if "high fidelity" in home theater is replication of the moviegoing experience at home, then ULF doesn't matter. If "high fidelity" in home theater is something else, or the term has no meaning (I subscribe to the "no meaning" view) then ULF may matter.


No, it's about a factual inquiry that provides data reasonable people can use to determine whether or not it is subjectively worth it to them, considering the program material they enjoy and expect to enjoy, to pursue extremely low LF cutoffs in their systems, or to use a higher cutoff and focus more on efficiency/output from that LF cutoff up. Why you wish to personalize it is beyond me.

I have very little experience with OSX, but have you tried running spectrumlab through an emulator like wine? Or install windows under OSX using VMWare, virtualbox, etc?

-Mike

I have Parallels 6 - I do use Cripple Mode for box modeling in Bassbox Pro and Unibox, because alas there is still no OSX box modeling program and Unibox doesn't work in MS Excel 2011 - ...but it seems to have nuked my virtual machine from Parallels 5 and I've not had a chance to find my old XP and Office disks to build a new virtual machine under Parallels 6.

Even then, I'm not sure how to get the Cripple Mode side to "see" my iTunes library.

:

If you mean sarcasm, it's being dished out with enthusiasm in this thread. If you mean digs at another's POV, I expect it in threads where passions run high, e.g., subwoofers or OTA positions. Commenting on it doesn't generally have the desired effect. You can ignore it. Or them, literally, using the ignore this poster feature.

The problem I have with your line of interrogation is that you feel you can put myself or others on the spot while you remain intellectually lazy.

I've posted the following info many, many times over the past decade in many forums. It is info from many hours of research of studies, lab grade measurements results and examination of recorded source.

I use a Mac myself, but I bought a dedicated Windows PC and state of the art measurement equipment because Mac users are generally graphics people and not acousticians.

Why on earth you think it's incumbent upon me to find you hardware/software solutions is not worth thinking about. Get busy or take my word for it or stay ignorant, means nothing to me either way.

Let's start with the basic fact of life regarding ULF content in sound in the real world:

Results of measurements of the onset of a violin string, upright bass string, piano string, etc., pluck, hammer strike or whatever, have confirmed this phenomenon many times in many studies and tests. Here are the spectrograms of a few of them:




Here's a simple experiment I did myself. I recorded an actual door slam in my HT and compared it to a Foley door slam from a popular movie:



I scaled and laid over the 80 phon Equal Loudness Curve to show that a typical door slam follows what science has told us human hearing has adjusted to over the millennia, as most real event naturally occurring loud transients do. So, would you say that the Foley door slam is more realistic after having the ULF filtered in the recording process? You may take the easy way out and say it doesn't matter, but how can you possibly take the position that including the ULF content in that same movie soundtrack door slam would be unintended artifact or in any not more realistic?

There are consultant companies that make millions of dollars by (among other things) designing car door mechanisms and seals that purposely attenuate higher frequencies, therefore accentuating the ULF, which humans perceive as being of higher quality. This is not because the ULF is 120 dB when you close your car door, or pluck a violin string at 1,000 Hz fundamental, etc.

Would you say that, for example, if your preference in music is for live recording full orchestra classical, you get a more realistic reproduction of the transients if the recording or the playback system is filtered at 20 Hz or the entire process was unfiltered?

That's a rhetorical question. There isn't any question as to which method is truer to the real event.

As far as what recordings you might prefer to buy and their ULF content or lack thereof, have at it. If you're as discriminating an audiophile as you let on, you should be as discriminating in screening the recordings you buy.

I personally have a few dozen MC SACD and DVD-A music discs and otherwise don't buy/listen to music because most recordings are compressed, filtered, synthesized, effects affected garbage. So, I'm the wrong guy to ask to act as your filter. I don't care what recordings you like or dislike, nor do I care what system you prefer to play them back on. That's irrelevant to the Q.

As far as movie soundtracks, there is no question whatsoever, except to the most clueless poster, that the content is there, it is intended and it adds to the presentation to a significant degree. Whether one prefers it or not is not the question.

When I bought Pearl Harbor I was still using a big pair of (10 ft^3) ported boxes, each with 1-18" driver. They were from the ProLogic system and I believe they were tuned to 25 Hz. There were scenes in that movie that shook the room, but as I moved deeper into things I pretty much put the disc on the shelf as unworthy to collect dust.

I recently read an article that talked about <20 Hz content in the soundtrack, so I pulled it out and graphed a bunch of scenes. Here are 2 scenes that are pertinent to this thread. First, is the onset of the Japanese attack on the Pearl harbor fleet:



When you remove everything below 20 Hz, it should be obvious what the difference in presentation might be. Yes, to me it was like watching a whole new movie.

Here's another scene where Zeroes are strafing:



If you take everything below 20 Hz out of this scene, it becomes a complete non-event, certainly nothing like a real pair of low flying 20mm canons strafing you. Conversely, it's a whole new experience as recorded.

Like it or not, the facts are indisputable. Leave it in = more realistic. Take it out = not. Personal preference, budget and taste are irrelevant here. There are plenty of threads that focus on those aspects, but answering the question; "Purpose of a flat response below 20 Hz - why does it matter?" is specific enough to exclude all of that noise.

Bosso

The pressure and bass wave effects are in full force in my room during the Pearl Harbor attack sequence. Good choice, B.

On that note, I can say with utmost certainty that there was a marked improvement over the entire experience upgrading to the LLT's that I have now from the previous subwoofer system that I had. That system was tuned ~15hz but really was rolling off by around 25hz but it was a shallow rolloff until Fb. Going from that to the solid response down to 10hz changed the way this scene was perceived to me.

It's too bad it isn't super easy (and cheap) to get some of you guys over for a demo or something at my house. I mean, if you're interested in experiencing damn decent SPL down to 10hz if you haven't felt it before.

You have the relevant data, and a system that can reproduce it, so the simple fact of the matter is that you are in the best (only?) place to answer the question.

That you have chosen not to do so is also an implicit concession that the ULF content in that track is more likely than not simply a mistake and not at all musically relevant, of course.

It's not, obviously. But given that you do this stuff, it's not unreasonable to think you might know a good solution of the top of your head. After all, you're constantly recommending hardware and such, such as Marchand's overpriced and arguably obsolete one-trick pony...

Likewise, given that Sahak94 has specifically mentioned screening an iTunes library, I put the question to that poster as well, and received no answer.

Fact conceded. So I take it you can apply that knowledge to the actual question presented, which is how the ULF content you have measured in that Sting track is part of the musical performance.

After all, what is very much up for debate is the perceptual relevance of that ULF content in your examples is what of violin piece (in live or recording settings).

If ULF content falls well below known thresholds of human perception, who cares about it?

I would say that is entirely irrelevant to the actual question I asked you, which is the musical relevance of the ULF content in that particular Sting track.

That is not a rhetorical question at all, except to the unsophisticated.

The answer is...I honestly don't know, and haven't seen any studies that point to an answer pro or con.

It could go both ways, of course.

That's why I'm asking the question about the musical relevance of the ULF content in the one music track in which you have identified the presence of ULF content in this thread.

I'm not an audiophile, I'm a music lover.

I think that says a lot. Better to get all the slam out of well-produced crap than to enjoy art...

Actually, that question could in fact exist in the mind of a reasonable, clue-ful person. You are being intellectually dishonest by suggesting otherwise.

Again, the answer hinges on how one defines "high fidelity" in the context of a staged performance originally intended to be shown in a commercial movie theater, and whether the concept of "fidelity" is at all even relevant to the act of playing movies at home.

You actually paid money for that POS?

Thanks for that post Bosso. I have seen spectral analysis for cymbals and was looking for those for other instruments. You saved me a few hours today .

I have a Mac and went through at least 10 different programs yesterday before I liked one for spectral analysis but it does not accept 24 bit songs. It took me less than half an hour to find one and compare it to the others. Took me more time to convert my files from FLAC to WAV and then run an analysis. I still need to find a way to save the graphs as pictures. There is content below, it just depends if the mixer added a filter (some are brick walls).

I have some tracks from the same recording company. I've compared an unfiltered track to one of their filtered track. Both have content to at least 6 Hz. There is a drum test in a large live room also. The content when he announces the distance from drums to microphone has a peak of 1 mV at 14 Hz. When he is actually playing the drums, there are recorded values of 4.5 mV at 7 Hz. Another track with a drummer has almost no content below 20 Hz (.2 mV peak) but when the bass drum is used in the second half there is content at 9.6 mV at 7 Hz. Those are just some examples for instrument related.

As for outside noise, isn't that what connects a person to the event? Recordings of real events contain massive amounts of content below 20 Hz. Whether or not the person listens at a volume loud enough or if the noise floor in the environment is low enough is another matter as is the recording.

A larger 3 dimensional soundstage is generally attributed to the extension of the speakers. Does someone know at approximately what Hz this no longer pertains to?

Has anyone ever seen Ghost Hunters on Syfy?

I went with this suggestion. I wish I asked earlier. I would have them for the weekend. . Anyone selling their used REW measurement hardware and Antimode?

Cool. Let me know how well that setup works out.

Not sure what you would consider interesting. But, a good start would perhaps be Infected mushroom (dancing with khadaffi, never ever land) or Son Kite. Both artists use very low frequencies in their music. How about Patricia Barber then? I have a song from a live recording somewhere with an accoustic drum that goes very low (well below 20hz).

Or, are all suggestions going to be ignored because they are uninteresting to you and we end up with information from you that the only music you listen to are violin concerts? If so Im not sure what the point is.

BAHHHHH! I couldn't resist coming back to post something else. What about music from Bassotronics? There is some really low stuff in that music... sub 16hz (for ds).

Spectacular post, bossobass. Thank you!

Have you come across measurements other than dB/Hz and Hz/s that you have felt should be taken into account when reproducing sound?

Do you do anything in particular to accurately reproduce along the Hz/s axis, similar to what the *flat* part of the subject advocates for dB/Hz?

Do you know if there is something equivalent to Equal Loudness Curves for Hz/s that good recordings align themselves with?


edit: replaced dB/s with Hz/s throughout; apologies for any confusion.

Ah yes, that underwater type sensation. Like at the end of this clip.

http://www.youtube.com/watch?v=wru7XVriBdQ&feature=fvsr




Anyhow, how large is your room and how loud do you play that movie to get that effect? In other words, whre do you fit in with this protocall as far as room size and listening level is concerned? Is -10 to -15 below calibrated reference the level that you listen to get this effect?


http://www.audioholics.com/education...ofer-room-size

At what level?


Wait, 14Hz on human voice? That seems rather obviously to be an artifact of something.

And more generally, what do your mV values correspond to in terms of level? How far below (if any) are they from the average levels on the tracks? I ask because what I want to know is whether there's anything perceptually relevant.
(I don't care about content at 30kHz, either.)


Most of the time, what people think are "very low frequencies" are not ULF. Do you have numbers and relative levels?

For instance, I once read a study that measured the bass from Tube line under Royal Albert Hall - anyone who's ever heard a concert there will know what I'm talking about - at something around 25 Hz.


No musical program material will be ignored, except for the above-mentioned "sonic spectacular" disks that people only buy (myself included; I own both the Kunzel/CinnPops 1812 and, sadly, the Wellington's Victory) to demo the effects once or twice and maybe beyond that to show off the system to guy friends - never met a girl who gave a fig about bass from ordinance... - not for actual listening.

The point of my inquiry is to determine whether designing a system with the pointed goal of ULF reproduction (below 16Hz organ pedals) is useful for the reproduction of music. Not door slams, not 20mm cannon strafes, not dinosaur stomps, etc.