JapanDave dedicated theater build. - Page 18

WHY WHY ARE YOU IN JAPAN! Making it hard for me to visit...

What on earth do you listen to that you need flat to 5hz? Or is it just a "because I can" thing?

Btw, don't I remember you having an Aquarium? Or did my tiny little brain make that up?
Edited by premiertrussman - 12/13/12 at 6:54am

japan dave, have you heard the epik conquest before? I plan to also do 4x18 Fi IBs, just wondering how you think it compares. I think I can do 8x18 Fi IBs when I get the money, not sure how to power them though yet. Never did an IB build

Behringer EP4000 seems to be the go-to amp for IB setups. That is what I am using.

I can't answer for Dave, but I can share my perspective.

Many soundtracks contain moderate, to high level content down to 5hz and even lower.

When one experiences a well executed soundtrack, that fully utilizes the entire LFE spec's (3hz-120hz) bottom octaves, it truly adds an element to the playback experience that's quite exciting and certainly heightens the impact and realism of the intended effect.

Since our abiity to hear LF/ULF diminishes greatly with a lowering of frequency, to allow for inclusion of these freqs in the playback, seemingly high levels are required. However, these levels are often just a little above audibility.

At around 20hz, it takes about 75dB SPL for audibility.
At approx 16Hz, you need about 85dB SPL.
In the 10hz area, about 100dB SPL is audible.
Way down in the 5Hz deep, deep stuff, our threshold of audibility is about 110dB SPL.

---

As you may know, loudness, and SPL, are two different things. The difference is our manner of varying sensitivity according to frequency. Your question was regarding 5hz capability, and for a system to possess any meaningfull 5hz playback ability, it must really be able to hit 116dB or so to really add meaningfully to the reproduction. No small feat.

For comparism, down at 5hz, 110dB is barely perceptable. However, that same perceived loudness is essentially the same as one would perceive encountering 60dB@30Hz.

Again, I can't answer for Dave, just my perspective fwiw.


Thanks

what about tactile effects at the ULF? One could probably feel 5Hz signal at levels below 110dB. no first hand experience here, just a guess.

I wouldn't have guessed there was that much content available.

I ask myself that question in regards to 7.1 (or even 9.2/11.2 that people are goign to nowadays). When I last checked a couple years ago, only 5 movies a year were coming out in 7.x on bluray!?

There's been single digit extension material for decades in the music world. Way before the media could even handle it. Tone-arms used to physically jump out of the grooves. Then, upon digital media becoming mainstream with CD's in the early to mid 80's, those limitations left us and other limiting factors were present, but not dynamic in nature.

In theatrical releases on DVD/BluRay, I'm unsure when the first ULF (however one defines that) content appeared. But there's a lot out there already, and I'm convinced the measurements, charting and documentation performed in multiple forums over the last 10 years, doesn't convey the entire picture.

Myself, with (4)18s, and (4)15s, I've got significant capability in the bottom octaves. While enjoying various DVD/BR releases, I run into these huge wallops, incredible wavefronts of LF/ULF energy effects, that occur in the most unexpected scenes and films.

Many view these releases and just don't fully realize the full bandwidth of the effects they contain. Having the capability to resolve effects like these, increses the effect intended by the filmaking team. Likewise, not experiencing the intended effect fully, ... lessens the playback experience. Simple as that. Many enjoy debating this, on both sides. However, that doesn't change that they clearly add to the experience.

Either, one pursues this capability, or not.


Thanks

If the film mixers never heard it, why should anyone else?
Edited by Roger Dressler - 12/17/12 at 2:15am

Hi JD !


Spectacular build! Love the detail in your thread/posts. Will help a lot on my build coming up.

oh, THREE MORE ??????????????????????

Are you seriously seeking the capability of inducing (no pun intended there) BM's in you guests???????

Absolutely spectacular...wish I could hear it!!!
I`m a basshead too and love deep bass!

I already have 4x 21`s in my HT Room and am seriously considering adding 4x 18`s.

Must be wonderful in that room.

Congrats on a super build!
Hope you all enjoy it.

Regards,

japan dave is crazy! no crazier than us, but he has a little more dispensable income. xD! I want to hear the bass. I will replicate your bass setup, I cannot afford the rest, but bass is worth 5K to me.

JP, what  about the rear. Are you planning  for rear subs, and what type of setup? I have a simular size ht as yours. Recently i changed the sub cabinets to a different layout  shape a much flatter one. 

the subs rest between the two back pilars containing the back speakers at the rear. makes for a clean look and  the subs are well balanced at this location. i can post a picture  if you want. my profile pictures don't show the rear subs as some changes have since been made to my room.

It's good to see the continuing build and "never satisfied".
Good stuff!
Happy Holidays!

Mike

Very good question.



Despite the logistics of the film mixing, the sound design team includes it to facilitate the intended effect.

Why remove elements of the wavefront?

Master and Commander is the perfect example,...as the BluRay mixing inexplicably removed a very impactful range in the bottom octaves. The DVD version is full bandwidth. Clearly, one experiencing the cannon fire battle of each version, can easily discern the difference. The same can be said for other soundtracks whereby the bottom octaves are filtered. Why leave the energy in? Because it mimics the intended effect. Filter the energy out, the effect is lessened.. period.

The film mixers are there primarily for technical reasons, not necessarily artistic reasons. ToddAO (iirc) replaced their superb BagEnd, 8Hz extension system, with a vented Meyer pro audio system. And you're right, they don't audibly monitor accurately into the lowest range that he sound designers often include in their work. Screening rooms can possess this capability. It's bee explained to me that mixers can monitor these effects via metering.


That cannon blast is more effective with the energy, less effective without it. That's true whether it's the M&C epic battle, or Telarc's masterpiece from the 70's.

---

I'm sure many here realize, our ability to hear doesn't just cut off, ... it just takes more SPL to achieve a specific perceived loudness.

At approx. 16Hz, 85dB SPL is required to achieve audibility. Down at 10Hz, approx 100dB SPL is needed, and way way down at 5Hz, experiments have illustrated that our threshold is consistantly been shown be about 110dB SPL.

I'm guessing our perception is blurred between tactile and audible way down. Also, indoors, the high ULF levels often create pulsing, creaking, unintended sound that emanates from elements in our rooms. My non-dedicated room is no exception. I'm sure a more dedicated approach could largely feret out these issues.


Roger, I'm somewhat familiar with your work, and I've got the utmost respect in your contributions here. I've taken part in this disscussion quite often, however I don't believe I've ever seen you participate in this topic. Thus, I'm quite interested in your take. I've investigated and discussed the cability of screening rooms wrt LF/ULF. I'm aware of approx how many such rooms exist, and their bottom octave -3dB points.

What I'm most curious about, is facilities like Skywalker Ranch, and their resolving abilities in the bottom end of the spec. I know designers like Randy Thom certainly has an affinity for the deep deep stuff. Like other things in audio, the last bit of resolution comes at a cost,.. but the experience with and without this aspect of the intended effect is quite different.

Dave, sorry for the derail, but Roger threw out a great question.



Peace

I think M&C is a wholly different issue than the one we were discussing. This post refers to single-digit frequencies and ULF content. M&C was high-passed at 27 Hz, clearly removing significant bass that fits neither description.
As discussed more below, theater speakers do not plumb those depths. If, perchance, there are titles where bass was intentionally rolled off, say, somewhere <20 Hz, how would that sound any different than an acoustic rolloff at 20 Hz or higher (setting aside possible gains in headroom)?
I did not say they don't monitor accurately. I said they do not hear the ULF content. I would suggest that the new ToddAO system lets them more accurately hear what their soundtracks are going to sound like when they hit commercial theaters. The film industry is concerned about consistency and maintaining artistic intent. I think film mixers are, in fact, artists in their own right, and they want to know how well their art will "play in Peoria."
I agree with all of this. But it is beside the question I am asking. If the film mixers and moviegoers hear a consistent presentation, and that means ULF content is absent, should we be obligated to excavate that content and make it audible? That seems counter to hearing the presentation as the creators heard and intended.
I think we have to separate screening rooms (like Meyer's Pearson theater) from dubbing stages and commercial theaters. The Meyer room is a kind of magnificent laboratory and showcase for what is possible. So too may be high end home theaters where a "no holds barred" approach may be taken, like yours and our host, JapanDave's. That's also been the driving force behind exotic audiophile stereo systems for decades. Extracting more detail, texture, nuance, and spatiality than even the original creators probably heard. I am not trying to dissuade anyone from "going for it" and enjoying every drop of excitement it brings them. I am suggesting, by my question, that one can legitimately claim to achieving the full, and fully accurate, theatrical experience, as designed and as heard by the original creators, without that extreme level of bass extraction. Just being able to achieve bass performance at home as well as the best movie theaters is no small feat.

A last comment. I have occasionally heard some ULF content that was obviously unintended, wind or thuds that had no place in the scene, and probably just remained there because no one had the ability to reproduce it. Just to say, all that glitters is not gold.

That is one heck of a table saw set up you have there. What kind of saw is that?

Its an Incra jig....i.e. the best.

Dave - have you got a router attached to it?

I knew that much, I'm wondering more about the actual cabinet saw.

One of my all time favorite theaters! Makes me wish i lived in Japan! Looking forward to you finishing up soon and update your first post with all the changes you made regarding the audio,video and other stuff.
Regards
Vik