# DVD's with ultra low bass???



## Sonnie

I've been seeing a lot of DIY'ers talking about getting their subs to produce to 5hz.

I'm wondering what DVD's, whether it be movie or concert, offer this kind of response?

What are some of the lower response DVD's offered.... anything below 20hz or so?

I know there are certain music CD's that do the incredibly low bass, but I'm thinkin' more of along the lines of something I would actually use more often and I'm not much into listening to the music CD's just to get to subsonic frequencies.

So... is there a way to test certain scenes to determine what their lowest frequencies are? Or is there some place that offers a list of DVD's with the frequency response of certain scenes?


----------



## khellandros66

I know War of The Worlds has Fs as low as 7Hz in some scenes. 

WOTW
U-571
LOTR Trilogy Extended Cuts (down to the single digits for the scene where Gandalf faces the Bal Rog')
Saving Private Ryan
Band of Brothers


I am sure there are more but these are a few that will push you subs limits

~Bob


----------



## Sonnie

How are we verifying these figures though... just from what another forum poster somewhere has claimed or from a reliable source? Do we have any measurement data or a fact from the movie producer?


----------



## Danny

To Test the frequency range of a Disk you can just hook the line out of your amp to a frequency spectograph. This may cause a bit of discussion but I really don't see why you would need anything below about 20Hz, Most people can't even hear anything below 40Hz.


----------



## Alaric

Hi There,

Danny - I'm curious on this one, particularly measuring the low frequancy output of a DVD. I use a HTPC as a source so could i use a piece of software and measure this ???

The reason i'm interested in serious LFE is i drive a pair a buttkickers which go down to 5Hz, you don't hear them, you feel them.

Thanks,
Lee


----------



## Otto

khellandros66 said:


> I know War of The Worlds has Fs as low as *7Hz* in some scenes.
> LOTR Trilogy Extended Cuts (down to the *single digits *for the scene where Gandalf faces the Bal Rog')
> ~Bob


Not saying you're wrong, but what are your sources for those numbers?



Danny said:


> To Test the frequency range of a Disk you can just hook the line out of your amp to a frequency spectograph. This may cause a bit of discussion but I really don't see why you would need anything below about 20Hz, Most people can't even hear anything *below 40Hz*.


You're right! That comment may cause a bit of discussion... :laugh: I can easily hear in that frequency range. Now, get up in the higher frequencies (15 KHz? 17KHz and up? not sure on specific numbers, but it's pretty well known that human hearing will drop off at the high end, especially with age), and I'd say that most people probably can't hear a whole lot up there. Also, as Alaric notes, we ain't necessarily looking to "hear", but rather feel. :T 

Have a great day, everyone!


----------



## brucek

> Most people can't even hear anything below 40Hz.


I believe most people can hear down to 20Hz and perceive much lower through vibrations.

brucek


----------



## Sonnie

Exactly... this is not so much a hearing test but rather a feeling test. Although when I play an 18hz tone through my subs, I hear a noise and feel vibration.

I'm looking for verifiable numbers... not hearsay or speculation.

Seems like I remember seeing a program once that you could play a DVD via your computer and it would show the response, but I'm not sure exactly how it worked or what it was called.


----------



## Sir Terrence

When I am blown away by deep loud bass, I use Soundforge software to see the response of the LFE and main channels. I also have audiocontrol 1/3 octave spectrum analyzers for each of my channels to measure the respose between 20-20khz(it does not measure below 20hz). 

All of the new Star Wars movies have bass below 20hz (cannot be heard, but can certainly be felt if you subwoofer can produce it), TPM has very high levels of bass at 10hz, and the record goes to War of the Worlds from what I measured below 10hz at sustained high levels. U-571 has bass down to about 15hz in the underwater explosions. Saving Private Ryan has bass below 20hz at high levels (this is just reading the RTA's). You can also find high levels of near 20hz bass in the main channels of these releases as well. 

My subs peter out at 15hz and they have a 15" ELS (extremely long stroke) driver in a transmission line design 30x18x17 box. I have two of these in my room. A sub that produces 5hz would have to have an extremely long port with multiple 15" drivers in a very large box, or a huge sonotube that is tuned to that frequency. They would be huge, and not useable in many rooms.


----------



## Sonnie

Sir Terrence said:


> A sub that produces 5hz would have to have an extremely long port with multiple 15" drivers in a very large box, or a huge sonotube that is tuned to that frequency. They would be huge, and not useable in many rooms.


IB... mounted in the attic! Seems most all of those DIY'ers are getting response down to 5hz.


----------



## Danny

brucek said:


> I believe most people can hear down to 20Hz and perceive much lower through vibrations.
> 
> brucek


40Hz is around the point where older people can't hear from, young people should be able to hear down to 20Hz. You can feel the effect of low bass quite easily at any age. RE the highs audible range drops off around 10000Hz but you can still detect the absence of the higher frequencys up to about 20000Hz.


----------



## Alaric

Hi Sonnie,

_Seems like I remember seeing a program once that you could play a DVD via your computer and it would show the response, but I'm not sure exactly how it worked or what it was called._

Now that would be almost exactly what i'm looking for. I want to set-up some test tones for calibrating the Buttkickers which i can do, however due to some films having extream bass you find you can't just set and forget, and getting the right setting before a film by chance is slim....some people preview a film first, but once you've seen it, its already lost some of its impact, so being able to analyse a flim first would give me my ideal, and i could keep a listing or something.

Brain in gear please and remember, or at least point in right direction :wave: 

Ta,
Lee


----------



## Sonnie

Seems like I remember seeing it at AVS, but not knowing what it's called I don't know how to search for it. It was a while back too... so no telling how deep it's buried over there. Then again it might have been HTF where I saw it. 

It had a colored spectrum display of like you would see on a weather radar. The deeper the response the color would change. But I don't rightly remember the pattern or how you even measured it... other than I wanna say it was done with a computer program.

I wish I could remember more but that part of my brain has faded. It just can't hold much and I had to make room for some more stuff up there... something had to go and I guess it was part of that... only fragments left and no defragmenter. :dontknow:


----------



## Tommy

Sonnie I have a demo dvd that has or is supposed to have a bunch of scenes with all low LFE from different movies. Not sure if they go as low as you want or not though. Contact me and I'll see if I can upload it somewhere for you


----------



## Darren

The sub 20Hz bass is where the fun begins, lots of tactile feel. HT is all about the impact of a dynamic scene. I'm one of those IB guys who has measured flat to 10Hz so 5Hz is easily achieved. 

There have been tons of people who have measured the LFE of DVD's showing results in spectrograms. I'm not the technical guy... I just know the basics. I can't recall the specific threads but there is discussion of that on the "Cult" forum and other HT forums. Maybe it was AVS where I saw most of the measurements.

Here is one of my early IB measured plots as I configured:









Check out: http://www.avsforum.com/avs-vb/showthread.php?t=505286

And here is a site with CD's and DVD's with spectrograms... http://bass.jawmail.org/


----------



## Sir Terrence

Danny said:


> 40Hz is around the point where older people can't hear from, young people should be able to hear down to 20Hz. You can feel the effect of low bass quite easily at any age. RE the highs audible range drops off around 10000Hz but you can still detect the absence of the higher frequencys up to about 20000Hz.


Actually age related hearing loss does not usually manifest in the form of a roll off in the low bass. Its a roll off of the upper frequencies above 10khz and possibly a little lower. It is called presbycusis, and it is caused by damage or changes to the little hair like tenticles that are located in our inner ear. We use sensory and our ears to detect low bass, so most anyone regardless of age can hear a 30hz rumble, but the sounds becomes more tactile below 30hz. 

As far as upper frequencies hearing loss, once presbycusis begins to set in(usually around 40 y/o for most folks) the ability to hear, or even feel the pressure of a audio signal is pretty much gone. As a audio engineer I take very good care of my hearing mechanism and my last hear test confimed that I could hear 16khz very clearly, but 21khz just produced a pressure to my ears that gives me a headache.


----------



## rcarlton

Roger Russell comes through again! He has an article on hearing loss and age.


----------



## Danny

Great well you learn something new everyday, didn't know that low frequency loss is non existant.


----------



## Guest

Hey Sonnie,
Try this....
http://ibsubwoofers.proboards51.com/index.cgi?board=plots
This is a sub-forum devoted to thoses spectrgraphic Plots
Darrel


----------



## Sonnie

Thanks Darrel.... that is exactly what I was trying to describe.


----------



## Sonnie

The program is Spectrum Laboratory and is available here for download.


----------



## MACCA350

If you want to see what is actually recorded on the track try something like Sony Sound Forge. It has a built in spectrum analyser and sonogram. You can even see what is in each individual channel.

cheers


----------



## Sir Terrence

MACCA350 said:


> If you want to see what is actually recorded on the track try something like Sony Sound Forge. It has a built in spectrum analyser and sonogram. You can even see what is in each individual channel.
> 
> cheers


That's what I use and previously recommended.


----------



## Guest

Pipe organ is not everyone's cup of tea, but significant bass, some to 16 Hz. 

Dorian Recordings: Mussorgsky "Pictures at an Exhibition" DOR-90117


----------



## Manic Miner

It's not a DVD, but a piece of music that will put your sub to the test

Eiffel 65 - Your Clown










There is some strong 8.5hz in there, and I need to have my Plus in 12hz tune to get the most out of it. I really wish I could afford a second Plus to get an even better impact.


----------



## Ayreonaut

SVS has a great list in their FAQ.

Ones that I've heard at home include:

The Haunting
Apollo 13
Phantom Menace
Attack of the Clones
Cast Away
Contact
Fight Club
Finding Nemo
Godzilla 2000
The Hulk
The Incredibles
Lost in Space
The Matrix
Monsters Inc.
Titan AE


----------

