What makes a 15Hz tone "better" than a 30Hz tone? (1 Viewer)

[Lewis Besze]

quote: Why would I see this as a conspiracy? I am not bitter because I cannot
reproduce, say, 15Hz at 120db.[/quote]
warmer warmer

quote: The first time I played the "Jurassic Lunch" cut (from some
Telarc effects cd) over my Hsu 1220 (-3db @ 15Hz), the low-level, 10-12Hz
"footsteps" where almost disturbing, almost not identifiable as sound as such, more
like a "disturbance in the Force". Cool stuff.[/quote]
He he Jack,that's one fun demo stuff!
I've been using it for years,but not untill recently my latest sub did justice for this piece.
Most subs,just "gargle",only a few "roars" on this one!

[Edited last by Lewis Besze on November 12, 2001 at 04:36 PM]

 

[Bhagi Katbamna]

That particular track is unbelievable. It shakes my concrete floor(or seems like it) and my couch.

 

[Shane Martin]

Somehow I get the feeling this is related to the Powered Tower discussion that just won't go away. I could be wrong but I doubt it.
There is no better in this situation. It's either Proper & Realistic or improper and unrealistic. Cut and dry.
If a movie sound mixer was to mix a soundtrack and has some low bass mixed at 15hz, why would you not want to reproduce this faithfully? While I've heard that the human ear can't distinguish much below 18hz I do want to realisticaly reproduce every tone that the movie is supposed to reproduce. Thus if my sub can't reproduce it then I'm missing that tone below what I can play and feel like I'm not reproducing a soundtrack at its realistic and faithful to the film's level.
Let's put it this way. If my Tv can't reproduce proper black level how can I say that my viewing of a movie(which is truly dependant on this like Dark City) is proper? I can pretend that it is proper or act ignorant about it and say I'm producing it but if I've never heard it how can I say that is so?
I'm not saying this is the case in yourself but I'm just trying to prove a point about either discussion which does come up. And if It matters I don't currently have the capability to do either in my own system. I must go to a friends' house to see/hear the movie properly which is where I usually base alot of my opinions off of.
Clear as mud?

 

[Bob_A]

quote: Somehow I get the feeling this is related to the Powered Tower discussion that just won't go away. I could be wrong but I doubt it.[/quote]
What does this have to do with the powered tower discussion??? I'm completely lost here...
quote: If a movie sound mixer was to mix a soundtrack and has some low bass mixed at 15hz, why would you not want to reproduce this faithfully? While I've heard that the human ear can't distinguish much below 18hz I do want to realisticaly reproduce every tone that the movie is supposed to reproduce. Thus if my sub can't reproduce it then I'm missing that tone below what I can play and feel like I'm not reproducing a soundtrack at its realistic and faithful to the film's level.[/quote]
You are missing the point here. I am NOT asking if it is desireable to reproduce sub-20Hz material on DVD's. Of course this is desireable because it effective extends your frequency response. What I AM asking is why the sound engineers would decide to include material below, say, 15-20Hz for a sound effect when they could have set the sound effect at, say, 25-30Hz.
From this discussion, it seems that the main reasons for doing this are to add atmosphere/presence to the material and to add a "tactile" quality to the sound.
[Edited last by Bob_A on November 12, 2001 at 05:27 PM]

 

[Vietor]

What I AM asking is why the sound engineers would decide to include material below, say, 15-20Hz for a sound effect when they could have set the sound effect at, say, 25-30Hz.

Because its a different effect, simple as that. Its a silly question, that begs for another silly question. Why 25-30 and not 35-40? Or 45-50?
You see its absurd, why one and not the other? Because they sound/feel different, why this topic has to go on for 20+ responces, or why the question even has to be asked I do not know.
Why a 15 Hz effect? Because its a profond, earth shaking, gut wrenching, couch moving, effect. Why 15 Hz and not 30 Hz? Because 30 is Not an earth shaking, gut wrenching, couch moving, effect.
Ever had a large aircraft fly low overhead? It shrieks in and rumbles away, windows rattle, the cat freaks out, shit gets moved. That would not happen if the sound of a large jet flying overhead rolled off at 30Hz. Then it would just sorta rumble a bit, you would KNOW that a large aircraft just flew over, but you would not FEEL it in nearly the same way.
I mean seriously, why 15 and not 30, why any frequency and not any arbitrary other? Because they all sound different, simple as that.

 

[Shane Martin]

What does this have to do with the powered tower discussion??? I'm completely lost here...

Could it be that powered towers can't produce the 15hz tone as opposed to a 30hz tone and some folks are trying to see why it is desirable or better to be able to hear the 15hz tone? This would justify that argument well wouldn't it?
I don't need a powered sub to produce 25hz tone because it isn't better right? See my point? I'm sure others are thinking this too.

 

[Bob_A]

quote: Could it be that powered towers can't produce the 15hz tone as opposed to a 30hz tone and some folks are trying to see why it is desirable or better to be able to hear the 15hz tone? This would justify that argument well wouldn't it?[/quote]
Give it a rest already Shane. Even if my powered towers (which are -3db at around 23Hz) were -3db at 15Hz, I would still ideally want an external sub so that I could benefit from the additional output associated with boundary reinforcement.

I don't need a powered sub to produce 25hz tone because it isn't better right? See my point?

You said it...I sure didn't.
[Edited last by Bob_A on November 12, 2001 at 05:52 PM]

 

[Shad R]

My JBL sub goes to about 20 Hz without distortion...and I feel it sometimes. I wish it went lower! Is 20Hz good for accurate movie reproduction? how low do most subs go? How low do your subs go? I'm curious, to know what I'm MISSING!!

 

[Holadem]

I don't need a powered sub to produce 25hz tone because it isn't better right? See my point? I'm sure others are thinking this too.

I am definitly one of them
Seriously, this question is quite... strange. My answer (which, no offense but I would think obvious) is that 15Hz sounds/feels different than 30Hz... like others have said, it is deepeer, more ground shaking, more powerful etc... perhaps you think the difference is not significant? That would then be a matter of opinion I guess.
I will agree with jack on this: clean bass IS fun!
My question to you is: have you ever made the comparison between the two? If you did, that might answer your question. I don't think I have heard a clean 15Hz. Some day when I get a new computer and replace my 20-39 with a dual 16-49?

--
Holadem

 

[Tom Vodhanel]

If the conversation gets steered toward the performance capability of subs/speakers...remember citing a -3dB point means almost nothing(in this context). Remember, those figures are almost always measured using a rather low SPL...on the order of 85-90dB.And perhaps more importantly...knowing the -3dB point tells you nothing about the distortion being produced at those freqs. If you have a speaker that -3dB/25hz....it might be producing 20% THD at 80dB by then. So that's not good...you're 25dB UNDER reference,and the speaker is already straining badly. And if you want to substitute the speaker for a sub...then you're 35dB under minimum reference standards...and alreay producing gobs of distortion.What you should be worried about if the linear capability of the sub/speaker as the levels are increased to more common HT levels.
Of course, if you never listen above say 40dB under reference level...there's probably not much to worry about.
I believe me Klipsch KLF30s were measured/reviewed as having a 21hz(?)-3dB point. They're not bad to 35hz...but much under that and it's a joke(for serious HT performance).
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[Ned]

Didn't Bob get a real subwoofer yet I thought you had an HGS-15/18 or something?
Why 20hz? When you hear/feel it at a nice high level (cough, not from anything made by Definitive Tech), you'll know why more and more movie soundtracks have content in that frequency range.
And why does everyone say "all the punch is usually at a higher frequency"? When was the last time you were amazed by a burst of 40-50hz bass? Lemme think, oh ya, never.
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My Home Theater Page

 

[Bob_A]

LOL Ned...the DT 2000TL subs are surprisingly good...very tight and tuneful and relatively deep...but they will not compete with quality external subs down real low. Can I get away with an HGS-18 in my family room? hehe no way...I can't even get away with any external sub in the family room

If the conversation gets steered toward the performance capability of subs/speakers...remember citing a -3dB point means almost nothing(in this context).

Agreed.
[Edited last by Bob_A on November 12, 2001 at 10:18 PM]

 

[Bob_A]

My question to you is: have you ever made the comparison between the two?

This should be obvious, huh? Of course not

 

[Ron Stimpson]

"I can't even get away with any external sub in the family room"
And thus, Dear Reader, innocent questions such as that posed here become legend.
"Give it a rest...."
Indeed Bob.
Ron

 

[Jon_R]

Warning: Hearsay from uninformed and likely not exactly accurate sources!
While watching some TLC there was a program on crowd control and effective alternatives around the obvious, that being shooting everyone with large weapons. They had lots of neat things, net cannons, stink bombs (where the guy they shoot smells so bad, people can not stand it!) and a subsonic gun, that is fired at large targets of people and it causes the to retreat.
WHY?
This gun produces a tone under 15hz, somewhere in the range of 10 I believe, at a very high volume. Those frequencies at high volume are sorta like "the brown noise" (for southpark fans) Basically, it can make gotta go number 2 right then and there.
So perhaps, the best HT compliment is..
person "wow man, that rocked"
you "Yeah, it sure did.. really felt the bass"
person "I'd say! I shit myself!"
you "Whoa! so did I!"
Take the above for what its worth,
(which may be under 2 cents)
Jon

 

[Bob_A]

"Give it a rest...."
Indeed Bob.

Give what a rest? I do not follow you here...

 

[Hubert]

Why do these topcs always have to get dragged into a "lets bash powered towers" mentality? That's getting old people. By the way, I'm the one with a Velodyne HGS-18. However, even my Velodyne has no useful output at 15Hz. At least I don't believe it does. Although it can probably reproduce a 15Hz signal. A lot of subs can't even produce a 15Hz signal. Probably most. So I'm not worried about 15Hz. If it's there, it's there.
As for the limits of human hearing, it's 20Hz and 20KHz. The overwhelming majority of people cannot detect sounds above 20KHz or below 20Hz. Although I would imagine there are some very few people that can distinguish a few dbs below or above that.
As for 15Hz, I would imagine it's there for impact. Otherwise, someone else would know better than me.
[Edited last by Hubert on November 13, 2001 at 06:31 AM]

 

[Brian Bunge]

Bob,
OK, this is a real honest to goodness question for you. I'm not trying to be controversial or anything. OK? OK. Since you've stated that no external sub is acceptable (or allowable) would it be at all possible to have an infinite baffle sub? It could be installed in a separate storage space (closet, attic, stairwell) adjacent to your listening room. This could give you that last octave or so of bass performance without having a sub within the room.
I ask because this is an option for those that don't have the space for a large sub in their rooms. I just wonder if it's an option that you've considered.
Brian

 

[Lewis Besze]

As for the limits of human hearing, it's 20Hz and 20KHz. The overwhelming majority of people cannot detect sounds above 20KHz or below 20Hz.

The low end threshold is more like 16hz,for most humans,[below that is purely tactile]and they don't loose that with aging,The top end is another story.
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"You Hungarians always disagree"

 

[Tom Vodhanel]

Lowend *audibility* drops into the 3-7hz(three to seven) range. It can be argued if it's actually something you *hear* in the classical sense...because the ear mechanisms don't react to frequencies that low the same way. Of course,as with every frequency...it's audibility threshold depends on the amptitude of the signal.
As surface oriented folks like to point out...dolby *specs* the full range channels down to 20hz. They also *spec* the LFE down to 3hz. So I'm not sure how you can point at one spec as affirmation to a POV,and then shrug off the next spec because it's not important to your POV at the time. Also note... dolby's *speccing* a software algorithm's(and hardware) capabilities...they're not(afaik) focusing on the issue of low frequency acoustics in the typical home environment. I think the 3hz spec for the LFE channel proves this. Who can hit reference levels at 3hz again? So taken (and misintetpretted)literally...the *specs* at Dolby can obviously lead to some confusion.
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