so whats the deal with Fs?

[dman4486 5,000+ posts]

Why would you want to remove any audible frequencies? I agree that it is there to prevent mechanical damage, but from inaudible frequencies. Granted, many people have different purposes, but I'm supposing that we're trying to reproduce the recording here.
You mention it is a well-known term; I assert the opposite.

because depending on enclosure tuning in the case of vented enclosures, even a 30hz tone can damage the driver. someone tuned for SPL trying to play music at high power levels will have to crank the SSF in order to not damage the equipment.

for #2, how many amp manufacturers do you know that label their filter as an ISF? I can't think of one I have seen personally. Now compare that to the SSF numbers and thus well known.

 

[GregU 10+ year member]

Why would you want to remove any audible frequencies?

Only reason I can think of is if for some reason..... some strange reason.....if you were running a ported enclosure at say....80hz and you threw in a 20hz sine wave. I always set mine at the F3. But that's just me. Makes me feel comfortable.

 

[newusername 10+ year member]

I guess it depends on the definition of known. I don't consider constant misuse of a word to have anything to do with knowing. There is no reason, once knowing the truth, to continue using SSF.

 

[dman4486 5,000+ posts]

I guess it depends on the definition of known. I don't consider constant misuse of a word to have anything to do with knowing. There is no reason, once knowing the truth, to continue using SSF.

then what shall we call it since SSF is obviously not correct and ISF is not correct for the applications?

and how are you to propose it to every amplifier manufacturer.

 

[newusername 10+ year member]

Well, some manufacturers know but are hesitant to change things because it requires them to re-educate their clientele. I'll cite JL Audio as an example, as I have seen Manville Smith post a few times on forums, chastising people for misusing SSF as a term.

If we don't want to use ISF (even though this is what it's purpose is), we should simply call it a high-pass filter. HPF, not SSF.

 

[GregU 10+ year member]

for #2, how many amp manufacturers do you know that label their filter as an ISF? I can't think of one I have seen personally. Now compare that to the SSF numbers and thus well known.

I had an old Kenwood that had an ISF, but that's the ONLY one I've ever seen. And it was a Kenwood......(explains a lot)

 

[dman4486 5,000+ posts]

Well, some manufacturers know but are hesitant to change things because it requires them to re-educate their clientele. I'll cite JL Audio as an example, as I have seen Manville Smith post a few times on forums, chastising people for misusing SSF as a term.
If we don't want to use ISF (even though this is what it's purpose is), we should simply call it a high-pass filter. HPF, not SSF.

lol....HPF would make things really confusing for the average person trying to setup his system.

make sure to setup both your HPF and your LPF.

might as well consider just calling it a bandpass circuit.

and although I disagree ISF being the purpose, such as in the SPL genre, I must end my arguement until later:suave: *taking the ladyfriend to a musical:crap:*

 

[newusername 10+ year member]

Why would that make it confusing? You're already telling them to set-up a HPF and LPF, you're just using the wrong words to describe them.

The purpose of an audio system is to reproduce the recording. Accordingly, it makes no sense to filter out audible frequencies. Now SPL is a different purpose, and that's fine if you wish to make it adapt to that, but for the sake of design, we are designing to reproduce the recording.

 

[squeak9798 5,000+ posts]

Subsonic and supersonic describe only one thing: the speed of an object relative to the speed of sound in a sound-propagating medium. If something is travelling faster than the speed of sound, than it is supersonic. If it is travelling slower than the speed of sound, than it is subsonic.

son·ic (sŏn'ĭk) Pronunciation Key

adj.

1. Of or relating to audible sound: a sonic wave.

2. Having a speed approaching or being that of sound in air, about 1,220 kilometers (760 miles) per hour at sea level.

3. Slang Extremely exciting and fast-paced: a sonic lifestyle.

The American Heritage® Dictionary of the English Language, Fourth Edition

Copyright © 2006 by Houghton Mifflin Company.

Published by Houghton Mifflin Company. All rights reserved.

son·ic Listen to the pronunciation of sonic

Pronunciation:

\ˈsä-nik\

Function:

adjective

Date:

1923

1: utilizing, produced by, or relating to sound waves ; broadly : of or involving sound

2: having a frequency within the audibility range of the human ear —used of waves and vibrations

3: of, relating to, or being the speed of sound in air or about 761 miles per hour (1224 kilometers per hour) at sea level at 59°F (15°C)

Merriam-Webster dictionary

The latin Prefix 'Sub' can mean 'under', 'beneath', or 'below' (such as in the Word 'Subconscious'), 'inferior to', or 'part of' (such as in the Word 'Subhuman'), 'less than normal' (such as in 'Substitute'), or 'almost/nearly' (such as in the Word 'Subcentral').

If "sonic" can relate to a sound within the range of human audibility, then "subsonic" would relate to a frequency that is below audible sound. Seems to make perfectly logical sense to me.

 

[bass_lover1 10+ year member]

I'm not disagreeing that subsonic can also be defined as less than the speed of sound.
But you stated it does not and never will mean less than audible frequency, which is undeniably FALSE, as identified by the definition provided above which indicates subsonic can be defined as both being less than audible frequency and speed less than the speed of sound.

Welcome to the English language. Hope you stick around and enjoy the scenery.

EDIT: Oh yeah....and notice the 2nd definition provided there in your quote.....INFRASONIC.

Subsonic = Infrasonic, per the definition you provided.

Maybe I overstepped a bit there. I made a slight mix up, no biggie.

Regardless, you wouldn't describe infrasonic as an object traveling slower than the speed of sound, then why would you describe subsonic as a sound below the audible range? If it could go either way, why is there no reference to subsonic when you look up the definition of infrasonic? It seems that someone out there adapted to the common misuse of the word, but decided that it doesn't go both ways.

Welcome to the English language is right, it's as ****ed up as ever //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[squeak9798 5,000+ posts]

Regardless, you wouldn't describe infrasonic as an object traveling slower than the speed of sound, then why would you describe subsonic as a sound below the audible range?

See my above post //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

So, why do we call them submarines instead of inframarines //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif//content.invisioncic.com/y282845/emoticons/moon.gif.9d317aec3339ffe7fde0638df52c628a.gif

It appears to me, from my brief travels into linguistics.....that subsonic can refer to both a tone that is below the audibility of humans and travel at less than the speed of sound, but infrasonic describes specifically that which is below the audibility of humans.

I don't think it's wrong to use either in our context.

 

[IDSkoT 5,000+ posts]

wrong. the typical audible range for the human ear is from 20hz-20khz

x2

I think children can hear higher frequencies, like I'd say 22K? But I'm not really sure. I just know that as you get older, your ears hear lower and lower. The "mosquito" ring tone proved that true... for months after that came out all you'd hear in all of my classes was a high-pitched frequency and the kids would wince and grab their ears, and the teachers would just look confused.

 

[John_E_Janowitz 10+ year member]

holy cow, this thread has gone crazy. In any vented enclosure it's a good idea to have a highpass filter no lower than about 1/3 octave below tuning. If you're tuned to 30hz, you'd want the highpass around 25hz. Depending on the slope and Q of the highpass there is a little room to move it around.

Highpass filter is really not a hard terminology. Frequencies higher than the filter pass througha and get played. In the case of 30hz tuning you want frequencies higher than about 25hz.

Regarding human hearing, the general limits are given as 20hz-20khz. Women can typically hear higher and men can typically hear lower, but it depends a lot on the size and shape or your ear and ear canal. Men generally don't hear much above 15KHz. Low frequency limits are dependent on the SPL levels. It takes a much louder tone at 16hz to be heard than say 25Hz, but it can still be audible to the ear. Mostly under 20hz though frequencies are picked up through bone conduction and not heard with the ear drum.

John