AVS › AVS Forum › Audio › Subwoofers, Bass, and Transducers › The physics and understanding of low frequencies
New Posts  All Forums:Forum Nav:

The physics and understanding of low frequencies - Page 10

post #271 of 345
3/5/11 at 7:04am
Thread Starter 
Quote:
Originally Posted by ccotenj View Post

^^^

i'm not sure what the "best" way to learn is, but i'm pretty sure that asking questions about a topic you know nothing about and then telling those who do know what they are talking about that they are wrong isn't going to be an effective way of learning...

you still haven't bought the book i recommended to you yet, have you? if you had, you would realize how silly your assertions are...

short of that, if you really want to learn (and not just tell us we are wrong), you can accept some of the knowledge that people are trying to share with you... there's no "mystery" here, all of what you are trying to learn is very well understood...

you'll notice there's no disagreement amoungst the people who are trying to help you... on avs, the "lack of disagreement" is a VERY strong indicator that what you are being told is correct... as people here will argue over the shade of blue the sky is...

Saying my questions are silly is saying I should already understand how this stuff works. Some of you guys just enjoy me being here so you can have a few laughs.
Reply
Reply

AVS Top Picks

post #272 of 345
3/5/11 at 7:56am
Whew. I'm glad I saved this thread for a Saturday morning.
Reply
Reply
post #273 of 345
3/5/11 at 8:07am
@ymal...

i said your assertions were silly, not your questions...

the questions make sense (well... most of them)... but your responses to the answers that you get to those questions are, ummm, ill-informed... thus the "assertions" comment...

you admit you don't know anything about electromagnets, yet you insist you are right about how they work when they are implemented...

you present "idealized examples" that have no bearing on a how a speaker driver, it's cabinet, and the room it is in react in the "real world"...

and so on...

in either case... you need to be willing to learn... accept some of what people have told you, even if you don't understand it... as you learn more, it will "fit together" better...

and for crying out loud, spend 25 bucks and buy the book i keep telling you to buy... all of the basic questions are answered in a really understandable way... not that this subject is nearly as difficult, but it's analogous to you attempting to learn how to do calculus when you don't know how to do algebra (not to mention the fact that you are telling the people who DO know how to do calculus that they are doing it wrong )...
Reply
Reply
post #274 of 345
3/5/11 at 10:57am
Thread Starter 
removed comment
Reply
Reply
post #275 of 345
3/5/11 at 1:44pm
Ymal
Are you serious?
Take a real careful look at those two questions. Try asking them again using different and more accurate words.
Reply
Reply
post #276 of 345
3/5/11 at 3:23pm
Yaml
Do you ever listen to live music? Not amplified live music but orchestra, your cousins playing guitar in the back yard, the dudes playing trumpet at the grocery store liquor department for Cinco de Mayo? Just wondering what your frame of reference is.
Reply
Reply
post #277 of 345
3/5/11 at 9:58pm
Quote:
Originally Posted by ymalmsteen887 View Post

Saying my questions are silly is saying I should already understand how this stuff works. Some of you guys just enjoy me being here so you can have a few laughs.

I see you are genuinely interested in learning about this topic. I would have stopped posting a LONG time ago if this was not the case.
Reply
Reply
post #278 of 345
3/6/11 at 2:16pm
Thread Starter 
I am going to study this subject a great deal and have this discussion again and see where it goes. I am going to work on my grammar as well. I want to prove that people can change. I want to see if you guys are right about some of the things you say, for example someone said speakers have to vibrate at lower frequencies before they can vibrate faster but that doesnt seem logical to me so I've pointed that out and didn't get a response that I can understand. I will hang around other threads and try to learn some more and to get to know everyone. I would still like it if you guys could point out the specific things I said that were absolutely wrong. In order to understand how speakers don't reproduce sounds perfectly I need to know how other sounds are produced and how the brain is interpreting them. Paticularly a guitar string and how the waveform changes from the moment you strike it to its decay and how the shape, material and size of the body changes the sound and why a violin when plucked sounds different than a guitar or banjo or even piano. Why low frequencies travel farther than higher ones and how they interact when passing through, reflecting, or going around objects.

Just for fun can someone write this paragraph over but with correct pucntuation I want to see how much improvement I need?
Reply
Reply
post #279 of 345
3/6/11 at 2:26pm
Thread Starter 
Quote:
Originally Posted by petew View Post

Yaml
Do you ever listen to live music? Not amplified live music but orchestra, your cousins playing guitar in the back yard, the dudes playing trumpet at the grocery store liquor department for Cinco de Mayo? Just wondering what your frame of reference is.

March 19 I am going to see a guitar player by the name of Carlos Perez perform at the knoxville guitar society. It will be through loudspeakers so I don't know if that counts but any tips on what to listen for?

Also I play guitar fingerstlye.
Reply
Reply
post #280 of 345
3/6/11 at 4:06pm
Live acoustic is better in my opinion. That way you know you are hearing the instruments and the performance space, not the unnatural effects of eq, amplification and speakers.

I've helped a few people who have struggled with the written word. I've found it helpful to have the student write out something and then read it aloud. They usually end up laughing at the mess they wrote!

Do that with your first post, and then the post from 3:16 today. You have made tremendous progress and should be congratulated. Keep it up.

Please don't take this wrong, but have you had a hearing test before?
Reply
Reply
post #281 of 345
3/6/11 at 4:22pm
Thread Starter 
Quote:
Originally Posted by petew View Post

Live acoustic is better in my opinion. That way you know you are hearing the instruments and the performance space, not the unnatural effects of eq, amplification and speakers.

I've helped a few people who have struggled with the written word. I've found it helpful to have the student write out something and then read it aloud. They usually end up laughing at the mess they wrote!

Do that with your first post, and then the post from 3:16 today. You have made tremendous progress and should be congratulated. Keep it up.

Please don't take this wrong, but have you had a hearing test before?

I think even the way i would say things out loud would be incorrect.

What progress?

No I have not had a hearing test.
Reply
Reply
post #282 of 345
3/7/11 at 6:22am
Thread Starter 
Does anyone think this box is too big for these woofers?
http://www.youtube.com/watch?v=WD1E-ru1dh8

By too big I mean that there is no advantage with this size, is that right?

It seems like the bigger you make the box you just it too resonant at lower frequencies so depending on the size of your woofer too big may be taking away its potential. The only reason you can change the width height and stuff is depending on the place you need to fit it. So I think this could be in a smaller box and still be just as loud at those frequencies what do you think?

Unless the box isnt very hollow.
Reply
Reply
post #283 of 345
3/7/11 at 6:24am
That video is a car audio video. You do realize that this is a home audio subwoofer forum!!

I stopped caring about the silly world of Car audio and wasting trunk space when I have a real life, family, work and real needs for the car.
Reply
Reply
post #284 of 345
3/7/11 at 6:30am
Quote:
Originally Posted by ymalmsteen887 View Post

. I want to see if you guys are right about some of the things you say...

There are some posts from individuals with thousands of hours of education on this topic, to even post "I want to see if you guys are right" is kind of an insult. Its like sitting in a college class room and saying to the professor "Im here to find out if you are right"....Good way to get a C- in the class! Have you been to College yet?

Quote:


for example someone said speakers have to vibrate at lower frequencies before they can vibrate faster but that doesnt seem logical to me so I've pointed that out and didn't get a response that I can understand.

Who posted that??? A speaker moves the same rate peak to peak based on the frequency....ie. 20Hz its simply 20 cycles per second. It does not move faster or slower then 20 cycles per seconds when creating the 20Hz tone. The same goes for 30Hz, its simply 30 cycles per second and it does not move faster or slower then 30 cycles per second when creating the 30Hz tone. IMO, if a driver starts vibrating during any test tone then its probably not a good driver at all, its stored energy and distortion is off the charts.
Reply
Reply
post #285 of 345
3/7/11 at 6:40am
Quote:
Originally Posted by ymalmsteen887 View Post

I am not being obtuse. I agree that the best way to learn is not on this forum but now I have things to look into to see who's right and who's wrong. But I will say that the thing about the electromagnets is definetly on my side when I say the speaker moves back and forth just like you ear drum. Thats the entire purpose of the + and - on the back of the speaker if the speaker behaves wildly this would be unwanted and probably poor materials.

Everything I have learned about audio is from online forums like this one and hands on learning (Building, testing, measuring, over and over).

I do have a degree in Mathematics + a minor in Eelectrical Engineering from University but all the specifics about audio electronics, speaker, subwoofer design comes from forums like this. Your are wrong to think this isnt a great way to learn. Buying a couple of books doesn't hurt either (Loudspeaker design Cookbook from Vance Dickason is a good one).

Again, you should never question people (see who's right and who's wrong) when you have no knowledge on the topic itself. Instead you should read what is posted, break it down and try to understand it 100%. Asking questions, even silly ones is great. The only silly/foolish question is the one that is never asked.

Like others have posted if something is posted inaccurately, there would have been debates AMONGST US....we do that all the time so you should just accept that what is being posted is pretty good information for you to LEARN and NOT QUESTION.
Reply
Reply
post #286 of 345
3/7/11 at 6:44am
Quote:
Originally Posted by ymalmsteen887 View Post

....What progress?.......

Never mind
Reply
Reply
post #287 of 345
3/7/11 at 6:58am
Thread Starter 
Quote:
Originally Posted by penngray View Post

There are some posts from individuals with thousands of hours of education on this topic, to even post "I want to see if you guys are right" is kind of an insult. Its like sitting in a college class room and saying to the professor "Im here to find out if you are right"....Good way to get a C- in the class! Have you been to College yet?



Who posted that??? A speaker moves the same rate peak to peak based on the frequency....ie. 20Hz its simply 20 cycles per second. It does not move faster or slower then 20 cycles per seconds when creating the 20Hz tone. The same goes for 30Hz, its simply 30 cycles per second and it does not move faster or slower then 30 cycles per second when creating the 30Hz tone. IMO, if a driver starts vibrating during any test tone then its probably not a good driver at all, its stored energy and distortion is off the charts.

I have the right to say that. Its not an insult and yes someone did say that and I was completely in oh So no its those kinds of mistakes that you have to figure out this stuff on your on. What you said about the car audio is funny so what if you don't want to waste trunk space it doesn't mean you have a life I didn't realize there was one "right" way to live life. I just wanted to know why some people have drastic differences in box sizes when the speakers are the same size. About your the peak to peak thing your wrong if its vibrating at 20hz but only moving an inch fronm the center then its going slower to make that distance than if it moves from the center by 2 inches.
Reply
Reply
post #288 of 345
3/7/11 at 7:00am
Thread Starter 
Quote:
Originally Posted by petew View Post

Never mind

I don't know what you meant
Reply
Reply
post #289 of 345
3/7/11 at 7:08am
Thread Starter 
Quote:
Originally Posted by penngray View Post

Everything I have learned about audio is from online forums like this one and hands on learning (Building, testing, measuring, over and over).

I do have a degree in Mathematics + a minor in Eelectrical Engineering from University but all the specifics about audio electronics, speaker, subwoofer design comes from forums like this. Your are wrong to think this isnt a great way to learn. Buying a couple of books doesn't hurt either (Loudspeaker design Cookbook from Vance Dickason is a good one).

Again, you should never question people (see who's right and who's wrong) when you have no knowledge on the topic itself. Instead you should read what is posted, break it down and try to understand it 100%. Asking questions, even silly ones is great. The only silly/foolish question is the one that is never asked.

Like others have posted if something is posted inaccurately, there would have been debates AMONGST US....we do that all the time so you should just accept that what is being posted is pretty good information for you to LEARN and NOT QUESTION.

So what if I break it down and I see that some of the things that were said were just out of rhetoric. Yes that probably doesnt good on an internet forum but I dont mean that in an offensive way. You sound like a religious person trying to keep someone from discovering the truth. "LEARN and NOT QUESTION"
Reply
Reply
post #290 of 345
3/7/11 at 7:08am
Thread Starter 
Majority doesnt make right/
Reply
Reply
post #291 of 345
3/7/11 at 7:15am
Thread Starter 
You can't say silly as a universal you think its silly cause you don't have an interest in it. I was on here was to try to figure out the appeal to obessing over speakers. So your just as silly if you have a family and like to listen to a home theater system(not saying you are cause I would like to have one) some people would say thats childishshouldnt you occupy yourself with more importnat things. Having bass loud and pounding your chest is supposed to make you happy literaly. So its justified why people want to listen to it but obsessing over making the violin sound just right seems kinda silly(in my opinion not yours just trying to make a point you shouldnt say its silly as fact.)
Reply
Reply
post #292 of 345
3/7/11 at 11:20am
Quote:
Originally Posted by penngray View Post

Who posted that??? A speaker moves the same rate peak to peak based on the frequency....ie. 20Hz its simply 20 cycles per second. It does not move faster or slower then 20 cycles per seconds when creating the 20Hz tone. The same goes for 30Hz, its simply 30 cycles per second and it does not move faster or slower then 30 cycles per second when creating the 30Hz tone. IMO, if a driver starts vibrating during any test tone then its probably not a good driver at all, its stored energy and distortion is off the charts.

The specific example was when the speaker changes frequencies, it cannot go immediately and instantaneously (mechanically speaking) from 0hz to 20hz or from 100hz to 12,000hz. It does happen very nearly instantaneously however - obviously we do not hear a "warming up" sound audibly with speakers in the same way you can hear it on guitar or voice.

I guess it is possible the differing material properties and tolerances in construction of the speaker have no effect on this particular element of sound production, but I find it very hard to believe the response time/curves of every speaker would be the same regardless of differing materials and construction. It would more or less be something unique to speakers among all other mechanical systems.
Reply
Reply
post #293 of 345
3/7/11 at 11:26am
Quote:
Originally Posted by ymalmsteen887 View Post

I have the right to say that. Its not an insult and yes someone did say that and I was completely in oh So no its those kinds of mistakes that you have to figure out this stuff on your on. What you said about the car audio is funny so what if you don't want to waste trunk space it doesn't mean you have a life I didn't realize there was one "right" way to live life. I just wanted to know why some people have drastic differences in box sizes when the speakers are the same size. About your the peak to peak thing your wrong if its vibrating at 20hz but only moving an inch fronm the center then its going slower to make that distance than if it moves from the center by 2 inches.

because speaker diameter is only one parameter that determines box size...

i think penn knows what he is talking about here... you REALLY need to learn to either post less confrontationally OR learn to accept that what people tell you is correct...

hint: you aren't breaking new ground here... all of what you are asking about is well understood and well grounded in scientific principles...

let me guess... you STILL haven't bothered to educate yourself yet by buying the book i suggested to you....
Reply
Reply
post #294 of 345
3/7/11 at 11:29am
Quote:
Originally Posted by ymalmsteen887 View Post

So what if I break it down and I see that some of the things that were said were just out of rhetoric. Yes that probably doesnt good on an internet forum but I dont mean that in an offensive way. You sound like a religious person trying to keep someone from discovering the truth. "LEARN and NOT QUESTION"

lol, too remotely consider any of the discussion in terms of religion shows how little time you have spent in a formal class room.

Do you question your teachers in school constantly? That must be fun for them? Im really curious to what your last level of education or what work experience you have in any field remotely related to Audio or even science.

I did post that you should not question when you have zero education on the topic. Questioning is good but when you question you should produce facts that counter any opinion being posted.

I have no rhetoric to offer. I have simple audio science and experience to offer in the hopes of helping you understand. Im pretty sure 99.9% of all people reading this thread consider this pretty much a lost cause or you are just pulling our chains.

Im simply in the discussion still because its entertaining.
Reply
Reply
post #295 of 345
3/7/11 at 11:32am
Thread Starter 
Quote:
Originally Posted by ccotenj View Post

because speaker diameter is only one parameter that determines box size...

i think penn knows what he is talking about here... you REALLY need to learn to either post less confrontationally OR learn to accept that what people tell you is correct...

hint: you aren't breaking new ground here... all of what you are asking about is well understood and well grounded in scientific principles...

let me guess... you STILL haven't bothered to educate yourself yet by buying the book i suggested to you....

If thats true then I will find that out on my journey want I.

I know that box size isnt dependent on how big the box is sometimes it might be the size of the space you have available but most people like it as low as possible so the box should only be a certain size to take advantage of what the sub can do and those speakers arent really considered high end so I think he could have a smaller box and still get the car vibrating like that.
Reply
Reply
post #296 of 345
3/7/11 at 11:37am
Quote:
Originally Posted by enderland View Post

The specific example was when the speaker changes frequencies, it cannot go immediately and instantaneously (mechanically speaking) from 0hz to 20hz or from 100hz to 12,000hz. It does happen very nearly instantaneously however - obviously we do not hear a "warming up" sound audibly with speakers in the same way you can hear it on guitar or voice.

I guess it is possible the differing material properties and tolerances in construction of the speaker have no effect on this particular element of sound production, but I find it very hard to believe the response time/curves of every speaker would be the same regardless of differing materials and construction. It would more or less be something unique to speakers among all other mechanical systems.

Thanks, I now can connect the dots a little.....I still do not know how "vibration" was concluded.

The "warming up" as you describe is definitely a characteristic of any driver. Drivers have different mass, different material, different voice coils, different magnets.....heck we can look at the T/S specs of two driver and know they will have differences.

I think several of us posted back on the first couple of pages explaining that there are many, many measurements to track how each driver differs when playing the same tone. He ignored those links I posted and continues on questioning everything....There is a MOUNTAIN of information in this thread and yet we are just posting rhetoric..
Reply
Reply
post #297 of 345
3/7/11 at 11:40am
Quote:
Originally Posted by ymalmsteen887 View Post

You can't say silly as a universal you think its silly cause you don't have an interest in it. I was on here was to try to figure out the appeal to obessing over speakers. So your just as silly if you have a family and like to listen to a home theater system(not saying you are cause I would like to have one) some people would say thats childishshouldnt you occupy yourself with more importnat things. Having bass loud and pounding your chest is supposed to make you happy literaly. So its justified why people want to listen to it but obsessing over making the violin sound just right seems kinda silly(in my opinion not yours just trying to make a point you shouldnt say its silly as fact.)

Oh do not not worry, I know its silly that I own 6 18" woofers and 6 15" woofers, I know its also silly that I have over 10,000 Watts in amplication spread over 3 custom systems in my house.

Its silly good too but still definitely over the top compared to anyone I know.

I will just say that Car audio and Home audio are too different worlds and the science discussions around them are different. A car has completely different structure variables. I did the $5K system in a $3K car when I was 18......I have evolved
Reply
Reply
post #298 of 345
3/7/11 at 11:41am
Quote:
Originally Posted by penngray View Post

Thanks, I now can connect the dots a little.....I still do not know how "vibration" was concluded.

The "warming up" as you describe is definitely a characteristic of any driver. Drivers have different mass, different material, different voice coils, different magnets.....heck we can look at the T/S specs of two driver and know they will have differences.



I really wish I had access to some data on this - graphing the actual responses of a variety of speakers vs the input signal.

I would be surprised to not see as a general trend that more expensive speakers more closely and quickly match the input signal.
Reply
Reply
post #299 of 345
3/7/11 at 11:54am
Quote:
Originally Posted by ymalmsteen887 View Post

If thats true then I will find that out on my journey want I.

I know that box size isnt dependent on how big the box is sometimes it might be the size of the space you have available but most people like it as low as possible so the box should only be a certain size to take advantage of what the sub can do and those speakers arent really considered high end so I think he could have a smaller box and still get the car vibrating like that.

Like Penn said, when you make a statement like this, you need to back it up. Why do you think he could have a smaller box and achieve the same performance? Have you ever built or modeled any sub? Do you know how box size actually effects a sub's performance?

This is one of the reasons people are getting frustrated with you. You continually make statements like this with little knowledge about the subject, without anything to back it up and without any prior research. For this example, a quick google search came up with a number of pages already discussing this topic. Without knowing the port size, looking up the driver parameters and knowing the design goal of the box, you can't know if the box is too big.

-Mike
Reply
Reply
post #300 of 345
3/7/11 at 11:56am
Quote:
Originally Posted by enderland View Post



I really wish I had access to some data on this - graphing the actual responses of a variety of speakers vs the input signal.

I would be surprised to not see as a general trend that more expensive speakers more closely and quickly match the input signal.


Im not really sure what you are talking about with matching the input signal?

Are you talking about sweeps or single tones?


I have many, many woofers. I have $1000 woofers and $100 woofers, you would be surprised how much they actually match each other in room when played within their limits.

Its not just the driver that matters its how that driver is modelled/implemented and the used in room.
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home

AVS Top Picks

AVS › AVS Forum › Audio › Subwoofers, Bass, and Transducers › The physics and understanding of low frequencies