Fantastic article on frequency response

[yepimonfire]

http://forum.ecoustics.com/bbs/messages/34579/131062.html

 

[njedpx3]

http://forum.ecoustics.com/bbs/messages/34579/131062.html

Not a bad article on amplitude versus frequency and attenuation by Polk. 3dB is a doubling on the logrithmic scale.

Have you look at the Audioholics Acoustic Principle articles ? :
http://www.audioholics.com/education/acoustics-principles/allContents

Specifically the article: "Human Hearing Amplitude Sensitivity - Part !"
http://www.audioholics.com/education/acoustics-principles/human-hearing-amplitude-sensitivity-part-1

Peace, Good Luck, and Good Sound

Forest Man

 

[JerryLove]

I disagree with one of the premises. "Listening tests" let us qualify what the measurements quantify. Speaker A dips at 100Hz, and Speaker B does the exact same at 1000Hz. Listening gives us an idea which is more important.

With sufficient knowledge: the waterfall and FR charts mean *a lot*.

 

[son-yah-tive]

Sometimes I get headaches reading these types of articles. But then I think, regardless of GRAPHs and such, they don't always tell your ears what they want to hear. A good article otherwise.

 

[WmAx]

http://forum.ecoustics.com/bbs/messages/34579/131062.html

Man I know I am going to sound like the constant negative guy. LOL. But that is not a very good article. Nor very accurate. Determining sound of a speaker based upon measurements is possible, but it requires (1) very extensive measurements of different types [and] (2)a person extremely knowledgeable in human auditory response to the measured characteristics.

The person writing the article is from the MARKETING department, it says so at the start of the article. He did not even sufficiently describe importance/relevance of frequency response.

-Chris

 

[jamie2112]

Yeah Chris stop being so negative all the time....

 

[zhimbo]

Man I know I am going to sound like the constant negative guy. LOL. But that is not a very good article. Nor very accurate.

Wrong!

It is a good article.

Why? Because if the buying public was as informed as this article, or half as informed, it would be a vast improvement.

It's basically a good, readable first pass through the issues (compared to the Audioholics "Human Hearing" link, which is going to be utterly inpenetrable for most newbs. I've done psychophysical research, so the graphs, etc. aren't any particular challenge to me, but I wouldn't say that the link was especially illuminating in any practical sense for a typical speaker-shopper, whatever its sophistication and accuracy).

I also thought the writer was actually pretty clear about the article's limitations, for example:

"No matter how adept you might be at interpreting frequency response data, it should only be one data point among many in choosing a speaker

etc...

I know that if this was the first thing I came across when I was figuring speakers out, it would have been a big help in getting me on my way.

P.S. Yeah, that's right. I said Chris was wrong!

 

[yepimonfire]

Man I know I am going to sound like the constant negative guy. LOL. But that is not a very good article. Nor very accurate. Determining sound of a speaker based upon measurements is possible, but it requires (1) very extensive measurements of different types [and] (2)a person extremely knowledgeable in human auditory response to the measured characteristics.

The person writing the article is from the MARKETING department, it says so at the start of the article. He did not even sufficiently describe importance/relevance of frequency response.

-Chris

just about every post you make is to say something is wrong. and he did describe it. he described what the frequency response they slap every set of speakers with means.

 

[bandphan]

just about every post you make is to say something is wrong. and he did describe it. he described what the frequency response they slap every set of speakers with means.

you really need to check this book out

http://www.amazon.com/Sound-Reproduction-Acoustics-Psychoacoustics-Loudspeakers/dp/0240520092

 

[3db]

Wrong!

It is a good article.

Why? Because if the buying public was as informed as this article, or half as informed, it would be a vast improvement.

It's basically a good, readable first pass through the issues (compared to the Audioholics "Human Hearing" link, which is going to be utterly inpenetrable for most newbs. I've done psychophysical research, so the graphs, etc. aren't any particular challenge to me, but I wouldn't say that the link was especially illuminating in any practical sense for a typical speaker-shopper, whatever its sophistication and accuracy).

I also thought the writer was actually pretty clear about the article's limitations, for example:



etc...

I know that if this was the first thing I came across when I was figuring speakers out, it would have been a big help in getting me on my way.

P.S. Yeah, that's right. I said Chris was wrong!

I agree. For the layman, this a perfect quick reference check which will provide the public with some tools to make a more informed decision when buying speakers.

 

[3db]

Man I know I am going to sound like the constant negative guy. LOL. But that is not a very good article. Nor very accurate. Determining sound of a speaker based upon measurements is possible, but it requires (1) very extensive measurements of different types [and] (2)a person extremely knowledgeable in human auditory response to the measured characteristics.

The person writing the article is from the MARKETING department, it says so at the start of the article. He did not even sufficiently describe importance/relevance of frequency response.

-Chris

Your negative because you know too much about the subject. However, if you put yourself in the shoes of the average joe in terms of knowledge about audio, you would see that this is a great starter in making a more informed decision.

 

[JerryLove]

Your negative because you know too much about the subject. However, if you put yourself in the shoes of the average joe in terms of knowledge about audio, you would see that this is a great starter in making a more informed decision.

It does still make a false statement: that a speaker cannot be judged on measurments.

 

[3db]

It does still make a false statement: that a speaker cannot be judged on measurments.

I think thats a statement of context.. a layman cannot judge a speaker on specs alone.

 

[highfigh]

How many people who graduated high school didn't take a math class that used graphs? NONE OF THEM- every school uses graphs in at least one math class! This means that they should be able to think all the way back, sometimes more than 5 years (oh, the horrors!) and try to remember that the x axis is for one measurement, the y axis is for another and the z axis is for yet another- in the case of speaker measurement, x=frequency, y=amplitude and z=time. How hard is that? EVERYONE did this in math class and most rationalize failing math because "I'll never use this after I get out of here, so why bother learning it?".

Shows how smart high school students are and it shows that schools all over are failing to teach the ability to look forward.

This isn't rocket surgery. Even a C math student should be able to see that if the amplitude doesn't vary much across the frequency band, it's better than when the plot looks like the Himalayas. This means that most people should be able to use at least one graph in the speaker buying process. If they can use the information from a waterfall plot (showing the response over time), even better.

 

[3db]

How many people who graduated high school didn't take a math class that used graphs? NONE OF THEM- every school uses graphs in at least one math class! This means that they should be able to think all the way back, sometimes more than 5 years (oh, the horrors!) and try to remember that the x axis is for one measurement, the y axis is for another and the z axis is for yet another- in the case of speaker measurement, x=frequency, y=amplitude and z=time. How hard is that? EVERYONE did this in math class and most rationalize failing math because "I'll never use this after I get out of here, so why bother learning it?".

Shows how smart high school students are and it shows that schools all over are failing to teach the ability to look forward.

This isn't rocket surgery. Even a C math student should be able to see that if the amplitude doesn't vary much across the frequency band, it's better than when the plot looks like the Himalayas. This means that most people should be able to use at least one graph in the speaker buying process. If they can use the information from a waterfall plot (showing the response over time), even better.

There's a lot more to it than just amplitiude plots and most lay people can't make the correlation of sound to a flat frequency response. They need to know that a flat frequency response is better than one with dips and valleys so I disagree with an premise of knowing how to graph makes a layman be able to interpret good sound. You're also omitting personal preference of a listener as well. There's more to it than just an amplitude plot and most speaker vendors I know don't even offer that. Its just the usual 20Hz - 20 Khz +/- 3db.

 

[highfigh]

There's a lot more to it than just amplitiude plots and most lay people can't make the correlation of sound to a flat frequency response. They need to know that a flat frequency response is better than one with dips and valleys so I disagree with an premise of knowing how to graph makes a layman be able to interpret good sound. You're also omitting personal preference of a listener as well. There's more to it than just an amplitude plot and most speaker vendors I know don't even offer that. Its just the usual 20Hz - 20 Khz +/- 3db.

How does "Even a C math student should be able to see that if the amplitude doesn't vary much across the frequency band, it's better than when the plot looks like the Himalayas." substantially differ from you posting "They need to know that a flat frequency response is better than one with dips and valleys"?

I haven't seen many speaker manufacturers include impedance/phase plots and most beginners don't know how to interpret them, anyway. Graphs and plots are the results of objective testing and are only one of the ways to choose a product. Who cares about a speaker that has great specs and response if it sounds bad? Only the designer who wants to sell it based on anything BUT sound.

If you have read my posts, you'll see that I have repeatedly stated that personal preference is the most important criterion- if someone doesn't like it, it's not the right speaker for them.

I have sold audio equipment for more than 30 years and the thing that's lost on most "techy" people is that a huge percentage of people can't interpret technical data and most of them just don't care. The use of speakers isn't reading the specs and graphs- it's listening. For those who want to learn the technical aspects of audio/video gear, self-education is fine but from my experience with marketing types, not enough actually know enough to write this kind of paper or article. That should be left to the ones who really know the material, written simply so more people can understand it. There's no point in causing peoples' eyes to glaze over or induce deep sleep with the information.

 

[3db]

How many people who graduated high school didn't take a math class that used graphs? NONE OF THEM- every school uses graphs in at least one math class! This means that they should be able to think all the way back, sometimes more than 5 years (oh, the horrors!) and try to remember that the x axis is for one measurement, the y axis is for another and the z axis is for yet another- in the case of speaker measurement, x=frequency, y=amplitude and z=time. How hard is that? EVERYONE did this in math class and most rationalize failing math because "I'll never use this after I get out of here, so why bother learning it?".

Shows how smart high school students are and it shows that schools all over are failing to teach the ability to look forward.

This isn't rocket surgery. Even a C math student should be able to see that if the amplitude doesn't vary much across the frequency band, it's better than when the plot looks like the Himalayas. This means that most people should be able to use at least one graph in the speaker buying process. If they can use the information from a waterfall plot (showing the response over time), even better.

Sorry highfigh.. I interpreted the above to say that most layman because of basic math skills should be able to determine how good a speaker is based on specs .. We are in agreement than that its not true.

 

[highfigh]

Sorry highfigh.. I interpreted the above to say that most layman because of basic math skills should be able to determine how good a speaker is based on specs .. We are in agreement than that its not true.

My point was that anyone who took high school math should be able to read a graph. What I should have posted is that anyone who took biology should know a little about human hearing and anyone who took physics should be able to figure out that a frequency response graph indicates consistent energy over the audible range, or that it may fall short of that.

Graphs alone can't do it but for some people, if there are enough of graphs and plots, it's a good bet that the speaker will deliver the goods.

 

[JerryLove]

There certainly is more knowledge required.

Look at how that graph drops off at 60Hz.
Do I care more about the THD or FRQ chart?
Is that one spike in the waterfall a big deal or a little one?

I do think that it takes some understanding and either experience or a lot of trust to qualify the quantities that the graphs and charts give.

I think I can get a good idea of a speaker from several measurements. I think Chris can tell you it's mother's maiden name from them. I can understand that a layman would have trouble until he learned.

 

[lsiberian]

How many people who graduated high school didn't take a math class that used graphs? NONE OF THEM

Actually my best friend first saw a graph in the US. He graduated from high school in Germany.