What North Creek talks about?

andy2 · 21st November 2005, 06:59 PM

I've read this article from North Creek. Here is the full article:
http://www.northcreekmusic.com/Pegasus/Pegasus.htm

but this is the excerpt that I was trying to understand what he meant in the filter design section:

"Eventually it came to me that the problem with the W18¡¯s upper midrange is a two edged sword. The mechanical break up of the cone is a high Q mechanical resonance. The "low pass network plus trap" approach creates a second high Q resonance. The problem, then, is that there are two high Q resonances in the electrical/mechanical/acoustic system right in the middle of the range where the ear (at least mine) is most sensitive. My goal, then, became to design a low pass network with the target acoustic response, but without using this type of filter. Finally, some progress was being made."

Can you think of any type of filter that does this?

Ron E · 22nd November 2005, 02:16 AM

Why yes, yes I can. That would be the legendary hyperbolic filter. It uses a third active component called a hyperbole.

Stocker · 22nd November 2005, 02:35 AM

Quote:

Originally posted by Ron E
hyperbole.

LOL, you almost made me spit out my sandwich!

maxro · 22nd November 2005, 02:43 AM

Quote:

Originally posted by Ron E
Why yes, yes I can. That would be the legendary hyperbolic filter. It uses a third active component called a hyperbole.

The problem with this hyperbolic filter is that it does nothing to filter out hyperbole. It actually boosts it to the point that you can actually see the hot air coming from the port.

Max

gavinson · 22nd November 2005, 10:22 PM

Too Funny !

Ron E · 23rd November 2005, 10:34 PM

On a serious note, he posts the filtered and unfiltered response in the article, so you could subtract the two and get the filter response and find out - at least for the areas which show on both graphs.

It could be a high slope filter, or it could be a filter with an integral notch, or a different sort of notch filter - but in the vast majority of cases - like 99+% of the time - there is no new technology at work in any speaker product, just some new angle or advertising hype.

When you read something like this, always remember that these people are trying to sell you something.

21st November 2005, 06:59 PM	#1
andy2 diyAudio Member Join Date: Nov 2004 Location: Los Angeles	What North Creek talks about? I've read this article from North Creek. Here is the full article: http://www.northcreekmusic.com/Pegasus/Pegasus.htm but this is the excerpt that I was trying to understand what he meant in the filter design section: "Eventually it came to me that the problem with the W18¡¯s upper midrange is a two edged sword. The mechanical break up of the cone is a high Q mechanical resonance. The "low pass network plus trap" approach creates a second high Q resonance. The problem, then, is that there are two high Q resonances in the electrical/mechanical/acoustic system right in the middle of the range where the ear (at least mine) is most sensitive. My goal, then, became to design a low pass network with the target acoustic response, but without using this type of filter. Finally, some progress was being made." Can you think of any type of filter that does this?

22nd November 2005, 02:16 AM	#2
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	Why yes, yes I can. That would be the legendary hyperbolic filter. It uses a third active component called a hyperbole. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

23rd November 2005, 10:34 PM	#6
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	On a serious note, he posts the filtered and unfiltered response in the article, so you could subtract the two and get the filter response and find out - at least for the areas which show on both graphs. It could be a high slope filter, or it could be a filter with an integral notch, or a different sort of notch filter - but in the vast majority of cases - like 99+% of the time - there is no new technology at work in any speaker product, just some new angle or advertising hype. When you read something like this, always remember that these people are trying to sell you something. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

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22nd November 2005, 10:22 PM	#5
gavinson diyAudio Member Join Date: Jun 2005 Location: Austin Texas	Too Funny !

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