# Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..Help



## JimP (May 18, 2006)

I don't have Audyssey's dynamic equalization in my prepro and would like to set up a custom setting in my Velodyne SMS-1 to adjust subwoofer levels for lower SPLs.

My problem thus far is that I can't find anything that says how much you adjust which frequencies as the SPL decreases.

Does anyone know this or have a link?

Thanks in advance.


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## glaufman (Nov 25, 2007)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

I think what you're looking for are the Fletcher-Munson curves:


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## JimP (May 18, 2006)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

Thanks Greg.....that's exactly what I was trying to find.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*


The Fletcher-Munson curve dates back to 1933. According to Wikipedia, “A new experimental determination was made by Robinson and Dadson in 1956 which was believed to be more accurate, and this became the basis for a standard (ISO 226) which was considered definitive until 2003, when the standard was revised on the basis of recent assessments by research groups worldwide.”

In 2003 researchers in Japan, Germany, Denmark, UK and USA produced a study which resulted in the current standard, known as ISO 226:2003. Here is the current standard for equal loudness curves.










Regards,
Wayne


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## JimP (May 18, 2006)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

Thanks Wayne.

Just thinking out loud, what I think that I would need to do is to get the difference in the slopes for my two listening levels and use that as my house curve for the subwoofer range.


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## glaufman (Nov 25, 2007)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

Saving that for my archives. Thanks Wayne!


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## hoofenshnoz (Aug 5, 2009)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

and trying to accomidate for those peaks in the high mids and drops in the lows will give you an unnatural sound because of course, in nature. we hear things naturally with these perceived peaks and dips 

L


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## JimP (May 18, 2006)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*

L 

That's not the object of this exercise. Note that those peaks and dips remain constant across the spl axis.

What I'm after is how the low frequencies shift that occurs with a change in SPL.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Want to build a house curve that reflects the decrease in hearing sensitivity at lower volumes..*




JimP said:


> Thanks Wayne.
> 
> Just thinking out loud, what I think that I would need to do is to get the difference in the slopes for my two listening levels and use that as my house curve for the subwoofer range.


If that doesn’t prove satisfactory, you could try a variation of the 30 Hz – 100 Hz volume differential test outlined in my house curve article, at the low volume level you’re interested in. After that, re-adjust the subwoofer level to the mains.

Regards,
Wayne


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