# Flat Frequency "Loudness" @ Any Volume Level



## shkumar4963 (Nov 16, 2014)

Does anyone know a way to introduce a frequency equalizer in the line that changes the equalization curve based on volume. 

We all know that we perceive low frequency much less at lower volumes than at high volumes. In 80s, there used to be a bass boost switch that tried to correct for that. But it was a one step boost and not that accurate. Now with digital equalization technology it should be possible to get a flat frequency "perception" or "loudness"
curve at any volume level. 

I am hopeful that this is available from some manufacturer. But if it is not, would love to hear why you feel it is not needed.


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## istvan (Jul 5, 2013)

You are probably referring to the loudness button on older amps. Pressing it would boost the treble and bass by 2-4db. The theory being when playing at lower volumes that there is not enough power delivered to the speakers to reproduce the dynamics of sound inherent at those frequencies (bass drum - high hat). In my opinion its a limited view of what is pleasing in sound. There is an analogy in photography where warmer light makes people look better. Its completely unrealistic but its "pleasing to the eye". Electronic equalization, in my experience, does make my system sound "smoother" over a larger range of sound volumes. That being said I generally listen at two volume levels. One that is low enough that conversation can still take place 10 feet from the speakers. Another that sounds like the saxophone player is in the room with you. Smooth responses over a range of volumes is largely dependant on speaker response. The only way it could happen in realtime is if you have a mic in the listening area and a sophisticated speaker management system. Otherwise just EQ to the best of your abilities at your average listening volume and find the "sweetspots" when it comes to adjusting the volume to its highest level.


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## tonyvdb (Sep 5, 2007)

Sounds like your looking for a receiver with Ausyssey Dynamic EQ its the replacement for the old loudness control. It changes as you raise the volume level.


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## istvan (Jul 5, 2013)

If your talking 2 channel stereo music that do not use reference volumes then Dynamic EQ can be messy. Constantly adjusting equalization based on input. Surround sound is mastered at reference levels so Dynamic EQ has a chance at adjusting for dynamics. Personally I would pick a couple of listening levels and EQ for them. Not so keen on letting robots control my EQ proactively.


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## shkumar4963 (Nov 16, 2014)

Istvan is probably right. Just hold on to several EQ curves at different volumes and then apply them. Now how do we create those curves. What should we assume the reference level the music was mastered at. Any guesses? And how to come with THOSE EQ curves more methodically.


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## shkumar4963 (Nov 16, 2014)

Istvan: it probably was not about pleasing to listen. But it had to do with our perception of sound at different frequencies and different volume levels. Agreed it was a crude way of doing it but the idea was not bad.


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## istvan (Jul 5, 2013)

I think Dynamic EQ could work really well if ..
1. there is a calibrated microphone in the listening area at all times 
2. there is a forecasting system in software that "listens" to changes from the programmed material and compares that with what is actually sent out through the speakers in near realtime.

My understanding is Dynamic EQ today is a based on a baseline static measurement and not on active measurements and feedback.


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## shkumar4963 (Nov 16, 2014)

Till I figure out an automated system, I thought I would build three EQ one for low volume, one for medium and one for large. Medium volume will be flat. Does anone here know what should low and high volume EQ curves look like.


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## tonyvdb (Sep 5, 2007)

I would never be concerned about how an EQ curve "looks" its far more important as to how it sounds. That would totally be dependent on your speakers and the room they are in as to what would be ideal.


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## gdstupak (Jul 13, 2010)

shkumar4963 said:


> ... Just hold on to several EQ curves at different volumes and then apply them. Now how do we create those curves... And how to come with THOSE EQ curves more methodically.


Use a test disk that has test tones at multiple frequencies, all of the frequencies are recorded at the same level. Adjust the frequency equalizer until the output of all the frequencies are equal according to a SPL meter. 
If REW only tests at one output level, this is something they should look into changing, being able to test at multiple output levels for low, medium and high volumes.

I've never experienced well balanced sound using Audyssey Dynamic EQ.


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## Brenda (May 20, 2010)

I find a greater need for different EQ profiles at any particular volume level. The differences in recordings are massive, and in many cases disappointing. I would love another profile that made a gross adjustment for bass shy recordings. It seems today's engineers are more consistent and aware of room effects that may occur in their little engineering room behind the glass.


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## shkumar4963 (Nov 16, 2014)

Yes. May be it is better to just have different eq for different songs, store them with the song in the music player like Fubar2000 or such and then the song will use that when being played.


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## Brenda (May 20, 2010)

I didn't know you could do that. Seems like a nice option for music lacking in certain frequencies.
Will have a look at the Fubar2000.


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## shkumar4963 (Nov 16, 2014)

I don't know either. I was making a comment that it would be nice if we could do that. There are several players in the market. I will search Google to see if anyone have the capability to store custom equalizer with each song.


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## Brenda (May 20, 2010)

Would this be the same as mastering software - to re-engineer the piece ??


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## shkumar4963 (Nov 16, 2014)

Brenda said:


> Would this be the same as mastering software - to re-engineer the piece ??


That is definitely a possibility. But I am sure some players will allow us to same EQ file with the song.


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## AudiocRaver (Jun 6, 2012)

Foobar2000 will allow EQ via built-in graphic eq or vst plugin with parametric or convolution eq, have not seen how it would allow different eq setting per song. I think a different setting per volume setting would more than cover it, just my opinion.

JRiver, OTOH, has more extensive capability to customize settings in different ways, might do just what you want. Not sure about that, though.

As others have commented, Dynamic EQ can mess with imaging, causing images to shift as volume levels change. Not a glaring problem, but noticeable, and if you are particular about imaging and soundstage, it can be distracting.


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## lcaillo (May 2, 2006)

I have not looked, but I would be surprised if someone does not make software that amounts to a continuously variable loudness contour or at least a lookup table system like is used for color mapping in video systems. 

Yamaha had a loudness contour control on their receivers and preamps back in the 80s and some liked it a lot, many people did not. It never seemed like a priority to me as any listening that I do seriously is usually at pretty similar volumes, and when not listening seriously it does not matter to me.


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## AraiYuichi (Dec 8, 2014)

Does anyone know that the "Equal Loudness" compensation txt file. This is such as to compensate 70 phone to 80 phone or 60 phone to 80 phone. Of course those curve depends upon the acoustic condition of the room, how it recorded, loudness of the sound, like or dislike, etc. However, if those are already provided, we can easily choose them and download then into the equalizer such as miniDSP. 
Yuichi


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