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Device for Equal Loudness/Fletcher Munson Curve? Do Any Speakers Adapt to This?

stevenswall

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#1
Capture.PNG


Is there a device that will change the frequency response of a system to match this at normal listening levels?

Thinking about using a MiniDSP to make 4 presets for various volume levels, but I'm curious if there is device made for this. Recently Joe N Tell on Youtube uploaded a video with a Yamaha amp that could do something like this but instead of a button it was continuously variable. That would be a good second solution if there isn't a device that does this.
 

pierre

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#3
Jriver can do loudness compensation. Various audio plugin can dot it too.
 

Hayabusa

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#5
I use the Marantz AV8805 for this.
Audyssey makes sure the level is calibrated and you can still have an offset to the reference level in case your music material needs it.
 
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Krunok

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#6
View attachment 46320

Is there a device that will change the frequency response of a system to match this at normal listening levels?
I helped develop a feature in DRC plugin for Volumio which may help you to implement this. You can set up 6 volume dependent filters which are then swapped seemlesly as you change volume, 4 of them for listening below flat curve and 2 of them above flat curve. Those 2 can also be used to reduce LF amplitude for loud playing to reduce strain on woofers.
 

Ivanovich

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#7
I helped develop a feature in DRC plugin for Volumio which may help you to implement this. You can set up 6 volume dependent filters which are then swapped seemlesly as you change volume, 4 of them for listening below flat curve and 2 of them above flat curve. Those 2 can also be used to reduce LF amplitude for loud playing to reduce strain on woofers.
That sounds cool. What’s DRC?

Also, OP, that’s basically what the “Loudness” button on stereo receivers did, back in the day...
 

Krunok

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#8
That sounds cool. What’s DRC?
Digital Room Correction plugin for Volumio. It includes room EQ filter generation via DRC-FIR tool, BruteFIR convolution engine to run flters and VoBAF (Volume Based Active Filtering) feature that I mentioned in previus post.

BruteFIR convolution engine also accepts filters created by REW, rePhase, Audiolense, Acourate etc.

It is free for use, you can download it here.
 
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Ivanovich

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#9
Cool, thanks. As it’s not in my list of plugins in Volumio, I have no idea how to install it.

I’m working on a diy 3-way fusion amp based powered speaker project, plus a miniDSP 2x4HD for multiple subs. I’ll be doing my DRC using those two DSPs, and that’s gonna take me a while to get finished. I do like the idea of adjusting response curve based on volume, so it’s good to know for future.
 

Krunok

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#10
Cool, thanks. As it’s not in my list of plugins in Volumio, I have no idea how to install it.

I’m working on a diy 3-way fusion amp based powered speaker project, plus a miniDSP 2x4HD for multiple subs. I’ll be doing my DRC using those two DSPs, and that’s gonna take me a while to get finished. I do like the idea of adjusting response curve based on volume, so it’s good to know for future.
Plugin has not yet been officialy released so you don't see it in the plugin list but it is fully functional and will soon be released. Installation instructions are on the link I posted.

Here they are:

1. Enable SSH and connect to Volumio
To do that, have a look here : ssh in volumio

2. Download and install the plugin
Type the following commands to download and install plugin:

wget https://github.com/balbuze/volumio-plugins/raw/master/plugins/audio_interface/brutefir3/brutefir.zip
mkdir ./brutefir
miniunzip brutefir.zip -d ./brutefir
cd ./brutefir
volumio plugin install
cd ..
rm -Rf brutefir*
 

Krunok

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#11
Cool, thanks. As it’s not in my list of plugins in Volumio, I have no idea how to install it.

I’m working on a diy 3-way fusion amp based powered speaker project, plus a miniDSP 2x4HD for multiple subs. I’ll be doing my DRC using those two DSPs, and that’s gonna take me a while to get finished. I do like the idea of adjusting response curve based on volume, so it’s good to know for future.
Btw, plugin also supports filters for up to 4way active XO's but I didn't have a chance to test it.
 

Hipper

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#12
[Behringer's DEQ2496 is good for many things but it does not do anything for loudness curves - at least my one doesn't. All you can do is set a number different EQ levels and use them as you wish.
Edit I'm wrong! See post 18 below]

Old fashioned tone controls (bass and treble) would be almost as good. The loudness button on some gear was also used for this.

The only machine I ever heard of that used equal loudness curves as you altered the volume was TACT but they are no longer made and I believe were quite temperamental.

I wouldn't get to hung up about these curves. For a start there an individual thing - your curve may be different from mine; not by much perhaps but who knows. Secondly, if you look at the red curves and you increase the volume by 20dB (60 to 80 phons) there is no difference in the perceived volume at 10kHz and -5dB at 100Hz. Indeed it seems that mostly it is only the bass that is affected. Increase the volume by 4dB and we're talking -1dB at 100Hz.
 
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#13
Oddly car audio stereos have had this for years, it is basically a variable boost (pioneer do low/mid/high) of low and high end which is lessened as the volume rises
 

Krunok

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#14
Oddly car audio stereos have had this for years, it is basically a variable boost (pioneer do low/mid/high) of low and high end which is lessened as the volume rises
Not the same thing - in car audio FR characteristic is not changed with volume level, only absolute listening level is cchanged.
 
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#15
Not the same thing - in car audio FR characteristic is not changed with volume level, only absolute listening level is cchanged.
If you’d care to read what I wrote... pioneers version DOES change fr characteristic dependant on volume level, and a few others also, I just know pioneers do it as I’ve had a fair few and it can be applied in varying levels from a smaller boost at lower volume levels or a larger one, it’s not applied at all volumes equally
 

Krunok

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#16
If you’d care to read what I wrote... pioneers version DOES change fr characteristic dependant on volume level, and a few others also, I just know pioneers do it and it can be applied in varying levels from a smaller boost at lower volume levels or a larger one, it’s not applied at all volumes equally
Ah ok, sorry. Car audio systems usually self-adjust volume according to the level of the engine and outdoor noise so I thought you were speaking about that.
 

DonH56

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#17
My Emotiva XMC-1 claims to follow the loudness curves, as do many other "dynamic volume" systems in various AVRs/AVPs/etc. I find the boost to be too much at low levels, however, but like it "in the middle" at around maybe 70 dB average SPL (have not measured it, should do that at some point).
 

pkane

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#18
Behringer's DEQ2496 is good for many things but it does not do anything for loudness curves - at least my one doesn't. All you can do is set a number different EQ levels and use them as you wish. Old fashioned tone controls (bass and treble) would be almost as good. The loudness button on some gear was also used for this.

The only machine I ever heard of that used equal loudness curves as you altered the volume was TACT but they are no longer made and I believe were quite temperamental.

I wouldn't get to hung up about these curves. For a start there an individual thing - your curve may be different from mine; not by much perhaps but who knows. Secondly, if you look at the red curves and you increase the volume by 20dB (60 to 80 phons) there is no difference in the perceived volume at 10kHz and -5dB at 100Hz. Indeed it seems that mostly it is only the bass that is affected. Increase the volume by 4dB and we're talking -1dB at 100Hz.
look into the DYNamic option on DEQ, it has volume-related adjustable transfer function. While you can’t reproduce the exact F-M curves with it, you can experiment with curves that approximate it.
 
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#19
You may to do look at the various measurements. There are at least 4 different flavors of loudness curves, I show them in my post halfway through..
https://www.audiosciencereview.com/forum/index.php?threads/hearing-eq.9632/

All are measured at young people around 25, there are some published measured at elder people, the responses are very different. It is not clear to me what one does for music crossing from 60 to 90 dB while playing - floating correction?

I remember this being a great new thing around 1970, but then it slowly disappeared. I believe the 20db bass boost in some room curves is a leftover from those loudness corrections.
 

Hipper

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#20
look into the DYNamic option on DEQ, it has volume-related adjustable transfer function. While you can’t reproduce the exact F-M curves with it, you can experiment with curves that approximate it.
So there is! I've had the DEQ2496 for nearly fourteen years and I still don't know half the possibilities with it!

Apologies for the misinformation. I've edited my earlier post accordingly.
 
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