• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

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

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
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.
 

Hayabusa

Addicted to Fun and Learning
Joined
Oct 12, 2019
Messages
787
Likes
518
Location
Abu Dhabi
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.
 
Last edited:

Krunok

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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

Member
Forum Donor
Joined
Dec 17, 2019
Messages
88
Likes
86
Location
Ellicott City, MD USA
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

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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.
 
Last edited:

Ivanovich

Member
Forum Donor
Joined
Dec 17, 2019
Messages
88
Likes
86
Location
Ellicott City, MD USA
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

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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

Addicted to Fun and Learning
Joined
Jun 16, 2019
Messages
753
Likes
625
Location
Herts., England
[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.
 
Last edited:

Dumdum

Senior Member
Joined
Dec 13, 2019
Messages
338
Likes
219
Location
Nottinghamshire, UK
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

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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.
 

Dumdum

Senior Member
Joined
Dec 13, 2019
Messages
338
Likes
219
Location
Nottinghamshire, UK
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

Major Contributor
Joined
Mar 25, 2018
Messages
4,600
Likes
3,065
Location
Zg, Cro
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

Master Contributor
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
7,835
Likes
16,497
Location
Monument, CO
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

Master Contributor
Forum Donor
Joined
Aug 18, 2017
Messages
5,630
Likes
10,205
Location
North-East
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.
 

JoachimStrobel

Addicted to Fun and Learning
Forum Donor
Joined
Jul 27, 2019
Messages
518
Likes
303
Location
Germany
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

Addicted to Fun and Learning
Joined
Jun 16, 2019
Messages
753
Likes
625
Location
Herts., England
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.
 
Top Bottom