Another one of my ideas... Equal loudness contour

Chester01 · Mar 19, 2006, 10:52 AM

Just a thought, I feel it would be cool to have a plugin that was an equal loudness contour filter (the "ear" contour); at low levels, highs and lows would be boosted more so than at a high level. Here is my vision of such a plugin. First we would need to input ten or twenty
'presets' of different eq's of the loudness contour
http://www.extron.com/technology/img...ol_ts_2-lg.jpg
this would be the reference the plugin uses to change the eq to. Now, how would the plugin know what volume is actually produced when the card is outputing say -24 db? First the user would need to maintain a consistent stereo level ( just use a gain hq plugin to control my volume, apply the gain before the plugin...) next you would use a db meeter and send pink noise through the system to get a reference level (reference in relation to all the gains in the signal chain.) lastly the user would program in that -24 db on the soundcard is actually 90 db in the real world (or whatever the DB meeter says.)

If we wished to make a very complex plugin we could have the user program in the efficency of each speaker (say mids are 92.1 db/w/m and the subwoofer is 88 db/w/m) and the gain ratio of each amplifier, one may be 33db gain and one may be 31. I have done this to my system already however many never take such factors into consideration. Couppled with Tril's 5 channel time delay, we could move much closer to acoustic perfection

How I 'balanced' my system... (these are manufacturer specs, I didnt have a db meeter handy so i just went with factory specs)
Klipsch sysnergy SB-1=92 db/w/m
JL audio 13W7 = 86.3 db/w/m
Crown K1 (on Klipsch)=31.5 db
Crown K2 (on JL Audio)=33.1 db
therefore on the low end i have 86.3+33.1-31.5=87.9
the difference between low and high is 92-87.9= 4.1 db
therefore i reduce the high frequency output by 4.1 db

a plugin where people put in specs would be easier for most people though... also I am unsure if impedence would play a role in the calculation or not... I dont think it would... Thoughts and comments are welcome.

townkat · Aug 21, 2006, 07:22 PM

i try to make such a plugin, actualy i am almost done, it's just that... some strange things happen

when low or high booster have some specific values it enters some sort of resonance and the sound is very distorted... i don't know much about eq's but i am pretty sure that i force them to much

. Someone please help !

here is the plugin http://www.geocities.com/picacioiu/L...nsatorv001.bin (rename to .kxl)
if you need the sources here they are http://www.geocities.com/picacioiu/L...nsatorv001.zip

i made it by mixing 2 existing plugins and link some of their variables with some formulas (timbre and stereo volume). Eq 100% slider means the value where eq sliders have exactly 100% effect.

Chester01 · Aug 21, 2006, 08:37 PM

the link appears to be down

townkat · Aug 22, 2006, 05:53 AM

they work for me, can you try again please?

Chester01 · Aug 22, 2006, 07:59 AM

works now

Chester01 · Aug 22, 2006, 08:19 AM

it is a nice plugin, how do you set what the relative volume is though? (outside in the real world)? Maybe we have different ideas

My whole idea was to compare the actual gain on hte computer to the actual SPL level in real life. Granted you would need to assume an completely linear system playin in the real world. So, first you would set the realworld gains to whatever they will be normally. Then play a signal at say -20 db through the soundcard (-20 db showing up on a Peak plugin) Lets say that -20 db on the comptuer means 80 db in the real world after all the other gains on the external amplifiers. That would mean that if the comptuer is producing a signal at 0 db, there should be 100 db of spl in the real world. Knowing this we can reference the equal loudness contour to our gain scale; it would be using the contour of 80 db when the gain within the plugin is set to -20 db (you would use the gain of the plugin to control your overall volume). When you set the gain to 0 db, the plugin will know that the actual volume would be 100 db in the room things are playing into and would use the inverse frequency response contour at 100 db http://www.extron.com/technology/img...ol_ts_2-lg.jpg to equalize the sound comming through the sound card. What you have created looks like it is on the right track however I am unsure of how to 'set the reference point' Thanks for your help and hard work!

townkat · Aug 22, 2006, 10:11 AM

Yup, thats the way it should be in the final but now i am not sure if it is posible to gain low or high frequencies as high as 60db without those strange effects, as it is needed for this application.
Some instructions for this version :
-"Vol" slider 0 value means 85dB SPL = no eq needed
-When Vol slider have the same value as "Eq 100%" slider bass and trebble sliders have 100% effect, before that they have less efect and after that they have more effect.

I'll make it with included calculator in the final, with edit boxes etc., but now i want to see the effect correctly working first

Chester01 · Aug 22, 2006, 06:11 PM

k, makes sense. Thanks!

-Matt

Chester01 · Aug 22, 2006, 09:07 PM

btw, are you planning on using the treble and bass eq thing or will you be using a more accurate inverse curve? I will try and find an equation for the equal loudness curve if you dont have one, I believe I have seeon one before...

townkat · Aug 23, 2006, 06:37 AM

an equation would be good of corse, i searched for one too but i didn't find anything
also if anyone knows how to make eq for kx with about 60-80dB boost please help

Chester01 · Sep 6, 2006, 05:44 PM

I have been using the EQ P5 (two of them) to create an eq that should be close to the ear response curve. I played a 2000 hz tone (where the threshold of hearing approaches 0 db for the quietest we can hear) and found a total system dynamic range of 110 db. I really need to get a db meeter to check it but I will be running my system with a reference of 110 db at '+-0 db" gain out of the card. I will post a table of values (excel sheet) when I am done. Basically I am eyeballing an equal loudness contour sheet to find good approximations for gains and am using the 'peaks' and 'valleys' for crossover points. With the EQ P5 I can visually see the output of the filter which is helpful when matching it to the ear response curves. In conjunction with changing my gains I will then change the presets of these (I will make 6 presets, since I usually only have a -60 db gain HQ plugin as the quietest the system is)
It would be nice if I were able to program this

If we had an EQ P7, (maybe P8 for the low frequency boost) I could do it all with one plugin (assuming it had a -60 db range on the prein)

Chester01 · Sep 25, 2006, 09:07 PM

http://n.1asphost.com/Chesteta/Ear%2...r%20values.xls
This is the table of values I came up with in reguards to an equal loudness contour. I looked at an image I found on google image search that listed the 'phons' and 'db'... I use two EQ P5's to modify the signal. One for the low end and one for the high end.
Low end:
1: Low S-Shelf
Freq: 59hz
Q:1.00
Gain: 17.5db

2. Low S-Shelf
Freq: 59hz
Q:1.00
Gain: 0.0 db
NOTE: the low end needs two gains for when you pass an 18 db gain.

High end:
1. Bell
Freq: 404.4hz
Q:0.74
Gain: -5.0 db

2. Bell
Freq: 3.97 khz
Q:0.57
Gain: -10.0 db

3. Bell
Freq: 9.09 khz
Q:0.72
Gain: 5.0 db

4. Bell
Freq: 13.5 khz
Q:0.26
Gain: -2.0 db

5. High S-Shelf
Freq: 19.3 khz
Q:0.94
Gain: 4.0 db

** If you compare the gain values with the EQ values given you will see that I had my output set for 80 db

the gains are the variable, use the excel sheet to find gains for different levels. you will need to find what -x db on your computer means in the real world though. The chart I was using had the levels marked for every 20 db so I averaged the values. I figured out the Q values by trying to match the points where the graph I was gathering values off of crossed the '+-0db' for the loudness level. I know this was a very inaccurate way to gather my data however I had no other means to. If anyone has any published values for equal loudness contours please share!

My "dream plugin" would be one that we could have one gain slider that would then modify these gains smoothly. This plugin could serve as the loudness filter and a volume control. Peace.

EDIT:
Here is an image of the EQ's
http://n.1asphost.com/Chesteta/Eq.JPG
NOTE: How I currently use the EQ's is I have 12 (6 high and 6 low) presets, each set for a 10db difference in output. If there were ever a volume control plugin made, it would be even cooler if it could incorporate an AGC to control the gains of the EQ section.

Mar 19, 2006, 10:52 AM	#1
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	Another one of my ideas... Equal loudness contour Just a thought, I feel it would be cool to have a plugin that was an equal loudness contour filter (the "ear" contour); at low levels, highs and lows would be boosted more so than at a high level. Here is my vision of such a plugin. First we would need to input ten or twenty 'presets' of different eq's of the loudness contour http://www.extron.com/technology/img...ol_ts_2-lg.jpg this would be the reference the plugin uses to change the eq to. Now, how would the plugin know what volume is actually produced when the card is outputing say -24 db? First the user would need to maintain a consistent stereo level ( just use a gain hq plugin to control my volume, apply the gain before the plugin...) next you would use a db meeter and send pink noise through the system to get a reference level (reference in relation to all the gains in the signal chain.) lastly the user would program in that -24 db on the soundcard is actually 90 db in the real world (or whatever the DB meeter says.) If we wished to make a very complex plugin we could have the user program in the efficency of each speaker (say mids are 92.1 db/w/m and the subwoofer is 88 db/w/m) and the gain ratio of each amplifier, one may be 33db gain and one may be 31. I have done this to my system already however many never take such factors into consideration. Couppled with Tril's 5 channel time delay, we could move much closer to acoustic perfection How I 'balanced' my system... (these are manufacturer specs, I didnt have a db meeter handy so i just went with factory specs) Klipsch sysnergy SB-1=92 db/w/m JL audio 13W7 = 86.3 db/w/m Crown K1 (on Klipsch)=31.5 db Crown K2 (on JL Audio)=33.1 db therefore on the low end i have 86.3+33.1-31.5=87.9 the difference between low and high is 92-87.9= 4.1 db therefore i reduce the high frequency output by 4.1 db a plugin where people put in specs would be easier for most people though... also I am unsure if impedence would play a role in the calculation or not... I dont think it would... Thoughts and comments are welcome. __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 21, 2006, 07:22 PM	#2
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	i try to make such a plugin, actualy i am almost done, it's just that... some strange things happen when low or high booster have some specific values it enters some sort of resonance and the sound is very distorted... i don't know much about eq's but i am pretty sure that i force them to much . Someone please help ! here is the plugin http://www.geocities.com/picacioiu/L...nsatorv001.bin (rename to .kxl) if you need the sources here they are http://www.geocities.com/picacioiu/L...nsatorv001.zip i made it by mixing 2 existing plugins and link some of their variables with some formulas (timbre and stereo volume). Eq 100% slider means the value where eq sliders have exactly 100% effect. __________________ mixy kx plugins http://www.geocities.com/picacioiu/

Aug 21, 2006, 08:37 PM	#3
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	the link appears to be down __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 22, 2006, 05:53 AM	#4
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	they work for me, can you try again please? __________________ mixy kx plugins http://www.geocities.com/picacioiu/

Aug 22, 2006, 07:59 AM	#5
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	works now __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 22, 2006, 08:19 AM	#6
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	it is a nice plugin, how do you set what the relative volume is though? (outside in the real world)? Maybe we have different ideas My whole idea was to compare the actual gain on hte computer to the actual SPL level in real life. Granted you would need to assume an completely linear system playin in the real world. So, first you would set the realworld gains to whatever they will be normally. Then play a signal at say -20 db through the soundcard (-20 db showing up on a Peak plugin) Lets say that -20 db on the comptuer means 80 db in the real world after all the other gains on the external amplifiers. That would mean that if the comptuer is producing a signal at 0 db, there should be 100 db of spl in the real world. Knowing this we can reference the equal loudness contour to our gain scale; it would be using the contour of 80 db when the gain within the plugin is set to -20 db (you would use the gain of the plugin to control your overall volume). When you set the gain to 0 db, the plugin will know that the actual volume would be 100 db in the room things are playing into and would use the inverse frequency response contour at 100 db http://www.extron.com/technology/img...ol_ts_2-lg.jpg to equalize the sound comming through the sound card. What you have created looks like it is on the right track however I am unsure of how to 'set the reference point' Thanks for your help and hard work! __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 22, 2006, 10:11 AM	#7
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	Yup, thats the way it should be in the final but now i am not sure if it is posible to gain low or high frequencies as high as 60db without those strange effects, as it is needed for this application. Some instructions for this version : -"Vol" slider 0 value means 85dB SPL = no eq needed -When Vol slider have the same value as "Eq 100%" slider bass and trebble sliders have 100% effect, before that they have less efect and after that they have more effect. I'll make it with included calculator in the final, with edit boxes etc., but now i want to see the effect correctly working first __________________ mixy kx plugins http://www.geocities.com/picacioiu/

Aug 22, 2006, 06:11 PM	#8
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	k, makes sense. Thanks! -Matt __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 22, 2006, 09:07 PM	#9
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	btw, are you planning on using the treble and bass eq thing or will you be using a more accurate inverse curve? I will try and find an equation for the equal loudness curve if you dont have one, I believe I have seeon one before... __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Aug 23, 2006, 06:37 AM	#10
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	an equation would be good of corse, i searched for one too but i didn't find anything also if anyone knows how to make eq for kx with about 60-80dB boost please help __________________ mixy kx plugins http://www.geocities.com/picacioiu/

Sep 6, 2006, 05:44 PM	#11
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	I have been using the EQ P5 (two of them) to create an eq that should be close to the ear response curve. I played a 2000 hz tone (where the threshold of hearing approaches 0 db for the quietest we can hear) and found a total system dynamic range of 110 db. I really need to get a db meeter to check it but I will be running my system with a reference of 110 db at '+-0 db" gain out of the card. I will post a table of values (excel sheet) when I am done. Basically I am eyeballing an equal loudness contour sheet to find good approximations for gains and am using the 'peaks' and 'valleys' for crossover points. With the EQ P5 I can visually see the output of the filter which is helpful when matching it to the ear response curves. In conjunction with changing my gains I will then change the presets of these (I will make 6 presets, since I usually only have a -60 db gain HQ plugin as the quietest the system is) It would be nice if I were able to program this If we had an EQ P7, (maybe P8 for the low frequency boost) I could do it all with one plugin (assuming it had a -60 db range on the prein) __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Sep 25, 2006, 09:07 PM	#12
Chester01 DriverHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 487 Rep Power: 0	http://n.1asphost.com/Chesteta/Ear%2...r%20values.xls This is the table of values I came up with in reguards to an equal loudness contour. I looked at an image I found on google image search that listed the 'phons' and 'db'... I use two EQ P5's to modify the signal. One for the low end and one for the high end. Low end: 1: Low S-Shelf Freq: 59hz Q:1.00 Gain: 17.5db 2. Low S-Shelf Freq: 59hz Q:1.00 Gain: 0.0 db NOTE: the low end needs two gains for when you pass an 18 db gain. High end: 1. Bell Freq: 404.4hz Q:0.74 Gain: -5.0 db 2. Bell Freq: 3.97 khz Q:0.57 Gain: -10.0 db 3. Bell Freq: 9.09 khz Q:0.72 Gain: 5.0 db 4. Bell Freq: 13.5 khz Q:0.26 Gain: -2.0 db 5. High S-Shelf Freq: 19.3 khz Q:0.94 Gain: 4.0 db ** If you compare the gain values with the EQ values given you will see that I had my output set for 80 db the gains are the variable, use the excel sheet to find gains for different levels. you will need to find what -x db on your computer means in the real world though. The chart I was using had the levels marked for every 20 db so I averaged the values. I figured out the Q values by trying to match the points where the graph I was gathering values off of crossed the '+-0db' for the loudness level. I know this was a very inaccurate way to gather my data however I had no other means to. If anyone has any published values for equal loudness contours please share! My "dream plugin" would be one that we could have one gain slider that would then modify these gains smoothly. This plugin could serve as the loudness filter and a volume control. Peace. EDIT: Here is an image of the EQ's http://n.1asphost.com/Chesteta/Eq.JPG NOTE: How I currently use the EQ's is I have 12 (6 high and 6 low) presets, each set for a 10db difference in output. If there were ever a volume control plugin made, it would be even cooler if it could incorporate an AGC to control the gains of the EQ section. __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands... Last edited by Chester01; Sep 25, 2006 at 09:13 PM.