Introducing EQ Chart

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Chris_Allen
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Introducing EQ Chart

#1 Post by Chris_Allen » Sat Dec 03, 2011 6:55 pm

It's time for another crazy little tool.

Built on the same framework of SPLChart, it's objective is to display the slider positions of an EQ for a given db gain and given frequency positions. The input charts are all the same files as SPLChart.

EQs are complicated things in they way that they all behave differently, so this tool, like SPLChart, is intended for guidance only.

[eq eqgain=12]J110M12[/eq]

Code: Select all

[eq eqgain=12]J110M12[/eq]
I considered doing fancy sampling for ranges from the charts but I felt it wouldn't add much to the tool and just cause unnecessary complexity.

So, here are the commands:

eqtype
freqs
eqgain
dbmin
dbtarget
fmin
fmax
sliders
highlight
nochart
alpha
width
height

eqgain
The range of db gain available on the EQ.

eqtype
There are a number of preset EQ slider positions:
1) 7 Band 2) 31 band 3) 15 band 4) 9 band 5) 3 band
You don't have to use these, you can define your own frequency positions using freqs

freqs
Define the frequency positions being displayed in the visible curve. This can be used in conjuction with eqtype or on it's own. The frequencies blocks are comma separated but the frequency blocks are colon ':' separated. The definition of a frequency block is the frequency, the db gain [optional] and the visibility [optional].
<frequency>:<db gain>:<visibility>,<frequency>:<db gain>:<visibility>,...
With the db gain and visibility being optional you can just state the frequency:
<frequency>,<frequency>,...
or combinations
<frequency>:<db gain>,<frequency>,<frequency>:<db gain>,<visibility>,<frequency>:<db gain>,....
using the db gain will override the calculated value from the spl chart and visibility will turn off the red dots.

Using these three together, this is what you get:

[eq eqgain=15&eqtype=4]J110M12[/eq]

Code: Select all

[eq eqgain=15&eqtype=4]J110M12[/eq]
[eq eqgain=6&eqtype=3]J110M12[/eq]

Code: Select all

[eq eqgain=6&eqtype=3]J110M12[/eq]
You notice in the bottom chart the EQ sliders are bottomed out. This is caused because the range for the chart is calculated across the frequency range which is 20Hz-16kHz in this EQ. The lowest dB is 77.56 and the highest is 106.82. The tool calculates the midpoint as being 92.19, so that is what it tries to correct the EQ to. With a gain range of only 6dB on the EQ, it can't possibly cover the 30dB in the chart

There are two ways round this.

dbmin
The minimum db on the splchart that should be used

dbtarget
The target sensitivity of the EQ

[eq eqgain=6&eqtype=3&dbtarget=100]J110M12[/eq]

Code: Select all

[eq eqgain=6&eqtype=3&dbtarget=100]J110M12[/eq]
[eq eqgain=6&eqtype=3&dbmin=85]J110M12[/eq]

Code: Select all

[eq eqgain=6&eqtype=3&dbmin=85]J110M12[/eq]
So, looking at the top of those two graphs, I don't think boosting a full 6dB at 40Hz is a good idea and I want to lift the 10k a little, so I use the freqs command:

[eq eqgain=6&eqtype=3&dbtarget=100&freqs=40:3,10000:-4]J110M12[/eq]

Code: Select all

[eq eqgain=6&eqtype=3&dbtarget=100&freqs=40:3,10000:-4]J110M12[/eq]
I would also probably smooth out the 1k and 1.6k as the variation isn't that severe but it just depends where on the chart the sampling lands.

I going to post this in a series of posts and compile afterwards.

Here are the supported cabs:

8x10Sealed
ATDMCM8
D2510
D2512
D3012HO
D3015LF
DBeta10
DBP102
DR200 (unported)
DR200ASD1001 (ported)
DR250 (unported)
DR250ASD1001 (ported)
DR280 (unported)
DR280NSD2005 (ported)
DS2010
EVSX100
EVSX300
J110ASD1001
J110
J110M12
J110NSD2005
J112D2512ASD1001
J112D2512
J112D2512M16
J112D3012
J115D2515
J115D2515M20
J115D2515ASD1001
J115D2515NSD2005
J210F12
JBLMRX525
JBLSRX718
JBLSRX728
JBLVRX915M
JBLVRX932LAP
LABSUB
Mackie1501
Mackie1501M
MackieS218
O105D2510 [Obsolete]
O105D2510P1005 [Obsolete]
O10D2510 [Obsolete]
O12 [Obsolete]
O15D3015 [Obsolete]
O15DEVM [Obsolete]
O12D2512DA6AAPT80
O12DBP102X2DA6AAPT80
O15D2515DA6AAPT80
O15DD12LFX2DA6AAPT80
OT12D2512M12
OT12D2512ASD1001
OT12D3012NSD2005
OT12P [Obsolete]
OT15P20M [Obsolete]
OT15M20
OT15D3015CDASD
OT212P [Obsolete]
OT215P [Obsolete]
peavey112
PiezoMA20OnAxis
PiezoMAOnAxis
PiezoSA16OnAxis
PiezoSAOnAxis
RAD1
RAD2
sb4112ht
SLA
SLAPRO4ALPHA6
T24W16D2010
T24W16DBP102
T24W24D2010
T24W24DBP102
T30W16D2010
T30W16D3012LF
T30W24D2010
T30W24D2010x2
T30W27D3012LF
T30W27D3012LFX2
T30W30D3012LF
T36W25D3015
T36W27D4012X2C2
T36W27D4012X2C4
T36W27D4012X2
T39W14D2010
T39W16D3012
T39W18D2010
T39W20D102VC2
T39W20D10
T39W20D3012
T39W24D3012LF
T39W24D3012LFC2
T39W24D3012LFC4
T39W24D3012LFC8
T39W30D12
T39W30D3012
T48W14DHL10C
T48W15D3012
T48W18D3015
T48W18D4012
T48W24D3012
T48W24D3015
T48W36D3015
T60W15DLab12
T60W20DLab12
T60W27DLab15
T60W30DLab12X2
THTW15DLab12
THTW30DLab12
THTW18DTempest
THTW30DTempest
TLAH
TTW16DMCMCorner
TTW16DMCMFree
TTW16DMCMWall
W10D2510M
W10 [Obsolete]
W8M
W8DLA8MB [Obsolete]
Yamaha112V
Yamaha115V
Yamaha215V
Last edited by Chris_Allen on Thu Jan 24, 2013 12:40 pm, edited 1 time in total.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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Bill Fitzmaurice
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Re: Introducing EQ Chart

#2 Post by Bill Fitzmaurice » Sat Dec 03, 2011 7:23 pm

You don't want to boost any cabs below the tuning frequency, as all that will do is stress the driver unnecessarily. For that matter you want to cut below where the cab is down 10dB, as that's the lower limit of useful response.

hermanmonker
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Joined: Thu Jun 16, 2011 11:51 am
Location: Bridgend. S.Wales U.K

Re: Introducing EQ Chart

#3 Post by hermanmonker » Wed Dec 07, 2011 5:05 pm

What a great idea,how exactly do I use the codes for a specific eq curve of a cab.

Charles Warwick
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Location: Ames, Iowa

Re: Introducing EQ Chart

#4 Post by Charles Warwick » Mon Apr 16, 2012 12:30 am

Bill Fitzmaurice wrote:You don't want to boost any cabs below the tuning frequency
What is the tuning freq of the Jacks? I don't recall that in the plans...

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: Introducing EQ Chart

#5 Post by Tom Smit » Mon Apr 16, 2012 9:12 am

looking at the charts, fourth one down, it seems that the answer is around 70hz.
TomS

byacey
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Location: Edmonton, Alberta, Canada

Re: Introducing EQ Chart

#6 Post by byacey » Thu Jan 24, 2013 1:11 pm

I think if you try and EQ the boxes ruler flat, you will find them unnatural and excessively bright sounding.
Built
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WH8s
SX212

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DJ Higgumz
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Location: Wisconsin

Re: Introducing EQ Chart

#7 Post by DJ Higgumz » Fri Jan 25, 2013 9:06 am

Thank you Chris that is a great app addition!
Before Fitzmaurice, big bass could only be had with just a hook and a nightcrawler.
Building
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Built
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1 30" T39
3 Autotubas with GTO804
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LelandCrooks
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Re: Introducing EQ Chart

#8 Post by LelandCrooks » Sat Jan 26, 2013 9:02 am

This is a great app.
If it's too loud, you're even older than me! Like me.
http://www.speakerhardware.com

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kekani
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Re: Introducing EQ Chart

#9 Post by kekani » Sat Jan 26, 2013 1:55 pm

Okay, I know I'm supposed to play with the charts, then delete the chart, but I'd like to confirm that I understand the usefulness of the results pertaining to baselining the cab utilizing the reverse of the spl as mentioned elsewhere.

Basically, this tool better defines the frequencies closer to match the equalizer, in this case, 31 channel.
Since its not recommend to boost below what the cab is able to produce, I did "freqs=25:-12,31.5:-6,40:-1" and "freqs=25:-9,31.5:-3,40:-1" to take those frequencies out (and see the scale), but I left the 10k region and opened it up to 12 db just to see what's there.

So, if I take the results of this chart and duplicate the boosts and cuts on the 31 channel, I should have a cab that starts as "flat", and I can tweak from there.

Do I have this correct?

[eq width=650&height=450&eqgain=12&eqtype=2&dbtarget=100&freqs=25:-12,31.5:-6,40:-1]J112D2512M16[/eq]


[eq width=650&height=450&eqgain=12&eqtype=2&dbtarget=100&freqs=25:-9,31.5:-3, 40:-1]DR200ASD1001[/eq]
Last edited by kekani on Mon Apr 03, 2017 2:10 pm, edited 15 times in total.
Wedgehorn 6 (x2)
Jack 110 Lites (x2)
XF212 (Egnater style)
DR200 ASD (Yes! Finally!)

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Chris_Allen
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Re: Introducing EQ Chart

#10 Post by Chris_Allen » Sat Jan 26, 2013 5:24 pm

Each physical EQ is going to have a different 'Q' on each frequency band which is going to effect things but as a 'guide', your charts look good to me.

As mentioned by Bill, everything below the corner frequency shouldn't be boosted,
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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Bill Fitzmaurice
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Re: Introducing EQ Chart

#11 Post by Bill Fitzmaurice » Sat Jan 26, 2013 5:43 pm

Chris_Allen wrote:Each physical EQ is going to have a different 'Q' on each frequency band which is going to effect things but as a 'guide', your charts look good to me.

As mentioned by Bill, everything below the corner frequency shouldn't be boosted,
There are other issues as well. Unless specified otherwise the charts are half-space. Put a sub against a wall and it's in quarter space, put it in the corner and it's in eighth space. That won't affect the response by a lot, but it will by some.
Put a full range cab on the floor and it's in half space below the baffle step, but quarter space above the baffle step. That will cause a 6dB higher sensitivity through the mids than the chart shows. Put it against the wall and it's in quarter space across the bandwidth. Put it on a pole and it's in half space above the baffle step, full space below the baffle step, which causes a drop off in the lows. That's why using the inverse of the SPL chart is a start, but only a start, if you want to get it right an RTA has to be done to each room.

DaveK
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Location: Sacramento CA

Re: Introducing EQ Chart

#12 Post by DaveK » Wed Jul 03, 2013 4:59 pm

Chris,

Is there an option to remove the original SPL curve (the red line) and the heavy black line for the target SPL? They are very distracting when using a chart to set the sliders on a graphic EQ. I tried the sliders, nochart, and alpha options, but they don't seem to do anything.

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Chris_Allen
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Re: Introducing EQ Chart

#13 Post by Chris_Allen » Thu Jul 04, 2013 1:19 am

DaveK wrote:Chris,

Is there an option to remove the original SPL curve (the red line) and the heavy black line for the target SPL? They are very distracting when using a chart to set the sliders on a graphic EQ. I tried the sliders, nochart, and alpha options, but they don't seem to do anything.
Not at the moment but I can certainly look at it.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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