Equalizer APO, REW and Rephase WOW!

[JohnnyInBris]

You can also do this with one double click on a desktop shortcut. Just create shortcuts to batch files that simply use the copy command to overwrite config.txt
eg: copy /y config1.txt config.txt

[KaffiMann]

Originally Posted by JohnnyInBris

You can also do this with one double click on a desktop shortcut. Just create shortcuts to batch files that simply use the copy command to overwrite config.txt
eg: copy /y config1.txt config.txt

Thank you for this. No need to open the gui at all. :-)
Like previously mentioned this is very handy for a/b(/c) comparison of settings, we can fool ourselves with memory, better to quickly swap settings frequently to find the pro's and cons.

[33Polkhigh]

I've been posting about this over in another thread, over in the full range section. Basically I've been using my PC with equalizer APO as the crossover in my fast system. I designed the speakers with this in mind using metal drivers that I can control well.

Basically I apply a variable band equalizer to each driver and shape the contour of the frequency responses so that they sum to flat. It seems to be working fine.

I've read some comments about this kind of linear phase equalization not being in phase or free from artifacts. It sounds like the OP is suggesting a different way using equalizer apo and rephase software.

Whats wrong with just using the variable band equalizers?

[GDO]

Originally Posted by 33Polkhigh

I've read some comments about this kind of linear phase equalization not being in phase or free from artifacts.

I don't understand what kind of Eq you are using, but one thing is sure, if it is linear phase, it is plain wrong.

If you want to correct amplitude issues use minimum phase eqs.

Generally we need to correct both amplitude and related phase issues, and this is what min phase Eqs do, whereas linear phase eqs do correct amplitude, but mistakenly live the phase untouched.

Phase can also be Equed living amplitude untouched, but it's a different question.

A linear phase Eq is... well a sound fx of some kind that some guys involved in music production seem to find usefull, but to correct the response of a loudspeaker it is the wrong tool...

[dlwearl]

I having a hard time getting this software to work properly as an active crossover. I'd like to power my 3-way speakers through a 7.1 receiver (Pioneer VSX74-TXVi).

My file syntax is below. I receive weird results with the treble and midrange, but the bass seems to work just fine. Anyone willing to take a look? Note that I have not measured my speakers yet, so this is a quick-and-dirty attempt at a crossover. I am reading Joe D'Appolito's book on how to conduct measurements properly, and also working with VituixCAD.

#Channel Assignment Standards
# 1=Left, 2=Right, 3=Center, 4=Subwoofer, 5=Rear left, 6=Rear right, 7=Side left, 8=Side right
#Use left, center, and surround left for the bass, midrange, and treble speakers on the left speaker.
#Use right, rear right, and side right for bass, midrange, and treble speakers on the right speaker.

Device: VSX-74TXVi Intel(R) Display Audio {6691a411-ecd1-4f85-8ce0-42f47aa0c665}
Copy: R=R C=R RR=R
# Copy: L=L RL=L SL=L

#Woofer, right speaker
Channel: R
Preamp: 8.6 dB
Filter: ON LP Fc 250 Hz
Filter: ON LP Fc 250 Hz

# Channel: L
# Preamp: 9 dB
# Filter: ON LP Fc 250 Hz
# Filter: ON LP Fc 250 Hz

#Midrange
Channel: RR
Preamp: 4.6 dB
Filter: ON HP Fc 250 Hz
Filter: ON HP Fc 250 Hz
Filter: ON LP Fc 1700 Hz
Filter: ON LP Fc 1700 Hz

# Channel: SL
# Preamp: 4 dB
Equaliser: Generic
# Filter: ON HP Fc 200 Hz
# Filter: ON HP Fc 200 Hz
# Filter: ON LP Fc 1700 Hz
# Filter: ON LP Fc 1700 Hz


#Horn
Channel: C
Preamp: -6 dB
Filter: ON HP Fc 1700 Hz
Filter: ON HP Fc 1700 Hz

# Channel: RL
# Preamp: 0 dB
# Filter: ON HP Fc 1700 Hz
# Filter: ON HP Fc 1700 Hz

[HammerSandwich]

If that's a pure copy/paste from your config file, you need to remove some comments.

[dlwearl]

Yes, it was a straight copy and paste. I had one speaker disabled while troubleshooting the connections to the other one.

So, this is not the problem, but thank you for pointing that out.

[jiiteepee]

You could try this 4th order LR4 (Linkwitz-Riley) 3-way crossover script:

# This code creates 3-Way Crossover preset
# Brought to you by jiiteepee@yahoo.se
# 
# ==========================================
# Set cut off frequencies
# ==========================================
# High
Eval: fcT = 1700

# Mid
Eval: fcML1 = 250
Eval: fcMH1 = 1700

# Low 
Eval: fcW = 250
#===========================================

# Check the channel configs
# Equalizer APO / Documentation Wiki / Configuration reference
# Channels (7.1) L,R,C,SUB,RL,RR,RC,SL,SR
#                1,2,3,4,  5, 6, 7, 8 ,9
#
Copy: C=L SUB=R
Copy: RL=L RR=R
Copy: SL=L SR=R

# ==========================================
# CALCULATIONS AND FILTERING
# ==========================================

#-----------------------------------------
# High
#-----------------------------------------
Channel: SL SR

Eval: wc=2*pi*fcT
Eval: wc2=wc*wc
Eval: wc3=wc2*wc
Eval: wc4=wc2*wc2
Eval: k=wc/tan(pi*fcT/sampleRate)
Eval: k2=k*k
Eval: k3=k2*k
Eval: k4=k2*k2
Eval: sqrt2=sqrt(2)
Eval: sq_tmp1=sqrt2*wc3*k
Eval: sq_tmp2=sqrt2*wc*k3
Eval: a_tmp=4*wc2*k2+2*sq_tmp1+k4+2*sq_tmp2+wc4

Eval: b0 = 1
Eval: b1=(4*(wc4+sq_tmp1-k4-sq_tmp2))/a_tmp
Eval: b2=(6*wc4-8*wc2*k2+6*k4)/a_tmp
Eval: b3=(4*(wc4-sq_tmp1+sq_tmp2-k4))/a_tmp
Eval: b4=(k4-2*sq_tmp1+wc4-2*sq_tmp2+4*wc2*k2)/a_tmp

Eval: a0=k4/a_tmp
Eval: a1=-4*k4/a_tmp
Eval: a2=6*k4/a_tmp
Eval: a3=a1
Eval: a4=a0

Filter: ON IIR Order 4 Coefficients `a0` `a1` `a2` `a3` `a4` `b0` `b1` `b2` `b3` `b4`
Filter: ON HP Fc 10 Hz

#-----------------------------------------
# Mid (Low)
#-----------------------------------------

Channel: C SUB

Eval: wc=2*pi*fcML1
Eval: wc2=wc*wc
Eval: wc3=wc2*wc
Eval: wc4=wc2*wc2
Eval: k=wc/tan(pi*fcML1/sampleRate)
Eval: k2=k*k
Eval: k3=k2*k
Eval: k4=k2*k2
Eval: sqrt2=sqrt(2)
Eval: sq_tmp1=sqrt2*wc3*k
Eval: sq_tmp2=sqrt2*wc*k3
Eval: a_tmp=4*wc2*k2+2*sq_tmp1+k4+2*sq_tmp2+wc4
Eval: b0 = 1
Eval: b1=(4*(wc4+sq_tmp1-k4-sq_tmp2))/a_tmp
Eval: b2=(6*wc4-8*wc2*k2+6*k4)/a_tmp
Eval: b3=(4*(wc4-sq_tmp1+sq_tmp2-k4))/a_tmp
Eval: b4=(k4-2*sq_tmp1+wc4-2*sq_tmp2+4*wc2*k2)/a_tmp

Eval: a0=k4/a_tmp
Eval: a1=-4*k4/a_tmp
Eval: a2=6*k4/a_tmp
Eval: a3=a1
Eval: a4=a0

Filter: ON IIR Order 4 Coefficients `a0` `a1` `a2` `a3` `a4` `b0` `b1` `b2` `b3` `b4`

#-----------------------------------------
# Mid (High)
#-----------------------------------------

Eval: wc=2*pi*fcMH1
Eval: wc2=wc*wc
Eval: wc3=wc2*wc
Eval: wc4=wc2*wc2
Eval: k=wc/tan(pi*fcMH1/sampleRate)
Eval: k2=k*k
Eval: k3=k2*k
Eval: k4=k2*k2
Eval: sqrt2=sqrt(2)
Eval: sq_tmp1=sqrt2*wc3*k
Eval: sq_tmp2=sqrt2*wc*k3
Eval: a_tmp=4*wc2*k2+2*sq_tmp1+k4+2*sq_tmp2+wc4
Eval: b0 = 1
Eval: b1=(4*(wc4+sq_tmp1-k4-sq_tmp2))/a_tmp
Eval: b2=(6*wc4-8*wc2*k2+6*k4)/a_tmp
Eval: b3=(4*(wc4-sq_tmp1+sq_tmp2-k4))/a_tmp
Eval: b4=(k4-2*sq_tmp1+wc4-2*sq_tmp2+4*wc2*k2)/a_tmp

Eval: a0=wc4/a_tmp
Eval: a1=4*wc4/a_tmp
Eval: a2=6*wc4/a_tmp
Eval: a3=a1
Eval: a4=a0
Filter: ON IIR Order 4 Coefficients `a0` `a1` `a2` `a3` `a4` `b0` `b1` `b2` `b3` `b4`

#-----------------------------------------
# Low
#-----------------------------------------
Channel: L R

Eval: wc=2*pi*fcW
Eval: wc2=wc*wc
Eval: wc3=wc2*wc
Eval: wc4=wc2*wc2
Eval: k=wc/tan(pi*fcW/sampleRate)
Eval: k2=k*k
Eval: k3=k2*k
Eval: k4=k2*k2
Eval: sqrt2=sqrt(2)
Eval: sq_tmp1=sqrt2*wc3*k
Eval: sq_tmp2=sqrt2*wc*k3
Eval: a_tmp=4*wc2*k2+2*sq_tmp1+k4+2*sq_tmp2+wc4

Eval: b0 = 1
Eval: b1=(4*(wc4+sq_tmp1-k4-sq_tmp2))/a_tmp
Eval: b2=(6*wc4-8*wc2*k2+6*k4)/a_tmp
Eval: b3=(4*(wc4-sq_tmp1+sq_tmp2-k4))/a_tmp
Eval: b4=(k4-2*sq_tmp1+wc4-2*sq_tmp2+4*wc2*k2)/a_tmp

Eval: a0=wc4/a_tmp
Eval: a1=4*wc4/a_tmp
Eval: a2=6*wc4/a_tmp
Eval: a3=a1
Eval: a4=a0

Filter: ON IIR Order 4 Coefficients `a0` `a1` `a2` `a3` `a4` `b0` `b1` `b2` `b3` `b4`

Check the channel mapping to match yours!

[dlwearl]

Speaking of channel assignments, this, I think, is where the confusion is starting.

I have tried your program, but without success here too, perhaps because of the channels. My receiver uses the following names:

Front R
Front L
Center
Surround R
Surround L
Surround Back R
Surround Back L

Which numbers or letters do all of the surround channels map to in EqAPO?

Also, how do I add a preamplification to each channel independently? I would like to be able levels match each driver independently. I also have struggled to get this to work consistently.

Thanks,
David

[33Polkhigh]

This is what I do on my two way set up. The soundcard is set to quadraphonic so theres no center or sub channels. I think it will work with more than 4 channels but haven't tried it.

Copy: L=L+RL R=R+RR
Copy: RL=L RR=R

This mirrors the rear channels with the front.

Then I use a channel selector, an equalizer and preamp on each of the channels to control the two sets of drivers independently.

Last I switch the channel selector to all and use an equalizer to apply baffle step.

After some experimentation I've found that just a straight drop (infinite slope) down to -95db sounds the best. Overlapping the drivers creates lobing which hurts imaging (unless drivers are playing low frequencies)


I've attached a picture of a woofer.