A Second Order Elliptic Equalizer for Vinyl Mastering

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mediatechnology
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Re: A Second Order Elliptic Equalizer for Vinyl Mastering

Post by mediatechnology » Thu Aug 24, 2017 9:28 pm

The EEQ boards pass test...

Image
Second-order Elliptic Equalizer First Build

Crosstalk Curves for 75, 150, 300 Hz

Left-only input.
Top trace is left out.
Bottom traces are the right channel output with the EEQ switched from 75 to 150 and 300 Hz.

Image
Second-order Elliptic Equalizer Crosstalk Curves for 75, 150, 300 Hz


Comparison of 6 dB vs. 12 dB Per Octave Lateral Versus Vertical Response

Left-only input. EEQ set at 300 Hz.
Top trace is lateral (mono) response.
Bottom traces are the vertical output with the EEQ plotted at 6 and 12 dB per octave.

Image
Second-order Elliptic Equalizer Lateral vs Vertical at 300 Hz with 6 or 12 dB per octave slope


Comparison of 6 dB vs. 12 dB Per Octave Crosstalk Response

Left-only input. EE set at 300 Hz.
Top trace is left out.
Bottom traces are the right channel crosstalk with the EEQ plotted at 6 dB and 12 dB per octave

Image
Second-order Elliptic Equalizer Crosstalk Comparison at 300 Hz with 6 or 12 dB per octave slope

I'll be posting some sound files soon.

Conclusions

1) The steeper highpass slope of the EEQ's second-order vertical response permits, for the same amount of filtering, a lower EEQ frequency to be used.

2) The steeper low pass response of the second-order crosstalk curve improves midrange separation and imaging.

3) Factors 1 and 2 in conjunction lower the crosstalk significantly to maintain midrange stereo imaging.

4) The summed output is mono compatible.

Applications

The applications for the EEQ include vinyl cutting, "bass focus" to improve low-end on headphones, earbuds and small speakers, subwoofer steering and vinyl playback warp reduction.
"There does seem to be a pattern where, the more difficult a truth is to stomach, the higher the hysteria levels go internally at Google."
Visit RockmoreLabs on Etsy https://www.etsy.com/shop/RockmoreLabs
http://www.ka-electronics.com

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mediatechnology
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Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
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Re: A Second Order Elliptic Equalizer for Vinyl Mastering

Post by mediatechnology » Fri Sep 29, 2017 12:59 pm

I updated the Elliptical Equalizer comparison table I had posted in an MS thread. (viewtopic.php?f=6&t=622&p=7414#p7414)

Image
Elliptical Equalizer Comparison. Neumann EE-70/EE-77, VAB-84, LR±S Width, MS Mid Side, MS Mid Side with Correction Allpass.
"There does seem to be a pattern where, the more difficult a truth is to stomach, the higher the hysteria levels go internally at Google."
Visit RockmoreLabs on Etsy https://www.etsy.com/shop/RockmoreLabs
http://www.ka-electronics.com

User avatar
mediatechnology
Posts: 2683
Joined: Sat Aug 11, 2007 2:34 pm
Location: Oak Cliff, Texas
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Re: A Second Order Elliptic Equalizer for Vinyl Mastering

Post by mediatechnology » Tue Oct 10, 2017 5:46 pm

For those interested in a PC board for the Elliptic EQ send me a PM.

I don't currently have inventory of bare boards but have pre-orders for a couple and need commitments for a few more before I submit an order for more.

EEQ-12 Elliptic Equalizer: http://www.ka-electronics.com/kaelectro ... tic_EQ.htm
"There does seem to be a pattern where, the more difficult a truth is to stomach, the higher the hysteria levels go internally at Google."
Visit RockmoreLabs on Etsy https://www.etsy.com/shop/RockmoreLabs
http://www.ka-electronics.com

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