#### er|κzvio1in

##### Member

Dear All, I've bought a MiniDSP nanodigi, 2 8" subwoofers and a UMIK-1 and I've been experimenting with them for 20+ hours now. For my latest configuration, I have done the following:

1. REW sweep measurements in bass region for each of the 4 drivers for 3 LPs, I used acoustic reference on the same speaker and made sure the timing was correct

2. Imported the raw measurements in MSO as 4 subs

3. Let MSO compute filters and settings based on the following constraints:

5. Performed moving mic measurements for L, R and L+R to create a couple of additional PEQ filters up to approx. 300 hz for correction and for implementing something that resembles a Harman curve

6. Listening tests

I did some listening tests, but because my hearing is not trained very thoroughly I find it difficult to draw conclusions from what I'm hearing. I can do comparison tests with older configurations in the MiniDSP, but I find it hard to draw conclusions other than that all corrective configs sound better than the uncorrected.

The reason for applying all pass filters is that my subs do not have a lot of headroom for shaving frequency peaks and I suspect it allows optimal integration of subs and mains. I have tried to find more information on the application of all-pass filters but other than a little bit of information regarding pre-ringing there is not much to be found. I am looking for some technical expertise here to guide me if I am on the right track and what your experience is. Some specific questions: (1) can I use higher Qs for the allpass filters or not? (2) should I apply FDW in REW before exporting the measurements to MSO?

I did some listening tests, but because my hearing is not trained very thoroughly I find it difficult to draw conclusions from what I'm hearing. I can do comparison tests with older configurations in the MiniDSP, but I find it hard to draw conclusions other than that all corrective configs sound better than the uncorrected.

Attached MSO screenshots before and after and below the MSO filter output for reference.

1. REW sweep measurements in bass region for each of the 4 drivers for 3 LPs, I used acoustic reference on the same speaker and made sure the timing was correct

2. Imported the raw measurements in MSO as 4 subs

3. Let MSO compute filters and settings based on the following constraints:

- 24 dB LR HPF/LPF between 40-120 hz for each speaker/subwoofer as applicable
- Fixed delay and gain value of main speaker closest to LP to maintain correct stereo image
- 2 overall PEQs (<150 hz)
- 3 second order all-pass filters per speaker with max Q of 1
- 1 first order all-pass filter per speaker
- 2-3 PEQs per speaker to fill up the 8 available biquad crossover slots
- max 9 ms delay for each sub (nanodigi limit)

5. Performed moving mic measurements for L, R and L+R to create a couple of additional PEQ filters up to approx. 300 hz for correction and for implementing something that resembles a Harman curve

6. Listening tests

I did some listening tests, but because my hearing is not trained very thoroughly I find it difficult to draw conclusions from what I'm hearing. I can do comparison tests with older configurations in the MiniDSP, but I find it hard to draw conclusions other than that all corrective configs sound better than the uncorrected.

The reason for applying all pass filters is that my subs do not have a lot of headroom for shaving frequency peaks and I suspect it allows optimal integration of subs and mains. I have tried to find more information on the application of all-pass filters but other than a little bit of information regarding pre-ringing there is not much to be found. I am looking for some technical expertise here to guide me if I am on the right track and what your experience is. Some specific questions: (1) can I use higher Qs for the allpass filters or not? (2) should I apply FDW in REW before exporting the measurements to MSO?

I did some listening tests, but because my hearing is not trained very thoroughly I find it difficult to draw conclusions from what I'm hearing. I can do comparison tests with older configurations in the MiniDSP, but I find it hard to draw conclusions other than that all corrective configs sound better than the uncorrected.

Attached MSO screenshots before and after and below the MSO filter output for reference.

Individual sub channels:

Channel: "Front L"

FL1: Gain Block

Parameter "Gain (dB)" = -0.5

This gain value is an intermediate calculation for reference only.

For final gain values, see "Final gain and delay/distance settings" at end of report.

FL2: HPF Linkwitz-Riley 24 dB/oct

Parameter "Cutoff freq (Hz)" = 40

FL3: Delay Block

Parameter "Delay (msec)" = 1.34203

This delay value is an intermediate calculation for reference only.

For final delay values, see "Final gain and delay/distance settings" at end of report.

FL7: All-Pass First-Order

Parameter "Freq of 90 deg phase (Hz)" = 90.1818

FL13: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 89.6752

Parameter "Boost (dB)" = -12.4179

Parameter "Q (RBJ)" = 17.5056

"Classic" Q = 35.7787

FL18: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 29.5369

Parameter "All-pass Q" = 0.295831

FL19: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 100

Parameter "All-pass Q" = 1

FL30: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 78.5432

Parameter "Boost (dB)" = -12.5153

Parameter "Q (RBJ)" = 16.2777

"Classic" Q = 33.456

FL33: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 37.9035

Parameter "Boost (dB)" = -15

Parameter "Q (RBJ)" = 27.8049

"Classic" Q = 65.9358

End Channel: "Front L"

Channel: "Front R"

FL5: HPF Linkwitz-Riley 24 dB/oct

Parameter "Cutoff freq (Hz)" = 40

FL16: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 33.2736

Parameter "All-pass Q" = 1

FL17: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 63.3438

Parameter "All-pass Q" = 1

FL27: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 90.8785

Parameter "Boost (dB)" = -13.91

Parameter "Q (RBJ)" = 21.189

"Classic" Q = 47.191

FL31: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 45.4416

Parameter "Boost (dB)" = -15

Parameter "Q (RBJ)" = 15.6943

"Classic" Q = 37.217

FL32: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 132.548

Parameter "Boost (dB)" = -15

Parameter "Q (RBJ)" = 30

"Classic" Q = 71.1412

FL34: All-Pass First-Order

Parameter "Freq of 90 deg phase (Hz)" = 77.7823

End Channel: "Front R"

Channel: "Sub L"

FL8: LPF Linkwitz-Riley 24 dB/oct

Parameter "Cutoff freq (Hz)" = 140

FL9: Delay Block

Parameter "Delay (msec)" = 6.82877e-11

This delay value is an intermediate calculation for reference only.

For final delay values, see "Final gain and delay/distance settings" at end of report.

FL11: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 67.9099

Parameter "All-pass Q" = 1

FL21: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 12.3105

Parameter "All-pass Q" = 1

FL24: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 10

Parameter "All-pass Q" = 0.168394

FL25: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 56.2667

Parameter "Boost (dB)" = -14.1603

Parameter "Q (RBJ)" = 12.6119

"Classic" Q = 28.4963

FL26: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 29.668

Parameter "Boost (dB)" = -11.3539

Parameter "Q (RBJ)" = 30

"Classic" Q = 57.6725

FL28: All-Pass First-Order

Parameter "Freq of 90 deg phase (Hz)" = 5

End Channel: "Sub L"

Channel: "Sub R"

FL4: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 103.633

Parameter "Boost (dB)" = -8.34235

Parameter "Q (RBJ)" = 20

"Classic" Q = 32.3287

FL6: Delay Block

Parameter "Delay (msec)" = 1.57309

This delay value is an intermediate calculation for reference only.

For final delay values, see "Final gain and delay/distance settings" at end of report.

FL10: LPF Linkwitz-Riley 24 dB/oct

Parameter "Cutoff freq (Hz)" = 140

FL12: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 43.1266

Parameter "All-pass Q" = 1

FL20: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 43.1267

Parameter "All-pass Q" = 1

FL22: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 61.0115

Parameter "Boost (dB)" = -13.5539

Parameter "Q (RBJ)" = 20

"Classic" Q = 43.6394

FL23: All-Pass Second-Order

Parameter "Freq of 180 deg phase (Hz)" = 84.687

Parameter "All-pass Q" = 0.1

FL29: All-Pass First-Order

Parameter "Freq of 90 deg phase (Hz)" = 100

End Channel: "Sub R"

Individual mains channels:

No mains channels defined

Shared sub channel:

FL14: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 67.0403

Parameter "Boost (dB)" = -9.10572

Parameter "Q (RBJ)" = 11.6896

"Classic" Q = 19.7443

FL15: Parametric EQ (RBJ)

Parameter "Center freq (Hz)" = 84.4684

Parameter "Boost (dB)" = -9.92316

Parameter "Q (RBJ)" = 19.5181

"Classic" Q = 34.5554

End shared sub channel

Shared mains channel:

No filters in this channel.

DSP Filter Channel Information:

Sample frequency 96000 Hz

Crossover filter/biquad info for Front L:

FL18: All-Pass Second-Order (crossover biquad1)

FL19: All-Pass Second-Order (crossover biquad2)

FL2: HPF Linkwitz-Riley 24 dB/oct (crossover biquad3, crossover biquad4)

FL7: All-Pass First-Order (crossover biquad5)

FL13: Parametric EQ (RBJ) (crossover biquad6)

FL30: Parametric EQ (RBJ) (crossover biquad7)

FL33: Parametric EQ (RBJ) (crossover biquad8)

Crossover biquads for Front L:

biquad1,

b0=0.993486515719481,

b1=-1.993482790688970,

b2=1.000000000000000,

a1=1.993482790688970,

a2=-0.993486515719481,

biquad2,

b0=0.993476410277674,

b1=-1.993433713330368,

b2=1.000000000000000,

a1=1.993433713330368,

a2=-0.993476410277674,

biquad3,

b0=0.998150511190451,

b1=-1.996301022380902,

b2=0.998150511190451,

a1=1.996297601769120,

a2=-0.996304442992684,

biquad4,

b0=0.998150511190451,

b1=-1.996301022380902,

b2=0.998150511190451,

a1=1.996297601769120,

a2=-0.996304442992684,

biquad5,

b0=0.994114965215307,

b1=-1.000000000000000,

b2=0.000000000000000,

a1=0.994114965215307,

a2=-0.000000000000000,

biquad6,

b0=0.999739483435889,

b1=-1.999280545635399,

b2=0.999575498165099,

a1=1.999280545635399,

a2=-0.999314981600988,

biquad7,

b0=0.999752362311937,

b1=-1.999324703912085,

b2=0.999598759185760,

a1=1.999324703912085,

a2=-0.999351121497696,

biquad8,

b0=0.999913033130990,

b1=-1.999782292438449,

b2=0.999875412929509,

a1=1.999782292438449,

a2=-0.999788446060499

There are no output biquads needed for Front L.

Crossover filter/biquad info for Front R:

FL17: All-Pass Second-Order (crossover biquad1)

FL16: All-Pass Second-Order (crossover biquad2)

FL5: HPF Linkwitz-Riley 24 dB/oct (crossover biquad3, crossover biquad4)

FL31: Parametric EQ (RBJ) (crossover biquad5)

FL27: Parametric EQ (RBJ) (crossover biquad6)

FL32: Parametric EQ (RBJ) (crossover biquad7)

FL34: All-Pass First-Order (crossover biquad8)

Crossover biquads for Front R:

biquad1,

b0=0.995862744208557,

b1=-1.995845591767512,

b2=1.000000000000000,

a1=1.995845591767512,

a2=-0.995862744208557,

biquad2,

b0=0.997824616136348,

b1=-1.997819878682893,

b2=1.000000000000000,

a1=1.997819878682893,

a2=-0.997824616136348,

biquad3,

b0=0.998150511190439,

b1=-1.996301022380878,

b2=0.998150511190439,

a1=1.996297601769096,

a2=-0.996304442992660,

biquad4,

b0=0.998150511190439,

b1=-1.996301022380878,

b2=0.998150511190439,

a1=1.996297601769096,

a2=-0.996304442992660,

biquad5,

b0=0.999815304734957,

b1=-1.999541870276283,

b2=0.999735409101519,

a1=1.999541870276283,

a2=-0.999550713836476,

biquad6,

b0=0.999750507602673,

b1=-1.999339647449781,

b2=0.999624507206545,

a1=1.999339647449781,

a2=-0.999375014809217,

biquad7,

b0=0.999718200870444,

b1=-1.999239266963041,

b2=0.999596299965548,

a1=1.999239266963041,

a2=-0.999314500835992,

biquad8,

b0=0.994922077799405,

b1=-1.000000000000000,

b2=0.000000000000000,

a1=0.994922077799405,

a2=-0.000000000000000

There are no output biquads needed for Front R.

Crossover filter/biquad info for Sub L:

FL11: All-Pass Second-Order (crossover biquad1)

FL21: All-Pass Second-Order (crossover biquad2)

FL24: All-Pass Second-Order (crossover biquad3)

FL25: Parametric EQ (RBJ) (crossover biquad4)

FL8: LPF Linkwitz-Riley 24 dB/oct (crossover biquad5, crossover biquad6)

FL28: All-Pass First-Order (crossover biquad7)

FL26: Parametric EQ (RBJ) (crossover biquad8)

Crossover biquads for Sub L:

biquad1,

b0=0.995565178639463,

b1=-1.995545467193461,

b2=1.000000000000000,

a1=1.995545467193461,

a2=-0.995565178639463,

biquad2,

b0=0.999194602611744,

b1=-1.999193953685364,

b2=1.000000000000000,

a1=1.999193953685364,

a2=-0.999194602611744,

biquad3,

b0=0.996120828513504,

b1=-1.996120400976130,

b2=1.000000000000000,

a1=1.996120400976130,

a2=-0.996120828513504,

biquad4,

b0=0.999734824585895,

b1=-1.999326902223854,

b2=0.999605635035747,

a1=1.999326902223854,

a2=-0.999340459621642,

biquad5,

b0=0.000020854776754,

b1=0.000041709553507,

b2=0.000020854776754,

a1=1.987041771010415,

a2=-0.987125190117430,

biquad6,

b0=0.000020854776754,

b1=0.000041709553507,

b2=0.000020854776754,

a1=1.987041771010415,

a2=-0.987125190117430,

biquad7,

b0=0.999672804296685,

b1=-1.000000000000000,

b2=0.000000000000000,

a1=0.999672804296685,

a2=-0.000000000000000,

biquad8,

b0=0.999954622604754,

b1=-1.999871808329881,

b2=0.999920955933966,

a1=1.999871808329881,

a2=-0.999875578538720

There are no output biquads needed for Sub L.

Crossover filter/biquad info for Sub R:

FL12: All-Pass Second-Order (crossover biquad1)

FL20: All-Pass Second-Order (crossover biquad2)

FL23: All-Pass Second-Order (crossover biquad3)

FL4: Parametric EQ (RBJ) (crossover biquad4)

FL22: Parametric EQ (RBJ) (crossover biquad5)

FL10: LPF Linkwitz-Riley 24 dB/oct (crossover biquad6, crossover biquad7)

FL29: All-Pass First-Order (crossover biquad8)

Crossover biquads for Sub R:

biquad1,

b0=0.997181353521915,

b1=-1.997173397525552,

b2=1.000000000000000,

a1=1.997173397525552,

a2=-0.997181353521915,

biquad2,

b0=0.997181348156926,

b1=-1.997173392130255,

b2=1.000000000000000,

a1=1.997173392130255,

a2=-0.997181348156926,

biquad3,

b0=0.946067441103700,

b1=-1.946037547552091,

b2=1.000000000000000,

a1=1.946037547552091,

a2=-0.946067441103700,

biquad4,

b0=0.999830852502162,

b1=-1.999405964112179,

b2=0.999621104969320,

a1=1.999405964112179,

a2=-0.999451957471482,

biquad5,

b0=0.999827964448357,

b1=-1.999548502540691,

b2=0.999736480207674,

a1=1.999548502540691,

a2=-0.999564444656031,

biquad6,

b0=0.000020854776754,

b1=0.000041709553507,

b2=0.000020854776754,

a1=1.987041771010438,

a2=-0.987125190117452,

biquad7,

b0=0.000020854776754,

b1=0.000041709553507,

b2=0.000020854776754,

a1=1.987041771010438,

a2=-0.987125190117452,

biquad8,

b0=0.993476340656558,

b1=-1.000000000000000,

b2=0.000000000000000,

a1=0.993476340656558,

a2=-0.000000000000000

There are no output biquads needed for Sub R.

There are no biquads needed for the shared mains filter channels.

Shared sub channel filter/biquad info:

FL14: Parametric EQ (RBJ) (biquad1)

FL15: Parametric EQ (RBJ) (biquad2)

Input biquads for shared sub channel:

biquad1,

b0=0.999794181274028,

b1=-1.999346957118293,

b2=0.999572022329180,

a1=1.999346957118293,

a2=-0.999366203603208,

biquad2,

b0=0.999829302835720,

b1=-1.999468102994653,

b2=0.999669356099772,

a1=1.999468102994653,

a2=-0.999498658935492

Raw uncorrected gain and delay values:

These gain and delay values are for reference only.

Unadjusted gain values of all gain blocks:

FL1 (Front L, gain block) gain: -0.50 dB

Unadjusted delay values of all delay blocks:

FL3 (Front L, delay block) delay: 1.34 msec

FL9 (Sub L, delay block) delay: 0.00 msec

FL6 (Sub R, delay block) delay: 1.57 msec

For final gain and delay values, see

"Final gain and delay/distance settings" at end of report.

Final gain and delay/distance settings:

Minimal gain settings:

Front L gain: -0.50 dB

Front R gain: 0.00 dB

Sub L gain: 0.00 dB

Sub R gain: 0.00 dB

Delay settings:

Front L delay: 1.34 msec

Front R delay: 0.00 msec

Sub L delay: 0.00 msec

Sub R delay: 1.57 msec