Phase of x degrees?

Chester01 · Dec 23, 2004, 08:02 PM

I am starting to look into DSP effect editing; I am starting out with trying to modify the phase change effect, looking at the default code it gives me 0x7ffffff which converts to decimal as 2147483647. Now based on logic, if I wanted a 90 degree phase change instead of 180 degrees, i would divide that number by 2 (and then convert back into hex) and replace that in the phase effect giving myself 90 degrees of offset. Am i correct here? If not, please give me some insight into the subject (I am going to look into making a controlable phase shift effect for speaker timing

)

My test to make sure it does SOMETHING
1. load a "normal" phase plugin, a stereo mix, and a peak plugin
2. connect some signal to the phase then to stereo mix and some unmodified signal to stereo mix; turn both settings to 100% and viwe output on peak. as expected the 180 degree phase change yields no signal once combined with the original
3. use same connection scheme but replace the orignal phase with the modified one (code at 0x3fffffff) NOTE: upon saving and re-editing it shows up as 0x40000000 any explination?

Observations:
something does happen; when my believed phase of 90 degres shift is applied to the original signal there is a -6 db drop in signal level (combining two of the modified plugins in series yields a +3 rise in level)

Thanks for any input you may have!

-Matt

Nappylady · Dec 23, 2004, 08:51 PM

The phase inversion is accomplished by simply inverting the signal; mathematically, an inversion of the signal is equivelant to a 180 degree phase shift.

Phase shifts of other values are harder to come up with...

Chester01 · Dec 23, 2004, 11:05 PM

I see, so do you think there ever will be a plugin for this type of application or is it impossible?

Nappylady · Dec 23, 2004, 11:10 PM

It's possible, and it has been done, but it requires custom DSPs most of the time. I don't think that the 10kx chips have the right kind of power to do this.

Just curious--why do you need arbitrary phase shifts?

Chester01 · Dec 23, 2004, 11:38 PM

I was going to time my speaker outputs (instead of using a delay, use a phase shift) I havent seen any variable delays either... or atleast not short enough ones

Chester01 · Dec 24, 2004, 02:08 AM

so what was i getting out from my modified plugin?

Lex Nahumury · Dec 24, 2004, 03:42 AM

Quote:

I was going to time my speaker outputs (instead of using a delay, use a phase shift) I havent seen any variable delays either... or atleast not short enough ones

To get that phase alignment you will need delay lines.
Short adjustable delays are relative easy to code.
However, although I'm not into speaker alignment stuff,
I think the way to go is a combination of filter/delay.
(most filters are delay lines themself)

Anyway;
Multiplying or deviding a signal in DSP simply amplify/attenuates that signal.
btw; shouldn't this be in the DSP section?

/LeMury
PS:
Keep in mind that theoreticly the shortest possible delay in KX DSP is;
1/48000 = 0.0208 msec

Chester01 · Dec 24, 2004, 03:49 AM

yes i suppose it should be in the dsp section, anyways, why did you say that about the multiplying or dividing? (is taht what 0x4000000 was doing?)

Lex Nahumury · Dec 24, 2004, 04:03 AM

macs outl, 0, inl, 0x3fffffff;
or;
macs outl, 0, inl, 0.5;
or;
macs outl, 0, inl, 0x40000000;

are practicly the same-> multipy by 0.5 is same as devide by two.
(See dane syntax for details)

/LeMury

Lex Nahumury · Dec 24, 2004, 04:44 AM

;//----------------------------------------------
name "delay5ms";
copyright "Copyright LeMury (c) 2004-2005.";
created "12/24/2004";
engine "kX";
comment "Adjustable 5msec delay";
guid "0311db5c-04bf-4bfc-8739-ac50ec14cc20";

itramsize 480 ;
output outL, outR;
input inL, inR;
control Delay=0.5;
const mt=0x78000;

idelay write w0 at 0;
idelay read r0 at 240;
idelay write w1 at 241;
idelay read r1 at 480;

macs w0, inL, 0, 0;
macs w1, inR, 0, 0;
macs outL, r0, 0, 0;
macs outR, r1, 0, 0;
macs &r0, &w0, mt, Delay;
macs &r1, &w1, mt, Delay;

end
;//--------------------------------

Short enough?

/LeMury

Chester01 · Dec 24, 2004, 02:59 PM

thanks man

kXfanatic · Dec 24, 2004, 10:17 PM

Why not use the "Delay" effect? Just feed one (right for instance) channel into the delay, set dry and feedback values to 0 and tweak delay time as you wish...

Dec 23, 2004, 08:02 PM	#1
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	Phase of x degrees? I am starting to look into DSP effect editing; I am starting out with trying to modify the phase change effect, looking at the default code it gives me 0x7ffffff which converts to decimal as 2147483647. Now based on logic, if I wanted a 90 degree phase change instead of 180 degrees, i would divide that number by 2 (and then convert back into hex) and replace that in the phase effect giving myself 90 degrees of offset. Am i correct here? If not, please give me some insight into the subject (I am going to look into making a controlable phase shift effect for speaker timing ) My test to make sure it does SOMETHING 1. load a "normal" phase plugin, a stereo mix, and a peak plugin 2. connect some signal to the phase then to stereo mix and some unmodified signal to stereo mix; turn both settings to 100% and viwe output on peak. as expected the 180 degree phase change yields no signal once combined with the original 3. use same connection scheme but replace the orignal phase with the modified one (code at 0x3fffffff) NOTE: upon saving and re-editing it shows up as 0x40000000 any explination? Observations: something does happen; when my believed phase of 90 degres shift is applied to the original signal there is a -6 db drop in signal level (combining two of the modified plugins in series yields a +3 rise in level) Thanks for any input you may have! -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...

Dec 23, 2004, 11:05 PM	Thread Starter #3
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	I see, so do you think there ever will be a plugin for this type of application or is it impossible? __________________ 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...

Dec 23, 2004, 11:38 PM	Thread Starter #5
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	I was going to time my speaker outputs (instead of using a delay, use a phase shift) I havent seen any variable delays either... or atleast not short enough ones __________________ 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...

Dec 24, 2004, 02:08 AM	Thread Starter #6
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	so what was i getting out from my modified plugin? __________________ 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...

Dec 24, 2004, 03:49 AM	Thread Starter #8
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	yes i suppose it should be in the dsp section, anyways, why did you say that about the multiplying or dividing? (is taht what 0x4000000 was doing?) __________________ 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...

Dec 23, 2004, 08:51 PM	#2
Nappylady DriverHeaven Addict Join Date: Jun 2003 Posts: 257 Rep Power: 0	The phase inversion is accomplished by simply inverting the signal; mathematically, an inversion of the signal is equivelant to a 180 degree phase shift. Phase shifts of other values are harder to come up with...

Dec 23, 2004, 11:10 PM	#4
Nappylady DriverHeaven Addict Join Date: Jun 2003 Posts: 257 Rep Power: 0	It's possible, and it has been done, but it requires custom DSPs most of the time. I don't think that the 10kx chips have the right kind of power to do this. Just curious--why do you need arbitrary phase shifts?

Dec 24, 2004, 04:03 AM	#9
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	macs outl, 0, inl, 0x3fffffff; or; macs outl, 0, inl, 0.5; or; macs outl, 0, inl, 0x40000000; are practicly the same-> multipy by 0.5 is same as devide by two. (See dane syntax for details) /LeMury

Dec 24, 2004, 04:44 AM	#10
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	;//---------------------------------------------- name "delay5ms"; copyright "Copyright LeMury (c) 2004-2005."; created "12/24/2004"; engine "kX"; comment "Adjustable 5msec delay"; guid "0311db5c-04bf-4bfc-8739-ac50ec14cc20"; itramsize 480 ; output outL, outR; input inL, inR; control Delay=0.5; const mt=0x78000; idelay write w0 at 0; idelay read r0 at 240; idelay write w1 at 241; idelay read r1 at 480; macs w0, inL, 0, 0; macs w1, inR, 0, 0; macs outL, r0, 0, 0; macs outR, r1, 0, 0; macs &r0, &w0, mt, Delay; macs &r1, &w1, mt, Delay; end ;//-------------------------------- Short enough? /LeMury

Dec 24, 2004, 02:59 PM	Thread Starter #11
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	thanks man __________________ 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...

Dec 24, 2004, 10:17 PM	#12
kXfanatic DriverHeaven Junior Member Join Date: Dec 2004 Posts: 88 Rep Power: 0	Why not use the "Delay" effect? Just feed one (right for instance) channel into the delay, set dry and feedback values to 0 and tweak delay time as you wish...