Hi there,
Forgive my noob question but I am playing around in VITUIXCAD and in the all-pass filter there are multiple options for shape.
I'm trying to linearize the phase of a tweeter that is part of a PC based active crossover system if that helps. I've put in a passive high pass filter for the tweeter because I'm afraid EQ APO will bug out and destroy my tweeters. Let me know if there's a better way for this.
E.g:
1st order,
2nd order,
1st order phase linearization,
2nd order phase linearization,
LR phase linearization,
Bessel phase linearization,
Butterworth phase linearization.
When looking at EQ APO there is only an option for Fc and Q for the All-pass. Can someone help me understand which one of these will EQ APO apply? I'm guessing either 2nd order or 2nd order phase linearization.
Thank you!
Forgive my noob question but I am playing around in VITUIXCAD and in the all-pass filter there are multiple options for shape.
I'm trying to linearize the phase of a tweeter that is part of a PC based active crossover system if that helps. I've put in a passive high pass filter for the tweeter because I'm afraid EQ APO will bug out and destroy my tweeters. Let me know if there's a better way for this.
E.g:
1st order,
2nd order,
1st order phase linearization,
2nd order phase linearization,
LR phase linearization,
Bessel phase linearization,
Butterworth phase linearization.
When looking at EQ APO there is only an option for Fc and Q for the All-pass. Can someone help me understand which one of these will EQ APO apply? I'm guessing either 2nd order or 2nd order phase linearization.
Thank you!
If you install REW you can measure the processing done for each channel using a cable loopback at the soundcard, It's a good idea to check the jack line
level outputs this way before connecting the amp and speakers.
This is the response plot of the EqApo Allpass measured by REW using a loopback. It looks like a 2nd order. Where Fc=1Khz and Q=[1,3,10] for comparison. You can also use polynomial function to create a different AP form if you want.
Are you sure you need one? Maybe the phase problem can be corrected by reversing a driver polarity.
level outputs this way before connecting the amp and speakers.
This is the response plot of the EqApo Allpass measured by REW using a loopback. It looks like a 2nd order. Where Fc=1Khz and Q=[1,3,10] for comparison. You can also use polynomial function to create a different AP form if you want.
Are you sure you need one? Maybe the phase problem can be corrected by reversing a driver polarity.
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Hi, thank you for your reply! There's no soundcard, it's HDMI straight to the AVR. I tried reversing the polarity but it didn't help aligning the phase.
Problem is, when I used a full-range driver in the past with this active crossover PC setup, various software would do different things. Like if I use Jriver for music, it has an option to use DirectSound so EQ APO can do it's thing reliably.
But if I use VLC to watch something, even though I have disabled passthrough for stuff like Dolby, it would sometimes do random things and completely bypass EQ APO, leading to a full signal being sent to the driver. I tried messing around in the settings of VLC, but absolutely nothing works.
Now I have a tweeter waiting in a box before I can figure this stuff out. I tried simulating a passive network for just the tweeter but the phase is not aligning.
Maybe I should go for something like a MiniDSP or Dayton 4x8 DSP? How would that work with an AVR? Mine's got pre-outs so I might need costly multichannel external amplification..
Can I send the signal from the MiniDSP/Dayton4x8 straight back into the AVR's amp section? I'm going through the manual and there is an input called Multi Channel Input for accepting signals from a "Multi format player/External Decoder (7.1)". Can I plug the outputs from the DSP back into this Multi Channel Input?" So that I can skip the need for external amplification and use the AVR amp channels? This way I can avoid the need for a passive crossover network and have all the benefits of active crossover.
Problem is, when I used a full-range driver in the past with this active crossover PC setup, various software would do different things. Like if I use Jriver for music, it has an option to use DirectSound so EQ APO can do it's thing reliably.
But if I use VLC to watch something, even though I have disabled passthrough for stuff like Dolby, it would sometimes do random things and completely bypass EQ APO, leading to a full signal being sent to the driver. I tried messing around in the settings of VLC, but absolutely nothing works.
Now I have a tweeter waiting in a box before I can figure this stuff out. I tried simulating a passive network for just the tweeter but the phase is not aligning.
Maybe I should go for something like a MiniDSP or Dayton 4x8 DSP? How would that work with an AVR? Mine's got pre-outs so I might need costly multichannel external amplification..
Can I send the signal from the MiniDSP/Dayton4x8 straight back into the AVR's amp section? I'm going through the manual and there is an input called Multi Channel Input for accepting signals from a "Multi format player/External Decoder (7.1)". Can I plug the outputs from the DSP back into this Multi Channel Input?" So that I can skip the need for external amplification and use the AVR amp channels? This way I can avoid the need for a passive crossover network and have all the benefits of active crossover.
While doing technical things, use technical terms like order, Q-factor etc. as opposed to phase linearisation, shape etc. and you'll be alright. Besides, making lazy people, software like yours also prevents them from learning and understanding how filters work by providing shortcuts to everything. And, when there's no shortcut, you end up on a forum like this not knowing what to do.
If you're looking to make filters from first principles / coefficients (a0-b2), read the following:
https://in.mathworks.com/help/sps/ref/secondorderfilter.html
https://en.wikipedia.org/wiki/Digital_biquad_filter
https://en.wikipedia.org/wiki/Bilinear_transform
https://www.w3.org/TR/audio-eq-cookbook/
All the best.
If you're looking to make filters from first principles / coefficients (a0-b2), read the following:
https://in.mathworks.com/help/sps/ref/secondorderfilter.html
https://en.wikipedia.org/wiki/Digital_biquad_filter
https://en.wikipedia.org/wiki/Bilinear_transform
https://www.w3.org/TR/audio-eq-cookbook/
All the best.
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Nothing wrong with using an AVR. All digital playback, single D/A stage, amplifiers built in, and possibly a remote control. The used market has great deals on these when they are a few years old. The MiniDSP and DSP408 have an additional undesired A/D stage and have less capability than EqApo on a PC.
The AVR has pre-out jacks and the PC motherboard should have at least a simple built in soundcard (mic, line_in, line_out) that you can use for loopback. The signal path would be PC_HDMI -> AVR_hdmi -> AVR_Pre_out -> PC_Line_In. You would have to move the cable to various Pre_Out channels to check channels 1 or 2 at a time before risking drivers.
I use EqApo for a 3way XO and have used its convolution engine as well. I playback from Spotify, Tidal, Chrome, VLC, MediaPlayer everything really seems to work properly through EqApo. I use an 8ch soundcard but that should make no difference to playback. So you may have a configuration issue.
Can you post the design and where the phase is not aligning ? Often phase wrap is used to display the phase in a -180 to 180 deg range.
