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TOPIC: 2x4 HD and 1024 tabs

2x4 HD and 1024 tabs 3 years 2 weeks ago #27940

  • Milev
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Hi there,

Am I missing something or 1024 tabs per output channel (2x4 HD) is by far not enough for any useful phase correction?

This is what I am getting with only so much tabs:







(The prediction is the same as measured after applying the filter)

Does this seem expected or I am not doing it right? Is there any way to optimize the calculations so that less tabs are used and more effectively? Thus far I am not able to achieve a single 180 degrees adjustment which seems strange.

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Last Edit: 3 years 2 weeks ago by Milev. Reason: Picture quality
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2x4 HD and 1024 tabs 3 years 2 weeks ago #27943

  • pos
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If you are only doing phase corrections then you can try rectangular windowing and energy centering.
download the last version of rephase here: rephase.org
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2x4 HD and 1024 tabs 3 years 2 weeks ago #27959

  • eclipseaudio
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Hi Milev,

Yes, flattening the phase down to near 50 Hz requires between 2000 and 3000 taps. 1024 taps is useful down to about 100 Hz.

Kind regards,
Michael
Eclipse Audio
Maker of FIR Designer and FIR Creator - filter design tools for loudspeakers.
www.eclipseaudio.com
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2x4 HD and 1024 tabs 3 years 2 weeks ago #28033

  • devteam
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@ Milev

1024 would be a low number for your LF, maybe you can consider reassigning Taps. i.e. lower other channels and then increase for the LF to 2048? Just a thought.

DevTeam
MiniDSP, building a DIY DSP community one board at a time.
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2x4 HD and 1024 tabs 3 years 1 week ago #28131

  • denver8me4dinner
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I use personally 1688taps on sub and 360 taps on midbass . Both using linear phase filters and not linearized filters. Works great. But linearized filters use less taps , just make sure your acoustical slopes match the electrical slopes using PEQ before implementing the linearization

If your keeping IIR filters and just correcting phase alone I would allocate all 2048 taps to sub and not worry about phase above 1k because you won't hear the difference as much as the saving taps for sub.

I have 2 2x4HD s, and have found once all the minimum phase issues are dealt with using PEQ holding hands with FR problems of course and use IIR crossovers in the 2x4HD than use fir to fix any small problems after that.

It's not meant to be used as a powerful fir engine to do all FIR , it's design screams to be used as a IIR supplement . Think efficiency and use it as efficient as possible using IIR everywhere you can first than you'll find the FIR is more than adequate . The end result will be the same as doing everything in the FiR.


If you're trying to do room correction you can get the Dirac plug-in for it and use it that way.

Andrew
Last Edit: 3 years 1 week ago by denver8me4dinner.
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