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Multi-Way Conventional loudspeakers with crossovers

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
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Old 12th November 2019, 12:59 PM   #2831
BYRTT is online now BYRTT  Denmark
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by mark100 View Post
Hi BYRTT, Hi POS,

I don't get why you guys say this.

It seems to me, the recording already possesses any natural phase rolloffs (or worse depending on mastering hpf, xovers, etc)....
.....and by not linearizing the stopbands we are increasing natural order rolloffs ..???

Would truly love to hear your thoughts here... thx, mark
...relax i did write one is free about it ...

A simple answer is because then i can get sound from recordings to sound as was it the analog happening itself, whenever i allow any excess phase to whatever audio band performance it can sound good but always then it sounds as a recording flavoured with a more or less modern kind of synthetic signature add on, guess having varius numbers of excess phase didn't happen in the old days before any dac or modern compensated amps was out, at that time excess phase was only to find as a cosequence in multiway speakers from their summing XO points and those we can more or less linearize nowadays with up to very good or fully transperent results.

Now i hate above is nothing but my own subjective conclusion on stuff but think a logic point is if we manipulate natural physics we get a effect proccessor and effects belong to recording or mastering process not to a reproduce chain that should be as natural as possible a reference system.

Deviation from my view is fine and admit real world it could be hard agree my point probably because multi way speaker systems acoustic sum and possibility for more or less distorting errors can be a complicated animal in itself and also the varius temporary indoor enviroment we benchmark in to establish our subjuctive conclusion is also not easy to make precise controlled from each trial setup to the next trial setup, what helped me most get a feel and probably better conclusion on phase is execute various phase distortons or tweaks into a head phone domain and Rephase have been the fantastic tool to do these exercices thanks to pos.
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Old 12th November 2019, 03:58 PM   #2832
mark100 is offline mark100  United States
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Sorry if I didn't sound relaxed...cause i really am...was just my way of saying I don't understand

And thanks for the reply.
I can see why we can get used to the sound of stopband rolloff and prefer to keep it.

I guess i do see that as a preference...a preference for a certain level of group delay.
I'd think logically, there is already group delay in the recording, and then we add some more with playback driver's natural rolloff (and crossover in systems not using linear phase xovers).
So two stages of group delay..recording and playback. And if we get used to that, we may well want to keep it all.

My question is: technically, why would we want to double up on final net group delay??? (Assuming I'm correct in thinking there are two stages introduced)
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Old 12th November 2019, 05:18 PM   #2833
emailtim is offline emailtim  United States
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Quote:
Originally Posted by pos View Post
I would favor tools from the "filter linearization" tab over phase EQ, when possible.

Also make sure polarity is right beforehand (or does REW automatically handle this when deducing excess phase? I must confess I have never used that feature.)
POS, the CROSSOVER section of the "Filters Linearization" tab appears to work well for my LR96 XO's, but I have a couple of additional questions about the "Filters Linearization" tab.

1) Can it address an internal mid/tweeter asymmetric 6/18dB XO (if so, how) ?
2) Are there any specific settings for OB/Dipole speakers. I just see CROSSOVER, BOX(closed, vented) and SUBSONIC sections.

TIA

Last edited by emailtim; 12th November 2019 at 05:24 PM.
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Old 12th November 2019, 06:30 PM   #2834
BYRTT is online now BYRTT  Denmark
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by mark100 View Post
Sorry if I didn't sound relaxed...cause i really am...was just my way of saying I don't understand

And thanks for the reply.
I can see why we can get used to the sound of stopband rolloff and prefer to keep it.

I guess i do see that as a preference...a preference for a certain level of group delay.
I'd think logically, there is already group delay in the recording, and then we add some more with playback driver's natural rolloff (and crossover in systems not using linear phase xovers).
So two stages of group delay..recording and playback. And if we get used to that, we may well want to keep it all.

My question is: technically, why would we want to double up on final net group delay??? (Assuming I'm correct in thinking there are two stages introduced)
Maybe because we dont want to improve the group delay or timing isolated on its own is because the physical amplitude signal really isnt there and we then end break physics for timing in natural sounds, know its too simplistic but take below theoretical example from a recording chain, red curve is raw bandwidth of a acoustic bass guitar with 1st order stop bands at 41Hz and 7kHz, and if we feed or say cascade that bandwidth thru a very good microphone bandwidth with 1st order stop bands at 6Hz and 20kHz we end up a bit limited domain in the blue curve. Amplitude and timing (phase) for that new blue curve is what the other musicians plus mix and master process will base their cooperation or work on and therefor will guess if we change blue curves original blue phase to be the red phase we add a timing distortion because the wider amplitude performance of red curve we never get back because of the cascaded chain.

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool-m_1-png
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Old 15th November 2019, 02:34 AM   #2835
emailtim is offline emailtim  United States
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Here are my "initial" (after a few tries) results using REW's AutoEQ (cuts only, not boosts) and RePhase's "Filters Linearization" tabs. I had to estimate some XO's and then slightly change them to get the predicted phase plots to bend accordingly. I did not use the phase sliders, only the "Filters Linearization" tab.

These plots are of a stereo 3-way active XO to integrate stereo OB/dipole subs, bi-amp planar/ribbon speakers and to correct their passive internal mid/tweeter XO.

Constructive critique, criticism and suggestions is very much welcomed.

My main question is the left side (blue line) of the after Step Response. Is this downward dip before 0 expected/correct ???

Here is the before(green) and after(blue) frequency response with "cuts only".
Click the image to open in full size.

Here is the before(diagonal/blue) and after(horizontal) phase correction for the left, right and combined channels.
Click the image to open in full size.

Here is the before(green) and after(blue) Impulse Response.
Click the image to open in full size.

Here is the before(green) and after(blue) Step Response.
Click the image to open in full size.

Here is the before(green) and after(blue) Group Delay.
Click the image to open in full size.

Here is the before(green) and after(blue) Impulse Response reflection peaks.
Click the image to open in full size.

Last edited by emailtim; 15th November 2019 at 02:43 AM.
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Old 15th November 2019, 04:25 AM   #2836
Oabeieo is offline Oabeieo  United States
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Quote:
Originally Posted by emailtim View Post
Here are my "initial" (after a few tries) results using REW's AutoEQ (cuts only, not boosts) and RePhase's "Filters Linearization" tabs. I had to estimate some XO's and then slightly change them to get the predicted phase plots to bend accordingly. I did not use the phase sliders, only the "Filters Linearization" tab.

These plots are of a stereo 3-way active XO to integrate stereo OB/dipole subs, bi-amp planar/ribbon speakers and to correct their passive internal mid/tweeter XO.

Constructive critique, criticism and suggestions is very much welcomed.

My main question is the left side (blue line) of the after Step Response. Is this downward dip before 0 expected/correct ???

Here is the before(green) and after(blue) frequency response with "cuts only".
Click the image to open in full size.

Here is the before(diagonal/blue) and after(horizontal) phase correction for the left, right and combined channels.
Click the image to open in full size.

Here is the before(green) and after(blue) Impulse Response.
Click the image to open in full size.

Here is the before(green) and after(blue) Step Response.
Click the image to open in full size.

Here is the before(green) and after(blue) Group Delay.
Click the image to open in full size.

Here is the before(green) and after(blue) Impulse Response reflection peaks.
Click the image to open in full size.

Looks like we have another expert gang,

Okay Iím jel
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Old 15th November 2019, 04:37 AM   #2837
emailtim is offline emailtim  United States
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Quote:
Originally Posted by Oabeieo View Post
Looks like we have another expert gang,

Okay Iím jel
If that is sarcasm, please let me know what I did wrong.

I am trying to learn.
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Old 15th November 2019, 07:03 AM   #2838
Oabeieo is offline Oabeieo  United States
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Quote:
Originally Posted by emailtim View Post
If that is sarcasm, please let me know what I did wrong.

I am trying to learn.


No! No!

Not at all. That looks great. Believe me buddy I’m more a novice than you, although I can promise you my room is definitely more complex to work in (a car) which is where I get stuck on a lot of things, but that looks great! It’s better than what I can do on my own.

Last edited by Oabeieo; 15th November 2019 at 07:06 AM.
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Old 15th November 2019, 12:46 PM   #2839
BYRTT is online now BYRTT  Denmark
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by emailtim View Post

...Constructive critique, criticism and suggestions is very much welcomed.

My main question is the left side (blue line) of the after Step Response. Is this downward dip before 0 expected/correct ???...
For main quistion will say that is normal and expected because when we manipulate some typical excess phase lag in time domain it has to be a pre operation view into impulse or step response graphs that would cost some overall processing systen lag to repair.

In general looks you have a good feel on stuff

As some general tip for where you are now say everything is really perfect based, then remember than any wish for other house curve adjustment or left verse right channel calibrations has to be global adjustments. What i mean is stay away any house curve adjustments per selective band pass unlesh you really happen find some errors there, because even small EQ changes per pass band will often or probably need a new time allignment setting and that operation can often be a big workload.
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Old 15th November 2019, 09:17 PM   #2840
fluid is offline fluid  Australia
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Quote:
Originally Posted by emailtim View Post

These plots are of a stereo 3-way active XO to integrate stereo OB/dipole subs, bi-amp planar/ribbon speakers and to correct their passive internal mid/tweeter XO.

Constructive critique, criticism and suggestions is very much welcomed.

My main question is the left side (blue line) of the after Step Response. Is this downward dip before 0 expected/correct ???
Those graphs look good Remember to listen to the correction and see if you like it, I have made many graphs that look great and sound terrible.

So you have an active crossover between dipole subs and main speakers with an unknown passive crossover?

As Byrrt said the change in the step response before the peak and the increased preringing in the impulse is the result of the phase manipulation. You have gone from 1700 degrees of phase turn to 360 degrees 20-20k so something has to give.

Are these in room averaged listening positions measurements like in SwissBears tutorial?

If so a flat room response will tend to be too bright. You could try adding in a room curve in REW to see how you like it. By using minimum phase EQ at that stage you should not upset the rest of the phase correction too much as you only used filters linearization,

Here is an example to start with

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool-curve-jpg

REW settings to get that curve, change the target level to suit your measurement

rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool-screen-shot-2019-11-16-7-01-34-am-png
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File Type: jpg Room Curve.jpg (44.9 KB, 107 views)
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