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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 4th December 2016, 04:38 PM   #1331
jmbee is offline jmbee  France
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Quote:
Originally Posted by soundcheck View Post
rePhase will also correct the microphone phase issues in conjunction with the other phase issues.
Hello,

Trying to évaluate the phase response of a miniDSP Umik, with rePhase "invert" fonction, gives that curve:
Click the image to open in full size.

meaning the phase measurement / correction error, using a calibration mic file without phase informations,
may be around 60° at low and high end.

cdt
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Old 4th December 2016, 04:46 PM   #1332
wesayso is offline wesayso  Netherlands
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Soundcheck,

If you look closely at what Pano said: phase will closely follow frequency response, so if you use a calibration file to correct the frequency response deviations on your measurement microphone it should correct the phase as well.

To me it looks like Acourate is your desired tool. So why not use that?

I've had plenty of fun with both RePhase and DRC-FIR. DRC-FIR works as advertised for me and I love the fact it is highly user adjustable with all of its variables. I did make my own templates though, and looked at each separate variable to determine what it was that I wanted to use.

The same with RePhase, it works very well for what it was designed to do. No worries there either. Just invest the time to learn these tools. It isn't magic, you are the one in control of both these tools. So I'd start looking at what you want to accomplish with it.
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Last edited by wesayso; 4th December 2016 at 04:48 PM.
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Old 4th December 2016, 05:33 PM   #1333
Pano is offline Pano  United States
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Mr Soundcheck. Please reread what I wrote. Then do some research of your own. There are threads here on the subject and entire books published.

Doing some reading and studying will help clear up your misunderstandings, some of which are fundamental. Don't let your audionervosa get the better of you .
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Old 4th December 2016, 05:50 PM   #1334
mwmkravchenko is offline mwmkravchenko  Canada
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by Pano View Post
Mr Soundcheck. Please reread what I wrote. Then do some research of your own. There are threads here on the subject and entire books published.

Doing some reading and studying will help clear up your misunderstandings, some of which are fundamental. Don't let your audionervosa get the better of you .
^2
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Old 5th December 2016, 11:45 AM   #1335
soundcheck is offline soundcheck  Germany
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Sorry Guys.

Things like

"...It should correct as well..." .

What's that supposed to mean!?!? Either it corrects or not.

"...Acourate is for me..."

It was just recently announced the filter quality with REW plus rePhase is en par with Acourate nowadays. ( No word about the preringing issue though)

Beside that Acourate cannot do anything about the recording chain either.

"...DRC-FIR works as advertised for me..."

What is that supposed to mean? As limited as advertised??

DRC-Fir is very well aware of the shortcomings and limitations. It's even
mentioned somewhere on the DRC pages. ( I ran a project myself some time back)

Looking at jmbee graphs IMO clearly confirms to me what I'm questioning.
There are potentially serious ( serious for people who're not having that "good enough" attitude) implications of phase issues and that's not just the microphone, no, the entire measurement chain up to the ADC might have issues.
Basically IMO the entire measurement-chain needs to be calibrated incl. phase and that
per samplerate - if you want rather correct and more than "good enough" results!
Otherwise you might even end up with false corrections.

I'm well aware that such a calibration is not easy.
I'm also aware that it is not easy to get calibration files other than 44.1kHz.
But things shouldn't be wiped under the carpet because there is no known solution to it.


Yep, "Mr." Pano. I reread what you wrote.
Beside other stuff:
"No mic is perfectly flat" - Thx for letting me/us know.
I havn't seen any mic that's remarkably flat - except a $600 Earthworks btw.

"The calibration file takes care of it" -- Yep. Under all conditions it (the FILE with whatever quality content ) will take care of it. Thx. Thx a lot for this.

"Sample rate does not matter except..." ...a little issue here and there. Yep.
There we have it again. It's "good enough".


Folks, why do you stay so vague all the time???
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Old 5th December 2016, 12:04 PM   #1336
pos is offline pos  Europe
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As far as calibration is concerned, sampling rate only affects bandwidth.
So if your calibration file covers the range you are looking for you don't need to question the sampling rate it was recorded/processed at.
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Old 5th December 2016, 03:28 PM   #1337
nc535 is online now nc535
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I'm a first time user of Rephase with a couple of questions. I did a 3-way speaker using MiniDSP 4x10 and got good response at 1m in room with excellent time alignment and reasonably flat phase. Measuring out at the LP is another story so I want to add a MiniDSP OpenDRC into the path and use it both for room correction and to fit to a room curve. The room effects I need to deal with are at least one longitudinal mode, and floor and ceiling bounce.

These are full range speakers, EQed flat to 20 Hz, in the front corners. I noticed that measuring below 100 Hz, the left and right speakers played simultaneously filled holes in each other's response. This is reasonable because the LP is 2' closer to one speaker than the other. So for the OpenDRC EQ process, I blended an LF measurement (<=100Hz) of both speakers with an HF measurement of the speaker being EQed. The HF measurement was an average of measurements taken at my two primary listening positions, the two ends of a couch. The averaging lost the phase info so I'm just EQing the gain. Does that make sense so far?

Looking at rephase, I see paragraphic gain equalization with 17 PEQs per bank. One bank is almost but not quite enough filters. Can I use multiple banks? Is it the case that RePHase creates a FIR filter defined by the collection of PEQs that I define this way?

I found it tedious to manually tune all those individual PEQs so I opened REW and used its automatic EQ to create and fine tune PEQs for a generic DSP. I then manually transferred those PEQs into RePhase. For some reason yet undiscovered, the predicted response in REW didn't match the predicted response in RePhase. There were a few bumps to smooth over but in spite of this it did save a lot of time and I got a better end result than I had gotten wholly manually. Does anybody know why there would be a mismatch between REW and RePhase?

I still have a lot to learn about RePhase and REW auto-eq process but my next step is to load the filters I just created into the OpenDRC, remeasure, and then listen. Getting these questions answered, and further hints or suggestions, will make me feel a little less trepidation about it.

Thanks in advance,
Jack
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Old 5th December 2016, 03:55 PM   #1338
Pano is offline Pano  United States
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rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by soundcheck View Post
Folks, why do you stay so vague all the time???
It's vague because you don't understand the bigger picture and some of the fundamentals. You really should do some more reading about measuring loudspeakers. Otherwise you'll just end up chasing your tail. We are trying to help you avoid that.

You want to use rePhase, or something like it, for room corrections and/or crossovers. To get a measurement to base your room corrections on you start with a measurement of your system at your listening position. But remember, move the mic a centimeters and that measurement will change. That's something you really have to understand.

Room measurement is a big subject, but not the subject of this thread.
I would suggest that you start out with a economic measurement mic, like the Dayton calibrated one. Start doing measurements and you will quickly learn how tricky and variable it can be. It takes time, patience and discipline, which I'm sure you have.

Get some good tools, start measuring and start learning! You will have all sorts of new questions that you didn't expect. Don't get caught up in the fine details right now. Learn to walk before you fly.
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Old 5th December 2016, 06:16 PM   #1339
wesayso is offline wesayso  Netherlands
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Quote:
Originally Posted by soundcheck View Post
"...DRC-FIR works as advertised for me..."

What is that supposed to mean? As limited as advertised??

DRC-Fir is very well aware of the shortcomings and limitations. It's even
mentioned somewhere on the DRC pages. ( I ran a project myself some time back)
If you want to know what it does for me, it's all hidden in a huge thread describing my project, you can find it here: http://www.diyaudio.com/forums/full-...ine-array.html
On the first post of that thread, I've made a couple of links to important parts. What DRC-FIR does for me is more than I can describe in a few words here. I'm pleased with it's outcome, my goals do differ from yours though. There are some links to reviews, written by fellow forum members.

If you really want to know about it, please start reading. You're not being any more clear than us by stating: "...I ran a project myself some time back..." which does not make us understand why DRC-FIR and yourself could not get along.
Clearly it did not work out for you. Any other DRC question you may have, please use this thread: A convolution based alternative to electrical loudspeaker correction networks. This thread was started to help people get a good start with DRC-FIR. It's packed with a tutorial and some custom templates.

It does not add anything useful to this thread to be talking about programs that do not have anything to do with what pos intended for RePhase.

For the rest of the points you made Pano was way more clear than I could ever be. We are trying to help, please realise that.
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Last edited by wesayso; 5th December 2016 at 06:33 PM.
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Old 5th December 2016, 09:35 PM   #1340
nc535 is online now nc535
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Quote:
Originally Posted by nc535 View Post
I'm a first time user of Rephase with a couple of questions. I did a 3-way speaker using MiniDSP 4x10 and got good response at 1m in room with excellent time alignment and reasonably flat phase. Measuring out at the LP is another story so I want to add a MiniDSP OpenDRC into the path and use it both for room correction and to fit to a room curve. The room effects I need to deal with are at least one longitudinal mode, and floor and ceiling bounce.

These are full range speakers, EQed flat to 20 Hz, in the front corners. I noticed that measuring below 100 Hz, the left and right speakers played simultaneously filled holes in each other's response. This is reasonable because the LP is 2' closer to one speaker than the other. So for the OpenDRC EQ process, I blended an LF measurement (<=100Hz) of both speakers with an HF measurement of the speaker being EQed. The HF measurement was an average of measurements taken at my two primary listening positions, the two ends of a couch. The averaging lost the phase info so I'm just EQing the gain. Does that make sense so far?

Looking at rephase, I see paragraphic gain equalization with 17 PEQs per bank. One bank is almost but not quite enough filters. Can I use multiple banks? Is it the case that RePHase creates a FIR filter defined by the collection of PEQs that I define this way?

I found it tedious to manually tune all those individual PEQs so I opened REW and used its automatic EQ to create and fine tune PEQs for a generic DSP. I then manually transferred those PEQs into RePhase. For some reason yet undiscovered, the predicted response in REW didn't match the predicted response in RePhase. There were a few bumps to smooth over but in spite of this it did save a lot of time and I got a better end result than I had gotten wholly manually. Does anybody know why there would be a mismatch between REW and RePhase?

I still have a lot to learn about RePhase and REW auto-eq process but my next step is to load the filters I just created into the OpenDRC, remeasure, and then listen. Getting these questions answered, and further hints or suggestions, will make me feel a little less trepidation about it.

Thanks in advance,
Jack
Never mind, found some pilot errors, answered my own questions, thinking there must be a better way but don't want a PC in my playback path
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