Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th September 2017, 12:10 PM   #2231
BYRTT is offline BYRTT  Denmark
diyAudio Member
 
Join Date: Dec 2009
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by torgeirs View Post
Well just provide some counter arguments why arrays not nesecarily is better than multiway. We are in the multiway section:-)
Line arrays talked about do XO to each other and are indeed multiple ways aren't they
  Reply With Quote
Old 13th September 2017, 12:19 PM   #2232
fluid is offline fluid  Australia
diyAudio Member
 
Join Date: Jan 2009
Quote:
Originally Posted by silverprout View Post
IMHO, It should be interesting to quantify the reduction of room influence.
Look at the big reflections sticking out at 4.5ms and just before 10ms in the first graph. The one at 4.5ms has gone from -14dB to about -30dB in the second graph. Comparisons to outdoor measurements in both to make it clearer.

Click the image to open in full size.

Click the image to open in full size.
  Reply With Quote
Old 13th September 2017, 12:33 PM   #2233
silverprout is offline silverprout  France
diyAudio Member
 
silverprout's Avatar
 
Join Date: Apr 2008
Quote:
Originally Posted by fluid View Post
Look at the big reflections sticking out at 4.5ms and just before 10ms in the first graph. The one at 4.5ms has gone from -14dB to about -30dB in the second graph. Comparisons to outdoor measurements in both to make it clearer.
Not bad, could you filter it at 60Hz or 100Hz ?
__________________
Things I Should Have Learned In School (But Probably Didn't)
  Reply With Quote
Old 13th September 2017, 05:24 PM   #2234
torgeirs is offline torgeirs  Norway
diyAudio Member
 
Join Date: Aug 2011
Quote:
Originally Posted by BYRTT View Post
Line arrays talked about do XO to each other and are indeed multiple ways aren't they
Hm, I'm confused. This is multiway, but I should discuss it in the full-range section:-)
Actually the 100 Hz XO question a few days ago is an interesting topic. Will the sound from two arrays sum as an coax if LF and HF array is placed in same heighth. So you don't really need LR filter because there is no LF/HF pathlength difference going up or down in in listening heigth
  Reply With Quote
Old 13th September 2017, 11:24 PM   #2235
wesayso is offline wesayso  Netherlands
diyAudio Member
 
wesayso's Avatar
 
Join Date: Jul 2007
Filtered wave shapes... using the filtered IR tab in REW, set to its max resolution of 1/3 octave. Shown result is the impulse tab.

Red = corrected stereo impulse, green is the generated Rephase equivalent.

63 Hz (because it's available as filter setting in REW)
Click the image to open in full size.

Moving up to midrange, 4 KHz, same story, red is corrected result, green IR from Rephase:
Click the image to open in full size.

Doing something a little more difficult, 8 KHz:
Click the image to open in full size.

Any other volunteers showing their IR results at the listening position? About 3 m from the array, optimized with DRC-FIR and REW.

If we want to take this further about arrays etc, lets move into an array thread, mine will do, you're welcome. Lets keep this thread about RePhase and the many uses it has for us as a learning tool, correction tool and what ever other use it might have for us.
__________________
Use Science to design your speakers and they will sound like a piece of Art...

Last edited by wesayso; 13th September 2017 at 11:28 PM.
  Reply With Quote
Old 14th September 2017, 12:00 AM   #2236
mitchba is offline mitchba  Canada
diyAudio Member
 
mitchba's Avatar
 
Join Date: Jul 2011
Location: Sunshine Coast
Quote:
Originally Posted by torgeirs View Post
Thank you for this measurement(s). It shows very well how the visuals of the time response measurements changes quite a lot inside the sweet spot. The sound is NOT perceived as very different inside the listening area, I guess.

Yes, if you read the linked paper from JJ on acoustics and psychoacoustics, it is the first arrival timbre that our ears care about most. As can be seen from the step response chart, the first arrival of sound at t=0 is indeed the same around a 6' x 2' grid area. After the driect sound, it does vary somewhat after that, but is not perceived as tonal change as per JJ's (and Toole's) research. I could show the same chart of 14 measures of the frequency response and one can see that it is virtually the same tonal response across the 6' x 2' listening area, but this thread is about rePhase.

Quote:
Originally Posted by fluid View Post
Hi Mitch, yes I did find the same result. It really works to reduce the amount of room influence in the measurement. It keeps the issues that are not position specific. The more measurements you use to average the more the room is suppressed. I have settled on Centre, 10, 30 and 50cm either side at ear level as being a good balance between room suppression and the time it takes to do the measurements. My first test had 22 in total and it took most of the day to do.
I posted an ETC on my thread here that shows the reduction quite clearly
Full Range TC9 Line Array CNC Cabinet

Hi fluid, cool. Yes, I did similar using the beamforming technique and moved the mic in 10 cm increments moving forward and back from the LP for 10 measurements in total. Does do a great job of suppressing the room and have similar ETC's like yours. Still considering if I like the sound versus a single measure. Some say that the multiple measurements also helps average the low frequency response and others say that for some DSP correction software, the averaging is built-in to the psychoacoustic filter...
  Reply With Quote
Old 14th September 2017, 03:03 AM   #2237
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
Quote:
Originally Posted by BYRTT View Post
... and before process had to lower track level in Audacity by 6dB else processing would show red overloads in Audacity window, which in a way scare me and makes me think i wanna start my first point in DSP engine by lowering level by 6dB...
Don't worry about clipping in programs like Audacity or Goldwave until you export into a PCM format. These programs work in float bit space, so there is no clipping. You'll see it indicated because it would clip if exported in a non-float format.

Just normalize before exporting to normal 16 or 24 bit formats. JRiver does it's DSP in 64 bit float, so no clipping there until you send it out to the DAC in PCM. That you do have to be aware of.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 14th September 2017, 03:41 AM   #2238
ttan98 is offline ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
Default Help Please

Hi,
Everyone I am new to using the rePhase software for the first time. I will outline what I have and generated and many questions to ask but limit to asking what I need to know first.

Speakers: 2 way open baffle(similar to LX Mini, cross at 750Hz)
Equipment: MinidspHD 2*4 way
Software:REW via Umik and Rephase

I generated a x-over at 750Hz Using LR 2nd order, then I used the REW to equalise the output to relatively flat. I downloaded to Rephase software and was I unable(due lack of knowledge of rePhase) to make the phase flat. Attached is my freq response and phase outputs, I would appreciate for advice on how to make the phase as flat as possible.
Questions:
1. the Rephase sequence/steps I should be considering to equalise the phase for any output response?
2. What curve smoothing should I use normally?

Rephase is a powerful software and maybe due to lack of documentation(text and video) I cannot really get a full understanding on how to to use it effectively.

ANY help is welcomed, thanks.
Attached Images
File Type: jpg equalised openbaffle response.jpg (77.4 KB, 29 views)
  Reply With Quote
Old 14th September 2017, 04:03 AM   #2239
fluid is offline fluid  Australia
diyAudio Member
 
Join Date: Jan 2009
Phase from an in room measurement will be a mess and you cannot flatten it or nor do you want to.

Try using a Frequency Dependent Window on the measurement the phase will look a lot cleaner. Go to IR Windows tab tick Add Frequency dependent window and then select the amount of cycles. 6 to 15 cycles will probably be best.

To undo the phase turn from the second order filters you can go into the Filters linearization tab in rephase select LR 12dB and your crossover frequency.

To remove the excess phase use a 6 cycle Frequency dependent window on the measurement and generate an excess phase version in REW from the all spl tab controls. Save that measurement as text, import the measurement into rephase and use the paragraphic phase EQ to make the phase closer to 0 avoid trying to get rid of the big jumps in phase because they will be due to reflections. Generate a filter as a wav file at 32 bit and load that into a convolver to test if you use a computer as a source, I can't help you with the best way to get that filter into a minidsp as I have never used one.

Swiss Bear wrote a tutorial linked somewhere in this thread search for his posts if you want to see some screenshots.
  Reply With Quote
Old 14th September 2017, 04:22 AM   #2240
ttan98 is offline ttan98  Australia
diyAudio Member
 
Join Date: Apr 2006
Location: Melb
Found the tutorial but in French is that right is there one in English?
  Reply With Quote

Reply


rePhase, a loudspeaker phase linearization, EQ and FIR filtering toolHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FIR linear phase plugin for MiniDSP? diyjb01 miniDSP 17 9th June 2016 01:35 PM
FIR filter design tool for Loudspeaker magnitude equalization ttmusic Software Tools 3 24th May 2013 08:30 PM
FIR Filtering experiences Olombo PC Based 8 10th February 2013 03:45 PM
AVX based FIR VST, crossover / EQ / DRC and delay KOON3876 PC Based 97 26th November 2012 07:18 AM
Phase EQ using FIR filters Grasso Multi-Way 2 2nd July 2003 10:37 PM


New To Site? Need Help?

All times are GMT. The time now is 05:27 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki