Xilica 4080 - Page 4 - Home Theater Forum and Systems - HomeTheaterShack.com

 3Likes
Reply
 
Thread Tools
post #31 of 94 Old 06-01-17, 08:14 PM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

John,
I only had time to do the Left channel tonight sorry, I think I have it all correct have a look. Also I just left everything setup for tomorrow, if I got this correct I will do the Right channel tomorrow during the day.
Jay Compton is offline  
Sponsored Links
Advertisement
 
post #32 of 94 Old 06-01-17, 10:36 PM
Elite Shackster
 
Join Date: Mar 2009
Location: Arizona, USA
Posts: 1,562
My System
Re: Xilica 4080

Thanks for the data.
Well, the measured result does not match the predicted result so there is a problem someplace. The EQ looks good and the drivers polarity is correct per the provided instruction. The delay of the MR horn is not correct however resulting in poor phase tracking and an SPL dip in the XO range. On close examination of the timing crosstalk the 3 drivers reference times do not fall on top of each other as expected. This suggests the REW loopback timing may not be working properly for some reason.

I suggest:
> Let's first confirm loopback timing is setup and working properly. Measure the MR Horn 6 times in succession still using the same 20-20k sweep. Post the file so I can confirm the impulse location of each measurement is identical.
> If the measurements do not confirm repeatability, we need to investigate further to determine where the problem is.
> When the repeatability test is successful we can we restart Step-2 delay settings from the beginning. that is, repeat the 3 driver measurements on the left channel to determine new delay recommendations.
> Since we will be starting Step 2 over you can change the mic height as needed to be on your line of sight from the LP to a point on the baffle between the 2 horns. [You indicated to me the 36" height I originally suggested was too low for your high seating position so you can make that height change now.
jtalden is offline  
post #33 of 94 Old 06-02-17, 07:02 AM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

Ok John,
Will have that done a in a few hours.
Jay Compton is offline  
 
post #34 of 94 Old 06-02-17, 10:29 AM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

OK John,
Six consecutive times.
Attached Files Left MR Only.mdat (15.96 MB) 
Jay Compton is offline  
post #35 of 94 Old 06-02-17, 12:26 PM
Elite Shackster
 
Join Date: Mar 2009
Location: Arizona, USA
Posts: 1,562
My System
Re: Xilica 4080

I reviewed the data and it looks okay for repeatability. Measurement #4 and #6 deviated very slightly from the other 4. Both may have been due to some ambient room noise during the measurements. I see no major problem with loopback timing repeatability in this data. The MR-horn timing however in the May-31 and Jun-01 measurements is significantly different that lead to this problem. I cannot be sure which timing is correct. Each of the 3 sessions is also slightly different in timing. Possibly that is because windows is locking onto an REW session using a slightly different latency??

The safest path forward is...
> Use one REW session for all the following measurements on the left channel. Nothing should change except the driver selected for measurement.
Measure in the following order: (do not deviate from this order)
> HF-horn
> MR-horn
> W
> HF-horn
> MR-horn
> W
> HF-horn
> MR-horn
> W

That is, measure each of the 3 drivers and then repeat that same series 3 times so there are 9 total measurement in the one file. If the file is then too large to post here you can then break the original file into 2 or 3 smaller files or even email the entire file to me directly.

This way I can confirm again that the timing is repeatable and if necessary I can also avoid using any odd measurement that appears to be corrupted in time or by noise. I will then provide new driver delay adjustments for the 4080 as needed.
jtalden is offline  
post #36 of 94 Old 06-02-17, 01:05 PM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

Ok John,
I will get started now and have the results soon.
Jay Compton is offline  
post #37 of 94 Old 06-02-17, 04:46 PM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

Here ya go.
Jay Compton is offline  
post #38 of 94 Old 06-02-17, 06:44 PM
Elite Shackster
 
Join Date: Mar 2009
Location: Arizona, USA
Posts: 1,562
My System
Re: Xilica 4080

Okay the analysis is complete.
The timing of the MR-horn was wrong. It did agree with the Post-31 so it is consistent with the last set of measurement. I can only conclude that my original analysis in Post-26 was erroneous.

The adjustment needed is to the MR-horn. It needs a delay increase of 0.58 ms.

The polarities are all correct as measured.

The charts of Post-26 still apply. Below is the overall phase response.
Xilica 4080-overall-spl-phase.jpg

Now we should confirm this analysis.
Measure Left Channel with the new MR delay:
> HF-horn
> MR-horn
> W

Measure Right Channel with the new setting and the appropriate mic position:
> HF-horn
> MR-horn
> W
jtalden is offline  
post #39 of 94 Old 06-02-17, 06:58 PM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

Ok John,
That's good news!!! Now adding the delay of 0.58ms plus the 4.083 that is already in would give me a total delay of4.663 ms correct?
Jay Compton is offline  
post #40 of 94 Old 06-02-17, 09:41 PM Thread Starter
Shackster
 
Jay Compton's Avatar
jcmusic
 
Join Date: Sep 2016
Posts: 99
Re: Xilica 4080

John,
I was able to measure the final Left Channel group and then the Right Channel group. Only thing is the Xilica would not give me the 4.663 ms I needed, it gave me 4.666 ms hope that's close enough.
Jay Compton is offline  
Reply

Bookmarks

Tags
4080 , xilica

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome