Help! Dialog in Films Unintelligible - Page 2 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #31 of 40 Old 09-27-2012, 01:08 PM
AVS Addicted Member
 
amirm's Avatar
 
Join Date: Jan 2002
Location: Washington State
Posts: 18,375
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 981 Post(s)
Liked: 547
Quote:
Originally Posted by Ben_Tech View Post

Here's a couple of different RT60 graphs as the measurement tends to vary a bit each pass. I don't see a way to average them.


Let me know if this is what you want to see, or if there is a better way to do it in REW. smile.gif
Hi Ben. Looks like you are just showing us the sub output. Since we care about dialog, please re-run it, set the vertical scale to 2-3 seconds, and only play the center channel. The frequency of interest is 500 Hz so give us a scan from 100 to 1000 Hz.

Amir
Retired Technology Insider
Founder, Madrona Digital
"Insist on Quality Engineering"
amirm is offline  
Sponsored Links
Advertisement
 
post #32 of 40 Old 09-27-2012, 02:06 PM - Thread Starter
Advanced Member
 
Ben_Tech's Avatar
 
Join Date: Apr 2003
Posts: 900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Ethan Winer View Post

That doesn't sound right. Unless I'm missing something. Do you have a sub with the receiver set for large mains anyway? Do you get anything from the sub?
When I asked to see an RT60 I meant the full range 20-20K, and I should have specified to display it as 1/3 octave. Then set the upper bound to 1 or 2 seconds, to better see the data rather than all scrunched up at the bottom.
--Ethan

Thanks Ethan. REW sends its test signal only on the right channel. My receiver therefore only outputs through the right front loudspeaker and the subwoofer. I unplugged the right loudspeaker in order to test only the sub per my understanding of what Amir was saying. This is with DPLIIx engaged in music mode. I think it would have to be a stereo source rather than a monaural source such as REW test signals to output all on 5.1 speakers.

Reading the Panny receiver manual, it says, quote: "When you set the front speakers (LR) as "Large" 1) The subwoofer also makes audio output in the bass range when you perform stereo playback of analog and PCM sources. 2) The subwoofer sends out only the LFE (low frequency effect channel) signal contained in 2-channel Dolby Digital or DTS sources when you play them in stereo." End quote.

I can take a measurement 20 Hz - 20 KHz with REW, however, my understanding is that it will be the right loudspeaker plus the subwoofer only. I'll try a Y-splitter momentarily to see if I can get the receiver to output the monaural signal to all channels.

I will post the results right away in the following post.

My Blog - Ask Toy Tech
Ben_Tech is offline  
post #33 of 40 Old 09-27-2012, 02:24 PM - Thread Starter
Advanced Member
 
Ben_Tech's Avatar
 
Join Date: Apr 2003
Posts: 900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Okay gentlemen, here is the RT60 center + subwoofer. I used the Y-splitter and DPLIIx "Movie mode" to get the desired results out of the receiver.

Please click the image to enlarge. Thanks in advance for your continued help!


My Blog - Ask Toy Tech
Ben_Tech is offline  
post #34 of 40 Old 09-27-2012, 02:32 PM - Thread Starter
Advanced Member
 
Ben_Tech's Avatar
 
Join Date: Apr 2003
Posts: 900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Just in case they would be useful, here are the SPL and Phase graphs from the same test:




My Blog - Ask Toy Tech
Ben_Tech is offline  
post #35 of 40 Old 09-28-2012, 11:38 AM
AVS Special Member
 
Ethan Winer's Avatar
 
Join Date: Apr 2003
Location: New Milford, CT, USA
Posts: 5,748
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 134
Quote:
Originally Posted by Ben_Tech View Post

REW sends its test signal only on the right channel.

Maybe you have an older version? I have 5.0 and it definitely sends the same sweep out both speakers. I just checked again to be sure.
Quote:
Reading the Panny receiver manual, it says, quote: "When you set the front speakers (LR) as "Large" 1) The subwoofer also makes audio output in the bass range when you perform stereo playback of analog and PCM sources. 2) The subwoofer sends out only the LFE (low frequency effect channel) signal contained in 2-channel Dolby Digital or DTS sources when you play them in stereo."

Well there you go then. I looked in my Pioneer receiver manual but it doesn't say anything specific about that.

--Ethan

RealTraps - The acoustic treatment experts
Ethan's Audio Expert book

Ethan Winer is offline  
post #36 of 40 Old 09-28-2012, 11:40 AM
AVS Special Member
 
Ethan Winer's Avatar
 
Join Date: Apr 2003
Location: New Milford, CT, USA
Posts: 5,748
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 134
Quote:
Originally Posted by Ben_Tech View Post

Okay gentlemen, here is the RT60 center + subwoofer.

That's not too bad, at least above 100 Hz.

--Ethan

RealTraps - The acoustic treatment experts
Ethan's Audio Expert book

Ethan Winer is offline  
post #37 of 40 Old 09-28-2012, 01:20 PM - Thread Starter
Advanced Member
 
Ben_Tech's Avatar
 
Join Date: Apr 2003
Posts: 900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Ethan Winer View Post

That's not too bad, at least above 100 Hz.
--Ethan

Thanks! Well then, here are a couple measurements (SPL and RT60) taken with no test signal, just the ambient room noise floor.



Can this be right? Note the 10 second scale...... I was trying to fit it all in there but it still runs off the edge:



Do you think, based on these results that quieting some of the fans in the room might help significantly with intelligibility? The subjective noise is not very loud, but still.

My Blog - Ask Toy Tech
Ben_Tech is offline  
post #38 of 40 Old 09-28-2012, 02:18 PM
AVS Addicted Member
 
amirm's Avatar
 
Join Date: Jan 2002
Location: Washington State
Posts: 18,375
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 981 Post(s)
Liked: 547
Quote:
Originally Posted by Ben_Tech View Post

Thanks! Well then, here are a couple measurements (SPL and RT60) taken with no test signal, just the ambient room noise floor.

Can this be right? Note the 10 second scale...... I was trying to fit it all in there but it still runs off the edge:

Do you think, based on these results that quieting some of the fans in the room might help significantly with intelligibility? The subjective noise is not very loud, but still.
No, this result doesn't mean anything smile.gif. RT60 is defined at how long it takes for an impulse to decay down 60 db. REW however does not wait that long as rooms typically have high noise floor relative to the test signal to ever see such a large gap. So instead, REW measures the drop off for a few db and then attempts to predict using different models what the time would have been if it could decline 60 db. The different algorithms it uses to do that are reflected in different color graphs. When you took away the signal that it uses as the reference, you confused its math because it now thinks the noise is the signal and notices that it hardly reduces as time goes by. So it gave you very high RT60 times which are meaningless. Garbage in, garbage out smile.gif.

I think your next step needs to be a new center channel. If that is not feasible, then turn up its level.

Amir
Retired Technology Insider
Founder, Madrona Digital
"Insist on Quality Engineering"
amirm is offline  
post #39 of 40 Old 09-28-2012, 04:04 PM - Thread Starter
Advanced Member
 
Ben_Tech's Avatar
 
Join Date: Apr 2003
Posts: 900
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by amirm View Post

No, this result doesn't mean anything smile.gif.

Thank you for the detailed explanation, Amir.

As to steps I have taken, I raised the center channel level a few dB. I am also looking at a certain computer system that is around ear height in terms of how to make it quieter.

Once I have done that, I will post a new RT60. Could be a while as the computer silencing project will take some time.

Thanks again to everyone!

My Blog - Ask Toy Tech
Ben_Tech is offline  
post #40 of 40 Old 09-30-2012, 06:14 AM
Advanced Member
 
joehonest's Avatar
 
Join Date: May 2011
Posts: 983
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 69 Post(s)
Liked: 30
Quote:
Originally Posted by Ben_Tech View Post

Thank you for the detailed explanation, Amir.
As to steps I have taken, I raised the center channel level a few dB. I am also looking at a certain computer system that is around ear height in terms of how to make it quieter.
Once I have done that, I will post a new RT60. Could be a while as the computer silencing project will take some time.
Thanks again to everyone!

Its the fans that make most of the noise you hear from a pc. With my HT pc I added more fans and are using the +5 volt tap not the +12 volt for all the fans. My HT pc is now undetectable from 3 feet away.. There are temperature apps that will monitor the cpu, vpu, hd, case temp and will warn if theres a temp problem..
Also theres the +5 +12 which is a +7 if the +5 is to slow.
joehonest is offline  
Reply Audio Theory, Setup, and Chat

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


Forum Jump: 

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off