Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 356 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 4344Likes
Reply
 
Thread Tools
post #10651 of 28216 Old 06-30-2014, 10:37 AM
AVS Forum Addicted Member
 
markus767's Avatar
 
Join Date: Apr 2009
Posts: 11,778
Mentioned: 187 Post(s)
Tagged: 0 Thread(s)
Quoted: 5651 Post(s)
Liked: 2695
Quote:
Originally Posted by jim19611961 View Post
Do you have a reference that shows image shift based on level differences?
Huh? Interchannel level differences is the main mechanism on which most recordings rely. Please read the Lip****z paper.

Markus

"In science, contrary evidence causes one to question a theory. In religion, contrary evidence causes one to question the evidence." - Floyd Toole
markus767 is offline  
Sponsored Links
Advertisement
 
post #10652 of 28216 Old 06-30-2014, 10:50 AM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by markus767 View Post
Huh? Interchannel level differences is the main mechanism on which most recordings rely. Please read the Lip****z paper.
I am not talking about the recording process, I am talking about measured SPL differences in the form of FR between L & R channels at specific frequencies. More specifically, I am interested in what a 1db, or 2db, or 3db level difference from R to L, means in terms of image shift.

Now, if your saying reading that paper addresses what I am after here, then link the article you mean and ill take a look at it.

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next
jim19611961 is offline  
post #10653 of 28216 Old 06-30-2014, 11:07 AM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Click image for larger version

Name:	Interchannel Level differences.JPG
Views:	80
Size:	109.6 KB
ID:	142538

http://www.sengpielaudio.com/Interch...fferences1.pdf

If I am understanding things correctly, this chart sums up what I am after I think. Yes?

If so, a 1db difference in level will shift a signal from direct center to 6-11% (depending on which study you look at) away from the speaker with the lesser level (-1db). 2db, 12-22% (depending on which study you look at), and so on?

So if ones speakers (mine) are 93" apart. A 2db difference at some given frequency, should a note or sound emanate from there, should move the stereo image 5.58" to 10.23" from center? (assuming it was center to begin with)

Math:

93 / 2 = 46.5" being center.
46.5 * 12% = 5.58"
46.5 * 22% = 10.23"

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next

Last edited by jim19611961; 06-30-2014 at 12:46 PM.
jim19611961 is offline  
Sponsored Links
Advertisement
 
post #10654 of 28216 Old 06-30-2014, 12:53 PM
AVS Forum Addicted Member
 
markus767's Avatar
 
Join Date: Apr 2009
Posts: 11,778
Mentioned: 187 Post(s)
Tagged: 0 Thread(s)
Quoted: 5651 Post(s)
Liked: 2695
Quote:
Originally Posted by jim19611961 View Post
Now, if your saying reading that paper addresses what I am after here, then link the article you mean and ill take a look at it.
That paper will provide even more but AES papers are not for free...

Markus

"In science, contrary evidence causes one to question a theory. In religion, contrary evidence causes one to question the evidence." - Floyd Toole
markus767 is offline  
post #10655 of 28216 Old 06-30-2014, 02:00 PM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by markus767 View Post
That paper will provide even more but AES papers are not for free...
So, you agree with post 10654?

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next
jim19611961 is offline  
post #10656 of 28216 Old 06-30-2014, 02:58 PM
AVS Forum Special Member
 
hifiaudio2's Avatar
 
Join Date: Oct 2001
Posts: 3,227
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 461 Post(s)
Liked: 121
Don't want to derail this thread, but how long does it normally take for Cross Spectum to reply or ship the mic? I ordered last Wednesday and have emailed and called and have gotten no response. The only thing I have is a Paypal receipt and $105 less.
hifiaudio2 is offline  
post #10657 of 28216 Old 06-30-2014, 02:58 PM
AVS Forum Special Member
 
artur9's Avatar
 
Join Date: Mar 2013
Location: near philly
Posts: 2,358
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1011 Post(s)
Liked: 392
Quote:
Originally Posted by jim19611961 View Post
If so, a 1db difference in level will shift a signal from direct center to 6-11% (depending on which study you look at) away from the speaker with the lesser level (-1db). 2db, 12-22% (depending on which study you look at), and so on?
Jim, I don't recall seeing the process you go through to maximize your soundstage solidity et al. Did I miss that?

Clearly, level matching L+R is part of it. You also did mention setting toe-in. Are there test tones you use?

Last edited by artur9; 06-30-2014 at 03:03 PM.
artur9 is offline  
post #10658 of 28216 Old 06-30-2014, 03:02 PM
AVS Forum Special Member
 
3ll3d00d's Avatar
 
Join Date: Sep 2007
Location: London, UK
Posts: 4,166
Mentioned: 267 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked: 2719
Quote:
Originally Posted by jim19611961 View Post
Does that bias show on FR curves when putting the R & L channel responses on top of each other?

What do you mean by "uncorrected"?
by uncorrected, I mean without any EQ on the mains. Correction is my case means an acourate generated set of filters running in jriver.

Here are some graphs for you, in each case red is L and green is R. I have limited the graph to 250Hz up so I can zoom in on the region of interest. FWIW the speakers are ~2m apart & ~3.1m away.

With no correction


With correction


According to these measurements, the L was stronger beforehand by 2-4dB above 1kHz.

Clearly my memory fails me with respect to the direction of bias though so I went back to an earlier post (written on another forum around the time I first got my acourate setup going). At the time, I wrote;

No correction produces;

* a stereo image that is obviously pulled to the left
* reduced perception of height
* a certain hollowness/metallic quality to the entire sound
Attached Thumbnails
Click image for larger version

Name:	after.JPG
Views:	253
Size:	61.9 KB
ID:	142938  

Last edited by 3ll3d00d; 06-30-2014 at 03:52 PM.
3ll3d00d is offline  
post #10659 of 28216 Old 06-30-2014, 03:16 PM
AVS Forum Special Member
 
3ll3d00d's Avatar
 
Join Date: Sep 2007
Location: London, UK
Posts: 4,166
Mentioned: 267 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked: 2719
Quote:
Originally Posted by cfraser View Post
Do you want to do something, or just think about it?
In response to the measurements I've made recently, which include looking more deeply at distortion, I have dialled back the EQ applied to extend the low end of my sub. The underlying reason for this change was because I'd underestimated the extent of room gain in my room but the prompt for delving into this more deeply was what I thought was an unusual escalation in distortion at the "same" output level (i.e. the same master volume and what I thought was a flat frequency response) to the extent it added an audible colour to the tone.

I have also started designing a new, bigger, sub so I can see what it would take to give me an upgrade in headroom big enough to make the effort worthwhile.
3ll3d00d is offline  
post #10660 of 28216 Old 06-30-2014, 03:48 PM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by artur9 View Post
Jim, I don't recall seeing the process you go through to maximize your soundstage solidity et al. Did I miss that?

Clearly, level matching L+R is part of it. You also did mention setting toe-in. Are there test tones you use?
Basically, I listen carefully. When I hear something that seems off, I try to find a correlation in my measurement data. Like most of you, I spend the most time on those measurements that seem the most important.

For instance, up in the treble range, there is some slight soundstage aberrations. I brought up level difference as it relates to image shift for a reason.

Click image for larger version

Name:	06 30 14 L and R at ear.jpg
Views:	73
Size:	135.0 KB
ID:	142978

If you look above 6K, there are some minor deviations.

edit: I occasionally use sine waves or warble tones. Depends what I am trying to do.

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next

Last edited by jim19611961; 06-30-2014 at 04:49 PM.
jim19611961 is offline  
post #10661 of 28216 Old 06-30-2014, 04:05 PM
AVS Forum Special Member
 
artur9's Avatar
 
Join Date: Mar 2013
Location: near philly
Posts: 2,358
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1011 Post(s)
Liked: 392
Quote:
Originally Posted by steveting99 View Post
^ Guys,

Came across this website: http://soundoctor.com/whitepapers/subs.htm regarding how to integrate sub(s) into the system. Scroll down to the part about "THE RECORDING PROCESS" which tells the sad tale of how music is now mastered to obtain soundstage.
That paper is interesting. It does have an explanation as to why my system sounds brighter after I reduced the masking effect of the distortion my subs were creating.
artur9 is offline  
post #10662 of 28216 Old 06-30-2014, 04:51 PM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by artur9 View Post
That paper is interesting. It does have an explanation as to why my system sounds brighter after I reduced the masking effect of the distortion my subs were creating.
Masking is whole other can of worms id like to discuss sometime.

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next
jim19611961 is offline  
post #10663 of 28216 Old 07-01-2014, 03:52 AM
Member
 
Saril's Avatar
 
Join Date: Jan 2013
Posts: 167
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 47 Post(s)
Liked: 21
Quote:
Originally Posted by artur9 View Post
That paper is interesting. It does have an explanation as to why my system sounds brighter after I reduced the masking effect of the distortion my subs were creating.
Does anyone know when that paper was written? There is no mention of Audyssey, ARC, YAPO, MCACC, etc., or REW. Is it even relevant to people who use these systems for analysis? Some of statements seem to contradict the core ideology of REW. Thanks for any insight.
Saril is offline  
post #10664 of 28216 Old 07-01-2014, 04:04 AM
Member
 
Saril's Avatar
 
Join Date: Jan 2013
Posts: 167
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 47 Post(s)
Liked: 21
Quote:
Originally Posted by hifiaudio2 View Post
Don't want to derail this thread, but how long does it normally take for Cross Spectum to reply or ship the mic? I ordered last Wednesday and have emailed and called and have gotten no response. The only thing I have is a Paypal receipt and $105 less.
I just received my UMIK-1 - took less than a week. I ordered off the CS website. Also, I had great response times from Herb on questions I emailed.
Saril is offline  
post #10665 of 28216 Old 07-01-2014, 04:08 AM
AVS Forum Addicted Member
 
markus767's Avatar
 
Join Date: Apr 2009
Posts: 11,778
Mentioned: 187 Post(s)
Tagged: 0 Thread(s)
Quoted: 5651 Post(s)
Liked: 2695
Quote:
Originally Posted by Saril View Post
Does anyone know when that paper was written? There is no mention of Audyssey, ARC, YAPO, MCACC, etc., or REW. Is it even relevant to people who use these systems for analysis? Some of statements seem to contradict the core ideology of REW. Thanks for any insight.
Not sure what you're asking. The paper is obviously a bit old although it says, "THIS PAGE LAST UPDATED July 10, 2013"
REW doesn't follow any ideology, it's a measurement software based on the swept-sine technique.

Markus

"In science, contrary evidence causes one to question a theory. In religion, contrary evidence causes one to question the evidence." - Floyd Toole
markus767 is offline  
post #10666 of 28216 Old 07-01-2014, 05:06 AM
AVS Forum Special Member
 
3ll3d00d's Avatar
 
Join Date: Sep 2007
Location: London, UK
Posts: 4,166
Mentioned: 267 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked: 2719
Quote:
Originally Posted by Saril View Post
Does anyone know when that paper was written? There is no mention of Audyssey, ARC, YAPO, MCACC, etc., or REW. Is it even relevant to people who use these systems for analysis? Some of statements seem to contradict the core ideology of REW. Thanks for any insight.
The page has been there for a long time, since at least 2007-2008 IIRC. It's definitely been fairly heavily revised in the last 18months or so though. FWIW the author was with M&K for a long time and now works for JL Audio.
3ll3d00d is offline  
post #10667 of 28216 Old 07-01-2014, 06:12 AM
AVS Forum Special Member
 
hifiaudio2's Avatar
 
Join Date: Oct 2001
Posts: 3,227
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 461 Post(s)
Liked: 121
Quote:
Originally Posted by Saril View Post
I just received my UMIK-1 - took less than a week. I ordered off the CS website. Also, I had great response times from Herb on questions I emailed.
OK thanks. I don't know what is up then. Tomorrow will be a week and I can't get a response of any kind.
hifiaudio2 is offline  
post #10668 of 28216 Old 07-01-2014, 07:48 AM
AVS Forum Addicted Member
 
Alan P's Avatar
 
Join Date: Jan 2003
Location: South Dakota
Posts: 11,787
Mentioned: 111 Post(s)
Tagged: 0 Thread(s)
Quoted: 6415 Post(s)
Liked: 5741
Hey guys - I finally got a laptop with HDMI the other day. Last night was my first time trying to use it with REW. Seems to work great!

One question; REW is still asking me to calibrate my levels (with the SPL meter) before I take a measurement....I thought that was not needed with and HDMI connection?

This is with a UMM-6, BTW.
Alan P is offline  
post #10669 of 28216 Old 07-01-2014, 07:56 AM
AVS Forum Special Member
 
3ll3d00d's Avatar
 
Join Date: Sep 2007
Location: London, UK
Posts: 4,166
Mentioned: 267 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked: 2719
Quote:
Originally Posted by Alan P View Post
Hey guys - I finally got a laptop with HDMI the other day. Last night was my first time trying to use it with REW. Seems to work great!

One question; REW is still asking me to calibrate my levels (with the SPL meter) before I take a measurement....I thought that was not needed with and HDMI connection?

This is with a UMM-6, BTW.
SPL calibration is avoided when your mic has a known sensitivity not when you output via HDMI. The UMIK-1 is the only mic with a known sensitivity AFAIK.
3ll3d00d is offline  
post #10670 of 28216 Old 07-01-2014, 08:07 AM
AVS Forum Addicted Member
 
Alan P's Avatar
 
Join Date: Jan 2003
Location: South Dakota
Posts: 11,787
Mentioned: 111 Post(s)
Tagged: 0 Thread(s)
Quoted: 6415 Post(s)
Liked: 5741
Ahhh, that's right! Thanks dood!
Alan P is offline  
post #10671 of 28216 Old 07-01-2014, 10:03 AM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by artur9 View Post
Jim, I don't recall seeing the process you go through to maximize your soundstage solidity et al. Did I miss that?

Clearly, level matching L+R is part of it. You also did mention setting toe-in. Are there test tones you use?
Quote:
Originally Posted by AustinJerry View Post
I follow the same general guidelines you mentioned. I place a piece of cardboard approximately two feed behind the MLP with a vertical line representing the midpoint between the left and right speakers. I then use a laser pointer to adjust toe-in so it is on the center line, crossing just behind the MLP.

Analyzing the soundstage is a topic that I have struggled with for quite some time. My ability to analyze audio depends on being able to devise A/B tests that I can toggle back and forth. I can't, for example, listen to a music passage, stand up, adjust toe-in, sit down and listen to the same music passage, and assess audible changes to the soundstage attributable to the change. I don't know why this is difficult for me, but it is.

So, for those of you with Golden Ears, walk me through how you assess a system's soundstage. Do you have a particular piece of music you are very familiar with? What exactly do you listen for? Is your audio memory good enough that you can adjust something and immediately assess the impact of the change?

If someone were able to coach me through how to optimize my soundstage, I would be forever indebted. Wouldn't this be good advice for anyone reading this thread?
I don't think I answered either one your inquires properly, so let me unpack my thoughts a bit more.

For me, it does start with a lot of careful listening. What I listen for is several fold:
1) That middle is middle
2) A balance of images over a range of different listening material in terms of equal amounts of image locations from extreme left to extreme right
3) Clarity and/or definition of images through different frequency ranges
4) The relationship of depth vs width of soundstage

This is my starting point. Over the previous months and years, there have been points where either the left or right seemed biased in terms of amounts of perceived images and/or there locations. Getting this right in terms of perception is tricky certainly. But evenness and balance from a perceptual point of view I think is the ultimate goal.

Let me speak a little more about each of the above:

1) The two items that I find most to dominate the exact middle are vocals and bass guitar in rock music. While this is certainly not always where these items appear, its fairly easy to tell when they are supposed to be in the middle vs those occasions where they obviously are supposed to appear elsewhere.

2) People have mentioned source material where a sound moves or is panned from extreme right to left. Where the sound first appears and disappears gives some sense of your extreme L & R image boundaries and how smoothly the sound mitigates across the soundstage. I find that I must listen to several of these for how far L & R they begin and end is not always the same in every recording, or intended to be.

I also listen carefully to middle left, middle right, far left and far right. When things are a bit off, there is a tendency for most images to appear either left, right or middle, with few to no images appearing elsewhere. Toe-in and speaker to speaker distance both seem to have some effect on this. Addtionally, at least on my system, there seems to be some trade off between the soundstage width and clarity of image location. The wider I make the stage, the broader the image sizes. A reduced width seems to help image localization and pinpoint location.

3) related to 2), I like to listen to how say, cymbals (treble) vs voices (midrange) vs drums (bass) pan or locate themselves across the stage and how defined they are. In my experience, the lower the frequncy of the instrument in question, the broader the image and less defined the location is in space to a certain extent.

4) The most affecting factor to this seems to be the shape of your speaker to speaker to LP triangle. In terms of room treatment, ceiling and floor seem to more affect depth, where sidewall treatment most affects width. Contrary to many folks recommendation, having your speakers right up against or very near the front wall reduces depth in my experience. The argument against me most cited is that soffit mounted speakers dont suffer from depth deprivation. I cant explain this apparent contradiction. Furthermore, I have never heard a soffit speaker mounted system.

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next

Last edited by jim19611961; 07-01-2014 at 10:06 AM.
jim19611961 is offline  
post #10672 of 28216 Old 07-01-2014, 11:34 AM
Newbie
 
mcnewt's Avatar
 
Join Date: Apr 2013
Location: Where the wind comes sweepin' down the plain
Posts: 12
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 14
Hi,

First time posting in this thread. Let me know if this is best posted somewhere else. I'm setting up my first dedicated theater room and I'm also pretty new to REW, so there's a high probability of "user error" here. Using the UMIK-1 from CSL, I've attached the response of my L, C, and R taken separately per the REW 101 guide (thanks to all who put that together!). All three speakers are the same, the EmpTek e55ti tower, and are located on a stage behind an AT screen. They're connected to a Denon x4000 AVR. I'm still researching acoustic treatments so most of the walls are bare and there's only a couch and wall-to-wall carpeting in the room. My question is: has anyone seen such a severe roll-off of the high frequencies like this before? The center isn't quite as bad (still not great), but I can't figure out what's up with the left and right. For reference, here's the audioholics review with their FR graph. Doesn't look like mine.
http://www.audioholics.com/tower-spe...i-measurements

I've tried toeing-in the left and right, but the response doesn't change at all. Could this just be because of the room's lack of treatments, or is there something else wrong?

Thanks for your help!
Attached Thumbnails
Click image for larger version

Name:	left right center tower rolloff tests.jpg
Views:	77
Size:	99.4 KB
ID:	143794  
mcnewt is offline  
post #10673 of 28216 Old 07-01-2014, 11:52 AM
** Man of Leisure **
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 20,901
Mentioned: 392 Post(s)
Tagged: 1 Thread(s)
Quoted: 11331 Post(s)
Liked: 6719
That is a pretty severe HF roll-off. My first thought is that there is something wrong with the speakers, but having a failed tweeter, for example, is unlikely to happen to both left and right at the same time.

You might try a near field measurement of the speakers to see if the speaker is indeed rolling of that quickly when the room is removed from the response. Place the mic 3-6" from the front of the speaker aimed directly at the tweeter and run a full-spectrum measurement.

Do you see any improvement after running Audyssey, i.e. is Audyssey successful in boosting the high end at all? And how does the system sound? Is it obviously missing the high end?
AustinJerry is online now  
post #10674 of 28216 Old 07-01-2014, 11:56 AM
** Man of Leisure **
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 20,901
Mentioned: 392 Post(s)
Tagged: 1 Thread(s)
Quoted: 11331 Post(s)
Liked: 6719
Quote:
Originally Posted by 3ll3d00d View Post
SPL calibration is avoided when your mic has a known sensitivity not when you output via HDMI. The UMIK-1 is the only mic with a known sensitivity AFAIK.
Please go to page 51 of the Guide. Both the EMM-6 and the UMIK-1 can be configured with sensitivity parameters, which will allow REW to automatically calibrate the mics.
AustinJerry is online now  
post #10675 of 28216 Old 07-01-2014, 11:56 AM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by AustinJerry View Post
That is a pretty severe HF roll-off. My first thought is that there is something wrong with the speakers, but having a failed tweeter, for example, is unlikely to happen to both left and right at the same time.

You might try a near field measurement of the speakers to see if the speaker is indeed rolling of that quickly when the room is removed from the response. Place the mic 3-6" from the front of the speaker aimed directly at the tweeter and run a full-spectrum measurement.

Do you see any improvement after running Audyssey, i.e. is Audyssey successful in boosting the high end at all? And how does the system sound? Is it obviously missing the high end?
Could be the result of measuring both channels at once, and the resulting high end cancellation. If that graph represents only one channel, something is a muck for sure.

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next
jim19611961 is offline  
post #10676 of 28216 Old 07-01-2014, 11:58 AM
** Man of Leisure **
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 20,901
Mentioned: 392 Post(s)
Tagged: 1 Thread(s)
Quoted: 11331 Post(s)
Liked: 6719
True, but looking at the legend, it looks like one channel at a time was being measured.
AustinJerry is online now  
post #10677 of 28216 Old 07-01-2014, 12:00 PM
AVS Forum Special Member
 
artur9's Avatar
 
Join Date: Mar 2013
Location: near philly
Posts: 2,358
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1011 Post(s)
Liked: 392
Quote:
Originally Posted by jim19611961 View Post
Masking is whole other can of worms id like to discuss sometime.
I meant masking in a more colloquial fashion, rather than the psycho-acoustics use of the term. I apologize for the misuse.

One thing that paper has gotten me curious about. Is there any way to do the phase measurements implied by the paper with REW? Every time it mentions measure phase it always says, "The equipment to do this is not readily available," or something to that effect.
artur9 is offline  
post #10678 of 28216 Old 07-01-2014, 12:01 PM
AVS Forum Special Member
 
jim19611961's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 1,829
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 451 Post(s)
Liked: 158
Quote:
Originally Posted by mcnewt View Post
Hi,

First time posting in this thread. Let me know if this is best posted somewhere else. I'm setting up my first dedicated theater room and I'm also pretty new to REW, so there's a high probability of "user error" here. Using the UMIK-1 from CSL, I've attached the response of my L, C, and R taken separately per the REW 101 guide (thanks to all who put that together!). All three speakers are the same, the EmpTek e55ti tower, and are located on a stage behind an AT screen. They're connected to a Denon x4000 AVR. I'm still researching acoustic treatments so most of the walls are bare and there's only a couch and wall-to-wall carpeting in the room. My question is: has anyone seen such a severe roll-off of the high frequencies like this before? The center isn't quite as bad (still not great), but I can't figure out what's up with the left and right. For reference, here's the audioholics review with their FR graph. Doesn't look like mine.
http://www.audioholics.com/tower-spe...i-measurements

I've tried toeing-in the left and right, but the response doesn't change at all. Could this just be because of the room's lack of treatments, or is there something else wrong?

Thanks for your help!
When listening, does it sound like that much of the high end is missing?

My Room
My Music
Rega - Apollo, Rega - DAC, Goldpoint Passive, Classe CA-100, Crown XLS 1002, miniDSP
Jenzen Next
jim19611961 is offline  
post #10679 of 28216 Old 07-01-2014, 12:06 PM
AVS Forum Special Member
 
3ll3d00d's Avatar
 
Join Date: Sep 2007
Location: London, UK
Posts: 4,166
Mentioned: 267 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked: 2719
Quote:
Originally Posted by artur9 View Post
One thing that paper has gotten me curious about. Is there any way to do the phase measurements implied by the paper with REW? Every time it mentions measure phase it always says, "The equipment to do this is not readily available," or something to that effect.
Yes you can, accurately comparing phase requires a timing source and some understanding of how to tweak the window settings. I wrote something here (links to another forum) which includes an example. There are a number of examples on HTS too if you want to read further.

Last edited by 3ll3d00d; 07-01-2014 at 12:15 PM.
3ll3d00d is offline  
post #10680 of 28216 Old 07-01-2014, 12:10 PM
Newbie
 
mcnewt's Avatar
 
Join Date: Apr 2013
Location: Where the wind comes sweepin' down the plain
Posts: 12
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 14
Jerry - You're correct. Each channel was tested separately. Regarding Audyssey, here's a before and after. It tries to boost everything, but doesn't really help with the roll-off. I'll definitely close-mic the tweeter tonight and see how it looks.
Click image for larger version

Name:	left tower with and without aud.jpg
Views:	82
Size:	92.2 KB
ID:	143938

Jim - I can't say I've ever noticed the top end missing while watching content. Also, the REW sweeps and the Audyssey chirps all sound like they get pretty high and "shrill", but I don't know if that means anything.

Thanks!
mcnewt is offline  
Sponsored Links
Advertisement
 
Reply Audio Theory, Setup, and Chat

Tags
Dayton , Dayton Audio , Room Equilizer Wizard Rew

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