Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 61 - AVS Forum
Forum Jump: 
 12Likes
Reply
 
Thread Tools
post #1801 of 10862 Old 03-04-2013, 01:44 PM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by AustinJerry View Post

Quote:
Originally Posted by mogorf View Post


Hey Jerry, why not move on to spectrograms? Waterfalls are becoming boring, spectrograms look nice and colorful. And they show what is going on from an "aerial" view before and after the sweep and everything in between. wink.gifsmile.gif No wonder JohnM's avatar is a spectrogram and not a waterfall. tongue.gif

 

I'm game, Feri.  Here is a first attempt:

 

 

Since I know nothing about these, are the axes set proprely?  What does the graph tell us?  Is there a link that explains spectrographs?

REW Help file has info...

kbarnes701 is offline  
Sponsored Links
Advertisement
 
post #1802 of 10862 Old 03-04-2013, 01:48 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by kbarnes701 View Post

REW Help file has info...
^^
Argh....just when I thought I was _out_.....they pull me back in!

Edit: I Googled 'spectrograph', and to be picky, it seems that the plot is a _spectrogram_ (as Feri indicated), and the instrument that collects such a chart is the spectrograph. But after a quick perusal of the HTS hits, what does a spectrowhaever tell us that a waterfall does not? Beyond a heat chart measure of the same, that is?

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1803 of 10862 Old 03-04-2013, 01:52 PM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by sdrucker View Post

Actually it's our second; Our first is now 15. Long story about the "why" part, but it ultimately came down to "now or never", for both biological and practical family reasons (and also, not wanting to leave our son as an "island" unto himself down the road). But yes, I think you're right that it does change your life. The irony is for the longest time, we'd planned on only being a one child family, but sometimes your priorities change where you rethink. Call it another version of "mid-life crisis" tongue.gif...even if it's not the norm to go from thinking about empty nesting to rebooting to our mid-30s:).

I must be one of the few people that would use family expansion as a direct excuse for improving a HT room cool.gif. So maybe I won't completely forget about the 20 Hz LOL:D At least until mid-September (current due date)...wink.gif

 

Twice the joy then. I had my twin girls when I was 42 - later than most have their first child I guess. I was too busy with my business and so on to get around to it earlier I suppose. No regrets about leaving it to 42 - more money, more patience etc. And they keep you young. Talking of excuses to improve the HT room, I am working on Mrs Keith to try to persuade her we need to move house, mainly so I can get a more suitable room ;) I am presenting it slightly differently to that of course ;)  If it comes off, it will be the most expensive upgrade in the history of AV LOL!

kbarnes701 is offline  
post #1804 of 10862 Old 03-04-2013, 01:52 PM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by sdrucker View Post

Quote:
Originally Posted by kbarnes701 View Post

REW Help file has info...
^^
Argh....just when I thought I was _out_.....they pull me back in!

biggrin.gif  Always another level in the rabbit hole, Stuart!

kbarnes701 is offline  
post #1805 of 10862 Old 03-04-2013, 02:00 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by kbarnes701 View Post

Twice the joy then. I had my twin girls when I was 42 - later than most have their first child I guess. I was too busy with my business and so on to get around to it earlier I suppose. No regrets about leaving it to 42 - more money, more patience etc. And they keep you young. Talking of excuses to improve the HT room, I am working on Mrs Keith to try to persuade her we need to move house, mainly so I can get a more suitable room wink.gif I am presenting it slightly differently to that of course wink.gif  If it comes off, it will be the most expensive upgrade in the history of AV LOL!

Now that's dedication: moving just to get a better HT room? eek.gif

I can sympathize with the business taking up your time. That hasn't changed; if anything it's gotten worse due to 12/5 work cycles in the marketing research business, and you need to be available to answer questions and emails on the weekend. You never quite get away, even when you're abroad. The Internet is both a blessing and a curse there. But it's the price you pay for being the "boss" (even if you're the only employee most of the time).

When we actually do move, I may see if I can move in the HT equipment early and "design from scratch" our listening room, as much as possible. Maybe I'll run a contest here if we get that far....

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1806 of 10862 Old 03-04-2013, 03:45 PM
AVS Special Member
 
jkasanic's Avatar
 
Join Date: Dec 2006
Posts: 1,137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 57
Quote:
Originally Posted by Pres2play View Post

Well, finally, here are a couple of graphs. Please refer to drawing for microphone positioning. Looks like you were right again, Jerry. The best listening spot (or least offensive) appears to be position 4, which is about 2.5 feet from the back wall. This is all with no eq and Anti-Mode in bypass.



 

 

Might as well try the full 3.5 ft that your standing wave graph showed now that you're in no man's land with your stool (as Jerry suggested)?! tongue.gif

 

At least it's good to see another example of theory supported by measurement.  In case you hadn't read far enough back, I have a severe null at 40Hz which was indicated by my standing wave graph.  Needless to say, I've been on measurement hiatus while I attend to some modifications to my false wall to relocate the sub to the middle of my front wall.  At least now I'll be prepared when I finally take the plunge into dual SubM's as I'll leave space for those with this round of modifications for when I retire my current single sub! biggrin.gif

jkasanic is offline  
post #1807 of 10862 Old 03-04-2013, 04:31 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
I just went into the data and ran the spectrogram. Same settings and source data as the waterfall:


And for comparison, here's my last waterfall:


I'm curious what this tells me/us differently than we don't already know from the waterfall? Besides a less boring, prettier chart cool.gif


And since we're on the subject of rabbit holes, I'll live dangerously and plot my ETC impulse graph. Left speaker only, no Audyssey run (wonder if I want to run this with Audyssey)


OK, maybe I'm _not_ done quite yet, not with all those above -20 db+ peaks!. I think I'd better look into picking up that Amazon Prime string LOL...but I have a practical problem. Treating a hard surface (a ceiling, IOW) is one thing. But to the left of the speaker, off angle, is our dining room, which is open to the living room (no walls). It's not like I'm going to hang pink fluffies on a dining room chair...and I can't exactly turn the dogs or the family into stationary room treatments....rolleyes.gif. Maybe if I'm lucky I can throw a blanket over the glass table and see if it helps:p

Regardless, it's awfully cool to remote into my home PC and plot stuff without being there. I never could have done this with OmniMic!

Thoughts?

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1808 of 10862 Old 03-04-2013, 04:58 PM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,831
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 244 Post(s)
Liked: 650

I don't think an open space would cause a reflection.  When my batteries are recharged, I'm going to delve back into the ETC graph and see if I can identify and temporarily treat some of the reflections.

AustinJerry is online now  
post #1809 of 10862 Old 03-04-2013, 05:10 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by AustinJerry View Post

I don't think an open space would cause a reflection.  When my batteries are recharged, I'm going to delve back into the ETC graph and see if I can identify and temporarily treat some of the reflections.

I don't think it's the open space either...but maybe the dining room table+chairs. Enjoy your recharging tongue.gif

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1810 of 10862 Old 03-04-2013, 05:43 PM
AVS Special Member
 
Pres2play's Avatar
 
Join Date: Jun 2008
Location: NYC
Posts: 1,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 43
Quote:
Originally Posted by jkasanic View Post

Might as well try the full 3.5 ft that your standing wave graph showed now that you're in no man's land with your stool (as Jerry suggested)?! tongue.gif

At least it's good to see another example of theory supported by measurement.  In case you hadn't read far enough back, I have a severe null at 40Hz which was indicated by my standing wave graph.  Needless to say, I've been on measurement hiatus while I attend to some modifications to my false wall to relocate the sub to the middle of my front wall.  At least now I'll be prepared when I finally take the plunge into dual SubM's as I'll leave space for those with this round of modifications for when I retire my current single sub! biggrin.gif

Sdurani also suggested 1/3rd point. I'll try the mic there and see if I can get a smoother roll-off at 30 Hz. I may end up using an AVR with some type of room correction instead of moving the couch. I want to even out the response - at least across the seats. You can see what I mean from the screen shots.



position 1 (red) vs 4 (blue)


Did you post any pics of your layout? Once I'm comfortable with REW I will think about replacing my single sub with two subs with larger drivers.
Pres2play is offline  
post #1811 of 10862 Old 03-04-2013, 05:49 PM
AVS Special Member
 
Pres2play's Avatar
 
Join Date: Jun 2008
Location: NYC
Posts: 1,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 43
What is the method for adding text to the graphs in REW? This is so much easier on the eyes.
Pres2play is offline  
post #1812 of 10862 Old 03-04-2013, 08:22 PM
Senior Member
 
ironhead1230's Avatar
 
Join Date: Jan 2006
Location: Laurel, MD
Posts: 428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 46
I recently received a Minidsp UMIK-1 mic and sent it to CSL to have it calibrated. Thought some might be interested in seeing a comparison between the stock minidsp calibration and what came from CSL. I also included the response of my CSL calibrated EMM-6 mic. I will be trying to get new measurements soon to compare the UMIK and EMM6 and to finally finish tweaking my dual subs and speaker placement so I can start on some room treatments. I guess I'm another that will soon fall down the rabbit hole. smile.gif



ironhead1230 is offline  
post #1813 of 10862 Old 03-04-2013, 08:28 PM
AVS Addicted Member
 
sdurani's Avatar
 
Join Date: Oct 2001
Location: Monterey Park, CA
Posts: 18,818
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 551 Post(s)
Liked: 633
Quote:
Originally Posted by Pres2play View Post

Sdurani also suggested 1/3rd point.
Yup, odd divisions (thirds, fifths) of room dimensions are good locations for seating, since frequency response has the least variation in those areas (smaller peaks and dips). By comparison, even divisions (halves, quarters, sixths) of room dimensions are good locations for subs and speakers, as we've already seen in this thread.

Sanjay
sdurani is online now  
post #1814 of 10862 Old 03-04-2013, 08:40 PM
AVS Special Member
 
LastButNotLeast's Avatar
 
Join Date: Feb 2007
Location: 08077
Posts: 4,401
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 96 Post(s)
Liked: 217
Quote:
Originally Posted by ironhead1230 View Post

I recently received a Minidsp UMIK-1 mic and sent it to CSL to have it calibrated. Thought some might be interested in seeing a comparison between the stock minidsp calibration and what came from CSL. I also included the response of my CSL calibrated EMM-6 mic. I will be trying to get new measurements soon to compare the UMIK and EMM6 and to finally finish tweaking my dual subs and speaker placement so I can start on some room treatments. I guess I'm another that will soon fall down the rabbit hole. smile.gif

So the calibrated UMIK and the calibrated EMM-6 bear no resemblance to each other?! confused.gif

 

Ancient proverb: A man with one watch knows what time it is; a man with two can never be sure.


Downloadable FREE demo discs:
http://www.avsforum.com/t/1475769/de...ently-authored 

Did you really need to quote that entire post in your reply?
LastButNotLeast is offline  
post #1815 of 10862 Old 03-05-2013, 02:30 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by sdrucker View Post

I just went into the data and ran the spectrogram. Same settings and source data as the waterfall:


And for comparison, here's my last waterfall:


I'm curious what this tells me/us differently than we don't already know from the waterfall? Besides a less boring, prettier chart cool.gif


And since we're on the subject of rabbit holes, I'll live dangerously and plot my ETC impulse graph. Left speaker only, no Audyssey run (wonder if I want to run this with Audyssey)


OK, maybe I'm _not_ done quite yet, not with all those above -20 db+ peaks!. I think I'd better look into picking up that Amazon Prime string LOL...but I have a practical problem. Treating a hard surface (a ceiling, IOW) is one thing. But to the left of the speaker, off angle, is our dining room, which is open to the living room (no walls). It's not like I'm going to hang pink fluffies on a dining room chair...and I can't exactly turn the dogs or the family into stationary room treatments....rolleyes.gif. Maybe if I'm lucky I can throw a blanket over the glass table and see if it helps:p

Regardless, it's awfully cool to remote into my home PC and plot stuff without being there. I never could have done this with OmniMic!

Thoughts?

 

I think the spectogram and the waterfall tell us the same thing AFAICT - but the spectogram is like the waterfall 'viewed from above' IYKWIM.

 

Those reflections look typical of an untreated room. They will likely be causing your imaging to be less than precise. Maybe also making dialogue a bit more difficult to follow sometimes. I was astounded at the difference in my room when I got rid of (most of) them.

kbarnes701 is offline  
post #1816 of 10862 Old 03-05-2013, 04:45 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,831
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 244 Post(s)
Liked: 650

For those of you who asked the question, "How do I calibrate my microphone without an SPL", I found the answer over on HTS:

 

"If a) your mic calibration includes its sensitivity figure (e.g. -39 dBV wrt 94 dB SPL), and you know b) the gain setting of your mic preamp and c) the full scale sensitivity of your A/D convertor, you can work it out.

You also need a way to see what signal with respect to full scale is coming out of your convertor."

 

Pretty simple, isn't it?

 

confused.gif

 

AustinJerry is online now  
post #1817 of 10862 Old 03-05-2013, 05:53 AM
Advanced Member
 
JD in NJ's Avatar
 
Join Date: Jan 2012
Location: Northern NJ
Posts: 645
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 35
Quote:
Originally Posted by AustinJerry View Post

For those of you who asked the question, "How do I calibrate my microphone without an SPL", I found the answer over on HTS:

"If a) your mic calibration includes its sensitivity figure (e.g. -39 dBV wrt 94 dB SPL), and you know b) the gain setting of your mic preamp and c) the full scale sensitivity of your A/D convertor, you can work it out.


You also need a way to see what signal with respect to full scale is coming out of your convertor."


Pretty simple, isn't it?

confused.gif


 

That makes me think of this video. http://www.youtube.com/watch?v=Ac7G7xOG2Ag

JD in NJ is offline  
post #1818 of 10862 Old 03-05-2013, 06:29 AM
Senior Member
 
ironhead1230's Avatar
 
Join Date: Jan 2006
Location: Laurel, MD
Posts: 428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 46
Quote:
Originally Posted by LastButNotLeast View Post

So the calibrated UMIK and the calibrated EMM-6 bear no resemblance to each other?! confused.gif

Ancient proverb: A man with one watch knows what time it is; a man with two can never be sure.

I don't think you are looking at the graphs correctly. These basically show the mics uncorrected response compared to CSL's reference mic. I would not expect the UMIK and EMM6 to look the same. The interesting part is the difference between the minidsp and CSL calibrations. We will not know how close they measure until I actually take some measurements. wink.gif
ironhead1230 is offline  
post #1819 of 10862 Old 03-05-2013, 06:41 AM
AVS Special Member
 
LastButNotLeast's Avatar
 
Join Date: Feb 2007
Location: 08077
Posts: 4,401
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 96 Post(s)
Liked: 217
Quote:
Originally Posted by ironhead1230 View Post

We will not know how close they measure until I actually take some measurements. wink.gif

For which I am waiting with bated breath.

Thanks.

Michael


Downloadable FREE demo discs:
http://www.avsforum.com/t/1475769/de...ently-authored 

Did you really need to quote that entire post in your reply?
LastButNotLeast is offline  
post #1820 of 10862 Old 03-05-2013, 10:45 AM
AVS Special Member
 
Pres2play's Avatar
 
Join Date: Jun 2008
Location: NYC
Posts: 1,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 43
Quote:
Originally Posted by Pres2play View Post

What is the method for adding text to the graphs in REW? This is so much easier on the eyes.

I found it.

For those of you new to REW (like me), you can add text, title information and the legend, in the Save Graph Image box, which pops up when you hit the Capture Image button next to the graph. The information will show up at the top of the graph in the image that you save.
Pres2play is offline  
post #1821 of 10862 Old 03-05-2013, 10:56 AM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by kbarnes701 View Post

I think the spectogram and the waterfall tell us the same thing AFAICT - but the spectogram is like the waterfall 'viewed from above' IYKWIM.

Those reflections look typical of an untreated room. They will likely be causing your imaging to be less than precise. Maybe also making dialogue a bit more difficult to follow sometimes. I was astounded at the difference in my room when I got rid of (most of) them.

Also, this is w/o Audyssey, because on Sunday, I hadn't run L, C, or R only post-Audyssey (just with subs). Not sure how much Audyssey will help, but I need to rerun, say, the left speaker or center, without the subs to get the data for it as per Jerry's REW Guide. What did you do, Keith: leave Audyssey on but turn off your subs?

I don't find center channel dialog that hard to follow except for older films at low volumes (say below -25 or so), even with DEQ engaged, and I don't go for fripperies like Dialog Enhancer (although I'll sometimes raise the center + 1 db, even though that's "preference" rather than "reference'). Maybe this indeed is a case where you don't realize what's broken until you see what "fixed" means with at least the treatments I can "hopefully" get away with. I can do a little tweaking of the CC and mains angle to see if it helps with reflections, but since I already have good post-calibration FR for the most part, treatments may be more productive.

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1822 of 10862 Old 03-05-2013, 11:05 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by AustinJerry View Post

For those of you who asked the question, "How do I calibrate my microphone without an SPL", I found the answer over on HTS:

 

"If a) your mic calibration includes its sensitivity figure (e.g. -39 dBV wrt 94 dB SPL), and you know b) the gain setting of your mic preamp and c) the full scale sensitivity of your A/D convertor, you can work it out.

You also need a way to see what signal with respect to full scale is coming out of your convertor."

 

Pretty simple, isn't it?

 

confused.gif

 

 

Crystal clear eh?  Whereas what I have to do is a) open the REW SPL meter, b) press calibrate and then c) adjust my AVR MV while observing my SPL. Hmm...

kbarnes701 is offline  
post #1823 of 10862 Old 03-05-2013, 11:10 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by sdrucker View Post

Also, this is w/o Audyssey, because on Sunday, I hadn't run L, C, or R only post-Audyssey (just with subs). Not sure how much Audyssey will help, but I need to rerun, say, the left speaker or center, without the subs to get the data for it as per Jerry's REW Guide. What did you do, Keith: leave Audyssey on but turn off your subs?
 

 

 

 

To measure L, C and R?  Yes, turn the subs off at their power switch. 

 

Quote:
I don't find center channel dialog that hard to follow except for older films at low volumes (say below -25 or so), even with DEQ engaged, and I don't go for fripperies like Dialog Enhancer (although I'll sometimes raise the center + 1 db, even though that's "preference" rather than "reference'). Maybe this indeed is a case where you don't realize what's broken until you see what "fixed" means with at least the treatments I can "hopefully" get away with. I can do a little tweaking of the CC and mains angle to see if it helps with reflections, but since I already have good post-calibration FR for the most part, treatments may be more productive.

 

Frequency response is only a part of the story. The ECT and waterfalls are, arguably, more important than striving to get a ruler flat FR. Those reflections you are seeing are really messing with your imaging, causing it to be a lot less precise and pinpoint than it really can be. I was amazed when I installed my treatments at how much the image snapped into focus - the precision is incredible now. Audyssey helps in this regard but there are limits as to what it can in the time domain - treatments are the real solution. You may not be able to accommodate them right now, but you can plan for them in your new room when you move house.

kbarnes701 is offline  
post #1824 of 10862 Old 03-05-2013, 11:11 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,831
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 244 Post(s)
Liked: 650

As far as reflections go, we don't know the difference reflections are causing until we run a comparison.  Fortunately, it is not that difficult or expensive.  First, we need to understand what is causing the reflections (the string technique).  Once we have identified the potential source of the first one or two bad reflections, we can use a make-shift treatment of one or more pieces of R-30 insulation, which is available from Home Depot in 9"-thick rolls for less than $10.  Cut a few squares, tape them in place, and re-run the ETC measurement.  Once the reflection is tamed, leave the temporary treatment in place long enough to listen to your system and see if you can hear the difference.  IMO, music is a better test to listen for the effects of reflections than movies.

 

If you can hear the difference, then you know the benefit of treatments before you spend the money.

 

Also, once you have identified the source of the reflection using the method above, remember to run several bandwidth-limited ETC measurements to see what frequency range needs to be tamed.  As you probably know, different treatments target different frequency ranges.

AustinJerry is online now  
post #1825 of 10862 Old 03-05-2013, 11:13 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,831
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 244 Post(s)
Liked: 650
Quote:
Originally Posted by kbarnes701 View Post

 

 

 

To measure L, C and R?  Yes, turn the subs off at their power switch. 

 

 

Frequency response is only a part of the story. The ECT and waterfalls are, arguably, more important than striving to get a ruler flat FR. Those reflections you are seeing are really messing with your imaging, causing it to be a lot less precise and pinpoint than it really can be. I was amazed when I installed my treatments at how much the image snapped into focus - the precision is incredible now. Audyssey helps in this regard but there are limits as to what it can in the time domain - treatments are the real solution. You may not be able to accommodate them right now, but you can plan for them in your new room when you move house.

 

Keith, have you posted an ETC measurement of your listening room since the latest round of treatments?  And a fresh waterfall?

AustinJerry is online now  
post #1826 of 10862 Old 03-05-2013, 11:23 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,647
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 588 Post(s)
Liked: 1283
Quote:
Originally Posted by AustinJerry View Post

 

Keith, have you posted an ETC measurement of your listening room since the latest round of treatments?  And a fresh waterfall?

 

 

 

kbarnes701 is offline  
post #1827 of 10862 Old 03-05-2013, 01:12 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by kbarnes701 View Post



To measure L, C and R?  Yes, turn the subs off at their power switch. 


Frequency response is only a part of the story. The ECT and waterfalls are, arguably, more important than striving to get a ruler flat FR. Those reflections you are seeing are really messing with your imaging, causing it to be a lot less precise and pinpoint than it really can be. I was amazed when I installed my treatments at how much the image snapped into focus - the precision is incredible now. Audyssey helps in this regard but there are limits as to what it can in the time domain - treatments are the real solution. You may not be able to accommodate them right now, but you can plan for them in your new room when you move house.

We're also likely to have wooden floors due to resale value, which will raise a whole new set of bass/sub issues than today's (wall to wall carpeting in the living room in the condo). Of course, with small dogs, wooden floors are...more hygenic.

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
post #1828 of 10862 Old 03-05-2013, 01:18 PM
AVS Special Member
 
angryht's Avatar
 
Join Date: Aug 2004
Location: Omaha, NE
Posts: 1,318
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
I'm gonna dive into the fish bowl to hopefully show how a seemingly small change in position can change the frequency response. Also, any help with respect to where to go from here.

My room layout (there is a dimension error, I think the back of the room is actually 9'-4" wide, not 9'-6"):


A graphical representation of the room modes including the location of the speakers and the 2 listening positions to be compared:

Please note that the there are 2 different widths shown because as you can see from my room layout, the front is 8' and the back is 9'-4". The arrows are the listening positions and the rectangles are the speakers. My center channel is flipped vertical.


Here are the SPL graphs comparing the center channel (position 1&2) and the left and right (position 1&2). Any comments would be appreciated. I've gone through this exercise once before over at HTS but a lot of it was figuring out how to use REW.


I looks to me like I've improved the frequency response by quite a bit but this stuff can drive me nuts. Move an inch or 2 in any direction and things really change a lot. Plus the fact that my room is tiny.

-Greg
angryht is offline  
post #1829 of 10862 Old 03-05-2013, 01:18 PM
AVS Special Member
 
Selden Ball's Avatar
 
Join Date: Jan 2001
Location: upstate NY
Posts: 6,459
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Liked: 327
sdrucker,

Large throw-rugs at the floor's reflection points should help some. Coil rugs might be appropriate: some are quite thick.

Selden
Selden Ball is offline  
post #1830 of 10862 Old 03-05-2013, 01:25 PM
AVS Club Gold
 
sdrucker's Avatar
 
Join Date: Feb 2006
Location: Chicago, IL
Posts: 2,049
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 120
Quote:
Originally Posted by Selden Ball View Post

sdrucker,

Large throw-rugs at the floor's reflection points should help some. Coil rugs might be appropriate: some are quite thick.

What I thought...but we'll cross the bridge when we get there. We're not moving for probably a good year at least, and right now the FR is in relatively good shape, at least (and I wonder how much of that is due to the fully carpeted room with my configuration). Impulse response is a different issue.

Stuart

 

Denon 4311 with XT32 and Audyssey Pro

Oppo 93 and 103

Panasonic VT50

Sherwood R-972 with its version of the Trinnov Optimizer

MiniDSP 10x10 HD

PSB Imagine T2, Center, and Surrounds (as of 5/2014); HSU ULS-15 subs (2)

 

The Audyssey FAQ Guide can be found here:

http://www.avsforum.com/...

sdrucker is online now  
Reply Audio theory, Setup and Chat

Tags
Dayton , Dayton Audio , Room Equilizer Wizard Rew

User Tag List

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