or Connect
AVS › AVS Forum › Audio › Audio theory, Setup and Chat › Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs
New Posts  All Forums:Forum Nav:

Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 93

post #2761 of 9564

Try this:  http://www.avsforum.com/t/1366724/comparison-of-small-room-acoustic-models-for-home-listening-spaces

Gear mentioned in this thread:

post #2762 of 9564

I subscribed to that thread and will put it on my reading list. I just realized that Jason said in his post that you'll find a link, so I was incorrectly assuming Jason documented the models in this thread.

My mistake.

Mark

Edit: Corrected due to my mistaken reading of a post.
Edited by giomania - 5/2/13 at 10:58am
post #2763 of 9564
Quote:
Originally Posted by giomania View Post

Perhaps the document would be useful to some in this thread, once it has been completed and subsequently vetted.

Mark

 

Mark - I can't speak for anyone else obviously, but I would love to have a copy of that document!  Please let us know when it is ready!

post #2764 of 9564
Quote:
Originally Posted by jevansoh View Post

... I'm all for an adult conversation with points to argue from reasonable and respectful individuals that are passionate about their field, but when folks who have an ulterior motive chime in only to disagree, start arguments, and confuse people that are just starting to learn, it's a real turn off for me and them.


For those of you who are NOT interested in moving forward in this fashion and are here to promote your name, company, products, or simply those of you who wish to be contrarian, I humbly suggest you bow out now. In fact, one person stated he'd do just that near the beginning of this thread and has not been a man of his word and has even gone on to badmouth me in other threads!!


Also, please don't fall into the trap of listening to the folks that are the loudest, IE: The folks with the most post counts and post in this thread the most often. If someone is here trying to dissuade you from the original goals and intent of this thread and move you to another form of thinking, their intentions probably aren't the best and that is not someone I'd want to associate with, but you must decide on your own what you believe and what your goals are.
 

 

J - I couldn't agree more with the above selections from your long post. I am grateful for the 'Ignore' button, but wish it worked on quoted responses too.

 

Thanks for the post and also for the suggestions of books to look at too. So far I have only the Master Handbook but it has been very helpful to me. I will seek out the others you mention.  Also thanks for the condensed version of 'The Life of J' - very interesting. You clearly have a lot of energy and have done well for yourself and I applaud you for it.

 

Quote:
The second part has always been Choosing an acoustical model. Folks need to start doing this. Although Keith, for instance, hasn't specified this, through his last several comments he has made it clear he prefers an NE (Non-Environment) model for his room. That's great! I can help him achieve that.

 

That is indeed my own preference, J. I wasn't even aware, until recently, that there was a name for what I preferred - I am glad there is as that very fact alone gives it a certain legitimacy! :) I shall research it further. 

post #2765 of 9564
Thread Starter 
Quote:
Originally Posted by kbarnes701 View Post

Quote:
Originally Posted by jevansoh View Post

... I'm all for an adult conversation with points to argue from reasonable and respectful individuals that are passionate about their field, but when folks who have an ulterior motive chime in only to disagree, start arguments, and confuse people that are just starting to learn, it's a real turn off for me and them.



For those of you who are NOT interested in moving forward in this fashion and are here to promote your name, company, products, or simply those of you who wish to be contrarian, I humbly suggest you bow out now. In fact, one person stated he'd do just that near the beginning of this thread and has not been a man of his word and has even gone on to badmouth me in other threads!!



Also, please don't fall into the trap of listening to the folks that are the loudest, IE: The folks with the most post counts and post in this thread the most often. If someone is here trying to dissuade you from the original goals and intent of this thread and move you to another form of thinking, their intentions probably aren't the best and that is not someone I'd want to associate with, but you must decide on your own what you believe and what your goals are.

 

J - I couldn't agree more with the above selections from your long post. I am grateful for the 'Ignore' button, but wish it worked on quoted responses too.

Thanks for the post and also for the suggestions of books to look at too. So far I have only the Master Handbook but it has been very helpful to me. I will seek out the others you mention.  Also thanks for the condensed version of 'The Life of J' - very interesting. You clearly have a lot of energy and have done well for yourself and I applaud you for it.
Quote:
The second part has always been Choosing an acoustical model. Folks need to start doing this. Although Keith, for instance, hasn't specified this, through his last several comments he has made it clear he prefers an NE (Non-Environment) model for his room. That's great! I can help him achieve that.

That is indeed my own preference, J. I wasn't even aware, until recently, that there was a name for what I preferred - I am glad there is as that very fact alone gives it a certain legitimacy! smile.gif I shall research it further. 

You're welcome, Keith.

For those of you wondering why I shared some of this information, it was specifically requested by at least two members of this thread earlier in the thread (a month or two ago) and I felt it necessary to share where most of my knowledge and expertise comes from plus show that I'm not in the "acoustics" business at all and will not be trying to sell anyone anything proving I have no vested interest and only wish to help since in another thread my qualifications by a certain poster were called into question.

I just wanted it to be clear who I am and what my goals are and of course to show there is no ulterior motive with the information I provide.

Thanks Keith and I hope to talk to you more soon.

--J
post #2766 of 9564
Quote:
Originally Posted by JsyBoy View Post

Finally made my way through the whole thread. Many thanks to all for the very helpful information and guides that have been provided. Below are my first set of measurements would really appreciate some opinions on the results. I have tried to follow the guidelines as in the brilliant guide and have spent the last couple of nights playing. I plan on investing in some acoustical treatments possibly GIK products could I please ask which measurements would be best suited to show what treatments I may need

Keep up the good work guys



Nice waterfall!  

post #2767 of 9564
Quote:
Originally Posted by kbarnes701 View Post

Nice waterfall!  
+1 as to "nice". If I read correctly, Jsyboy appears to be investigating treatment options which leads me to believe he doesn't have much in place currently, so may be safe to say that's partially due to having multiple subs (4 if I recall) which would contribute greatly to the response. It would be interesting if you could comment on your sub placement in your room.
Edited by fotto - 5/2/13 at 1:35pm
post #2768 of 9564
Quote:
Originally Posted by AustinJerry View Post

Unfortunately, yes. As I said, the comparison would involve a bit of work, but ultimately, you should want to know which option is better. If you plan on keeping the sub elevated no matter what, then maybe it isn't worth the effort.

I don't recall which AVR you have. Some Denon models allow you to do a network configuration save, so you can save the current calibration, re-position the sub, run a new calibration, and then restore the previous calibration when you elevate the sub again.

No problem moving the subs. I want the best location for bass reproduction. That's why I'm here smile.gif

I have the Onkyo 818 that you recommended. I believe you can store the Audyssey calibration using the 818's front panel, at least that's what I read in the Audyssey 101 guide.
Edited by Pres2play - 5/2/13 at 6:29pm
post #2769 of 9564
Quote:
Originally Posted by fotto View Post

It would be interesting if you could comment on your sub placement in your room.

Due to room constraints the subs are placed behind the listening position on the left and right side walls. They are roughly 2/3rds of the way back away from the screen. I took my time to make sure each stack of two subs was as close as possible to being equal distance away from the MLP. Like kbarnes701 I am based in the UK so my room is on the small side measuring 1584 cubic feet. Overkill perhaps biggrin.gif
post #2770 of 9564
Quote:
Originally Posted by jevansoh View Post

Hi everybody,

For those of you who don't want to wait and don't want to have to figure out who is right or wrong and who to listen to or not on this and many other threads, I highly recommend the following publications:

These are likely available at your local library and are all available in digital format for the Kindle through Amazon. Most of my education comes from reading, interpreting, and applying the knowledge gained in real world situations from these publications.

Acoustic Absorbers and Diffusers: Trevor Cox and Peter D'Antonio - This book is THE Bible on creating and implementing each and every type of absorber and diffuser and is written by the folks from RPG which are the original creators of several products such as the BAD panel and 1D QRD diffuser. There is a lot more to acoustics than just throwing up fuzzy stuff/glass on walls and getting rid of all the reflections and this is the book that will teach you how to design and build the proper acoustical treatments, once you understand exactly what your goals are.

Master Handbook Of Acoustics: I believe most in this thread who are interested in this topic have probably heard of this book. This is where I'd start and in fact where I did start many years ago. This is a great text with introductory information on all the topics I'd like to discuss here eventually.

Sound System Engineering: Don Davis - EVERYTHING you need to know is in this book. It is rather advanced and has yucky math, however, I cannot recommend this text enough. I just bought another copy (older print, but still very useful) on eBay for less than $5.00 for the sole purpose of sharing it/loaning it to whoever may be interested - contact me if you are interested in reading this book and cannot find it at your local library and/or cannot afford the almost $200 asking price.


--J

+1

SSE, especially - an utterly brilliant resource.
post #2771 of 9564
Quote:
Originally Posted by localhost127 View Post

+1

SSE, especially - an utterly brilliant resource.

+10x smile.gif

Davis/SynAudCon=superb

It's troubling so few understand that.

edit ... troubling, yes in general, but that's a reflection of this thread and those dedicating effort toward it ... good stuff here
post #2772 of 9564
Quote:
Originally Posted by FOH View Post

+10x smile.gif

Davis/SynAudCon=superb

It's troubling so few understand that.

it boggles the mind that so many are utterly unaware of what was happening re: the state of acoustics back in the heady days (how things came to be) ... and just who Davis was and how much he contributed by having some of the greatest minds in the industry come together to discuss and present in a cooperative and collaborative fashion. it was all about discovery and exploration.

take a wild guess which user here recently went out of his way to attempt to discredit Davis in a previous discussion a few months back. 'oblivious' is putting it mildly!!!
post #2773 of 9564

 

All the bickering aside in that thread, I probably read thru the first +100 posts and I still couldn't tell you the specifc differences between LEDE/RFZ and NE models particularly as they relate to measurements we all have obtained using REW and USB mics.  I resorted to Google but I'm still confused which model I would prefer in my listening space?!  The NE model (that Jason said Keith is after) appears to require a very reflective front wall which is in contradiction to some of the advice I was given about treating the front wall heavily with fiberglass or rockwool equivalent?! confused.gif

 

I'm very interested to advance this thread as Jason suggested in his previous post or even take the discussion of the various room models and how best to achieve them to a new thread (if that's what is decided), but as someone that is very new to acoustic measurement and modeling, I think it would benefit a lot of members following this thread to try and summarize the major differences of at least these two models?  Perhaps I'm in the minority so I will continue researching on my own but something tells me others may be just as confused as I am right now...

post #2774 of 9564
Quote:
Originally Posted by AustinJerry View Post

You don't provide enough information on your first issue for me to understand what exactly you are experiencing. Can you provide more detail, and perhaps screen shots of any warning or error messages?

Regarding the second issue, I experience this as well. During a typical REW session, it may happen as often as several times. Like you, I want to prevent any potential damage to the speakers, so I have gotten in the habit of keeping the cursor poised over the "Cancel" button. So what causes this? My theory is that it is an interaction between the ASIO beta drivers and something in the laptop (I don't think this is a REW issue, or everyone would be experiencing it). To support this theory, I can take numerous measurements in succession without changing the output source in the REW preferences screen and never get the distorted sound. Then, when I change the output source, e.g. from left speaker to right speaker, the first measurement produces the distorted sound. I fix it by forcing an HDMI handshake, i.e. unplugging and re-inserting the HDMI cable. To be honest, this is yet another annoyance that has detracted from the so-called "simplicity" of using ASIO/HDMI connections. I never had such issues using the legacy REW hardware.

If the issue makes using REW difficult, I would recommend switching to the Java interface and abandoning HDMI/ASIO completely.

Thanks - I thought in my item "1", I referenced my other post here stating the headroom error dialog shown. That's what I was getting consistently (the REW low headroom error message) and since the MV was approaching single digits (-10 to -6) that seemed to be very high.

Maybe its just a learning curve / getting used to the REW / or my AVR settings at the time was set incorrectly, because during another REW session, I was measuring 80dB with the MV at -13 (a few weeks ago) and now I am consistently getting 80dB with a MV at -22 and I'm not getting any headroom errors. I duuno if its my SPL meter used to calibrate but I put in a new battery and things seem to be working as I have run a ton of sweeps from scratch with Audyssey on / off in stereo only mode and the -22 MV seems to be the number. So for now I'll keep plugging away.

The cracking sweeps sounds continue, but I'm now used to the tell-tale signs of this and am ready with the mute + canceling the sweep before it gets loud. I typically just switch the output source to a different speaker and then switch back to the speaker I want to measure before selecting measure and that seems to "fix" the distortion issue - not every time though.

Additional questions:
1.. I’m using this Radeon HD 6570 graphics card (in my Dell tower)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150580

and am using its HDMI output to my AVR as the REW connection. Are there any issues with this method?

2. I'm using a Dayton EMM-6 with the MicMate USB and I want to purchase a replacement. Any recommendations on (USB) either the cross spectrum UMM-6 or the UMIK-1?

Thanks
Edited by Ratamacue - 5/4/13 at 6:58am
post #2775 of 9564
REW v5.01 Beta 17 released for download:

http://www.hometheatershack.com/forums/downloads-area/47460-v5-01-beta-downloads-asio-support.html#post610128

Includes a room simulator for rectangular rooms that simulates the interaction of up to 4 subwoofers and 2 speakers:

http://www.hometheatershack.com/roomeq/wizardhelpv5/help_en-GB/html/modalsim.html



Note the adjustable parameters in the pic above.

http://www.hometheatershack.com/forums/rew-forum/67316-room-simulation.html
post #2776 of 9564
Finally got around to doing some new measuring. First up is a comparison of my old CSL calibrated EMM6 mic with a tascam 122 and a CSL calibrated Umik-1 usb mic. They were taken from my laptop which does not have HDMI. So for the Umik, I used the tascam for output. I did my best to not move the mic stand when switching mics. Neither measurement uses a soundcard calibration.



Same data just offset.


There are some differences below 25hz. The EMM6 has larger corrections than the Umik. I think I've posted this before, but here are the corrections from CSL.



I did run into some issues during the Umik measurements. When I started taking higher level sweeps, I noticed some distortion around 60-120hz. I isolated it to the left speaker and could recreate the distortion during a sweep or an 80hz sine wave. I have not heard any distortion from this speaker during any program material or during any previous measurement sessions. Then I noticed a ticking sound coming from the speaker in between sweeps that went away when I changed inputs on the AVR. I powered on the right speaker and noticed the same tick. I've done previous measurements using the same hardware, so I figured it was a loose cable or some sort of feedback from the laptop. I didn't do any more troubleshooting because I was running out of time and still wanted to try measuring from my HTPC.

So next I setup REW on my HTPC using HDMI output to my AVR. I was unable to get any output using the ASIO drivers so I just used the java drivers.



Something strange is that the measurements from my laptop all have 1/48 smoothing, but from my htpc, the measurements have no smoothing. Next I tried to see fix the dips between 60-100hz, hoping they were just an integration issue between the 2 subs and the speakers.

Sub 1 alone, 80hz crossover



Sub 2 alone, 80hz crossover



After trying a bunch of different distances, this is the best I came up with.



Then I tried integrating the subs with the left and right speakers. I really couldn't get a "best" response by changing the distances. It really just moved the dips to different frequencies. The room is not a dedicated theater and is open to the entire floor, so I don't think the response is that bad, but definitely have more work to do. At some point this year, will be looking to add some room treatments.

Subs and left speaker



Subs and right speaker



Subs, left and right speakers



On a side note, I have no idea how anyone takes sweeps at 120+db. The highest level sweep I did was just over 100db and my windows, sliding glass door, anything hanging on the walls and dishes in the kitchen were already shaking like crazy.

-Mike
post #2777 of 9564

Nice report, Mike.  Is the UMIK-1 available for purchase from CSL, or did you just send it in to be calibrated?  I recall doing the same room measurements with both my new UMM-6 and my older EMM-6, both CSL calibrated, and while I can't locate the comparison graphs, the measurements were pretty close.  IOW, I don't see a reason for concern, nor do I see a reason for concern between your two mic's.

 

Getting the bass dialed in when you have a non-dedicated listening room with an open floor plan is definitely a challenge.  I'm sure treatments will produce some improvement, but the important think is how it sounds to you.  BTW, it's not clear--the sub distance tweak is usually done when playing both subs plus the center channel.  I get the impression you were tweaking the distance of the two subs when only the subs are playing.  The distance adjustment is supposed to improve the splice between the subs and the satellite speakers (starting with the center, and then fine-tunes using L+R).

 

You don't mention--are you using any kind of correction, e.g. Audyssey?  And how about providing a waterfall graph?  (Measure L+R+Subs--see the guide for specific instructions.)  Also, even though it is an open floor plan, do you have the measurements?  This might provide some insight WRT proper placement for both the subs and the mains.

post #2778 of 9564
Quote:
Originally Posted by ironhead1230 View Post

Something strange is that the measurements from my laptop all have 1/48 smoothing, but from my htpc, the measurements have no smoothing.
That is controlled by the 'Allow 96 PPO Log Spacing' option in the Analysis Preferences.

The Allow 96 PPO Log Spacing selection controls whether REW is permitted to convert frequency responses from linearly spaced data to logarithmically spaced data at 96 points per octave. The FFT that calculates the frequency responses produces data that is linearly spaced in frequency, i.e. there is a constant frequency step from each value to the next. For the high frequency parts of responses this means there are a very large number of points, using a lot of memory but not contributing anything useful to the displayed data. When this option is selected (it is on by default) REW will automatically convert frequency responses to more efficient logarithmic spacing with 96 data points in each octave of the response if this will reduce memory usage (which is usually the case for sweeps that end above 300Hz or so). As part of the conversion process REW first applies a 1/48th octave smoothing filter to the data to remove any high frequency combing from the response. The conversion takes place on any new measurement or when an IR Window is applied. Whether a measurement is log spaced or linearly spaced can be seen by bringing up the measurement info window by clicking the info button in the toolbar.
post #2779 of 9564
^ Thank you, John. Your participation in this thread is greatly appreciated!
post #2780 of 9564
Quote:
Originally Posted by ironhead1230 View Post

I really couldn't get a "best" response by changing the distances. It really just moved the dips to different frequencies.
Hi Mike,

Did you check if polarity of the sub helps with the dips? Could try the old method: park a sine wave at the crossover frequency. Flip polarity and or tweak delays such that at one polarity you create the deepest null possible, then invert to obtain good summation. If the sub is at different distances from the L and R speakers, find the delays needed for both then split the difference.
post #2781 of 9564
Quote:
Originally Posted by AustinJerry View Post

Nice report, Mike.  Is the UMIK-1 available for purchase from CSL, or did you just send it in to be calibrated?  I recall doing the same room measurements with both my new UMM-6 and my older EMM-6, both CSL calibrated, and while I can't locate the comparison graphs, the measurements were pretty close.  IOW, I don't see a reason for concern, nor do I see a reason for concern between your two mic's.

I don't think it is available for purchase. I was one of the early purchasers and got a good deal to send it to CSL so he could look at it. I'm not that worried about the differences down low. At this point I figure unless I shell out the money to buy an earthworks mic or something similar, anything measured at low frequencies is going to be a bit suspect. Having CSL calibrate the mic lets me know I'm at least in the ballpark.

Quote:
Originally Posted by AustinJerry View Post

Getting the bass dialed in when you have a non-dedicated listening room with an open floor plan is definitely a challenge.  I'm sure treatments will produce some improvement, but the important think is how it sounds to you.  BTW, it's not clear--the sub distance tweak is usually done when playing both subs plus the center channel.  I get the impression you were tweaking the distance of the two subs when only the subs are playing.  The distance adjustment is supposed to improve the splice between the subs and the satellite speakers (starting with the center, and then fine-tunes using L+R).

You don't mention--are you using any kind of correction, e.g. Audyssey?  And how about providing a waterfall graph?  (Measure L+R+Subs--see the guide for specific instructions.)  Also, even though it is an open floor plan, do you have the measurements?  This might provide some insight WRT proper placement for both the subs and the mains.

I should have added more details in my original post. I'm using a Denon 4311 and each sub is on a separate sub out so I can adjust each sub's distance individually. I was surprised to see the large dips in their combined response without the speakers. That's why I first adjusted the distances to get the subs playing nice together, before doing anything with the speaker interaction. I should have also measured the center with the subs, but just ran out of time. I do currently have XT32 engaged, but it's probably time for another run through.

Here is an approximate floor plan. The walls with arrows through them are not full walls. They are only about 4 ft high. Ceiling is 9ft. Staircase on the left is going up and is open on the left side. The staircase on the right is a regular door size opening going down.



Sub 1 is a submersive F2 and is being used as a center channel stand below the TV
Sub 2 is a submersive HP and is located under the window to the left of the couch
The front 3 speakers are Cat8Cs

Here is a waterfall and decay chart:





-Mike
post #2782 of 9564
Quote:
Originally Posted by JohnPM View Post

That is controlled by the 'Allow 96 PPO Log Spacing' option in the Analysis Preferences.

The Allow 96 PPO Log Spacing selection controls whether REW is permitted to convert frequency responses from linearly spaced data to logarithmically spaced data at 96 points per octave. The FFT that calculates the frequency responses produces data that is linearly spaced in frequency, i.e. there is a constant frequency step from each value to the next. For the high frequency parts of responses this means there are a very large number of points, using a lot of memory but not contributing anything useful to the displayed data. When this option is selected (it is on by default) REW will automatically convert frequency responses to more efficient logarithmic spacing with 96 data points in each octave of the response if this will reduce memory usage (which is usually the case for sweeps that end above 300Hz or so). As part of the conversion process REW first applies a 1/48th octave smoothing filter to the data to remove any high frequency combing from the response. The conversion takes place on any new measurement or when an IR Window is applied. Whether a measurement is log spaced or linearly spaced can be seen by bringing up the measurement info window by clicking the info button in the toolbar.

Thanks. I never changed that setting on either my laptop or htpc so not sure why it would be different, but will check tonight.

-Mike
post #2783 of 9564
Quote:
Originally Posted by Roger Dressler View Post

Hi Mike,

Did you check if polarity of the sub helps with the dips? Could try the old method: park a sine wave at the crossover frequency. Flip polarity and or tweak delays such that at one polarity you create the deepest null possible, then invert to obtain good summation. If the sub is at different distances from the L and R speakers, find the delays needed for both then split the difference.

The submersives do not have a polarity control. I can adjust the distance for each individual sub separately in the AVR.

-Mike
post #2784 of 9564
Om im not smart enough to figure it out but how are you guys choosing multiple outputs to test at the same time? I want to do the left+right+sub but can only select one of them at a time from the output drop down box. Im using ASIO with an HDMI hookup. I did get all the calibration done and got measurements for the left and right and sub all separately. Are you guys just overlaying the three for the waterfall graphs?
post #2785 of 9564
Quote:
Originally Posted by BoogerBomb View Post

Om im not smart enough to figure it out but how are you guys choosing multiple outputs to test at the same time? I want to do the left+right+sub but can only select one of them at a time from the output drop down box. Im using ASIO with an HDMI hookup. I did get all the calibration done and got measurements for the left and right and sub all separately. Are you guys just overlaying the three for the waterfall graphs?

It's relatively simple:
Choose the left and right channels ONLY, and make sure that you have bass management enabled on your AVR (or pre-pro, if you have separates).

If you have Subwoofer(s)=Yes and Speakers run as Small, any signal below the speaker crossover point will be routed to your subwoofers. For example, if you have an 80 Hz crossover, anything below 80 Hz will be routed to your subs.

From that point, you can do a standard waterfall on the measured response for your left and right speakers run as inputs.

Hope that helps.
post #2786 of 9564
Quote:
Originally Posted by ironhead1230 View Post

The submersives do not have a polarity control. I can adjust the distance for each individual sub separately in the AVR.
So then for polarity check, you have to reverse the wiring of the main speaker for this test.

Now that I see your speaker layout, with the sub on the left wall, it makes the distances quite different. Just curious, have you had the sub on the front wall at any point, between the R and C speakers?
post #2787 of 9564
Quote:
Originally Posted by sdrucker View Post

It's relatively simple:
Choose the left and right channels ONLY, and make sure that you have bass management enabled on your AVR (or pre-pro, if you have separates).

If you have Subwoofer(s)=Yes and Speakers run as Small, any signal below the speaker crossover point will be routed to your subwoofers. For example, if you have an 80 Hz crossover, anything below 80 Hz will be routed to your subs.

From that point, you can do a standard waterfall on the measured response for your left and right speakers run as inputs.

Hope that helps.

So measure LF with the sub turned on, unlike what I did earlier, then take a measurement with the RF with the sub turned on, then overlay the two?
post #2788 of 9564
^ Depends on what your objectives are. For a bass decay measurement (waterfall), select both left and right speakers at the same time. Overlaying the separate measurements provides little value.
post #2789 of 9564
That's the thing, I am unable to pick them both, the drop down only allows one at a time.
post #2790 of 9564

There are two drop downs.  Choose the second output in the drop-down under "Timing Reference Output".

 

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Audio theory, Setup and Chat

Gear mentioned in this thread:

AVS › AVS Forum › Audio › Audio theory, Setup and Chat › Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs