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Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 236

post #7051 of 9543
^^^^Glad to hear that Jerry. From all of my research on treatments, GIK has a pretty solid reputation so it's nice to see they stand behind their products. Hopefully, Glenn will report back on whether there were any anomalies with the construction that contributed to the results (or better lack thereof).

Gear mentioned in this thread:

post #7052 of 9543
That's definitely good to hear Jerry. Companies with good customer satisfaction tend to gain more from repeat business and word of mouth.


Max
post #7053 of 9543
Quote:
Originally Posted by AustinJerry View Post
 
Quote:
Originally Posted by kbarnes701 View Post

Jerry - I found that long post of J's to be very clear and very helpful. Perhaps incorporating the 'meat' of it into your Guide would be a good idea, and also save you a bit of work at the same time?

Yes, of course. I am grateful that J summarized the recommendations--his guidelines will be trusted more than anything I could have put together. IMO, a simple link in the guide to J's post will probably be better than my attempt to summarize his recommendations.

 

Personally, I'd prefer you just cut and pasted J's wording in its entirety than using a link. Reason: I print out the Guide as a handy reference to have by me when I am measuring and so a link isn't any use to me. Just my own personal 0.000024 of a Bitcoin.

post #7054 of 9543
Quote:
Originally Posted by AustinJerry View Post

As many of you recall, I conducted a review of the GIK Scopus tuned bass trap recently. After testing, I determined that the traps were not significantly reducing bass ringing at the targeted 40Hz frequency range, and decided to return them. I am pleased to report that GIK accepted the return and credited my account with not only the cost of the traps, but the shipping charges as well. In addition, I received a personal call from Glenn Kuras, President of GIK Acoustics, during which he and I reviewed the REW measurement file and discussed the results of the Scopus evaluation.

I mention this because it is rare to receive such excellent and personalized support from a vendor. I certainly makes me want to continue doing business with them.

 

Fabulous. They could do no more - this kind of customer focus will reward them a thousand times over from the goodwill it creates. Kudos to them!

post #7055 of 9543
Quote:
Originally Posted by kbarnes701 View Post
 

 

Personally, I'd prefer you just cut and pasted J's wording in its entirety than using a link. Reason: I print out the Guide as a handy reference to have by me when I am measuring and so a link isn't any use to me. Just my own personal 0.000024 of a Bitcoin.

 

OK, cut-and-paste it is, then, with the appropriate credits, of course.

post #7056 of 9543
Quote:
Originally Posted by AustinJerry View Post
 
Quote:
Originally Posted by kbarnes701 View Post
 

 

Personally, I'd prefer you just cut and pasted J's wording in its entirety than using a link. Reason: I print out the Guide as a handy reference to have by me when I am measuring and so a link isn't any use to me. Just my own personal 0.000024 of a Bitcoin.

 

OK, cut-and-paste it is, then, with the appropriate credits, of course.

 

Thanks Jerry. I think it helps to make the Guide a 'complete' resource to do it that way.

post #7057 of 9543

The REW Guide has been updated to ver 3.12.  Changes are:

 

 

3.11

Nov 14, 2012

-          Added wording to Spectrogram section (p. 63) clarifying the default settings.

3.12

Nov 16, 2013

-          Added Jevansoh’s tips to the Measurements Guidelines section

 

You can access the Guide by clicking the link in my signature.

post #7058 of 9543
Quote:
Originally Posted by AustinJerry View Post
 

The REW Guide has been updated to ver 3.12.  Changes are:

 

 

3.11

Nov 14, 2012

-          Added wording to Spectrogram section (p. 63) clarifying the default settings.

3.12

Nov 16, 2013

-          Added Jevansoh’s tips to the Measurements Guidelines section

 

You can access the Guide by clicking the link in my signature.

 

Thanks, as ever, Jerry.

post #7059 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

Then why is it different for Neo?
confused.gif
Quote:
Originally Posted by jkasanic View Post

@LBNL: I think because Neo doesn't route the signal from L and R through your C channel. What Roger is trying to say is that the responses you're trying to compare are of different channels (L and R vs C).
Correct! Notice how PLII Movie/Game looks the same as Neo:6 Cinema. Those modes work in a similar fashion for "test tones" anyway. If you go into PLII Music and set the center width control to max, it will look exactly like the Stereo plot.

Bottom line, the center speaker needs some attention, probably how it is placed. Where is it? What is it?
post #7060 of 9543

It's the center that matches the left and right, first generation Pioneers, aimed right at the MLP. I can certainly move it around some.

So I should use PLII movie/game and get FR to be close to stereo/flat?

Thanks.

Michael

post #7061 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

It's the center that matches the left and right, first generation Pioneers, aimed right at the MLP. I can certainly move it around some.
So I should use PLII movie/game and get FR to be close to stereo/flat?
Thanks.
Michael

Is the center sitting on a shelf or ledge of any kind? If so, do you have it sitting over the edge?
post #7062 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

It's the center that matches the left and right, first generation Pioneers, aimed right at the MLP. I can certainly move it around some.
So I should use PLII movie/game and get FR to be close to stereo/flat?
Thanks.
Michael

Measure L+Sub and C+Sub. If there's a large dip in the crossover region of one combination but not the other then the polarity of one speaker is probably reversed.
post #7063 of 9543
Quote:
Originally Posted by jkasanic View Post


Is the center sitting on a shelf or ledge of any kind? If so, do you have it sitting over the edge?
 
Yes, and yes.
Quote:
Originally Posted by markus767 View Post


Measure L+Sub and C+Sub. If there's a large dip in the crossover region of one combination but not the other then the polarity of one speaker is probably reversed.

 

Using a legacy system, so can't (easily) do that. But it's my project for the week.

Thanks for the help and suggestions. Graphs (20 to 300, no smoothing ;)) to follow.

Michael

post #7064 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

Quote:
Originally Posted by markus767 View Post

Measure L+Sub and C+Sub. If there's a large dip in the crossover region of one combination but not the other then the polarity of one speaker is probably reversed.

Using a legacy system, so can't (easily) do that. But it's my project for the week.
Thanks for the help and suggestions. Graphs (20 to 300, no smoothing wink.gif ) to follow.
Michael

The legacy part is irrelevant. When you measure L, C or R + sub you just need to make sure bass management is engaged (I.e. Set speakers to small which they should be already). For center, change the mode to Dolby PLII Cinema with both L and R connected). There has been some recent discussion about measuring all 3 together but I'm not sure if there is consensus on the best means to do so yet or not (e.g. Changing width mode in PLII or using all channel stereo). In any case, for now you're just interested in the three separate responses all overlayed on one FR plot. I would show 15-300 unsmoothed and 15-20k Hz at 1/6.
post #7065 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

Using a legacy system, so can't (easily) do that. But it's my project for the week.
Thanks for the help and suggestions. Graphs (20 to 300, no smoothing wink.gif ) to follow.
Michael

Why would this measurement be difficult on a legacy REW system? Measure center+sub by feeding the REW signal to both left and right channels and set output to PLII Cinema.
post #7066 of 9543

Because PLII Cinema produces sound in the left and right channels also, and I don't really want to disconnect the wires (though I can if I really have to).

post #7067 of 9543
This is the crux of your whole issue. When you measure a mono signal split to the left and right channel of your AVR/AVP, it will route sound to the center channel in PLII mode. If you select stereo then each signal is routed to L and R which gives a combined response measurement.
post #7068 of 9543

It is interesting that you mention listening levels. I've found, since treating my room, that I can listen at seemingly endless levels on the MV, in total comfort, even though the SPL meter is telling me that it is way too 'loud' really. It is just so clean and undistorted

os9n8Q

post #7069 of 9543

I will experiment this week. Thanks for the suggestions.

Michael

 

And, as long as I'm still here, does anyone still have a link to the "limp membrane traps" that were talked about a few pages (eons?) back? The search function here is useless and Google takes me everywhere but anywhere productive.

Thanks.

post #7070 of 9543
Quote:
Originally Posted by LastButNotLeast View Post

And, as long as I'm still here, does anyone still have a link to the "limp membrane traps" that were talked about a few pages (eons?) back? The search function here is useless and Google takes me everywhere but anywhere productive.
Thanks.

See here

It was actually the fourth hit on a search of "limp" in this thread. I find the fewer words the better.
post #7071 of 9543

That was it! Thanks.

And a great suggestion, too. I was using "limp membrane traps" and got a million hits on "membrane" and "traps," and the quotes didn't seem to do any good.

Hopefully, we won't get too sidetracked by the "limp" part.

;)

:D

post #7072 of 9543
Quote:
Originally Posted by LastButNotLeast View Post
 

Because PLII Cinema produces sound in the left and right channels also, and I don't really want to disconnect the wires (though I can if I really have to).

 

Sorry, that is not correct.  A mono signal is routed exclusively to the center channel.

post #7073 of 9543

I will continue to experiment; obviously, I'm doing something wrong.

Family matters to attend first, so thanks again to all.

Michael

post #7074 of 9543
I've been reading this thread for a while now (IIRC I joined it at about page 90, time flies) and thought I'd post some graphs up to see what people think. I have, I think, stuck to the spirit of the house rules but I'm not entirely sure what they are at this point in time given recent posts so hopefully you can bear with me smile.gif The one difference to note is that I measure with a loopback (not using USB) hence my IRs/ETCs don't start at 0 because I like to confirm the alignment audyssey comes up with manually via examination of the IRs. I have adjusted time limits on the x axis accordingly though so they should still look the same as yours.

A bit of background info.... My room is my lounge, albeit a lounge that is largely dedicated to the cinema, and is of fairly typical construction for a Victorian house in England (suspended wooden floors, brick walls, 10' ceilings, has an open fireplace). It's not a big room (roughly 14' x 12' x 10'), it has a lot of sofa in it and there is a window behind the MLP... all of which mean that placing treatments is not so easy. Speakers are MK MP150 Mk2 across the front 3 & S150T surrounds. I have a single 15" sub atm using the Fi Q15 driver powered by an inuke, this is powered by a Marantz AV7005/Cinepro 2k6 Mk3 combo. I am currently contemplating a move to a pure (HT)PC solution and replacing audyssey with PC based DRC (have done initial evaluation of acourate), partly because I'm not 100% happy with multeq xt but also because I clearly don't have enough tweakability in my life right now smile.gif

I know that bass decay could be better but I don't intend to consider that until the next time I do more structural work on the house & need to redecorate the room, at this point I will consider replacing the coving with soffit traps along the lengths of the room (corner traps are impossible because they would block the door or the sofa or the shelves). What I'm interested in are any views on the specular reflection side of things, they're obviously not perfectly given that I have no treatments but I tend to think they don't look too bad compared to other untreated rooms. Ultimately it's really just a Q of whether there is anything in here that anyone sees worthy of particular comment. Any views welcome!

L+SW and R+SW frequency response, unsmoothed


R+SW waterfall, noise floor in my room is ~45dB


Full Range L and R only ETC


Full Range L and R only ETC, first 3ms


Floor Plan (NB: rears are moved since I made this pic so they're not 1' above ear height and at 90 degrees to the MLP)


Cheers
Matt
post #7075 of 9543

Welcome to the thread, Matt!  And nice job with the measurement graphs.  I can tell you have been following our recent discussions with regards to the posting conventions.

 

I'm sure you will get some valuable comments from the experts who participate in this thread, but I have some observations I would like to share.  First of all, your sub seems to have a very good low end--that is a nice, flat response all the way to below 20Hz. The response in the 60-90Hz range indicates that there may be phase issues at the crossover point.  Have you tried adjusting the sub delay to see if it has any effect on the FR flatness?

 

The waterfall looks quite good, although I would have preferred seeing a 450ms window.  There is a bit of ringing shown by the "mountain" at approximately 90Hz.  the smaller time window might add some perspective.

 

I think the impulse measurement has some areas of concern.  I doesn't surprise me that you have quite a few reflections higher than -20dB, given that you haven't explored room treatments.  The very early reflections are actually quite severe, and are likely impacting the audio in your listening room.  At a minimum, I would recommend that you conduct some of the exercises described in this thread to at least isolate what might be causing the reflections.  This way you might find an easy way to improve the reflections without a lot of effort.  Those reflections must be coming from something quite close to the speakers or your listening point.  The font in the graph is quite small, but it seems as if the reflections colored in blue might be slightly worse.  Consider the "blocking technique" to identify where these are coming from.  Taming the reflections has the potential of significantly improving your listening experience, in my opinion.

 

Looking forward to your progress reports!

post #7076 of 9543
Quote:
Originally Posted by 3ll3d00d View Post
I am currently contemplating a move to a pure (HT)PC solution and replacing audyssey with PC based DRC (have done initial evaluation of acourate), partly because I'm not 100% happy with multeq xt but also because I clearly don't have enough tweakability in my life right now smile.gif

For which I sincerely hope you've seen Equalizer APO:

http://sourceforge.net/p/equalizerapo/wiki/Documentation/

Welcome aboard.

And be careful what you wish for.

;)

post #7077 of 9543
Quote:
Originally Posted by Digione View Post

The results you obtained are very similar to what I obtained when I added the 3" of Roxsul on the floor except as my ceiling is treated it doesn't introduce any significant reflections.

It is quite amazing how the floor is often neglected as a relevant reflective surface. I suppose it is because it is so difficult to easily treat. It would be great if some company introduced effective floor treatment that you could "walk on". smile.gif

Thanks for taking the time to post these measurements. Pity you didn't get a chance to listen to the changes.

I finally had a chance to listen. To summarise, I would have to say the imaging became much stronger. I'm quite surprised really, I have all the other early reflection points taken care of, apart from ceiling, and while I had pretty good imaging prior, it's in a whole nother world now. I'm not sure exactly how best to describe it, but it feels like there is more space (depth) from front to rear. Previously it was like the recordings come from a solid wall with some projection as recorded to the MLP, now it's like that wall has been removed, there is more space behind speakers.
I actually went up to the centre speaker at one point to ensure it wasn't producing sound, such is the strength of the imaging now.

I'm within 2.5M of the LR speakers and I had laid some pink fluffy length wise from the speakers towards to MLP, this won't work full time with wife and kids, so the next chance I have I'll try standing some pink fluffy on it's wide end so that it's taking less floor space.

Super keen to dampen the ceiling now rolleyes.gif
Edited by Audionut11 - 11/17/13 at 10:37pm
post #7078 of 9543
Quote:
Originally Posted by Audionut11 View Post



Super keen to dampen the ceiling now rolleyes.gif

Of all the treatments I have applied, I was most reluctant to place panels on the ceiling. However, after I did it, the ceiling panels resulted in the most audible improvements I have made to date.
post #7079 of 9543
Quote:
Originally Posted by AustinJerry View Post

Of all the treatments I have applied, I was most reluctant to place panels on the ceiling. However, after I did it, the ceiling panels resulted in the most audible improvements I have made to date.

More incentive wink.gif
post #7080 of 9543
I'm sorry if this question has been answered. I have mostly kept up with the thread but working 7 days a week as of recent I may have missed. I will post a clip from J's recent comment that I have yet to find a satisfying answer for. Again I have been keeping up mostly with the measurement technique discussion but didn't hear a direct answer.

If you decide to view a full range measurement with L+R+Sub(s) you will most likely be disappointed above about 1khz or so (most of the time and unless you are VERY careful and have very exact speaker and mic placement between the speakers) as the wavelengths start to become so small the slightest movement of the mic will cause phase interactions, comb filtering, and a very poor and inaccurate measurement in the higher frequencies. There really isn't any reason for this. Again, the only measurement necessary for L+R+Sub(s) - combined - should be to look at the overall bass response, below 300hz, unsmoothed.

I did accidentally do this the other day. On my Mac I have to switch audio output to sound flower 64ch as per JPA's wonderful guide to only get one speaker plus LFE channels at a time. I had switch back to my Denon, which allows for both LR to play, to listen to a song for differences during tuning and forgot to change it back. I did notice some not so good looking graph up in the top end.

Why don't we do this? It seems this would be the most important since we listen with both of these speakers (plus a center usually) during a movie or multichannel music. What is the simple answer?
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