Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 208 - AVS Forum
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Old 11-03-2013, 08:26 AM
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I see progress.

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Not doubt but understanding (of how equalization works).

BTW, this isn't limited to Audyssey, but all equalization. So coming to this realization is not anti-Audyssey.

Thank you, I take these comments as compliments. The discussion over the last several pages has been quite interesting. And special thanks to Stuart for his valuable insights.
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Old 11-03-2013, 09:39 AM
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What seems to be coming to the fro is prioritizing (re-examining) whats MOST important for good sound.

1) Reflection control (ETC)
2) FR
3) Decay

Certainly all these are important and some synthesis of the three is the answer to question. But I would put their importance in the above order and ill explain why.

I think FR is what we notice most immediately. But unwanted reflections (high gain early ones) are the most responsible for a poor FR in the first place. They alter the direct response by recombining with it within the psychoacoustic integration period (first 20ms). Early high gain reflections reduce or destroy our ability to discern a soundstage in that the phase cues offered by the direct response are muddled by addition cues from the room. The necessary room treatments (absorption) to effectively tame reflections also tends to help with decay.

When i speak of controlling early high reflections, a full band ETC is not adequate. You must look at different frequency regions via ETC slicing to see what different ranges are doing. It is quite common for example for the full range ETC to meet our goals (first 20ms < -20db) , but have the 1K or 500hz 1 octave slices fail miserably to meet this same goal. What we want here is early reflection attenuation across as broad a range as possible.

So my approach is that once you get early (first 20ms) reflections under control, the other two factors improve on their own. I put decay last on the list because although poor decay isnt desirable, its effects occur AFTER the psychoacoustic integration period and therefore do not alter our perception of the direct response.



Here is my 1K sliced ETC from June (Red) vs now (Blue). This difference was quite noticeable and well worth giving attention to.

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Old 11-03-2013, 09:48 AM
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Is that waterfall smoothed at 1/48? If it is that's OK - if not can you remake it again using 1/48. This is where the control is:




The waterfall is very good from 30Hz up. But is showing considerable ringing from 30Hz down. Even extending the time range out to 600ms still shows some ringing and I'd guess it might still be there at 800ms too. This is too long. The 'gold standard' for this thread is that all ringing has ceased by 300ms. This is almost impossible to attain though. A 'good' standard is 450ms and your waterfall to that standard is poor. The problem is that it is very difficult to fix ringing below 30Hz - you would need to ensure that your speakers and subs are optimally placed in relation to your listening distance and then you would need to treat the room with acoustic absorption. The problem with the latter course is that you would need absorption at least 2 feet thick to have much impact, and few people can accommodate that. If your bass sounds tight and clean to you, you may be inclined just to accept the room for what it is. Others with more experience than I have will no doubt contribute additional ideas.

Did you see my second response here? There are corrected graphs there.

I know that ringing under 30hz is hard to tame, but I just may have room for absorbers 2' thick or even more (I got a big room!). I'm gonna get a room layout uploaded as soon as I find some decent free software to create one....does anyone have a link for a good room design program?

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Old 11-03-2013, 09:50 AM
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Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

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Old 11-03-2013, 10:32 AM
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Originally Posted by jlpowell84 View Post

Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

 

Not me.  Keith is the current expert on this topic.

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Old 11-03-2013, 10:38 AM
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Interesting observations Stuart. But I think there is some conflation going on. Audyssey is an automated room correction system. That's it. It is for the guy who wants to spend 30 minutes running an automated routine and then saying "that's me done". And as such it is pretty good.

On the other hand, we have the 'serious acoustician' type of approach, where all room issues are analysed in depth and solutions brought forward to deal with those issues. The solutions include speaker choice, MLP, speaker and sub placement optimisation, the treating of the room acoustically and so on. If all of the latter are done to perfection, then Audyssey is history. You have gone beyond what Audyssey is meant to do.

The conflation seems to arise where we start to measure, or try to measure, what Audyssey is doing in the room, along with the other remedies we are also installing (such as treatments). Pro rooms seem to concentrate first on getting the room right and then they measure and then they apply a little EQ to fix the remaining issues that the physical measures couldn't fully resolve. But people in this thread are doing the reverse. They are using Audyssey as a major tool, and then measuring and then adding physical solutions afterwards, and then measuring to see how the two different approaches play together. IMO it isn't surprising if they do not always play well together.

If you are going to go 100% down the rabbit hole, then the aim must be to lose Audyssey altogether. It will just not be needed. In my room now I have found that Audyssey on and Audyssey off aren’t hugely different. They are different but nowhere near as different as they used to be before my own ingress into the lair of the gregarious burrowing plant-eating mammal, with long ears, long hind legs, and a short tail. This is what I’d hope for an expect. I still find the system sounds better with Audyssey engaged, and this is also what I would expect from looking at my measurements, so I continue to use it.

If I decided not to use Audyssey at all, I would find that I had created a bigger set of problems than are caused by using Audyssey, and - worse - that the bigger set of problems could possibly be unsolvable in my room.

Some very insightful thinking here. smile.gif

I have never had or used Audyssey, but observing those that do, it does seem it makes the MOST difference in untreated rooms and the LEAST in well treated ones. As you have pointed out, the further you move forward with room treatment, the less there is for Audyssey to try to fix in the first place. And I think we all agree acoustic treatment does a better job than Audyssey can hope to do.

So Audyssey's place in the world seems to reside with those that are constrained from treating the room fully. I will concede that Audyssey may still help in some matters wrt to partially treated rooms. But I am glad to see some here looking objectively at the cons as well as the pros as it pertains to how Audyssey operates. If at the end of the day, it sounds better with Audyssey engaged, by all means, use it. But I would encourage extended listening with it off and on, and continuing to do this as your room treatments improve, for there does seem to be a threshold where off is better than on.

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Old 11-03-2013, 10:46 AM
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I'm gonna get a room layout uploaded as soon as I find some decent free software to create one....does anyone have a link for a good room design program?

I like Sketchup because it's free and has an online database of pre-made models. Takes a little getting used to but relatively simple once you get the hang of it. Just search my posts in this thread to get a feel for what's possible.
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Old 11-03-2013, 10:49 AM
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Here is a decay graph...my first one so it's probably not right. smile.gif


Around 28hz and 70-80hz really show up here. While the 28hz maybe hard to fix, the 70-80hz area can probably be improved. Whats going on there (70-80hz) ?

1) sub XO ?
2) modal ringing?
3) SBIR?

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Old 11-03-2013, 10:54 AM
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Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

 

Yes - I did that just recently and reported on it at length in this thread. I have doubled up the amount of absorption in 6 or my corner traps. I did it to try to benefit an issue at 45-55Hz but it didn't have much impact on that. However, it did bring other benefits as reported here. Whether the improvements were worth the time and trouble is a moot point. But I am happy - any changes I make from her will always be incremental - all the big stuff has been addressed.

 

To your point above - an air gap is a good thing. But more insulation is a better thing.

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Old 11-03-2013, 10:55 AM
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Originally Posted by jlpowell84 View Post

Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

 

Not me.  Keith is the current expert on this topic.

 

:)  'Expert' is perhaps a tad optimistic, Jerry, but I thank you for it anyway :)   I don't know how jlp missed it - my report sparked a page or two if discussion only a few days ago. 

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Old 11-03-2013, 10:58 AM
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Originally Posted by jlpowell84 View Post

Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

From everything I've read thus far (admittedly not as much Ethan Winer except for some of his posts at GS), square soffit style bass traps should be more effective than either tri corner or superchunk style bass traps or straddling panels with an air gap of "similar" size. In fact, J even recommended that Keith fill his air gap with gubbins for better results so why is it you feel this is your best option? If you have space to use a 4" panel with air gap then wouldn't a similar size soffit style trap provide even better results or are you saying the incremental benefit isn't worth the effort?
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Old 11-03-2013, 11:00 AM
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Interesting observations Stuart. But I think there is some conflation going on. Audyssey is an automated room correction system. That's it. It is for the guy who wants to spend 30 minutes running an automated routine and then saying "that's me done". And as such it is pretty good.

On the other hand, we have the 'serious acoustician' type of approach, where all room issues are analysed in depth and solutions brought forward to deal with those issues. The solutions include speaker choice, MLP, speaker and sub placement optimisation, the treating of the room acoustically and so on. If all of the latter are done to perfection, then Audyssey is history. You have gone beyond what Audyssey is meant to do.

The conflation seems to arise where we start to measure, or try to measure, what Audyssey is doing in the room, along with the other remedies we are also installing (such as treatments). Pro rooms seem to concentrate first on getting the room right and then they measure and then they apply a little EQ to fix the remaining issues that the physical measures couldn't fully resolve. But people in this thread are doing the reverse. They are using Audyssey as a major tool, and then measuring and then adding physical solutions afterwards, and then measuring to see how the two different approaches play together. IMO it isn't surprising if they do not always play well together.

If you are going to go 100% down the rabbit hole, then the aim must be to lose Audyssey altogether. It will just not be needed. In my room now I have found that Audyssey on and Audyssey off aren’t hugely different. They are different but nowhere near as different as they used to be before my own ingress into the lair of the gregarious burrowing plant-eating mammal, with long ears, long hind legs, and a short tail. This is what I’d hope for an expect. I still find the system sounds better with Audyssey engaged, and this is also what I would expect from looking at my measurements, so I continue to use it.

If I decided not to use Audyssey at all, I would find that I had created a bigger set of problems than are caused by using Audyssey, and - worse - that the bigger set of problems could possibly be unsolvable in my room.

Some very insightful thinking here. smile.gif

I have never had or used Audyssey, but observing those that do, it does seem it makes the MOST difference in untreated rooms and the LEAST in well treated ones. As you have pointed out, the further you move forward with room treatment, the less there is for Audyssey to try to fix in the first place. And I think we all agree acoustic treatment does a better job than Audyssey can hope to do.

So Audyssey's place in the world seems to reside with those that are constrained from treating the room fully. I will concede that Audyssey may still help in some matters wrt to partially treated rooms. But I am glad to see some here looking objectively at the cons as well as the pros as it pertains to how Audyssey operates. If at the end of the day, it sounds better with Audyssey engaged, by all means, use it. But I would encourage extended listening with it off and on, and continuing to do this as your room treatments improve, for there does seem to be a threshold where off is better than on.

 

Agreed, Jim. If I had a bigger room and more options open to me, I would be working towards getting rid of Audyssey entirely, if I could. It is great as a 'set and forget' automated system and it is really great for anyone who cannot treat his room, for whatever reason. This is what it was designed for of course. But we, in this thread, have moved on, so we need to make some decisions about what we do going forward. In my awkward, square little room I suspect I will always need Audyssey or some form of EQ as well as treatments etc. But I’d love a room where I knew I could work towards no electronic EQ at all - or maybe more realistically, just the lightest touch of targeted EQ. That would be my goal. If we ever move house, right up on my priority list will be a suitable room with which to perhaps progress these aims into reality.

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Old 11-03-2013, 11:03 AM
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Originally Posted by jim19611961 View Post

What seems to be coming to the fro is prioritizing (re-examining) whats MOST important for good sound.

1) Reflection control (ETC)
2) FR
3) Decay

Certainly all these are important and some synthesis of the three is the answer to question. But I would put their importance in the above order and ill explain why.

I think FR is what we notice most immediately. But unwanted reflections (high gain early ones) are the most responsible for a poor FR in the first place. They alter the direct response by recombining with it within the psychoacoustic integration period (first 20ms). Early high gain reflections reduce or destroy our ability to discern a soundstage in that the phase cues offered by the direct response are muddled by addition cues from the room. The necessary room treatments (absorption) to effectively tame reflections also tends to help with decay.

When i speak of controlling early high reflections, a full band ETC is not adequate. You must look at different frequency regions via ETC slicing to see what different ranges are doing. It is quite common for example for the full range ETC to meet our goals (first 20ms < -20db) , but have the 1K or 500hz 1 octave slices fail miserably to meet this same goal. What we want here is early reflection attenuation across as broad a range as possible.

So my approach is that once you get early (first 20ms) reflections under control, the other two factors improve on their own. I put decay last on the list because although poor decay isnt desirable, its effects occur AFTER the psychoacoustic integration period and therefore do not alter our perception of the direct response.



Here is my 1K sliced ETC from June (Red) vs now (Blue). This difference was quite noticeable and well worth giving attention to.

Jim, just curious if what's going on at 25ms is intentional? I think it might be from our previous discussion on ISD gap but my memory isn't what it used to be...by a LOT!
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Old 11-03-2013, 11:05 AM
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When i speak of controlling early high reflections, a full band ETC is not adequate. You must look at different frequency regions via ETC slicing to see what different ranges are doing. It is quite common for example for the full range ETC to meet our goals (first 20ms < -20db) , but have the 1K or 500hz 1 octave slices fail miserably to meet this same goal. What we want here is early reflection attenuation across as broad a range as possible.

 

 

Jim, we recently spent some time receiving guidance on how to generate and interpret the Spectrogram, with good results.  I perceive this to be another opportunity to enhance the collective knowledge of thread participants.  I acknowledge you as being an expert on managing reflections, and an expert at using ETC as one of your tools.  Can you help us understand in more detail how to leverage the filtered impulse response to identify and correct room reflections?

 

Here are several snapshots of the same impulse response measurement (full range, 500Hz, 1000Hz, and 4000Hz, at both full octave and 1/3 octave):

 

 

 

 

 

 

 

Here are several questions that would help interpreting the graphs:

 

1.  For the 500Hz graphs, the same filter at 1/1 octave and 1/3 octave seems to show different reflections.  The 1/1 seems to show reflections at 12, 22, and 27ms, while the 1/3 is showing only a reflection at 18ms.  Please explain what we are seeing.

 

2.  Looking at 500Hz, 1000Hz, and 4000Hz, I seem to be seeing different reflections.  I recall from previous discussions that reflections that are present at higher frequencies, but missing at lower frequencies, are caused by smaller surfaces.  Is that correct, or is it the other way around?

 

3.  Using the filtered graphs, can you point out something that these graphs reveal that we might miss if we were only looking at the full-range graph?

 

4.  Can any of these measurements help in locating multiple-surface reflections, which seem to be especially difficult to identify and eliminate?

 

Understanding the impulse response measurement has become very important, IMO.

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Old 11-03-2013, 11:09 AM
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Quote:
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Hey guys, doing a bit of reading of some Ethan Winer material. Thanks Markus for reminding me. So it seems my wall to ceiling and wall to floor junctions will be best served by a 4 inch panel straddling with an obvious air gap behind created by putting a flat panel over a corner. I have seen such pics in Jerry's room. Now he mentioned stuffing some fiberglass behind in the air gap. That would surely be an interesting measurement. But I am curious if any of you have stuffed any more insulation behind in an air gap?

From everything I've read thus far (admittedly not as much Ethan Winer except for some of his posts at GS), square soffit style bass traps should be more effective than either tri corner or superchunk style bass traps or straddling panels with an air gap of "similar" size. In fact, J even recommended that Keith fill his air gap with gubbins for better results so why is it you feel this is your best option? If you have space to use a 4" panel with air gap then wouldn't a similar size soffit style trap provide even better results or are you saying the incremental benefit isn't worth the effort?

 

FWIW, if I was starting over again, I would make soffit traps around the entire ceiling/wall corners and then use 'fully filled' triangular traps, floor to ceiling in as many of the other corners as possible. Not forgetting the wall/floor corners which are the easiest of all to treat - just put the traps on the floor! 

 

In fact, even in this poxy little room, I could do the soffit idea. Hmmm.... I couldn’t make them huge, but I could do 15 inches square... that would be some serious absorption. And a fairly easy DIY job, even for me. 

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Old 11-03-2013, 11:12 AM
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^^^^Funny you should write that as I was in the process of a PM to ask the same and even suggest it as a further mod (even in your "tiny" space).
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Old 11-03-2013, 11:12 AM
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Jim, just curious if what's going on at 25ms is intentional? I think it might be from our previous discussion on ISD gap but my memory isn't what it used to be...by a LOT!

 

Not Jim, but that is the mark of a true LEDE design, and represents one of Jim's crowning achievements, IIRC.

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Old 11-03-2013, 11:38 AM
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Jim, we recently spent some time receiving guidance on how to generate and interpret the Spectrogram, with good results. I perceive this to be another opportunity to enhance the collective knowledge of thread participants. I acknowledge you as being an expert on managing reflections, and an expert at using ETC as one of your tools. Can you help us understand in more detail how to leverage the filtered impulse response to identify and correct room reflections?

Here are several snapshots of the same impulse response measurement (full range, 500Hz, 1000Hz, and 4000Hz, at both full octave and 1/3 octave):



Here are several questions that would help interpreting the graphs:

1. For the 500Hz graphs, the same filter at 1/1 octave and 1/3 octave seems to show different reflections. The 1/1 seems to show reflections at 12, 22, and 27ms, while the 1/3 is showing only a reflection at 18ms. Please explain what we are seeing.

2. Looking at 500Hz, 1000Hz, and 4000Hz, I seem to be seeing different reflections. I recall from previous discussions that reflections that are present at higher frequencies, but missing at lower frequencies, are caused by smaller surfaces. Is that correct, or is it the other way around?

3. Using the filtered graphs, can you point out something that these graphs reveal that we might miss if we were only looking at the full-range graph?

4. Can any of these measurements help in locating multiple-surface reflections, which seem to be especially difficult to identify and eliminate?

Understanding the impulse response measurement has become very important, IMO.

Firstly, add some smoothing to the graphs to make them more comprehensible (.1 or .2 ms should be enough)

Ideally, you want to lay different bands on top of each like this:



Black = 500hz
Orange = 1k
Green = 2k
Purple = 4k

But I dont know how to do this in REW. Maybe a REW expert can work this out. But again ideally, you want all the ranges to run together. That is, you want your reflections to emulate the direct response as in fairly equal to one another. I have found that the lower frequencies always want to run higher than higher ones. High frequencies just absorb and decay so much quicker, its probably impossible to get them even. Still, even if you cant plot them together, much can be gleened from looking at them individually. Treat each band as it own ETC. Apply the same interpretation to it as you would a full range ETC. Where you have early high gain reflections, this is where work needs doing.

As one can see, the sliced ETC (above) shows much a full range ETC (below) does not.


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Old 11-03-2013, 11:42 AM
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Originally Posted by jkasanic View Post

Jim, just curious if what's going on at 25ms is intentional? I think it might be from our previous discussion on ISD gap but my memory isn't what it used to be...by a LOT!

Yes it is. Its called a Haas trigger or ISD termination.

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Old 11-03-2013, 11:43 AM
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^^^^Funny you should write that as I was in the process of a PM to ask the same and even suggest it as a further mod (even in your "tiny" space).

 

Yes, I just sat in there for a few minutes and it could be done. I don't have the enthusiasm to rip the room apart, having only recently got it into a state where it is giving really good results, but it is something to consider for the future for sure. It would look fairly good as well, although it's so dark in there that is very much a secondary consideration.

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Old 11-03-2013, 01:02 PM
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smile.gif  'Expert' is perhaps a tad optimistic, Jerry, but I thank you for it anyway smile.gif   I don't know how jlp missed it - my report sparked a page or two if discussion only a few days ago. 

No I remember now Keith. My life is is as busy at it has ever been, and thats an understatement! But I remember now, and I remember how you ended up cleaning up down low a good bit. I can certainly stuff some pink fluffy back in the gap as long as i butt the panels up to one another smile.gif

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Old 11-03-2013, 01:41 PM
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From everything I've read thus far (admittedly not as much Ethan Winer except for some of his posts at GS), square soffit style bass traps should be more effective than either tri corner or superchunk style bass traps or straddling panels with an air gap of "similar" size. In fact, J even recommended that Keith fill his air gap with gubbins for better results so why is it you feel this is your best option? If you have space to use a 4" panel with air gap then wouldn't a similar size soffit style trap provide even better results or are you saying the incremental benefit isn't worth the effort?

I am planning on doing 15x15 soffits in the front LR vertical corners of my room. that dimension was just barely less performing than the GIK dimension 17x17 soffit. 15x15 is kinda right at my limit. My room is small...and its a rental so I don't want to get crazy with mounting stuff everywhere. Although I am willing to do quite a bit but keep it modest. Actually mounting soffits would take up less screws in the wall. But I was just thinking a 15x15 soffit in the vertical corners, wall to floor junctions, ceiling to wall junction (side walls and from tv wall) would be quite intrusive on the appearance and feel of the room. So I thought, "what if I did a little miniature soffit?" But according to the porous calculator they won't perform all that well at a 9x9. Which for appearances would be less shocking to the room. Really I need to find the line I am willing to rub up against and plan from there. I mean all of the sudden I find myself considering 15z15 soffits all around! But my future wife I don't think would like it. Although she would be willing.

Also I mentioned above that if I did a panel then I would stuff it, not leave it bare;)







Now the pics do do any justice, a 15x15 soffit all around would add a shrinking feeling to the room. Now a 24 inch panel all along the front wall, and a couple coming back along the side walls will be doable. And I could stuff some pink fluffy back there

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Old 11-03-2013, 01:48 PM
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FWIW, if I was starting over again, I would make soffit traps around the entire ceiling/wall corners and then use 'fully filled' triangular traps, floor to ceiling in as many of the other corners as possible. Not forgetting the wall/floor corners which are the easiest of all to treat - just put the traps on the floor! 

In fact, even in this poxy little room, I could do the soffit idea. Hmmm.... I couldn’t make them huge, but I could do 15 inches square... that would be some serious absorption. And a fairly easy DIY job, even for me. 

DO IT!!!!

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Old 11-03-2013, 02:05 PM
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Can you elaborate on why you're banned? I mean, assuming it was due to a difference of opinion on technical matters.

That and some people using the report button too often.

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Old 11-03-2013, 02:09 PM
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Quote:
Originally Posted by jlpowell84 View Post

Quote:
Originally Posted by jkasanic View Post

From everything I've read thus far (admittedly not as much Ethan Winer except for some of his posts at GS), square soffit style bass traps should be more effective than either tri corner or superchunk style bass traps or straddling panels with an air gap of "similar" size. In fact, J even recommended that Keith fill his air gap with gubbins for better results so why is it you feel this is your best option? If you have space to use a 4" panel with air gap then wouldn't a similar size soffit style trap provide even better results or are you saying the incremental benefit isn't worth the effort?

I am planning on doing 15x15 soffits in the front LR vertical corners of my room. that dimension was just barely less performing than the GIK dimension 17x17 soffit. 15x15 is kinda right at my limit. My room is small...and its a rental so I don't want to get crazy with mounting stuff everywhere. Although I am willing to do quite a bit but keep it modest. Actually mounting soffits would take up less screws in the wall. But I was just thinking a 15x15 soffit in the vertical corners, wall to floor junctions, ceiling to wall junction (side walls and from tv wall) would be quite intrusive on the appearance and feel of the room. So I thought, "what if I did a little miniature soffit?" But according to the porous calculator they won't perform all that well at a 9x9. Which for appearances would be less shocking to the room. Really I need to find the line I am willing to rub up against and plan from there. I mean all of the sudden I find myself considering 15z15 soffits all around! But my future wife I don't think would like it. Although she would be willing.

Also I mentioned above that if I did a panel then I would stuff it, not leave it bare;)



First things first...get yourself some blackout shades for those windows! eek.gif If you find anything with good absorption properties then let me know as I've been looking for something to treat my sliding glass door on the rear wall that is dual purpose! wink.gif

As for the soffits, corners and ceilings are one thing but I think floor would be a tough sell for anyone especially considering WAF let alone the "shrinkage" factor (I guess it's not just cold water that causes this!). If you can treat the floor then I agree soffits all around would be very intrusive especially if you treat the ceilings this way. My only point was that if you're going to straddle panels at the ceiling boundaries, a square soffit is the best bang for your buck as far as I can tell.
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Old 11-03-2013, 02:11 PM
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Would smoothing help?

No. Normalization would make the frequency response at t=0 a flat line. The necessary boost to do so would be applied to all successive slices of a waterfall/spectrogram.
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Old 11-03-2013, 02:20 PM
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But I dont know how to do this in REW. Maybe a REW expert can work this out.

By no means an expert but I seem to recall the way to handle this is by importing the same measurement into REW multiple times. Since I'm not 100% clear on exactly how to slice the ETC, I'm hoping Jerry will understand what I'm saying and expand on it further in the guide.
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Old 11-03-2013, 02:24 PM
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By no means an expert but I seem to recall the way to handle this is by importing the same measurement into REW multiple times. Since I'm not 100% clear on exactly how to slice the ETC, I'm hoping Jerry will understand what I'm saying and expand on it further in the guide.

I tried that and it does work, but you loose the ability to smooth the plots which kinda makes it a mess when you have 4 or more together.

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Old 11-03-2013, 02:25 PM
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I found my two major reflection points one is uncontrollable since it's a picture window. (Even with our nick drapes closed no bueno). And the rear wall. The rear wall I will be doing very soon smile.gif

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Old 11-03-2013, 02:30 PM
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Quote:
Originally Posted by jkasanic View Post

By no means an expert but I seem to recall the way to handle this is by importing the same measurement into REW multiple times. Since I'm not 100% clear on exactly how to slice the ETC, I'm hoping Jerry will understand what I'm saying and expand on it further in the guide.

I tried that and it does work, but you loose the ability to smooth the plots which kinda makes it a mess when you have 4 or more together.

Hopefully John is reading then and can advise or put it on the "to-do" list!
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