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Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 182

post #5431 of 9570
Quote:
Originally Posted by AustinJerry View Post

I don't understand how the measurement of both subs after the Audyssey calibration can look worse than the two subs without Audyssey. Did you run the calibration without moving the subs?

Yes - Didn't touch the setup frown.gif I'm working on manually tweaking the distances on the Denon and have achieved a little better results. I'll post them shortly.

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post #5432 of 9570
Well, here's the best I could manage with Auddessy off while changing speaker distances manually. As you can see it's a slight improvement over what the response was when I used Auddessy set distances. However, once I Turn Aud on again with my distances things deteriorate quickly:

post #5433 of 9570
Hold on. If you did the following:

- Position the subs.
- Measure combined response with the REW mic placed EXACTLY at the MLP at ear height.
- Run an Audyssey calibration with the first mic position at EXACTLY the same position as when you took the REW measurement.
- Run a post-calibration REW measurement with the mic at EXACTLY the same position as above.

Then there is no way I can think of that the post-calibration measurement can be worse than the pre-calibration measurement. You need to stop and re-assess what you are doing. Manually adjusting the sub distances is not the correct thing to be doing.
post #5434 of 9570
Quote:
Originally Posted by AustinJerry View Post

Hold on. If you did the following:

- Position the subs.
- Measure combined response with the REW mic placed EXACTLY at the MLP at ear height.
- Run an Audyssey calibration with the first mic position at EXACTLY the same position as when you took the REW measurement.
- Run a post-calibration REW measurement with the mic at EXACTLY the same position as above.

Then there is no way I can think of that the post-calibration measurement can be worse than the pre-calibration measurement. You need to stop and re-assess what you are doing. Manually adjusting the sub distances is not the correct thing to be doing.

Well the only variance I can think of is the distances that were predetermined in the receiver before I started doing my original round of calibrations. With Audyssey off, what distances should the sub be set at in the receiver when I measure the initial round of responses with REW? - If they are set at one thing when I do the measuring, when I re do set up and Audyssey rearranges my distances - won't that effect my response at the MLP?

I'll start measurements again - but let me try to make sure we're clear - 1. Auddessy is off. 2. What should the sub distances be set at before I do the initial REW measurements?

the ONLY thing I did between those initial measurements that looked not to bad and the new ones that sucked was run auddessy. I didn't touch the subs position / volume and placed the mic in the same position as where I had been doing the rew sweeps to begin with. I'm completely stumped. Sorry man - I'm sure this must be frustrating for you, and I appreciate your help. Believe me it's driving me bonkers too. 8 hours of measurements and I'm no better off then I was this morning.

Perhaps as long as the subs are set to an equidistant figure in the receiver before running auddessy - it will be like having a splitter coming off one sub out, and they'll get equal signals. If one distance is set differently by a couple of feet when running auddessy then perhaps it will skew the initial REW calibration?
Edited by Sean Spamilton - 10/16/13 at 5:44pm
post #5435 of 9570
Moving room in process. Here are some measurements. Width is now 15ft 8 inches. Length to the back is 23ft 5 inches. But the left back has the kitchen counter sticking out into the room about 5 ft width wise and about 8ft from the back wall forward. MLP is 9ft 8 inches. This keeps me out of the middle! Graphs to come soon!
post #5436 of 9570
@Sean:

To be honest, when I have moved subs around looking for the best position, I have never adjusted the distances in the AVR during the process. I am not sure it is that important. If you are obsessing about sub distances and changing them every time you move a sub, you may be doing more harm than good.

If , however, you are convinced that it makes a difference, then follow this procedure:

- Move the subs to a spot you want to measure.
- Run a quick 1-position Audyssey calibration and hit the Calc button.
- Observe the sub distances.
- Set the sub distances manually.
- Run the REW measurement and analyze the resulting graph.
- Repeat for each potential sub position.

I repeat, I have never gone to this trouble when moving my subs around. Perhaps someone else can share an opinion as to whether they think this is necessary or not.
post #5437 of 9570
Quote:
Originally Posted by jlpowell84 View Post

Moving room in process. Here are some measurements. Width is now 15ft 8 inches. Length to the back is 23ft 5 inches. But the left back has the kitchen counter sticking out into the room about 5 ft width wise and about 8ft from the back wall forward. MLP is 9ft 8 inches. This keeps me out of the middle! Graphs to come soon!

A rough diagram of the new room layout with dimensions as well, please.
post #5438 of 9570
Quote:
Originally Posted by AustinJerry View Post

@Sean:

To be honest, when I have moved subs around looking for the best position, I have never adjusted the distances in the AVR during the process. I am not sure it is that important. If you are obsessing about sub distances and changing them every time you move a sub, you may be doing more harm than good.

If , however, you are convinced that it makes a difference, then follow this procedure:

- Move the subs to a spot you want to measure.
- Run a quick 1-position Audyssey calibration and hit the Calc button.
- Observe the sub distances.
- Set the sub distances manually.
- Run the REW measurement and analyze the resulting graph.
- Repeat for each potential sub position.

I repeat, I have never gone to this trouble when moving my subs around. Perhaps someone else can share an opinion as to whether they think this is necessary or not.

Not just that: you might need a fitness boot camp to pull this off without gettting wiped out from exhaustion cool.gif .

Better stretch those quads....
post #5439 of 9570
Quote:
Originally Posted by AustinJerry View Post

@Sean:

To be honest, when I have moved subs around looking for the best position, I have never adjusted the distances in the AVR during the process. I am not sure it is that important. If you are obsessing about sub distances and changing them every time you move a sub, you may be doing more harm than good.

If , however, you are convinced that it makes a difference, then follow this procedure:

- Move the subs to a spot you want to measure.
- Run a quick 1-position Audyssey calibration and hit the Calc button.
- Observe the sub distances.
- Set the sub distances manually.
- Run the REW measurement and analyze the resulting graph.
- Repeat for each potential sub position.

I repeat, I have never gone to this trouble when moving my subs around. Perhaps someone else can share an opinion as to whether they think this is necessary or not.


Just out of curiosity, do you have dual sub outs on your avr? Just that if they are the same level from a single out I can see it wouldn't make a diff - but with different outputs directed to the sub with a dual out I can't help but to think it would. In fact that seems the only difference between my measurements being good - then re doing set up and being bad. I dunno - maybe I'm missing something.

I think at this point the easier thing to do - is just move the subs and run set up blindly then re measure to see what the results are. It seems like I'm doing too many steps here - and it's not working to my advantage. If there's only 3 possible positions to put the subs - then in this case I think it makes sense to just run auddessy at each of the three configurations - running REW afterward, and deciding what comes out best and keeping it. ( Also comparing it to just the ONE sub in case the two are doing more harm then good, and / or aren't to my benefit in any way )
post #5440 of 9570
Quote:
Originally Posted by sdurani View Post

When the wavelength of a certain frequency matches one of your room dimensions, it resonates. Rather than fade away normally, the sound at that resonant frequency just keeps on lingering, standing in the air for longer than other frequencies around it. Which is why room modes are sometimes called standing waves or resonances.

Is that the thrumming or throbbing sound? That's the technical term for those?
post #5441 of 9570
Quote:
Originally Posted by artur9 View Post

Is that the thrumming or throbbing sound? That's the technical term for those?
Dunno. I'm not very technically minded, so not up on the latest technical terms.
post #5442 of 9570
Here's another attempt - Last for the night. This represents a PRE Aud Setup - Having run some tests and finding a decent enough spot for my subs, represented by the red line. The Post Cal with Aud OFF is Purple and the Post cal with Aud ON is green. Not so good. Oh well. Thanks to all who gave suggestions. Big thanks to AustinJerry - appreciate the patience.

post #5443 of 9570
If nothing else has changed, how can a pre-cal Audyssey off be different from a post-cal Audyssey off?
post #5444 of 9570
Pics of layout










Ok here I go. I think I can tell it sounds much better and even just from running noise I level match subs. Of course Submersives go in clicks so both are 3 Vicks from bottom. Back soon!
post #5445 of 9570
It may just be the pics, but is your new layout centered left to right?
post #5446 of 9570
Quote:
Originally Posted by AustinJerry View Post

If nothing else has changed, how can a pre-cal Audyssey off be different from a post-cal Audyssey off?
Speaker distance

Sorry let me elaborate - If the subs are set to say, 7 feet each from MLP when I take the original REW measurements, I get whatever graph I originally get. When I run Auddessy - it changes those two speaker distances to something different, thus after auddessy the sound is getting to the mic at a different time, altering the graph. If I turn Auddessy off - it still keeps the distances it just set, so now even without auddessy correction the receiver is using the new distances. If I went back and manually changed them to the distances I had set before, with Aud off - I should get the same result as I originally got. Of course this completely defeats the purpose of having sub eq in the first place. So I dunno.
Edited by Sean Spamilton - 10/16/13 at 8:20pm
post #5447 of 9570
post #5448 of 9570
Quote:
Originally Posted by AustinJerry View Post

It may just be the pics, but is your new layout centered left to right?

Nope it's just the window. Center of tv and tv stand is exactly 7ft 10 inches in the middle. Squared to back wall is the tv stand and screen. Couch is centered with measurements from sides and length. Subs are 7 inches if walls both ways. All within a quarter inch
post #5449 of 9570
Quote:
Originally Posted by jlpowell84 View Post

Nope it's just the window. Center of tv and tv stand is exactly 7ft 10 inches in the middle. Squared to back wall is the tv stand and screen. Couch is centered with measurements from sides and length. Subs are 7 inches if walls both ways. All within a quarter inch

OK, it was natural to assume the window was centered. I'm pleased you paid attention to this important detail.
post #5450 of 9570
Quote:
Originally Posted by jlpowell84 View Post

Pics of layout

Now THAT'S a symmetrical set-up!

post #5451 of 9570
Quote:
Originally Posted by Sean Spamilton View Post

Speaker distance

OK, but that dip still looks strange. What are the post calibration results for sub distances and trims? And what is the crossover set to?
post #5452 of 9570
Quote:
Originally Posted by AustinJerry View Post

OK, I need help from someone knowledgeable.  Here is a frequency response measurement:




Using the same measurement, I generated three waterfalls, varying the lower limit from 40dB to 45dB to 50dB.  Same measurement, but each waterfall obviously looks different.  What information do the differences convey to me?  The 5odB waterfall "looks better", but since they are all the same measurement, it can't be better.  Why am I having difficulty understanding this?











And here is a spectrogram using the same measurement.  Can someone walk me through how to interpret this graph?  Thanks!


Jerry, not sure what to say about the waterfalls, but I personally do like the spectrogram as another way to view things. I've heard this compared to taking a top down look at your waterfall. Think of red as high temp/spl and blue as cool temp/low spl. As example, if you compare the spectrogram to time = 0 on your waterfall graph, look at the spl peak level you have between 55 and 70 hz on your waterfall, and you'll see this represented in the spectrogram as higher temp spl or more red shading. At 90 hz you have a dip, which appears on the spectrogram as light green, or getting cooler/lower spl. If you had a flat frequency response you would have a steady shade of red across the x axis. Y axis is showing decay time at a particular frequency. Note your ringing at around 30 hz slowly decaying into the off into the cool blue lower limit of 52 dB by around 600ms. Sorry if you already knew this and was asking for something more meaningful.
post #5453 of 9570
Quote:
Originally Posted by AustinJerry View Post

OK, but that dip still looks strange. What are the post calibration results for sub distances and trims? And what is the crossover set to?

Sorry I actually added to the above post to elaborate more. I was on using my phone to respond at the time as I was in the middle of re doing set-up. I'll copy and paste the above:

Sorry let me elaborate - If the subs are set to say, 7 feet each from MLP when I take the original REW measurements, I get whatever graph I originally get. When I run Auddessy - it changes those two speaker distances to something different, thus after auddessy the sound is getting to the mic at a different time, altering the graph. If I turn Auddessy off - it still keeps the distances it just set, so now even without auddessy correction the receiver is using the new distances. If I went back and manually changed them to the distances I had set before, with Aud off - I should get the same result as I originally got. Of course this completely defeats the purpose of having sub eq in the first place. So I dunno.

As far as distances and trims, in this case it set them to 12.2 at the front and 10.9 at the back. Trims are -1 at the front and -3 at the back, and of course I set my crossovers to 80 all around. The Crossovers remain consistent in the measurements, pre and post, but depending on the position of the subs the distance and trim doesn't. For example if right now I turned Aud off - and moved my rear sub to the front to run a 2/5 and 4/5 set up, my rew measurements would be made with the distances set as 12.2 and 10.9 with the corresponding trims. Of course this wouldn't be accurate because those distances and delays don't apply any more since I've moved one of the subs. If I manually equal out or measure the new sub distance and enter it into the receiver, and set both sub trims to 0 before measurement - that measurement, even if it looks awesome - will change as soon as I run set up again because Auddessy will set it's own trim and distance, which in turn changes the frequency response at the MLP again. Don't know how to avoid this circle. The receiver uses Auddessy's distance and trim measurements whether it's set to on or off.
post #5454 of 9570
Ok I got some good info and progress in tonight. The room is symmetrical within a quarter inch. Center of tv, seating, subs, speakers (not active yet but have an equilateral triangle). All is measured precisely. One thing is my photo capture captions have run into my EQ line. I didn't realize this until I had saved everything. I will adjust my graph a little higher. The good out of that is I have gained some natural gain smile.gif
Anyway here are all the graphs. I measured SEVERAL spots pre Audyssey to get a feel for my room. And then a few with an Multi EQ XT 8 mic calibration engaged. I am pleased with the results on the graph. I will have to measure again since I boosted my lfe 6dbs. I honestly don't know how anyone would like flat in my room and my subs. I demoed the intense World War Z grenade scene and the Olymous Has Fallen Washington monument scene and neither were anything near impressive flat. But +6dbs were nice, perhaps a little more. I don't think it's the "you need to get used to a flat bass EQ." I went through that with my first HSU sub. So here are the graphs. Again my bad for the captions running into the line. You can still make out all the info.

A quick reminder of the room change






This is an eyeball of centered front to back of room, just to see what is there


And more around the seating area, again just so I could understand what is going on in my room




And the magic! Look at 20-80hz!!!




And in closing I will say I am going to run another calibration because I may have messed up but didn't remember for sure until after I pressed buttons. Submersives have PGM 1 and PGM 2. I "might(?)" have had one on each setting. Like I said I can't remember for sure. Mark says to run Audyssey in one and change after if you like sub 35-45 +3-5db boost. I certainly like the low end boost. In fact I took a graph of the low end boost not engaged and it was not satisfactory to me.


Last thing is I think my waterfalls will be terrible due to my wood paneling in this rental. I can't complain because the monthly cost is so good. But perhaps modest gains can be made there. I am happy with tonight and look forward to improving more!
post #5455 of 9570
Quote:
Originally Posted by Sean Spamilton View Post

As Requested three times: Old Sub:

...

New Sub:

...

How far from the diaphragm and port did you place the mic in each case?
post #5456 of 9570
Quote:
Originally Posted by AustinJerry View Post

Using the same measurement, I generated three waterfalls, varying the lower limit from 40dB to 45dB to 50dB.  Same measurement, but each waterfall obviously looks different.  What information do the differences convey to me?  The 5odB waterfall "looks better", but since they are all the same measurement, it can't be better.  Why am I having difficulty understanding this?

...

And here is a spectrogram using the same measurement.  Can someone walk me through how to interpret this graph?  Thanks!

Not sure what the question really is. If you look at a range of 40-100dB instead of 50-100dB you'll see more of the waterfall. It's like zooming in and out. It's the same picture, just the perspective changed.

A spectrogram is just like a waterfall looked onto from above.
Edited by markus767 - 10/17/13 at 12:02am
post #5457 of 9570
Quote:
Originally Posted by jlpowell84 View Post

Multi EQ XT

Do yourself a favor and get an Onkyo 818 with XT32. When I looked at the filter response of the lower MultEQ versions, I always had the feeling the resolution is way to coarse.
Quote:
Originally Posted by jlpowell84 View Post

I honestly don't know how anyone would like flat in my room and my subs.

A flat in-room curve is not perceived as flat. I'd recommend to switch on Dynamic EQ.
post #5458 of 9570
Quote:
Originally Posted by markus767 View Post

How far from the diaphragm and port did you place the mic in each case?

I measured about 3 inches away from the driver, and with the mic on top of the port ( on a stand with the actual speaker about 2 inches away from the top). I managed to get the driver and port in about perfect synchronicity gain matching this way ( after the initial disaster that was my first attempt ). Unfortunately I had a little less luck with sub positioning for the next 5 hours of trials.
post #5459 of 9570
Quote:
Originally Posted by markus767 View Post

Do yourself a favor and get an Onkyo 818 with XT32. When I looked at the filter response of the lower MultEQ versions, I always had the feeling the resolution is way to coarse.
A flat in-room curve is not perceived as flat. I'd recommend to switch on Dynamic EQ.

Dyn EQ is on. With it on and me leaving the bass trim as Audyssey set it it was very thin and weak. I have a couple well recorded songs in alac format that I resort to that have a very nice clean, impacting kick drum. Couldn't hardly tell if the sub was on. So I bumped it up 6-8 db sand hey it sounded amazing and gave a tactile feel to it as well. Volume about -10 to -15 ish area with dyn EQ on.

The AVR I would get would be the Denon X4000 if I upgraded now. I may wait, maybe not. I have mains as the next upgrade.
post #5460 of 9570
So is my 15hz drop a cancellation or something else? Any way to bring that up?
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