Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 361 - AVS Forum
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post #10801 of 10818 Old Yesterday, 04:57 PM
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Originally Posted by Alan P View Post

Adding more subs won't necessarily get you flatter, but it will make the response flat over a wider area (less seat-to-seat variance).
Not necessarily true, Alan. By carefully placing multiple subs, there can be a measurable flattening of the frequency response, both at the MLP, and over the wider area.

I have provided an example: AustinJerry's Set-Up
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post #10802 of 10818 Old Yesterday, 05:18 PM
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Originally Posted by HDgaming42 View Post
Is this as true for music as for movies?
Don't you have music in movies you are watching? Sure it is true!

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Originally Posted by HDgaming42 View Post
I see advice like the following posted around the net...
If we tell about acoustics when we tell about the distance we actually tell about the delay. As long as you have control on the delay you have control on the acoustic distance. The physical distance doesn't matter and with subs is usually differ from acoustical one. Up to 80Hz with 24db/oct slope (acoustical one again, electrical doesn't matter) works best.

The rules you quoted apply if you do not have decent bass management in your processor.
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post #10803 of 10818 Old Yesterday, 08:49 PM
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Originally Posted by AustinJerry View Post
Not necessarily true, Alan. By carefully placing multiple subs, there can be a measurable flattening of the frequency response, both at the MLP, and over the wider area.

I have provided an example: AustinJerry's Set-Up
I'm aware Jerry, that's why I said "won't necessarily".

Since HD is only worried about a flat response at the MLP and isn't considering multiple subs at this time, I think we can safely forego any multiple sub scenario for now.
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post #10804 of 10818 Old Today, 07:32 AM
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Originally Posted by HDgaming42 View Post
Next up--I'm guessing--will be to treat the back wall. My back corners have a door on one side, and a cubby for an equipment rack on the other, so no easy way to trap those corners unfortunately.
I haven't done my back wall yet (that's next), but I did see a huge improvement when my ceiling panels went up.

Pictures here of the entire process so far:
http://imgur.com/a/YOLoo

I suspect that this has more to do with surface area more than anything else. These are basically 4' x 4' or 16 square feet each. So, there's 64 square feet of absorption up there. Six inches thick + 2 inch air gap.

I'm planning on doing about 40 square feet (5 panels of 2' x 4') on the rear wall. (6" + 2" again, but this time with Roxul AFB instead of the pink fluffy that is in the cloud). I suspect that will help as well.

-Kevin
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post #10805 of 10818 Old Today, 09:10 AM
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http://www.audiocheck.net/audiotests...calization.php
Low Frequency Sound Localization Test

This test will help you determine at what frequency localization in the bass region ceases. Download the files and listen. On my ears and system, localization seemed to definitely suffer starting at about 80hz, and was completely gone by 50hz. ( I ignored the part about turning off my subs for I wanted to see how things are perceived in my room as I normally listen to them).

In further reading today, I am not sure there is a universal number. The size of your woofers, speakers in general, and room size all seem to play a part. With all this talk recently of sub XO points and such, I wanted to gain more depth on the subject. 80hz gets tossed around as the prime XO a lot. Perhaps for good reason. But there maybe means to extend localization lower through better understanding.

My Room
http://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html

My Music
http://rateyourmusic.com/~jim1961

My Equipment

Rega - Apollo
Rega - DAC
Goldpoint Passive
(2) Classe CA-100 bridged power amps (350w)
Jenzen Next ( http://www.troelsgravesen.dk/Jenzen-NEXT.htm )
...

Last edited by jim19611961; Today at 09:17 AM.
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post #10806 of 10818 Old Today, 09:10 AM
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Originally Posted by KevinG View Post
I haven't done my back wall yet (that's next), but I did see a huge improvement when my ceiling panels went up.

Pictures here of the entire process so far:
http://imgur.com/a/YOLoo

I suspect that this has more to do with surface area more than anything else. These are basically 4' x 4' or 16 square feet each. So, there's 64 square feet of absorption up there. Six inches thick + 2 inch air gap.

I'm planning on doing about 40 square feet (5 panels of 2' x 4') on the rear wall. (6" + 2" again, but this time with Roxul AFB instead of the pink fluffy that is in the cloud). I suspect that will help as well.

-Kevin
I've checked out your progress in the past--didn't realize you were still going! Do you have before and after graphs? Could be good to motivate myself!
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post #10807 of 10818 Old Today, 10:31 AM
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Originally Posted by HDgaming42 View Post
I've checked out your progress in the past--didn't realize you were still going! Do you have before and after graphs? Could be good to motivate myself!
Yep, still going...just a bit slower now. :-) I have 2 more "wall panels" mostly built, but not sure where to put them (if anywhere).

I have mental plans for how to build the rear wall panels, but haven't purchased the wood for it yet.

I *do* have before and after graphs. Mostly I was concentrating on the impulse graphs to try to get things down by 20db within 20ms. I'm not quite there yet, but the overall drop is huge. I actually haven't really looked at SPL over the spectrum recently...nor have I measured with Audyssey turned back on. I should get around to doing that.

Anyway, I'll try to find time to put together a post with the before and after graphs soon. They aren't subtle.

-Kevin
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post #10808 of 10818 Old Today, 10:43 AM
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Originally Posted by KevinG View Post
Yep, still going...just a bit slower now. :-) I have 2 more "wall panels" mostly built, but not sure where to put them (if anywhere).

I have mental plans for how to build the rear wall panels, but haven't purchased the wood for it yet.

I *do* have before and after graphs. Mostly I was concentrating on the impulse graphs to try to get things down by 20db within 20ms. I'm not quite there yet, but the overall drop is huge. I actually haven't really looked at SPL over the spectrum recently...nor have I measured with Audyssey turned back on. I should get around to doing that.

Anyway, I'll try to find time to put together a post with the before and after graphs soon. They aren't subtle.

-Kevin
Posting before/after room measurements are probably the most helpful, encouraging and inspiring posts we can make. Not to single you out, we should all do this.

To start this tradition, here is my first FR for the right channel. I had mild treatment at that time. Additionally, I have changed main speakers and added subs as well.

then and now 07 30.jpg
(1/24th octave smoothing)

Red = Then
Green = Now

My ETC data only goes back about a year, and look similar to now, so I didnt post them.

My Room
http://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html

My Music
http://rateyourmusic.com/~jim1961

My Equipment

Rega - Apollo
Rega - DAC
Goldpoint Passive
(2) Classe CA-100 bridged power amps (350w)
Jenzen Next ( http://www.troelsgravesen.dk/Jenzen-NEXT.htm )
...

Last edited by jim19611961; Today at 10:54 AM.
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post #10809 of 10818 Old Today, 10:49 AM
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Quote:
Originally Posted by jim19611961 View Post
http://www.audiocheck.net/audiotests...calization.php
Low Frequency Sound Localization Test

This test will help you determine at what frequency localization in the bass region ceases. Download the files and listen. On my ears and system, localization seemed to definitely suffer starting at about 80hz, and was completely gone by 50hz. ( I ignored the part about turning off my subs for I wanted to see how things are perceived in my room as I normally listen to them).

In further reading today, I am not sure there is a universal number. The size of your woofers, speakers in general, and room size all seem to play a part. With all this talk recently of sub XO points and such, I wanted to gain more depth on the subject. 80hz gets tossed around as the prime XO a lot. Perhaps for good reason. But there maybe means to extend localization lower through better understanding.
...and, sometimes you may think you're localizing when your really not. Case in point; I've had subs in the rear of my room and thought I could localize them (particularly in the right rear, closest to MLP) but when I moved all subs up front, I still get a "sense" of more bass emanating from the right rear corner.

The room plays a big part in all of this, more than may seem apparent at times.
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post #10810 of 10818 Old Today, 10:54 AM
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Originally Posted by jim19611961 View Post
http://www.audiocheck.net/audiotests...calization.php
Low Frequency Sound Localization Test

This test will help you determine at what frequency localization in the bass region ceases. Download the files and listen. On my ears and system, localization seemed to definitely suffer starting at about 80hz, and was completely gone by 50hz. ( I ignored the part about turning off my subs for I wanted to see how things are perceived in my room as I normally listen to them).

In further reading today, I am not sure there is a universal number. The size of your woofers, speakers in general, and room size all seem to play a part. With all this talk recently of sub XO points and such, I wanted to gain more depth on the subject. 80hz gets tossed around as the prime XO a lot. Perhaps for good reason. But there maybe means to extend localization lower through better understanding.
I can't find the link now but I have read something in the past on this subject that suggests that, while your ability to localise such frequencies is weak, you can still perceive some element of the interaural phase difference & hence multiple, non colocated, subs are beneficial to SQ not just via the effect on frequency response. This paper provides some evidence to support that (though I don't know whether this has since been refuted)

Another point that I'm sure I've come across before is that higher frequency content will effectively steer your perception of the LF content. This argues against using localisation as the only criteria for setting the XO as most content is not just purely LF energy (i.e. your perception of direction will be dominated by the accompanying HF energy).

In general I can't see how you can push the localisation boundary lower (short of growing a giant head) but I can see ways you could push it higher.
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post #10811 of 10818 Old Today, 11:07 AM
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I can't find the link now but I have read something in the past on this subject that suggests that, while your ability to localise such frequencies is weak, you can still perceive some element of the interaural phase difference & hence multiple, non colocated, subs are beneficial to SQ not just via the effect on frequency response. This paper provides some evidence to support that (though I don't know whether this has since been refuted)

Another point that I'm sure I've come across before is that higher frequency content will effectively steer your perception of the LF content. This argues against using localisation as the only criteria for setting the XO as most content is not just purely LF energy (i.e. your perception of direction will be dominated by the accompanying HF energy).

In general I can't see how you can push the localization boundary lower (short of growing a giant head) but I can see ways you could push it higher.
What I meant was, we may be inadvertently/artificially pushing it higher than need be. No, we are not going to surpass the capacity of the human condition, but there may be aspects of our setup that contribute to it being higher than it should.

I agree that the harmonics of lower register instruments/sources steer our perception of localization given they are easier to localize. I am not saying low frequency localization should be the only thing to consider for your XO point. But I submit it as one among many.

If one does the test I mentioned, and localization is already difficult at 200hz, for instance, I would say that something is interfering with your ability to make this discernment, and quite possibly a setup correction is in order.

My Room
http://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html

My Music
http://rateyourmusic.com/~jim1961

My Equipment

Rega - Apollo
Rega - DAC
Goldpoint Passive
(2) Classe CA-100 bridged power amps (350w)
Jenzen Next ( http://www.troelsgravesen.dk/Jenzen-NEXT.htm )
...

Last edited by jim19611961; Today at 11:20 AM.
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post #10812 of 10818 Old Today, 11:10 AM
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Originally Posted by Alan P View Post
...and, sometimes you may think you're localizing when your really not. Case in point; I've had subs in the rear of my room and thought I could localize them (particularly in the right rear, closest to MLP) but when I moved all subs up front, I still get a "sense" of more bass emanating from the right rear corner.

The room plays a big part in all of this, more than may seem apparent at times.
That is a good case in point. A phenomena I would try to fix if I could.

My Room
http://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html

My Music
http://rateyourmusic.com/~jim1961

My Equipment

Rega - Apollo
Rega - DAC
Goldpoint Passive
(2) Classe CA-100 bridged power amps (350w)
Jenzen Next ( http://www.troelsgravesen.dk/Jenzen-NEXT.htm )
...
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post #10813 of 10818 Old Today, 11:49 AM
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Originally Posted by jim19611961 View Post
To start this tradition, here is my first FR for the right channel. I had mild treatment at that time. Additionally, I have changed main speakers and added subs as well.

Attachment 187962
(1/24th octave smoothing)

Red = Then
Green = Now
Very nice. Is "before" without room correction, and after with room correction? (meaning electronic correction, not treatments).

I plan on posting before (without Audyssey), after (without Audyssey), and after (with Audyssey).
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post #10814 of 10818 Old Today, 11:50 AM
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Very nice. Is "before" without room correction, and after with room correction? (meaning electronic correction, not treatments).

I plan on posting before (without Audyssey), after (without Audyssey), and after (with Audyssey).
I don't have or use processors of any kind, now or before.

Edit: Come to think of it, there was some EQ on the "before"(red) graph.

My Room
http://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html

My Music
http://rateyourmusic.com/~jim1961

My Equipment

Rega - Apollo
Rega - DAC
Goldpoint Passive
(2) Classe CA-100 bridged power amps (350w)
Jenzen Next ( http://www.troelsgravesen.dk/Jenzen-NEXT.htm )
...

Last edited by jim19611961; Today at 12:43 PM.
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post #10815 of 10818 Old Today, 01:23 PM
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Very nice. Is "before" without room correction, and after with room correction? (meaning electronic correction, not treatments).

I plan on posting before (without Audyssey), after (without Audyssey), and after (with Audyssey).
Ultimately if I could be selfish--this is what I'd love to see from those able to post their results. And the resulting waterfalls would be interesting too.
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post #10816 of 10818 Old Today, 01:23 PM
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Originally Posted by jim19611961 View Post
What I meant was, we may be inadvertently/artificially pushing it higher than need be. No, we are not going to surpass the capacity of the human condition, but there may be aspects of our setup that contribute to it being higher than it should.

I agree that the harmonics of lower register instruments/sources steer our perception of localization given they are easier to localize. I am not saying low frequency localization should be the only thing to consider for your XO point. But I submit it as one among many.

If one does the test I mentioned, and localization is already difficult at 200hz, for instance, I would say that something is interfering with your ability to make this discernment, and quite possibly a setup correction is in order.
(I agree with the above) the interesting thing there is that there are systems that deliberately run *much* higher crossovers. An example of that is a steinway lyngdorf setup. IIRC these crossover to a pair of corner loaded 12" woofers at ~400Hz (as per e.g. http://www.steinwaylyngdorf.com/tech...oundary-woofer) and sound pretty impressive to say the least (as you'd hope they would for >£50k!). It's never been entirely clear to me how they get away with this given the physical constraints of localisation.
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post #10817 of 10818 Old Today, 01:44 PM
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Originally Posted by HDgaming42 View Post
Ultimately if I could be selfish--this is what I'd love to see from those able to post their results. And the resulting waterfalls would be interesting too.
My system, Audyssey Off:



Audyssey On:



As you can see, I've got a giant null to contend with as well.
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post #10818 of 10818 Old Today, 01:50 PM
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And the corresponding waterfalls:

Aud Off:



Aud On:

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