Room treatment to fix issues and add depth

[No.4]

 Good day, I am seeking some guidance on the topic of room treatment. I feel my system is at a point where the most beneficial changes will come from addressing the listening space rather than component tweaks. My goal is to use treatments to make my listening space seem to have more depth, and to reduce or treat as many negatively influencing elements as possible. In my little bit of spare time I have done some reading about bass traps for the corner and ceiling, absorption panels for first reflections and diffusion for the back walls and everywhere else. Most resources I have found seem to prescribe different combinations of all of these elements. 

 

All of the resources I found are addressing direct radiating speakers that are out of the corners. I am using la scala clones that are in the corners. Hopefully this will spawn some discussion that will specifically address room treatments that are relevant to corner placed speakers and their interaction with the corner and the increase or decrease in performance that room treatments may cause. I do not use any components that have any built in room correction software, so all correction will have to be achieved through room treatments.

 

One common issue mentioned by most threads and many "professional" resources is over treating and under treating. These are claimed to be the common mistakes made by those creating a "hi-if" listening space. The mention of electronic measurement is mentioned by some and totally ignored by others. REW gets quite a bit of mention on this forum and many others as the go to for in room measurement. Unfortunately for me I can not use REW because All I have for measurement is an iPad and iPhone. I did purchase a umik-1, however in my haste I did not realize that REW is not compatible with iPads. Oops. Faber makes measurement software that is designed for i devices but I have not found much discussion of its implementation. The software is not free which is my guess as to why it is not as popular. If anyone has any experience with the faber software or any others that are compatible with the umik and I devices please share. This does not have to be ultra high end software, just good enough to get useful measurements. 

 

I know there are many threads on this topic but I have not found any that have similar discussions about a room and system similar to mine. I have a relatively small room with some openings to other rooms and a large window that is located at a first reflection point for one channel. I will attach some photos of my room so the description will make sense. My system consists of the afore mentioned la scala clones, a 5ish watt SET, a stepped attenuator as a pre, an ERC-3 and a long style table tuba sub that fires towards the ceiling in one of the rear corners. I have some waf considerations when it comes to treating the room, but I think I can blend most treatments in an aesthetically pleasing way that should keep me off the radar.

 

I would like to take the RIGHT measurements before I start building and placing any kind of room treatments. This is where the info I have found on the process appears to stray off in different directions. I know at least a few of you have some experience on this topic, so please share. Of course if there are any resources that any of you know of that are more specific my setup, please share them as well. 

 

The following are the first steps of the process as I understand it so far, (which could be totally wrong or missing several components).

 

To begin, The first measurement should be in an untreated room running a signal through the full frequency range at a specific spl to get a good baseline. Both channels need to be measured individually and then both together. Ok, if that is correct, then here come the questions. Do these measurements need to be taken from the listening position at ear height? Do I leave the sub on for all of these measurements? What precisely should I be measuring for? Am I measuring the decay time of frequencies and then addressing those that appear to last longer than the others? How do I determine which treatment is appropriate for those frequencies and where they need to be placed? Is it trial and error? Is it build, place, measure repeat? Did I get any of that right? What did I miss? Thanks in advance.

 

 

[No.4]

Left side from listening position

[No.4]

Right Side from listening position

[No.4]

Listening position, the multicolored wall piece is filled with denim insulation.

[Chris A]

1 hour ago, No.4 said:

Unfortunately for me I can not use REW because All I have for measurement is an iPad and iPhone.

I think it's much better to buy a dedicated netbook at low cost and use REW.  These can be had for much less than $100:

 

https://www.amazon.com/s/ref=lp_1232596011_st?rh=n%3A172282%2Cn%3A!493964%2Cn%3A541966%2Cn%3A13896617011%2Cn%3A565108%2Cn%3A1232596011&qid=1495389142&sort=price-asc-rank

 

The advantages of doing it this way significantly outweigh trying to find an app for a iPad that can do even a fraction of what REW can do, and you're basically on your own with an iPad app.

 

1 hour ago, No.4 said:

I would like to take the RIGHT measurements before I start building and placing any kind of room treatments.

You can do it that way...but I've found that using a few fuzzy blankets or comforters tacked up on the side walls just even with the midrange horn mouths and extending toward the listener by about 2 feet--works wonders.  Put some down on the floor, too, just in front of the bass bins and extending perhaps 4 feet in front of each bass bin.

 

Listen to the difference in center phantom imaging when you do this--it should immediately become very strong and focused. This should be a fairly dramatic change in the soundstage imaging--for the better.

 

1 hour ago, No.4 said:

The first measurement should be in an untreated room running a signal through the full frequency range at a specific spl to get a good baseline. Both channels need to be measured individually and then both together.

This is good to have, but my question is "why"?  What are you going to do with the untreated measurements?  Doing an A-minus-B measurement is interesting, but what actually matters is how it sounds to you.  If you had hard and fast criteria on what you were going to achieve (like a mixing/mastering control room), then those measurements would be useful. 

 

But in my experience, you need something in the corners (bass traps in two of the four corners, preferably the front corners) and early reflection absorption panels on the side walls and perhaps absorption on large acoustically reflective objects between your La Scalas (try blankets temporarily).

 

The notion of "first reflection point treatments" is basically urban myth in my experience.  What I've found to be key is controlling only the early reflections from within 3-4 feet of your loudspeakers, and corner bass traps to control "boom"--if you have a flat ceiling of 8 feet or higher and a rectangular-shaped room

 

Measuring left and right channels together isn't a fruitful exercise in my experience unless you like looking at comb filtering effects and finding out just how sensitive the microphone position is to what you're measuring.  If you measure at your listening position, get used to the fact that all your phase measurements will be garbage (unless you have a heavily absorption overtreated room). 

 

1 hour ago, No.4 said:

Do these measurements need to be taken from the listening position at ear height?

Not the first thing to do--in my experience.  One metre in front of each loudspeaker centered on the front panel of the loudspeaker for the first measurements--as this will give you real information about what is going on.  Once you get that under control, then moving to the LP and ear height is the next step.  But recognize that all you're going to be doing at the LP is measuring frequencies below the Schroeder frequency of the room (i.e., less than 200 Hz) which have much less to do with stereo imaging than the side wall treatments and 1-metre microphone measurements.  All the LP measurements are doing are showing you how much the room modes and placement of the listening position(s) interact at lower frequencies.

 

1 hour ago, No.4 said:

Do I leave the sub on for all of these measurements?

One measurement with the sub off, one on.

 

1 hour ago, No.4 said:

What precisely should I be measuring for? Am I measuring the decay time of frequencies and then addressing those that appear to last longer than the others?

REW will show you the calculated RT curves vs. frequency.  This is a gross measurement capability that tell you if you need more absorption in-room.  As far as when those strongest reflections show up, you'll need REW's impulse and waterfall plots. We can go through those a step at a time.

 

1 hour ago, No.4 said:

How do I determine which treatment is appropriate for those frequencies and where they need to be placed?

That comes from looking at the waterfall and spectrogram plots within REW.

 

1 hour ago, No.4 said:

Is it trial and error? Is it build, place, measure repeat? Did I get any of that right?

Basically, this is correct.  You're looking at placing some absorption/diffusion in-room and looking at the differences--once you get the near-field absorption under control.

 

1 hour ago, No.4 said:

What did I miss?

You basically got the main points, but I believe that you missed talking about the present sound of your room: what is it that you hear that you don't like?

 

Chris

[No.4]

2 hours ago, Chris A said:

I think it's much better to buy a dedicated netbook at low cost and use REW.  These can be had for much less than $100:

 

https://www.amazon.com/s/ref=lp_1232596011_st?rh=n%3A172282%2Cn%3A!493964%2Cn%3A541966%2Cn%3A13896617011%2Cn%3A565108%2Cn%3A1232596011&qid=1495389142&sort=price-asc-rank

 

The advantages of doing it this way significantly outweigh trying to find an app for a iPad that can do even a fraction of what REW can do, and you're basically on your own with an iPad app.

Finding very few threads anywhere citing this software had me worried. Sadly I have a laptop graveyard in my closet, but I think your right having the support that comes with the popularity of REW will be worth the price of a cheap laptop.

Quote

 

This is good to have, but my question is "why"?  What are you going to do with the untreated measurements?  Doing an A-minus-B measurement is interesting, but what actually matters is how it sounds to you. 

I want to have them for comparison to better understand the differences in what I may be hearing. Maybe more for my curiosity than anything.

Quote

 

But in my experience, you need something in the corners (bass traps in two of the four corners, preferably the front corners) and early reflection absorption panels on the side walls and perhaps absorption on large acoustically reflective objects between your La Scalas (try blankets temporarily).

My first notion was to start building bass traps for the corners and treat the walls next to the mid and high frequency horns, however the more I read the more I thought I should measure first.

Quote

 

The notion of "first reflection point treatments" is basically urban myth in my experience.  What I've found to be key is controlling only the early reflections from within 3-4 feet of your loudspeakers, and corner bass traps to control "boom"--if you have a flat ceiling of 8 feet or higher and a rectangular-shaped room

 

Measuring left and right channels together isn't a fruitful exercise in my experience unless you like looking at comb filtering effects and finding out just how sensitive the microphone position is to what you're measuring.  If you measure at your listening position, get used to the fact that all your phase measurements will be garbage (unless you have a heavily absorption overtreated room). 

 

Not the first thing to do--in my experience.  One metre in front of each loudspeaker centered on the front panel of the loudspeaker for the first measurements--as this will give you real information about what is going on.  Once you get that under control, then moving to the LP and ear height is the next step.  But recognize that all you're going to be doing at the LP is measuring frequencies below the Schroeder frequency of the room (i.e., less than 200 Hz) which have much less to do with stereo imaging than the side wall treatments and 1-metre microphone measurements.  All the LP measurements are doing are showing you how much the room modes and placement of the listening position(s) interact at lower frequencies.

 

All good to know, thank you.

 

One measurement with the sub off, one on.

 

REW will show you the calculated RT curves vs. frequency.  This is a gross measurement capability that tell you if you need more absorption in-room.  As far as when those strongest reflections show up, you'll need REW's impulse and waterfall plots. We can go through those a step at a time.

 

That will be very helpful!

 

Quote

That comes from looking at the waterfall and spectrogram plots within REW.

 

Basically, this is correct.  You're looking at placing some absorption/diffusion in-room and looking at the differences--once you get the near-field absorption under control.

 

You basically got the main points, but I believe that you missed talking about the present sound of your room: what is it that you hear that you don't like?

 

Chris

The present sound in my room is pretty good. The sound stage is pretty good All in all. The bass I feel at times could be more accurate. There is some echo in the room especially now that the warmer weather has drawn the plants out of the room. I don't know if there is anything I don't really like, I just want to get the most out of my current system. Thanks Chris!

 

[Chris A]

Listening position (LP) measurements can be useful in finding the severity, direction, and timing of strong first reflections and to get an idea of measured reverberation time (RT) curves vs. frequency for the area of the room from where you're listening.  But to get good LP measurements that are understandable, one metre measurements are the key enabler.  Once you understand what your corner-loaded horn loudspeakers are doing in the absence of strong first reflections, then carrying those measurements back to the LP is a much easier task.  Separating first reflections from direct arrival acoustic energy is always of interest (hence the use of anechoic chambers to test loudspeakers). 

 

Since no anechoic chambers are available at home then the next best thing are the one metre measurements.  Using one metre measurements will get you much better impulse response understanding (even though the software is using up-sweeps).  Phase of the different frequencies that make up a loudspeaker's impulse response is key to picking out the problematic reflections in the near field, such as side walls, front wall, ceiling, floor, and large object (furniture and racks) reflections. Using the one metre measurements will allow you to track those strong near field reflections to the LP measurements in order to help pick out direction of arrival.

 

17 hours ago, No.4 said:

Hopefully this will spawn some discussion that will specifically address room treatments that are relevant to corner placed speakers and their interaction with the corner and the increase or decrease in performance that room treatments may cause.

 

I agree that almost everything on the web and in print is dealing with direct radiating loudspeakers.  The issue with these is that they have constantly changing polar coverage that's a function of frequency, and real issues with too-wide coverage at many frequencies bouncing off the room boundaries and furniture.  For those reasons, you see a lot of advice to space those type of loudspeakers away from the room boundaries.  This is a terrible price to pay for using direct radiators, because DRs already have many more issues with extremely high bass modulation distortion and placing any loudspeaker away from the walls makes this problem even worse.  Having loudspeakers away from the walls out onto the floor of the room takes up a lot of valuable real estate (dipole-type DR loudspeakers take the cake in this category). 

 

17 hours ago, No.4 said:

I do not use any components that have any built in room correction software, so all correction will have to be achieved through room treatments.

 

If you are placing all your eggs into the room treatment basket, then IMO, this actually increases the need for understanding what your loudspeakers are actually doing, even though you have little control over their frequency response by not using room correction EQ.

 

17 hours ago, No.4 said:

I have a relatively small room with some openings to other rooms and a large window that is located at a first reflection point for one channel.

 

The issue for these room openings is diffraction of sound at the door boundaries.  When you listen to your loudspeakers playing and then move close to a door opening, you will hear a disruption of the stereo imaging and frequency response around those areas.  Non-symmetry of room openings with the left-right channel loudspeaker positions is also an issue.

 

17 hours ago, No.4 said:

Of course if there are any resources that any of you know of that are more specific my setup, please share them as well.

 

Strangely, this is apparently a difficult subject about which to find written information. That's why I wrote the corner-horn imaging FAQ many years ago--to share what I had independently found through trial and error, and talking to at least one Klipsch engineer (Roy Delgado) about the major differences in using controlled directivity loudspeakers in room corners.  Even PWK didn't write very much on this subject other than to say how to position Khorns symmetrically in the room corners or to use false corners.  Many of the points made in the corner horn imaging FAQ were made via personal discovery and thinking about the acoustics and psychoacoustics involved for each topic.

 

If you decide to continue your room acoustic treatment efforts, feel free to ask more specific questions regarding measurements and acoustic panel placement suggestions.  There is much that is context-specific that would be long and laborious to write down in one long posting.

 

Chris

[Chris A]

REW support recently switched to this new forum.  Here is a list that the REW author recently put together for tutorials and help files: https://www.avnirvana.com/threads/some-guides-to-rew-and-acoustic-measurement.121/

[Chris A]

BTW:  REW also runs on Macintosh OS X and Linux...for those that run those OSes: http://www.roomeqwizard.com/

[Peter P.]

I'm gonna question whether it's possible your speakers are too "acoustically large" for the small room. You may not be able to sit far enough away from them for optimal results.

 

I think your room dimensions, the exposed hardwood floor, and the room openings are a bigger factor than you imagine. With all that escaping air, I question how much positive effect any room treatments will have.

[dirtmudd]

On 5/21/2017 at 1:24 PM, No.4 said:

 Good day, I am seeking some guidance on the topic of room treatment. I feel my system is at a point where the most beneficial changes will come from addressing the listening space rather than component tweaks. My goal is to use treatments to make my listening space seem to have more depth, and to reduce or treat as many negatively influencing elements as possible. In my little bit of spare time I have done some reading about bass traps for the corner and ceiling, absorption panels for first reflections and diffusion for the back walls and everywhere else. Most resources I have found seem to prescribe different combinations of all of these elements. 

 

All of the resources I found are addressing direct radiating speakers that are out of the corners. I am using la scala clones that are in the corners. Hopefully this will spawn some discussion that will specifically address room treatments that are relevant to corner placed speakers and their interaction with the corner and the increase or decrease in performance that room treatments may cause. I do not use any components that have any built in room correction software, so all correction will have to be achieved through room treatments.

 

One common issue mentioned by most threads and many "professional" resources is over treating and under treating. These are claimed to be the common mistakes made by those creating a "hi-if" listening space. The mention of electronic measurement is mentioned by some and totally ignored by others. REW gets quite a bit of mention on this forum and many others as the go to for in room measurement. Unfortunately for me I can not use REW because All I have for measurement is an iPad and iPhone. I did purchase a umik-1, however in my haste I did not realize that REW is not compatible with iPads. Oops. Faber makes measurement software that is designed for i devices but I have not found much discussion of its implementation. The software is not free which is my guess as to why it is not as popular. If anyone has any experience with the faber software or any others that are compatible with the umik and I devices please share. This does not have to be ultra high end software, just good enough to get useful measurements. 

 

I know there are many threads on this topic but I have not found any that have similar discussions about a room and system similar to mine. I have a relatively small room with some openings to other rooms and a large window that is located at a first reflection point for one channel. I will attach some photos of my room so the description will make sense. My system consists of the afore mentioned la scala clones, a 5ish watt SET, a stepped attenuator as a pre, an ERC-3 and a long style table tuba sub that fires towards the ceiling in one of the rear corners. I have some waf considerations when it comes to treating the room, but I think I can blend most treatments in an aesthetically pleasing way that should keep me off the radar.

 

I would like to take the RIGHT measurements before I start building and placing any kind of room treatments. This is where the info I have found on the process appears to stray off in different directions. I know at least a few of you have some experience on this topic, so please share. Of course if there are any resources that any of you know of that are more specific my setup, please share them as well. 

 

The following are the first steps of the process as I understand it so far, (which could be totally wrong or missing several components).

 

To begin, The first measurement should be in an untreated room running a signal through the full frequency range at a specific spl to get a good baseline. Both channels need to be measured individually and then both together. Ok, if that is correct, then here come the questions. Do these measurements need to be taken from the listening position at ear height? Do I leave the sub on for all of these measurements? What precisely should I be measuring for? Am I measuring the decay time of frequencies and then addressing those that appear to last longer than the others? How do I determine which treatment is appropriate for those frequencies and where they need to be placed? Is it trial and error? Is it build, place, measure repeat? Did I get any of that right? What did I miss? Thanks in advance.

 

 

that's nice !

[dirtmudd]

On 5/21/2017 at 1:24 PM, No.4 said:

 Good day, I am seeking some guidance on the topic of room treatment. I feel my system is at a point where the most beneficial changes will come from addressing the listening space rather than component tweaks. My goal is to use treatments to make my listening space seem to have more depth, and to reduce or treat as many negatively influencing elements as possible. In my little bit of spare time I have done some reading about bass traps for the corner and ceiling, absorption panels for first reflections and diffusion for the back walls and everywhere else. Most resources I have found seem to prescribe different combinations of all of these elements. 

 

All of the resources I found are addressing direct radiating speakers that are out of the corners. I am using la scala clones that are in the corners. Hopefully this will spawn some discussion that will specifically address room treatments that are relevant to corner placed speakers and their interaction with the corner and the increase or decrease in performance that room treatments may cause. I do not use any components that have any built in room correction software, so all correction will have to be achieved through room treatments.

 

One common issue mentioned by most threads and many "professional" resources is over treating and under treating. These are claimed to be the common mistakes made by those creating a "hi-if" listening space. The mention of electronic measurement is mentioned by some and totally ignored by others. REW gets quite a bit of mention on this forum and many others as the go to for in room measurement. Unfortunately for me I can not use REW because All I have for measurement is an iPad and iPhone. I did purchase a umik-1, however in my haste I did not realize that REW is not compatible with iPads. Oops. Faber makes measurement software that is designed for i devices but I have not found much discussion of its implementation. The software is not free which is my guess as to why it is not as popular. If anyone has any experience with the faber software or any others that are compatible with the umik and I devices please share. This does not have to be ultra high end software, just good enough to get useful measurements. 

 

I know there are many threads on this topic but I have not found any that have similar discussions about a room and system similar to mine. I have a relatively small room with some openings to other rooms and a large window that is located at a first reflection point for one channel. I will attach some photos of my room so the description will make sense. My system consists of the afore mentioned la scala clones, a 5ish watt SET, a stepped attenuator as a pre, an ERC-3 and a long style table tuba sub that fires towards the ceiling in one of the rear corners. I have some waf considerations when it comes to treating the room, but I think I can blend most treatments in an aesthetically pleasing way that should keep me off the radar.

 

I would like to take the RIGHT measurements before I start building and placing any kind of room treatments. This is where the info I have found on the process appears to stray off in different directions. I know at least a few of you have some experience on this topic, so please share. Of course if there are any resources that any of you know of that are more specific my setup, please share them as well. 

 

The following are the first steps of the process as I understand it so far, (which could be totally wrong or missing several components).

 

To begin, The first measurement should be in an untreated room running a signal through the full frequency range at a specific spl to get a good baseline. Both channels need to be measured individually and then both together. Ok, if that is correct, then here come the questions. Do these measurements need to be taken from the listening position at ear height? Do I leave the sub on for all of these measurements? What precisely should I be measuring for? Am I measuring the decay time of frequencies and then addressing those that appear to last longer than the others? How do I determine which treatment is appropriate for those frequencies and where they need to be placed? Is it trial and error? Is it build, place, measure repeat? Did I get any of that right? What did I miss? Thanks in advance.

 

 

put the speakers on the long wall

[Chris A]

8 minutes ago, Peter P. said:

I'm gonna question whether it's possible your speakers are too "acoustically large" for the small room. You may not be able to sit far enough away from them for optimal results.

Where did you get this notion of "too acoustically large"?  I'd like to read on this subject.

 

Chris

[Chris A]

2 minutes ago, dirtmudd said:

put the speakers on the long wall

Is this a commandment or a question?

[minermark]

10 minutes ago, Peter P. said:

too "acoustically large"

Oh my God, shoot me now.

I think im a victim of this, thanx for pointing out.

 

.......Note to self, increase Volume........

[dirtmudd]

Just now, Chris A said:

Is this a comment or a question?

it is a comment

 

http://stereonomono.blogspot.com/2016/06/klipsch-la-scala.html

[minermark]

On 5/21/2017 at 10:39 AM, No.4 said:

Listening position, the multicolored wall piece is filled with denim insulation.

If your married, you have a good wife.

[Chris A]

6 minutes ago, dirtmudd said:

it is a comment

 

http://stereonomono.blogspot.com/2016/06/klipsch-la-scala.html

 

I actually don't agree...for the room shown.

 

See: https://community.klipsch.com/applications/core/interface/file/attachment.php?id=66006...page 4.

 

 

[jason str]

The only way i have experienced speakers too large for a room is sitting too close to them and not getting a coherent blending of sound.

 

For instance tweeters firing 3 feet over your head.

[derrickdj1]

Hmmmm......  Can a speaker be to large for a room, it depends?  Correct question, are those speaker to large for that room.