# Home Theater Help needed in Pakistan



## shumail (Dec 9, 2012)

Hello Everyone,

I am in the process of building a new house and I've set aside a 15' X 20' room to be set up as a home theater in my basement. The two walls ("L" shape) are made of 4" Clay Brick backed by 5" reinforced concrete, one wall (intended projection wall) is 4" clay brick and the fourth wall is 9" clay brick. All 4 walls are to be covered with portland cement plaster (approx. 1" thick). The ceiling and floor are 5" thick reinforced concrete.

The entrance door is 3' wide and in a corner on the projection wall. It only takes about 1.5' from the 15' as the rest of the door is in a slight recess in the wall.

I've been searching the web and all I've done is gotten myself confused.

Unfortunately, here in Pakistan there is not a whole lot of technical expertise available at hand so I will have to do a lot of hand holding and supervise the contractors myself.

I have questions about everything:

1. How big should the screen be? I have 150" of space from the edge of the door to the wall with a height of 110". (I intend on using a projector)
2. How many rows of seating can I easily accommodate?
3. How high should each successive row be?
4. How wide should each row of seating be?
5. How do I treat the walls?
6. How do I treat the ceiling and floors?
7. How much space should I leave behind the last row of seating?
8. How high should the screen be from the floor?

I'm ready to pull my hair out just writing this post... Heeeeeellllllppppp Pleeeeaaseeee


----------



## JQueen (Jan 11, 2012)

Welcome to the Shack! Your house looks like it will be beautiful ..I don't have the answers but someone will, I just wanted to welcome you


----------



## chrapladm (Jun 17, 2009)

Hello and welcome to HTS. If you post your thread in Home Theater Design and Construction you will get all the answers you need.


----------



## ALMFamily (Oct 19, 2011)

Welcome to HTS! :wave:

Start up a build thread in the construction area - build threads attract a lot of people! :bigsmile:

Enjoy your time with us on the forums and be sure to subscribe to our newsletter!


----------



## Mike P. (Apr 6, 2007)

Welcome to the Home Theater Shack, glad to have you with us!

Thread moved to the Home Theater Design and Construction forum.


----------



## drdoan (Aug 30, 2006)

Welcome to the Forum. I would make sure your projector will produce a picture at the screen size you select. The distance from the projector to the screen is a factor. Also, ambient light will determine how bright the projector needs to be. Remember to leave room for speakers, subwoofers, equipment, and wiring. Have fun. Dennis


----------



## sdurani (Oct 28, 2010)

shumail said:


> The entrance door is 3' wide and in a corner on the projection wall. It only takes about 1.5' from the 15' as the rest of the door is in a slight recess in the wall.


I would urge you to reconsider which wall you're going to use for projection. Better to have the entrance at the back of the room than up front. Switching your layout 180 degrees will also make the side walls in the front of your set-up more consistent (no cut-out) from left to right, which will give you greater consistency in the front soundstage (more important to have consistency up front than in the surround field).


shumail said:


> I have questions about everything:


I'll make suggestions for the audio part; hopefully someone will chime in with help on your video-based questions.


shumail said:


> 2. How many rows of seating can I easily accommodate?


With a 20' room length, you can accomodate a couple of rows comfortably. Rather than compromise the sound in both rows, I would optimize for one row and let the other fall where it may. If one of the rows is going to be compromised anyway, why compromise the other when you can optimize it. With that in mind, I would make the front row your main listening position. When guests visit, you can sit in the back and give them the better experience. After all, you'll be living there and will have access to the front row whenever you want. 

Typically, one of the 1/3rd or 1/5th divisions of room length is where you get the least variation in frequency response (fewer/smaller peaks & dips). So I would put the front row (i.e., the listeners' ears in the front row) at 12 feet from the front wall, which is 3/5ths of room length. Build a riser/platform behind the seating, so you can push your front row seats up against it, and stretch the riser all the way to the back wall. This will give you a platform around 7 feet deep (front to back), which will allow some flexibility in placement (move the second row seats back and forth until you are comfortable with the leg space).


shumail said:


> 4. How wide should each row of seating be?


According to the diagram you posted, looks like your room is 14'9" wide. A quarter of the room width (44") in from the side walls is where you get a null (quiet zone in the low frequencies due to sound waves cancelling). So I would try to keep the seats (well, at least the listeners' ears) away from those nulls, keep your seating less than 7'-7.5' wide.


shumail said:


> 5. How do I treat the walls?


Even in this day and age of surround sound, the front soundstage remains critical; that's where your attention will be focused, whether watching a movie or listening to music. With that in mind, it doesn't help to have sound from the surround speakers reflect off the front wall, thereby muddying the soundstage by coming from the same direction as the front speakers. So lots of absorbtion on the front wall. 

I would use less absorbtion on the back wall, keeping it inbetween the rear speakers and using diffusion out side of that. The main goal is to keep dialogue and other sounds in the front soundstage from reflect off the back wall and reaching your ears from behind you (can sometimes sound like someone whispering back there). 

Some of this comes down to preference. Research into statistical listener preference over the last 60 years shows that most people don't like reflections from in front and behind them (roughly +/-40 degrees from the listener's centre line). By comparison, blind testing showed that most listeners really like early reflections off the side walls, especially near the front, because it broadens the soundstage and improves speech intelligibility (easier to understand dialogue). 

The only absorbtion I would place on the side walls is to catch the first reflection of the opposite speaker: i.e., first reflection of the left front speaker on the right side wall, and vice versa. If you can cut down on sounds from the left side of the soundstage coming (however subtly) from the right side of the room, directionality up front sounds a bit more precise.


shumail said:


> 6. How do I treat the ceiling and floors?


Double padding under the carpeting for a little help with sound absorbtion. I like thick carpeting under my bare feet, but that's up to you. I would pick a dark colour to help cut down light reflections. The jury is still out on whether reflections from the ceiling up front help or hurt. Personally, I would treat the ceiling up front with either absorbtion or diffusion (to break up and scatter the reflection). You don't have to use too much, just where the front speakers reflect off the ceiling. 

Finally, even though you didn't ask, some suggestions for speaker placement: 

I would put the front L/R speaker about 2.5' from the side walls. For your room width, this should cut down on some of the peaks & dips in the low frequencies, giving you smoother bass/mid-bass/upper-bass response (the frequencies where your speakers interact most with the room). Point each speaker to the person on the opposite end of the row, so that the nearby speaker doesn't dominate. Keeping the same speaker spread (about 10' apart), moving them close will widen the soundstage: speakers on the front wall will give you narrower than a 45 degree soundstage (too narrow for my tastes), moving the speaker plane 2' closer will give you a 53 degree soundstage (my preference), and moving them 3.5 feet from the front wall will result in a 60 degree wide soundstage (sounds good with music, though some people find it too wide). 

Side speakers can go directly to the sides of the listening area, mounted at least a couple of feet above ear level, aimed down towards the listening area. This will stabilize lateral imaging AND give you excellent side-vs-rear separation in the surround field. Rear speakers should go on the back wall, spread roughly 9.5'-10' apart, mounted at least a couple of feet above ear level, aimed at the person at the opposite end of the front row. Our human hearing is not so good behind us, so spreading the rear speakers at least 60 degrees apart will make it easier to hear left-vs-right stereo separation behind you. 

For your size room, the latest research shows that placing a couple of subs, each at the midpoint of the left and right wall, will give you the greatest consistency in the low frequencies across your seating area. If you need more output, then use 4 subs: each at the midpoints of the 4 walls, or at the quarter points of room length (5' from back wall, 5' from front wall) on the side walls. If you plan to use a receiver with room correction, like Audyssey, then having greater seat-to-seat consistency will make it easier for the system to do equalization. The more similarity it sees in the frequency response at different seats, the more problems (peaks & dips) it can fix at all the seats. 

BTW, what receiver were you planning on using?


----------



## shumail (Dec 9, 2012)

JQueen said:


> Welcome to the Shack! Your house looks like it will be beautiful ..I don't have the answers but someone will, I just wanted to welcome you


Thank you very much for the vote of confidence... it's always a question mark with new construction... http://www.hometheatershack.com/forums/images/smilies/shakehousedown.gif


----------



## shumail (Dec 9, 2012)

Thank you for the vote of confidence... it's always a question mark with new constructions....


----------



## shumail (Dec 9, 2012)

Thank you


----------



## shumail (Dec 9, 2012)

Hello Sanjay,

Thank you very much for your detailed feedback.



sdurani said:


> I would urge you to reconsider which wall you're going to use for projection. Better to have the entrance at the back of the room than up front. Switching your layout 180 degrees will also make the side walls in the front of your set-up more consistent (no cut-out) from left to right, which will give you greater consistency in the front soundstage (more important to have consistency up front than in the surround field). I'll make suggestions for the audio part; hopefully someone will chime in with help on your video-based questions.


Hmmm... I was hoping to use the length of the room in front of the door as the walkway. If I were to turn the whole thing around then I would have a ledge to the left side of the door due to the risers. This would also mean that I would have to allocate extra space for the walkway... one going up to the screen and then one coming back up the risers to the seats. What is your opinion on this?



sdurani said:


> With a 20' room length, you can accomodate a couple of rows comfortably. Rather than compromise the sound in both rows, I would optimize for one row and let the other fall where it may. If one of the rows is going to be compromised anyway, why compromise the other when you can optimize it. With that in mind, I would make the front row your main listening position. When guests visit, you can sit in the back and give them the better experience. After all, you'll be living there and will have access to the front row whenever you want. Typically, one of the 1/3rd or 1/5th divisions of room length is where you get the least variation in frequency response (fewer/smaller peaks & dips). So I would put the front row (i.e., the listeners' ears in the front row) at 12 feet from the front wall, which is 3/5ths of room length. Build a riser/platform behind the seating, so you can push your front row seats up against it, and stretch the riser all the way to the back wall. This will give you a platform around 7 feet deep (front to back), which will allow some flexibility in placement (move the second row seats back and forth until you are comfortable with the leg space). According to the diagram you posted, looks like your room is 14'9" wide. A quarter of the room width (44") in from the side walls is where you get a null (quiet zone in the low frequencies due to sound waves cancelling). So I would try to keep the seats (well, at least the listeners' ears) away from those nulls, keep your seating less than 7'-7.5' wide. Even in this day and age of surround sound, the front soundstage remains critical; that's where your attention will be focused, whether watching a movie or listening to music. With that in mind, it doesn't help to have sound from the surround speakers reflect off the front wall, thereby muddying the soundstage by coming from the same direction as the front speakers. So lots of absorbtion on the front wall.


Agreed... I was toying with the attached excel worksheet I found over the internet and the first row as close a 7' was meeting the THX and SMPTE standards with a 110' wide screen. After this I was actually thinking of putting in 4 rows. Am I reading the data wrong somewhere? I agree that there should be one row that the sound should be optimized to. If I limit the seating to 7' feet I think I will only be able to put about 2 seats per row.



sdurani said:


> I would use less absorbtion on the back wall, keeping it inbetween the rear speakers and using diffusion out side of that. The main goal is to keep dialogue and other sounds in the front soundstage from reflect off the back wall and reaching your ears from behind you (can sometimes sound like someone whispering back there). Some of this comes down to preference. Research into statistical listener preference over the last 60 years shows that most people don't like reflections from in front and behind them (roughly +/-40 degrees from the listener's centre line). By comparison, blind testing showed that most listeners really like early reflections off the side walls, especially near the front, because it broadens the soundstage and improves speech intelligibility (easier to understand dialogue). The only absorbtion I would place on the side walls is to catch the first reflection of the opposite speaker: i.e., first reflection of the left front speaker on the right side wall, and vice versa. If you can cut down on sounds from the left side of the soundstage coming (however subtly) from the right side of the room, directionality up front sounds a bit more precise. Double padding under the carpeting for a little help with sound absorption. I like thick carpeting under my bare feet, but that's up to you. I would pick a dark colour to help cut down light reflections. The jury is still out on whether reflections from the ceiling up front help or hurt. Personally, I would treat the ceiling up front with either absorbtion or diffusion (to break up and scatter the reflection). You don't have to use too much, just where the front speakers reflect off the ceiling.



Please elaborate... if I'm reading this right, are you suggesting that the front half of the wall should have less insulation as compared to the rear half.




sdurani said:


> Finally, even though you didn't ask, some suggestions for speaker placement:
> 
> I would put the front L/R speaker about 2.5' from the side walls. For your room width, this should cut down on some of the peaks & dips in the low frequencies, giving you smoother bass/mid-bass/upper-bass response (the frequencies where your speakers interact most with the room). Point each speaker to the person on the opposite end of the row, so that the nearby speaker doesn't dominate. Keeping the same speaker spread (about 10' apart), moving them close will widen the soundstage: speakers on the front wall will give you narrower than a 45 degree soundstage (too narrow for my tastes), moving the speaker plane 2' closer will give you a 53 degree soundstage (my preference), and moving them 3.5 feet from the front wall will result in a 60 degree wide soundstage (sounds good with music, though some people find it too wide).
> 
> ...


Oh Wow... this sounds exciting... lot of subs and thank you for volunteering this information. I have a sony 5.1 system that I was planning on initially using. I'm hoping it will help me to get the thing going. Upgrades will come in due course.

I even read somewhere that woofers are installed in the floor to enhance to experience... is this true? How will a concrete floor vibrate?



JQueen said:


> Welcome to the Shack! Your house looks like it will be beautiful ..I don't have the answers but someone will, I just wanted to welcome you


----------



## shumail (Dec 9, 2012)

Mike P. said:


> Welcome to the Home Theater Shack, glad to have you with us!
> 
> Thread moved to the Home Theater Design and Construction forum.


Thank you... I'm still learning how to navigate the forum....onder:


----------



## sdurani (Oct 28, 2010)

shumail said:


> If I were to turn the whole thing around then I would have a ledge to the left side of the door due to the risers. This would also mean that I would have to allocate extra space for the walkway... one going up to the screen and then one coming back up the risers to the seats. What is your opinion on this?


The riser doesn't have to be the entire width of the room. Your room is 14'9" across, let's say you use a sofa or seating that is a wide 7'9", that still leaves you 3.5 feet of distance to the wall on either side. 

So make a riser that gives you 9" of floor space on either side of the sofa. Then divide the height of the riser in half, to create a step. For example, if your riser is 14" high, then create a step that is 7" high by 9" deep. This will make it easier for people to step up to the riser. For safety, the step should run the entire length (front to back) of the riser, so that there isn't a spot where someone will drop 14" if they step off the riser when the room is dark. And just so they don't fall off the front, the step should wrap around the front of the riser, stopping at your first row seating. 

To recap: seating = 7'9" wide, riser top = 9'3" wide, with step = 10'9" wide. That _still_ leaves you 2' on either side for a walkway. So people walk in to the entrance nook, 2 feet away they take a couple of short steps up to the riser. Or they can turn right and walk about 7.5-8 feet down to the front row. With the door in the back of the room, any entering and exiting during the movie happens behind the audience.


shumail said:


> I was toying with the attached excel worksheet I found over the internet and the first row as close a 7' was meeting the THX and SMPTE standards with a 110' wide screen. After this I was actually thinking of putting in 4 rows. Am I reading the data wrong somewhere? I agree that there should be one row that the sound should be optimized to. If I limit the seating to 7' feet I think I will only be able to put about 2 seats per row.


You can make the rows wider, just understand what happens to the sound at the quarter width points of the room. 

Also, your attached worksheet shows that the front row will have a 66.4 degree viewing angle. That's huge (30 degrees wider than the THX recommended viewing angle of 36 degrees). In this day and age of 1080p hi-def, I can understand going as wide as 45 degrees. But 66.4 degrees would be like watching a badminton match, with my head constantly swinging from left to right to catch the action.


shumail said:


> Please elaborate... if I'm reading this right, are you suggesting that the front half of the wall should have less insulation as compared to the rear half.


For your room size, you don't want too much energy from the speakers to be absorbed. That will just make you turn up the volume, putting unneeded strain on the amps and speakers. Better instead to scatter the sound with diffusers on the ceiling and in the surround field. To preserve energy in the room, I use absorbers in a more surgical fashion. 

The only place on the side walls where I would put absorbers would be at the contra-lateral first reflection points. Sit in the middle of the front row, have someone walk along the side wall with a mirror. Where you see the right front speaker reflected off the left side wall, place a 4'x4' absorber there. Do the same for the left front speaker reflection off the right side wall.


shumail said:


> Oh Wow... this sounds exciting... lot of subs and thank you for volunteering this information. I have a sony 5.1 system that I was planning on initially using. I'm hoping it will help me to get the thing going.


Not that many subs, just 2, placed at the midpoints of the side walls will give you excellent seat-to-seat consistency in the low frequencies. The only reason I suggested possibly going to 4 subs is because it takes a lot of bass energy to presurize a 2700 cubic foot room. 

Your Sony 5.1 system should do fine for now. However, since you'll only have one pair of surrounds, you should split the difference between where the side and rear speakers would go in a 7.1 set-up. For the moment, mount your single pair of surrounds about 3 feet back from the first row. This will give a decent compromise between side and rear directionality in the surround field. When you move to a 7.1 layout, use the placement suggestions from my previous post.


shumail said:


> I even read somewhere that woofers are installed in the floor to enhance to experience... is this true? How will a concrete floor vibrate?


Never heard of that. Maybe you mean bass shakers or tactile transducers (typically mounted to the underside of the seating to allow bass frequencies to be heard and felt).


----------



## shumail (Dec 9, 2012)

Here are some images of the room. I've taken pictures of both the walls that could possibly have the screen on them. Sanjay, as you suggest that if I rotate the theater 180 degrees. Please note that there is a niche in the wall that I was planning to put all the electronics in. 

1. Will this create the same acoustics problems that the door was creating at the opposite end. 

2. Will the electronics sitting next to the screen create any light problems?


----------



## ALMFamily (Oct 19, 2011)

Not sure about #1, but having the gear in the front should not cause light issues. That said, the blinking lights could be a distraction when you are watching the screen.


----------



## sdurani (Oct 28, 2010)

shumail said:


> Will this create the same acoustics problems that the door was creating at the opposite end.


It can, but it doesn't have to. The bad news is that the left and right walls will be different (one has a big cut-out), which means that the front speakers will reflect differently on the left and right walls, therefore cause the soundstage to appear inconsistent from one side to the other. Absorbing the early reflections is not an option since you can't cover the front of the equipment with thick absorbers. 

However, the good news is that there may be a way to minimize the problem, depending on the position of your speakers and location of the cut-out. With that in mind, how large is the opening (wide & tall), how high is it from the floor and how far is it from the front wall?


shumail said:


> Will the electronics sitting next to the screen create any light problems?


It can. Before mounting a screen on the wall, most people temporarily frame the screen area on the wall using some masking tape. This lets you get a good idea of whether you are comfortable with the screen size and its height off the floor. When you do this, sit in your main seat and have someone move a mirror across the screen area. Where you see the reflection of the equipment cut-out is where the light from their front panels will be bouncing off the screen. 

Now, your screen isn't a mirror, but it is designed to do a good job of reflecting light. You can minimize this problem by setting the front panel displays on your electronics to the dimmest possible setting (on whichever pieces of equipment allow you to do so). Also, if you are going to be using the on-screen display, then you don't need to rely on the front panel displays, and can cover them up with some black electrical tape (make sure not to cover up the infra-red receptor, otherwise you'll be wondering why none of your remote controls work).


----------



## shumail (Dec 9, 2012)

I tired to make a 3D sketch as per the invaluable suggestions received... please let me know what you guys think...


----------



## shumail (Dec 9, 2012)

sdurani said:


> It can, but it doesn't have to. The bad news is that the left and right walls will be different (one has a big cut-out), which means that the front speakers will reflect differently on the left and right walls, therefore cause the soundstage to appear inconsistent from one side to the other. Absorbing the early reflections is not an option since you can't cover the front of the equipment with thick absorbers.
> 
> However, the good news is that there may be a way to minimize the problem, depending on the position of your speakers and location of the cut-out. With that in mind, how large is the opening (wide & tall), how high is it from the floor and how far is it from the front wall? It can. Before mounting a screen on the wall, most people temporarily frame the screen area on the wall using some masking tape. This lets you get a good idea of whether you are comfortable with the screen size and its height off the floor. When you do this, sit in your main seat and have someone move a mirror across the screen area. Where you see the reflection of the equipment cut-out is where the light from their front panels will be bouncing off the screen.
> 
> Now, your screen isn't a mirror, but it is designed to do a good job of reflecting light. You can minimize this problem by setting the front panel displays on your electronics to the dimmest possible setting (on whichever pieces of equipment allow you to do so). Also, if you are going to be using the on-screen display, then you don't need to rely on the front panel displays, and can cover them up with some black electrical tape (make sure not to cover up the infra-red receptor, otherwise you'll be wondering why none of your remote controls work).


Sanjay,

I've redone the number in the sheet. With a screen size of 90X50 I am getting an angle of 41-Degrees at 10' distance. Please see my other reply as well. I've attached a 3D that I did up after your recommendations.

I could just cover the niche in the wall and use it for DVD/ storage and bring the amp etc. in a little stand below the screen. It will also make the remote pointing a little more natural. I could also make the area below the screen like a little stage with curtains and all for the effect. The sub, center speaker, etc can be tucked underneath the platform.

As far a the height of the niche is concerned... it is flexible... it can be increased or decreased from the bottom... the top is flush with the ceiling and it is also flushed with the front wall. :innocent:


----------



## sdurani (Oct 28, 2010)

shumail said:


> I could just cover the niche in the wall and use it for DVD/ storage and bring the amp etc. in a little stand below the screen. It will also make the remote pointing a little more natural.


IF you place your front L/R speakers as I suggested in my first post (2.5 feet in from the side walls and 2 feet away from the front wall), then their first reflections on the nearby side walls will be roughly 4.5 feet from the front wall, meaning it will miss the 3-foot wide niche by a good 1.5 feet. So the niche won't interfere with left-to-right consistency of the front soundstage. 

The first reflections on the opposite side walls will be roughly 8 feet from the front wall, so that's a good place to put a 4'x4' absorber panel (you don't want sounds from each speaker coming at you from the opposite side of the room and muddying soundstage directionality). 

Since most audio components are 17-19 inches wide, your 3-foot wide niche is better suited for storing media (BD, DVD, CD). And good idea to place your electronics on a small rack at the front wall. You're right: it is a natural reflex to point the remote in that direction. So why not make the theatre ergonomically friendly. I hadn't taken those things into consideration.


shumail said:


> The sub, center speaker, etc can be tucked underneath the platform.


The centre speaker should be as close to ear height as possible, meaning as close to the bottom of the screen as you can get it. In fact all 3 front speakers should be the same height, so that when a car drives across the screen, its sound doesn't go up and down in height. 

If you can move the bottom of your screen up by at least 10 inches, so that it starts around 3 feet off the floor, then that will help not only the listeners in the front row but will also help listeners in the back row that have to hear over the heads of the listeners in the front row. Placing your speakers too low means that listeners in the back row will have trouble hearing them, since the listeners and seats in the front row will be blocking the sound.


----------



## shumail (Dec 9, 2012)

sdurani said:


> IF you place your front L/R speakers as I suggested in my first post (2.5 feet in from the side walls and 2 feet away from the front wall), then their first reflections on the nearby side walls will be roughly 4.5 feet from the front wall, meaning it will miss the 3-foot wide niche by a good 1.5 feet. So the niche won't interfere with left-to-right consistency of the front soundstage.
> 
> The first reflections on the opposite side walls will be roughly 8 feet from the front wall, so that's a good place to put a 4'x4' absorber panel (you don't want sounds from each speaker coming at you from the opposite side of the room and muddying soundstage directionality).
> 
> ...


Hello Sanjay...

I've done up a new layout what do you think....


----------



## sdurani (Oct 28, 2010)

Lookin' good! The speaker locations for your Surrounds are fine for 5.1 but if you ever go 7.1 then move the Side speakers closer to the first row and place the Rears in the back corners of the room. That will give you excellent rear-vs-side separation AND wrap-around envelopment in the surround field.


----------



## shumail (Dec 9, 2012)

sdurani said:


> Lookin' good! The speaker locations for your Surrounds are fine for 5.1 but if you ever go 7.1 then move the Side speakers closer to the first row and place the Rears in the back corners of the room. That will give you excellent rear-vs-side separation AND wrap-around envelopment in the surround field.


Another question... How high should the front speakers be... I know they say ear height but I have small satellite speakers... at these measurements they would be in mid air.

>>What about the surround speakers... what should be the height for those

>>We have risers for seating, would that effect the height of the surrounds.


----------



## orion (Sep 18, 2009)

You are correct that the mains should be around ear height. I have never experimented to see how important that is though. Surrounds are supposed to be higher up on the walls. I have mine around 70 inches high to the center of the speaker and it does sound good to me.


----------



## ALMFamily (Oct 19, 2011)

IIRC, the tweeter of the mains should be about ear level. The surrounds should be around 1-2' above ear level.


----------

