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Friends with Benefits《朋友也上床》精讲之二
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本片段剧情：杰米带迪伦来到了“纽约版的山顶”看星星，畅谈心事，还带迪伦来到时代广场参加“快闪族”的活动。本来很厌烦纽约的迪伦反而被这里吸引了。他答应了杰米，接受了这份工作。
Dylan: Shaun White seems really great. Nice dude. How do you know him again?
Jamie: I took his virginity.
Dylan: So you guys have known each other for a while?
Jamie: No, it was like eight months ago.
Dylan: So does the carpet match the drapes?
Jamie: It's hardwood floors, if you know what I mean.
Dylan: My God! Terrible visual.
Jamie: Totally kidding, by the way. Just an old friend of mine.
Dylan: You guys use the same leave-in conditioner. His hair had nice body.
Jamie: Can I get two gyro number sixes, extra sauce?
Dylan: What are you looking for?
Jamie: The cops. Come on.
Dylan: The cops?
Jamie: Yep... Come on!
Dylan: Where are you taking me?
Jamie: You'll see. Well, here's your open space. Run, gazelle. Run!
Dylan: Wow. This is unbelievable.
Jamie: I know.
Dylan: Okay, this was not on Seinfeld.
Jamie: Come on, what's your dad think about all this?
Dylan: About what?
Jamie: Well, he must have an opinion. He used to write for the LA Times for 23 years.
Dylan: Somebody did their homework.
Jamie: I have this thing at work. It's called Google. Come on, what's he think about the job?
Dylan: Actually, I didn't ask him.
Jamie: Well, then you must know what he'd say.
Dylan: He'd tell me to go with my gut and that he'd be proud of me no matter what I did.
Jamie: Sounds like a really great man.
Dylan: Yeah, he is.
Jamie: Hey, do you want to see something really cool?
Dylan: I always want to see something really cool. What...
Jamie: Come on.
Dylan: Okay.
Jamie: Only place in the city you can actually see the stars.
Dylan: Wow.
Jamie: Yeah.
Dylan: It's pretty awesome.
Jamie: I know. I like to come up here to think. Just when it gets a little too much for me down there, it's like... It's like my New York version of a mountaintop. Best part, no cell reception.
Dylan: You take all your recruits up here?
Jamie: Actually, never really taken anyone up here.
Dylan: Really?
Jamie: Yeah.
Dylan: Thanks.
Jamie: If you tell anyone about this, I will rip your ears off and staple them to your neck.
Dylan: Everyone in this city seems really violent.
Jamie: Come on, let's go. One last stop.
Dylan: We're just getting comfortable.
Jamie: I know you are. Come on, buddy. It's New York. Now hustle. Come on. Come on, come on.
Dylan: You're showing me Times Square. This is not touristy at all!
Jamie: Would you shush? Come on.
Dylan: Do we have to power-walk everywhere we go?
Jamie: Yes.
Dylan: So everybody just kind of walks wherever they want, then.
Jamie: OK. How 'bout right here?
Dylan: What do you mean?
Jamie: We're here.
Dylan: Oh, my God, it's 1988.
Jamie: All right, smartass, give it five seconds.
Dylan: What is this?
Jamie: It's a flash mob.
Dylan: Like on Oprah!
Jamie: Exactly.
Dylan: Should we get out of the way?
Jamie: No, no. Enjoy it. Take it all in.
Dylan: It's pretty damn cool.
Jamie: Right? It's kind of rad.
Dylan: Do these people get paid for this?
Jamie: No. No. They kind of just do it for fun. It's nice to feel like you're a part of something. New York can be a little bit lonely at times.
Dylan: And you're trying to sell me on it.
Jamie: Every place can be a bit lonely sometimes. Be careful!
Dylan: Oh, my God.
Jamie: Come down.
Dylan: Okay. Shit. Get back down.
Jamie: Okay.
Dylan: I'm in.
Jamie: What?
Dylan: You sold me.
Jamie: Really?
Dylan: I'll take the job.
Jamie: Oh, my God!
Dylan: What, are you surprised?
Jamie: No! No. Oh, you are gonna crush it! Amazing. You can all go home now! Thank you!
Dylan: Very funny.
妙语佳句 活学活用
1. dude: （美俚）男人，男孩，也可以翻译为老哥，老兄。
例如：Dude, don't rub my face in your crazy single life!（老兄，别用你疯狂的单身生活刺激我。）
dude在美语里一般指“花花公子，纨绔子弟”，在美国方言中，也可以指从美国东部去西部牧场度假的城里人
2. gazelle: 小羚羊。迪伦一直喜欢广阔的户外空间，杰米这里是在讽刺他。
3.Somebody did their homework: 看来有人早摸过底了。do one's homework就是我们平时说的“做足了功课”，提前进行了调查摸底。
4. gut: 勇气，胆量，毅力，比如a man with plenty of guts（相当有魄力的人）
5. best part: 最好的是，最爽的是。
6. no cell reception: 这里没有手机信号。
7. shush: 使安静，嘘声，示意安静下来。
8. power-walk: “劲走”或称“快走”，即：大跨步地行走。迪伦这里的意思是：我们去哪儿都得跟打了鸡血一样吗？
9. flash mob: 快闪族。
10. crush: 破坏，毁坏。
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本栏目最新推荐I want to marry this Star Magazine cover and have its snobby, elitist Goop-babies.
Yes, after blanketing every media outlet for MONTHS to promote her cookbook, her movie, her lifestyle and her beauty, the tabloids have finally reached their tipping point.
I’m not saying that Star Magazine is a harbinger of some kind of major Anti-Goop Movement, but I think the anti-Goopsters amongst us deserve to have our kind of stories told in the media.
Star hasn’t released
yet, so this should just serve as a preview:
*Apparently, producers don’t want to work with Gwyneth anymore.
An insider claims, “Gwyneth has annoyed people to the point where no one wants to deal with her anymore.
She has always been pretentious, but over the past few years she has gone from pretentious to unbearable.”
*Everybody in Hollywood hates her: “Madonna wants nothing to do with her, Reese Witherspoon ignores her, Kate Hudson thinks she’s elitist (and Kate bashes Gwyneth to their friends), Jennifer Garner thinks she’s like a high school mean girl, and Jennifer Lopez has no patience for the ‘whiny little rich girl.’”
*Even Chris Martin wants Gwyneth to tone it down, and he’s pissed that she talked about the miscarriage.
Chris is also concerned that Gwyneth’s “oversharing problem” has “become a problem for her kids’ school” – because the school expressly forbid Gwyneth from writing about them in a Goop-letter.
*Gwyneth is “obsessed with getting Angelina to like her because she knows Angelina has class and power.”
*Insider quote: “She thinks she is untouchable and can say whatever she wants without consequences.
Her mouth is finally getting her into trouble, and it’s long overdue.”
*Reese in particular is still pissed off because Gwyneth said something bitchy about her in a 2006 interview (Gwyneth wondered aloud why Reese did “stupid romantic comedies” and now an insider says: “Reese could care less about what Gwyneth’s opinion of her is. She joked about how the woman who made Shallow Hal really has no place giving career advice to anyone else.”
For what it’s worth,
from Goop’s rep, but it’s the kind of Mean Girl-denial that is totally Goop – the rep says Goop is “good friends” with Reese and Kate and merely “acquaintances” with Jennifer Lopez.
No mention of Madonna or Jennifer Garner or Angelina, huh?
Meanwhile, I missed this new Goop interview last week – she was promoting Boss Jour Pour Femme, the new Hugo Boss fragrance that she now represents.
– there are some ass-kissy quotes from the Hugo Boss people, like: “Gwyneth Paltrow embodies hard work, femininity and sophistication.
She is a woman that has so many different roles, each and every day. From being an actor to being a mother, a writer, a businesswoman…”
But let’s hear what Gwyneth has to say about her super-difficult life and how she’s so inspirational:
“I have had a really good experience working for Boss, and I always say this, but it really is such a perfect job when you have kids.
I can only really do one film a year now because of my family and how it all works out, so it’s so nice for me to be able to work for a great company and, you know, I’m going to Spain next week for two days so I still get to travel and meet really interesting people and have a work interaction. But it’s not like I am out of the house for three months,” added Paltrow at the Mandarin Oriental Hotel here ahead of the official launch in Valencia, Spain, this week.
Paltrow added that she is something of a collector of fragrances. “I am one of those people who have a whole closet full of perfume. I I have always loved it and have always had a wardrobe full of scent,” she said, admitting to having at least a hundred in her possession.
“I think that Jour is the perfect name for it — it’s very uplifting,” she said of the new scent. And uplifting may be just what she needs given her regular morning routine. “I wake up at 7 a.m., I get [the kids] fed, and I get them dressed in their uniforms, any bits of homework are finished,” Paltrow explained. “I take them to school. She [Apple, now 9] gets dropped off at 8:25 a.m., and he [Moses, now 7] gets dropped off at 8:45 a.m., so we have a croissant together in his school dining room and we do reading together. Then I go home and I work for one hour on all the e-mails that come in overnight from L.A. Then I exercise from about 10 a.m. to 12 p.m. Then I work on Goop [the digital media and e-commerce company she founded] pretty much the rest of the day until I pick up my kids and then they have various activities.”
Um, is it just me or do her kids get to go to school really late in the morning?
And she’s basically saying that she “works” about three hours a day.
Did you catch that?
She spends an hour doing emails and looking at cat videos in the morning, then it’s off for her daily 2-hour workout… and though she doesn’t include it, I’m assuming there’s about a half-hour for showering and primping.
And then 12:30-ish to 2:30-ish she “works” on Goop (every day?!) and then she goes and picks up her kids.
That’s it.
Her life is super-busy, y’all.
I wonder what would happen to Gwyneth if she was dropped into the average working mother’s life for just one day?
We would never hear the f—king end of it, I can tell you that much.
Here are Goop’s Hugo Boss ads:
Photos courtesy of WWD/Hugo Boss.
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You can follow any responses to this entry through the
Even though I think majority or most of the story is fake, the cover is hilarious.
Especially with the ‘quotes’ from Ben Affleck’s wife, Ben Affleck’s ex-fiance and Pitts’s fiance .
Latest CommentsStudio Acoustics
ACOUSTIC TREATMENT FOR HOME STUDIOS
Part 1: Soundproofing
Silence is golden, or at least pretty expensive. Commercial
recording studios cost hundreds of thousands of dollars to build
because they must allow absolutely no sound to enter from a usually
noisy urban environment. Double and triple walls, isolated concrete
slabs, custom steel doors are all standard but high priced items used
in their construction. A studio's sound is its number one asset and
most owners will go to any lengths to get it right.
Luckily, electronic music does not normally require the extreme
isolation needed for recording live ensembles. The use of microphones
is infrequent enough that it can be scheduled for predictably quiet
times, and close mic techniques, (which are usually appropriate for
sampling or vocal lines) don't pick up much noise. Given a reasonably
quiet, solidly built house to start with, a decent home studio can be
created with modest expense and effort.
Some Theory
Sound can travel through any medium-- in fact it passes through
solids better than through air. Sound intensity is reduced in the
transition from one material to another, as from the air to a wall
and back. The amount of reduction (called the transmission loss) is
related to the density of the wall-- as long as it doesn't move in
response to the sound. Unfortunately, all walls are somewhat
flexible. Any motion caused by sound striking one side of the wall
will result in sound radiated by the other side, an effect called
coupling. If the sound hits a resonant frequency, the wall will boom
like a drum. Most isolation techniques are really ways to reduce
coupling and prevent resonances.
New Construction
The most effective soundproofing must be designed into a house
when it is first built. A typical residential wall is made of a frame
of 2x4 wood studs covered with 5/8" thick gypsum board. Properly
built (no holes!) this will provide about 35 dB of isolation.
Fiberglas filler, R-7 or better, will increase this by 5 to 8 dB and
decrease wall resonance. Doubling the thickness of gypsum gives
another 3 to 6 dB of overall isolation, but its most important effect
is lowering the resonant frequency, hopefully below the audio range.
There are two common strategies for reducing coupling between the
two sides of the wall. One is to make the gypsum to stud connection
springy, either by using metal studs or by hanging the gypboard on
resiliant metal bars. The most effective trick is to use separate
studs for each face of the wall so there is no direct connection.
This eats up a lot of space, but can give a transmission loss of over
60 dB. This is actually better performance than simple cinder block
or poured concrete construction!
Fig. 1 Construction Details
These same principles can be applied to floors and ceilings. A
heavy false ceiling hung on springs can match the performance of a
double wall-- If there is a room below the studio, it should get a
double ceiling too.
Interior Windows
The window between control room and studio used to be a
traditional feature of a recording facility. The home studio doesn't
really need one, because you can get a decent video camera and a
large monitor for less than what a good window costs to build. If you
want a window, figure 2 shows what has to be done:
Figure 2. The traditional window.
The effectiveness of these kinds of construction depends a great
deal on the craftsmanship of the builder. There must be no loose
studs, and the sill plates must really hug the floor. The gypboard
must be well fitted and all potential cracks must be caulked. (Caulk
is soft and will not crack when the building settles.) Do not put
holes in sound walls for outlets or pipes-- use surface mount
electrical fittings and caulk around any wires that pierce the
gypboard.
Structure Born Noise
The peskiest isolation hassle is dealing with sounds transmitted
through the frame of the building. The problem is caused by machinery
such as air conditioners and refrigerators which are mounted on
floors or walls and can actually shake the structure. Footsteps can
cause similar effects to a somewhat lesser extent. This is usually
not severe with wood frame construction but can be a nightmare in a
concrete and steel building.
This kind of noise must be treated at the source. Walking areas
should be carpeted, and heavy appliances have to be mounted with
shock absorbers or placed on thick rubber pads. In a wooden house
sound tends to be transmitted along the floor joists, so some
problems can be solved by simply moving the offending machines. With
concrete and steel buildings, you usually wind up completely
"floating" the studio floor, a very complex and expensive operation.
Water pipes are distressingly efficient at carrying sound. If any
pass under the floor of the studio (pipes in the walls are a definite
no-no) make sure they are on flexible hangers. If your pipes are
prone to "water hammers" consult a plumber about possible cures.
Retrofitting
We seldom have the luxury of building our home studio from
scratch. More often we are trying to fix up an existing room, and
budget or landlords limit the techniques we can use. The best
approach to adding soundproofing is to try simple techniques first
and to move to the high caliber options only when needed.
Step One: The Obvious
You can reduce the amount of isolation you need if you give some
careful thought to the choice of rooms you are putting your studio
in. Pick a room that does not adjoin a kitchen or bathroom, or the
place where your housemate does taxes or watches TV. In other words,
put some space between the studio and the noisemakers or sound
sensitive activities. The fewer walls in common with the rest of the
building, the better. Clearly, a house is a better location than an
apartment because you don't have to worry as much about sound
traveling through the ceiling or floor. An outside corner room away
from the street would be a good choice, a basement would be even
better.
Some people consider a garage the ideal location for a studio.
This may be true, but you will encounter special problems with the
big door and with getting heat and ventilation. The way most garages
are built, you are really working outdoors.
Step Two: Tighten Up
Most builders are more concerned with how walls look rather than
how solid they really are. This is unfortunate, because any air path
from one room to another will limit the wall's effectivness. You can
make an amazing contribution to keeping the sound in your studio by
filling all cracks and holes, no matter how small or indirect.
The worst sound leaks will be around doors. Your neighborhood
hardware store has the fittings and gaskets to fill these up, sold
for weatherstripping but effective for sound too. Some common styles
of gasket are illustrated in fig.3.
Fig. 3 Gaskets
The flat rubber type is used in a door that doesn't fit well,
rubber and metal gaskets work on doors that are pretty tight already.
The brush material is for sliding surfaces. Don't forget the bottom
of the door-- the best gaskets are spring loaded and drop down when
the door is closed.
Once the door is sealed there still may be leaks around the door
frame. Carefully remove the trim and fill any gap between the frame
and gypsum board with caulk or spray polystyrene foam. As long as you
are pulling off trim, check for gaps behind the baseboards and around
any window frames.
Incidentally, many interior doors are hollow and light and don't
really stop sound well even when tightly gasketed. Such a door should
be replaced with a solid one. Manufacturers will supply data on the
amount of transmission loss a door can provide. Alternatively, the
door can be reinforced with a layer of thick plywood, or you may want
to hang a second door that opens the other way in the frame. If none
of this is practical, a really heavy curtain over the door will help
some.
External windows are a real problem, since a single layer of
ordinary glass is only slightly better sound insulation than nothing
at all. Storm windows are a big help, especially if you fill the
space between panes with fiberglas. (You don't really need to see
outside, do you?) Thermal glass is actually worse than a single pane
window because the narrow air space tends to resonate. Seal the
movable part of the window with good gaskets, then cover the whole
opening with heavy drapes. Make sure the drapes fit snugly against
the wall all the way around. An inexpensive alternative to drapes is
a solid piece of 3/4" plywood, gasketed just like a door. This can be
hinged to the wall as shutters or in a sliding track, just as long as
it fits tightly.
Electrical fittings are another source of leakage. Take the plates
off light switches and receptacles, fill the gaps between the box and
the gypboard, and add a sealing gasket when you put the plate back
on. If switches or receptacles are found back to back in both sides
of the wall, the gasket will not be enough to stop sound. Replace the
electrical box with a surface mount type, and patch over the original
hole. If you aren't up for rewiring, cover the offending outlets with
a weatherproof hinged cover.
Air ducts present a special problem. You don't want to cover them
up (even keyboard players have to breathe), but they are a veritable
freeway for sound. To soundproof air vents build a baffle as
illustrated in figure 4. Start with a rectangule of 3/8 in plywood as
large as you can fit into the space. Cut a series of slots for the
air to pass through, and cover the back with fiberglas, leaving the
slots clear. Hang this at an angle in front of the duct and fit
triangular pieces over the ends.
Fig. 4 vent baffles
Put one of these on each vent connected to the studio ducts, even
those in other rooms. If this isn't enough, you can add a second unit
in front of the first.
Step 3: Beef It Up
As I mentioned earlier, low frequency sound can actually resonate
a gypsum board wall just as it will rattle a drum head. When this
happens, the bass might seem louder in the next room than it is in
the studio! The only cure short of tearing the wall down and
rebuilding is to add weight, usually another layer of gypboard. This
is most effective if the new gypboard is thicker than the original
and if it is glued in place rather than nailed to the studs.
There is no point in doing this halfway-- you must cover all
internal walls, preferably on both sides. Additional gypsum gives
diminishing returns, but an intermediate layer of soft fiber board
can be helpful.
Even if there is no direct air route for sound to follow, there
can be flanking paths around heavy walls through thin ceilings or
floors. The sound will then pass through the attic or crawl space
into adjoining areas.
You can add gypboard to a ceiling either directly on top of the
existing material or suspended a few inches below. In some cases it
would be simpler to extend the side walls all the way up to the roof.
A properly built hardwood floor should not leak much sound, but
sometimes contractors cut corners when a house has wall to wall
carpet-- you should lift a corner of the carpet and see what is
really below.
The Ultimate Solution: Double Up
Truly isolated spaces are created by building a separate room
within the room. Both the external room and the internal room have to
be tight and heavy and there must be no solid connection between the
two, not even the floor. You can buy prefrabricated isolation rooms
(at a hefty cost), or you can build one using construction techniques
similar to that of the house. Something like this should really be
designed by an architect to fit your situation, but here is a typical
plan to give you the idea.
Fig 5 Plans for a room within a room.
The inner room is built on a platform of 2X4s covered with two
layers of 3/4 inch plywood. The platform is supported by neoprene
pads that line up with the floor joists. There must be no other
connection between the room and the house. The walls and ceiling are
built on the platform using 2X4 studs and double gypboard on the
inside only. The space between the walls should be at least one inch
(wider if practical) and lined with fiberglas. The air duct should be
very long and lined with sound absorptant material. Get the heaviest
solid door and frame you can find, and add gaskets as described
above.
These steps can result in a very quiet space, but they get
progressively more expensive-- the real question is when is it quiet
enough? The easy test is to make a recording of the space. No sound,
just a tape of the mic levels at their usual setting with nothing
going on. Now turn up the gain and play it back. If you can't hear
any difference between the unrecorded and recorded portions of the
tape you have reached your goal.
The only way to get an objective measurement of sound levels is to
use an SPL meter. (There are some inexpensive models by Gold
Line/loft or Radio Shack.) As measured by the "C" scale on these
meters you will find the following numbers appropriate for these
uses.
Good resturant 35-45
Quiet office 30-40
Hospital room 25-35
Church 20-30
Concert hall 15-25
Recording studio 10-20
A decent home studio should measure in the 20s. Assuming all noise
sources are outside the room, you can calculate the amount of
transmission loss the walls have to provide by measuring the sound
level with the door open. Close the door and you can figure what you
already have. If the level does not change when you close the door,
you know where to start!
Part 2: Room Treatment
Has this ever happened to you? You are playing your latest
masterpiece at a party at a friend's place, and when the best song
comes on you want to hide under the couch-- the bass is boomy, the
highs screech, and along with the backup vocals you can definitely
hear Gilligan's Island. If you find this experience familiar, you are
probably the victim of BAD ACOUSTICS.
You won't be surprised to hear that the shape and furnishings of a
room can affect the way things sound-- we have all experienced
extreme cases such as large echoey bathrooms and overstuffed
restaurants. These effects can easily happen in a subtle way in your
studio, causing inaccuracies in the sound from the monitors. When you
record or mix you adjust the music till it is right in your control
room, but when you play the tape in a neutral environment the sound
is overcompensated and strange.
There are expensive instruments available to measure the quality
of sound in a space, but the best ones are on the sides of your head.
You can compare rooms by listening to familiar recordings. (It
doesn't have to be on CD-- you can tell a lot from the quality of
hiss on a tape.) In a good room, the bass is balanced and clear,
cymbals "shine" without being harsh, you can understand words without
effort. A mono signal appears to come from a spot exactly between the
speakers, and that spot does not jump around with changes of pitch.
Now listen to the quiet-- can you hear a refrigerator, a TV, traffic
on the street? Clap your hands--you should hear a slight broadening
of the sound, but little reverberation and certainly no pitches or
echoes.
These simple tests should tell you about any severe problems the
room may have. Subtle ones will show up in the music produced in the
room, as described above. You may be surprised to find that the
control of the sound of a room is not really very complicated and can
usually be accomplished with inexpensive materials.
Some More Theory
The goal is very simple-- we want to get the sound from the
speakers to your ears without messing it up. This is really just a
matter of what becomes of the sound after it passes your ears.
There are three things that can happen when sound hits a wall. It
can be reflected, absorbed, or diffused. If the wall is flat and
hard, the sound will be reflected. A single strong reflection can
sometimes be heard as an echo, but in most rooms a lot of reflections
(including reflections of reflections) combine into the
reverberation. The aspect of reverberation you hear about the most is
reverberation time. This is the amount of time it takes a loud short
sound to die away. "Dying away" can be defined more scientifically as
a drop in loudness of 60 dB, so acousticians call reverberation time
RT60.
The amount of reverberation desired in a room depends on the
activity going on. Musicians like fairly long
between one and two seconds. This allows them to hear themselves play
and enhances the harmonic effects of the music. (In larger rooms even
more reverb is desirable because it helps fill the hall with sound.)
For listening to speech or music played through loudspeakers this
amount of reverb is too much-- values around a second are more
comfortable, and for critical listening to speakers the RT60 should
be close to a half second.
Reverberation time is determined by the volume of the room. It can
be reduced by replacing some of the hard, reflective parts of the the
walls with soft, absorptive sections. Every material has some
absorptive qualities. This is described by its coefficient of
absorption, a number between 0 and 1, with 0 being totally reflective
and 1 being an open window. For instance the COE of brick is 0.04,
whereas that for heavy drapes is around 0.6. The effective absorption
of a surface is simply the COE times the area of the surface in
square feet. These numbers can be used to compare materials and to
predict the results of treatment. The absorption ability of most
materials is frequency dependent, which can cause problems as
described later.
Reflections off flat walls can sometimes combine to produce
undesirable effects. The worst of these is the standing wave.
Standing Waves
Standing waves are created when you have two parallel facing
walls. There will be a particular set of frequencies that are
reinforced by the distance between the walls (the sound makes exactly
one round trip on each cycle of the speaker and the pressure fronts
pile up). This is what happens in bathrooms- you probably know one
where the deep tones of your voice are tremendously supported
(doesn't everybody sing in the shower?). Most rooms have three pairs
of parallel surfaces, and the dimensions are usually just right to
affect music. An eight foot ceiling, for instance, reinforces 70 hz.
( This is called a room mode.)
This phenomenon can be prevented by designing the room with
nonparallel walls. It can be cured in existing rooms by making one of
the walls absorptive or by breaking up the flat surfaces. When sound
is reflected off a rounded or complex surface, it is diffused.
Diffusion spreads the reverberant sound evenly throughout a room,
which not only prevents standing waves but also eliminates "dead
spots"-- places where components of the sound are missing.
We can break up flat surfaces by hanging large objects called
diffusers. The shapes chosen for diffusers are really a matter of
taste and cost. Avoid concave curves, which focus sound instead of
dispersing it, but otherwise pyramids, lattices, or computer designed
random surfaces all work well. The depth of a diffuser determines the
lowest frequency that will be affected. A diffuser one foot deep will
scatter sound down to 160 hz.
Fig 6. Some popular shapes for diffusers.
Reflections can cause a further problem when the principal
activity in a room is listening to loudspeakers.
Interference
You may be familiar with phase interference from recording work
with multiple microphones. If a sound arrives at a single point via
two paths at slightly different times, certain frequencies will be
reinforced and others will be weakened. You can easily hear this by
putting your ear close to a wall: the quality of sound will change
because the reflections off the wall interfere with the direct sound.
The effect is at its worst when the distance the reflected sound
travels is only slightly longer than the direct distance.
Phase interference is attacked by careful consideration of the
placement of speakers and the listener. In general avoid locating
either so that there are short reflective paths off of walls,
ceiling, or equipment. The worst problems occur when a speaker winds
up in a corner. If this is unavoidable, figure out where the
reflections occur, and make that part of the wall or ceiling
absorptive.
Coloration
What I've said so far might seem to imply you can take care of all
acoustic problems by making every surface absorptive, completely
deadening the room. Actually, such a room is rather unpleasant to
work in, but even if it weren't, any attempt to create it would
probably be a disaster. The problem is that all absorptive materials
are frequency selective. As a general rule, high frequency sound is
absorbed more readily than low, so as absorption is added to a room,
the reverberation becomes more and more bassy in tone. Some of this
coloration is ok, even preferable, but eventually the room develops a
tubby response. If we need a very dead room and bass buildup occurs
there are devices called bass traps and Helmholtz resonators that
absorb a restricted range of very low frequencies. The specifics for
designing these are beyond the scope of this article, but the general
principle is the larger they are, the lower the frequency. The moral
is that absorption should be used only in moderation, and only
materials that soak up the full range of sound should be used.
Such materials need not be expensive. In fact, ordinary R-19
fiberglass insulation (about 6 inches thick ) is as good a general
purpose absorber as you can find and costs about 30 cents a square
foot. You can tack it right to the wall, paper side down. Of course
this is ugly as sin and breathing fiberglass is not good for you, so
you want to cover it up with some lightweight cloth. More attractive
absorbers can be made from Insul-shield (a solid wall insulation
material) or various foam products sold through audio supply houses.
(Again see sidebar) These all work down to 100 hz or so. Carpet on a
thick pad is a decent absorber down to about 250hz. It is the
simplest way to control floor to ceiling standing waves, and if hung
in deep pleats works well as a wall treatment also.
We can get away with materials that poop out below 100 hz because
normal wall and floor construction is absorptive in the low end but
very reflective above 200 hz. This means that the reverb in an empty
room is almost always bass shy.
These facts suggest a fairly simple recipe for tuning a room: Add
absorption until you reach the point where the new material balances
the original curve of the room, yielding a reverberation with a nice
flat frequency response. Place the first panels near the speakers
where they will eliminate interference paths, then spread the rest
through the room to cut out any standing waves. If you are left with
parallel hard surfaces, put diffusers on them. This method does not
allow direct control of the reverberation time, but for any room
smaller than 2000 cubic feet the RT60 should fall into the usable
range.
A Sample Design
As an example of how to apply these principles, let us look at an
ordinary room in a typical house. (All right, it's my wife's studio
in my house!) This room is rectangular, about 11' by 13' with an
eight foot ceiling. There is a large closet at the back of the room
and a window at the front looking onto a suburban street. The closet
helps isolation because it provides something of a double wall
between the studio and the living room.
Fig. 7 A treated room.
There was a plush carpet over a thick pad on the floor, but no
other absorptive material in the room to start with. The clap test in
the empty room suggested a moderately long, primarily high frequency
reverberation and produced the characteristic "chirp" of a severe
standing wave problem.
Some Isolation
After adding gaskets to the doors, isolation from the rest of the
house is adequate as long as recording is limited to quiet times. (We
checked this out before we moved in!) Noise from the street is an
occasional problem which was helped a little by drapes on the window.
An additional drape across the doorway made only a slight improvement
in isolation and was really in the way, so we gave it up.
Positioning the Equipment
After some experimentation, we decided to locate the speakers each
side of the window. Since speakers tend to move gypsum as well as
air, outside walls are always your first choice if you are concerned
with sound control. Incidentally, these are obviously not near field
speakers. Near field monitors should not be against a wall, but most
large systems depend on a wall backing for extended bass response.
The speakers were hung about 6 ft from the floor. This is a bit on
the high side, but was necessary to allow the placement of a writing
table underneath them.
The speakers wound up eight feet apart. This placed the "sweet
spot" eight feet from the wall along the center line of the room.
This in turn dictated the location of the mixing board and other
equipment. Once the equipment was set in place, we checked for
reflective phase interference from the console or cabinet tops. This
can be tested with a mirror and a flashlight. Set the mirror on the
console and hold the flashlight by your ear aimed at the mirror. If
the light beam falls on or near the speakers there is a potential
reflection problem. This can usually be fixed by propping up the back
of the board.
Wall Treatment
At this point we were down to two problems: the rising frequency
response of the reverberation and the standing wave. We attacked both
problems at the same time with some carefully placed absorptive
panels. These were made of R-19 fiberglass and measured 2 ft by 6 ft.
(They do not need to extend down to the floor because the furniture
scatters sound at that level.) Most of this absorption wound up on
the walls near the speakers-- this cleaned up the last of the short
delay reflections and resulted in a very clear sound image between
the speakers. The absorption was brought along the side walls to soak
up the standing wave. We wanted to keep the room symmetrical, so we
spaced out the absorptive panels, winding up with a pattern where
bare wall on one side was opposed by absorption on the other. A large
section of absorptive wall near the left speaker created a dead
corner for recording vocals.
The curtain over the window Is too light to be a really broadband
absorber, but it combines with the low frequency absorption of the
glass to give a reasonably flat overall effect. The carpet and wooden
floor interact in much the same way.
We found the sound to be balanced in frequency when the walls were
about one third covered with fiberglass. This left the side walls
near the back of the room untreated so we added diffusion. This is
provided by some homemade diffuser panels on one side and some very
cluttered bookshelves on the other.
Evaluation
This particular project cost about $30, and I must say I am quite
pleased with the results. Gilligan stays in the bedroom down the
hall, and quiet activity in adjoining sections of the house causes no
problems with close mic recordings. A mono signal fed to both
speakers appears to be centered precisely between them, and any
imbalance in a stereo signal is immediately obvious. The room has a
soft, comfortable ambience and the music produced there sounds just
fine out in the real world.
Further Study
There is a lot more to acoustics than the principles explained
here, but these techniques are the most likely to be effective in an
existing small room with a limited budget. If you are planning a new
building or just want to study more you can find some excellent
articles in Handbook for Sound E edited by glen Ballou, and
Sound Studio Construction on a Budget by F. Alton Everest.
Petr Elsea 1996}