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The Article Section is dedicated to accumulating information about sound recording quality issues and specifically soundproofing, sound dampening and acoustic room treatment.
We invite everyone to share your knowledge and experience in this area.
Please submit your article on the contact page and describe your recent project.


The purpose of acoustic room treatment is to remove reflections and echo from getting recorded and interfering with the direct sound, by being recorded with slight delay making the original sound muddy, and by so called comb filtering that changes the original sound by reinforcing some sound waves and cancelling others.
So if that is the case then the open cotton field would be ideal environment fore audio recording.
This theory was tested in this stop of our VOMO – tour.
We tested three options:
Open microphone,
COVB – Carry-on Vocal Booth 2.0
and VOMO – Complete mobile recording studio with the Surround Sound Hood.
So what do you think?
Naturally, the wind makes it difficult to judge the sound in the open Nature.

 

VOMO Carry-On Portable Vocal Booth for vocal recording.
VOMO Carry-On Portable Vocal Booth for vocal recording.

Rachael Naylor Recording audio for Virgin Atlantic using prototype of COVB3.0 with SSH

 

V O M O – Voice Over MObile recording Studio

New features and Benefits compare to CoVB2.0

Voice Over Mobile recording studio ( VOMO)  with Surround Sound Hood (SSH) is the next step in Portable audio recording studio development allowing the voice actor to completely eliminate room tone and reflections in their recordings.

 

VOMO  Based on the COVB2.0 , so I will not describe the features of the booth itself in detail, but stop on the differences and benefits.

The demand for improving on the COVB2.0 came from professional customer’s feedback and chasing a better, more accurate sound.

There three main complaints:

1) the room tone was still being heard in the recording.  People were solving that problem by adding an extra blanket over their heads.

2) the loops for accessories were a bit annoying, people did not want to look at the accessories while recording, they were also getting in the way when opening or closing the booth

3) bottom strap was  not durable.  Arches would rip the grommet holes and fall out of the base strap.

4)  Support Rods were sliding out of the channels and piercing the cover

5)  booth mounted on a mic stand was wobbly.

 

People never returned a single booth, for the reasons of the above issues, because everybody acknowledged the high quality recording environment it provided.  It was more like wishful thinking.

Eventually Dean Wendt, ordered the first custom “hood” to be made.  He did not know that it was going to be a hood. He said that he saw a demo I had made “not for public” where I suggested a small blanket to be thrown over the head,  and he wanted the actual fitted attachment to be made.

So it is with his blessing I would say, that the VOMO was born.

 

We started offering custom made SSH prototype and soon noticed that most people were ordering  COVB with the SSH.

New elements:

  1. Surround Sound Hood – SSH – A sound absorption hood made out of Producer’s choice blankets and designed to cover the sides and the back of the voice actor while using the COVB. SSH designed to attach to the COVB by means of special hooks and rings.   SSH in combination with COVB provides 360 enclosure all around and from the top.  There is no other portable device that allows such coverage using highly sound absorptive materials.  Ceiling is usually the least acoustically treated area in home VO studios, yet this is a huge reflective surface.  VOMO gets this under control.

SSH  made as a three sided “box” with no bottom. There are two rigid fiberglass support rods built into the “roof” of the SSH.  Note: when attaching the SSH to the COVB the rod channels should be on the lower ( inner) part of the Hood, not on the outside ( top) part. Outer end of the Rod channel equipped with D-rings to connect to the Snap hooks on the COVB.

The rod channels are not parallel. They are spreading outwards to provide better support of the hood.

When using the hood it should NOT be rested on your head. It should be completely supported by itself.

  1. SSH Attachments : There are several additions that had to be made to the COVB 2.0 to make it compatible with the hood.
    a) Case corner links with two D-rings, Inner and Outer. These links are there to create a connection of the booth to the Stabilizer strap. There is one link on each corner of the Blue outer case..
    b) Snap Hooks on the booth canopy. Bottom Hooks and Top Hooks.

Bottom hooks designed to connect to the Case Corner link’s Inner D-rings.

Top Hooks designed to connect to the SSH D-ring.
c) Stabilizer strap. Stabilizer strap is a 8 ft long adjustable strap with two Snap hooks on each end.  Stabilizer strap designed to be hooked onto the Case Corner link’s OUTER D-rings and run under the Microphone stand. It can also be used with a weight, such as sand bag, dumbbell etc.  Stabilizer strap helps to counterweight the booth when the SSH attached to it. Even without the SSH the Stabilizer strap  makes the COVB mounted on a Mic stand less wobbly.

3. Accessories bag. In the COVB2.0 we were very proud creating a way of holding all the accessories on the booth’s back wall.  In reality it did not prove to be a good idea…. The Accessories were getting in  way of opening the booth, then if you put something in it – it would damage the pop filter. And when it looked like a “garage wall” with tools hanging all over. People did not really like it and some let us know about it.

So in the COVB3.0 we introduced an accessory bag, that is attached to the bottom of the support table by Velcro strips and it holds you basic accessories, such as script holder, Pop Filter, Miniboom and Micromic stand.  Only the Microphone mount was left inside the booth.

The accessory bag also has an additional functionality of balancing the COVB and making it a little more stable.

  1. Base strap.  The base strap design was a pain and I knew it.  But I could not come up with any other decent idea without making the whole design overly complicated and expensive.  Eventually I designed a special buckle that would support the arches and allow then to swing and at the same time would protect the booth, slide easier without damaging the booth and be more durable and easier to use with the strap.

A special mould was created and after few tries the final buckle emerged.   The arches are installed in the buckle and have screws as axels to allow them swing into open/close position.

Currently buckles com assembled with straps sewn on it. But the ends of the buckle where the strap is connected to includes a self-locking design so if for whatever reason the strap needs to be replaced it can be easily done even without sewing.

  1. Secure Support rods channels. The Support rod channels designed in a way that the Rod can never get out on its own.  There channel made out of a strap folded in a way that it forms a loop that holds the rod in place by itself.  To take the rod out of a channel you just need to pull it from the side opening.
  2. Bottom side stitched. The sides of the booth used to be joined by Velcro. Initially the thought was that it will be easier to take the booth apart or open the sides if necessary. But over time we realized that nobody actually taking it apart. Also if the booth washed  Velcro gets all smooshy and wrinkled and during the wash it rips into the blanket cover and makes total mess. So instead of Velcro we just stitched the sides together.  There is still an opening in the back of the booth for the cables and wires to get in.

 

Wobbliness.  Even though we had tried to address the “wobbliness “issue, it is hard to defeat gravity.

The booth itself weighs approximately 12 lbs.  With the SSH it weighs about 15 lbs.

Obviously if you balance 15 lbs on a ½ inch stick 5 ft in the air it will be a little wobbly.

This is where a shorter person can clearly claim an advantage!

If there is no need to raise the booth high , telescopic design of mic stand usually has enough strength to provide adequate support.at abut 4 ft height. Raise it another foot and the Mic stand gets “overextended”, which is never a good thing!

Stabilizer strap works well, but make sure that you tighten the mic stand well, otherwise the tension of the strap adds to the weight of the booth and can pull it down.

Second mic stand might provide additional security, if you just stick it under the booth as extra support.

7)  LIGHT! I almost forgot about the LIGHT!

 

I consider new LED light is a huge improvement over the COVB2.0.

And not just because it is cute, but it  is much brighter, the light is nice white, it is rechargeable, it charges from USB cord and can work from your computer or wall outlet.  It can stand on its own and it can clip to anything inside the booth.  We found that the best way is to clip the light to the base strap on your left or on your right .  I suppose you can also clip it to the hood, so it hangs down, or we left the elastic loops at the top of the booth, “just in case”

 

 

And now : pictures that “speak louder than words”.

(And if I add words to the pictures would that make them sing? Or just shout?)

VOMO portable vocal booth with Accessory Case shown
VOMO-Accessory Case shown

Accessories bag located at the bottom portion of the table. It may be hidden by the Blue outer case.  It might be a little challenging to take the contents out of the bag, but I thought that you only do the set up once and I did not see any other inconspicuous place to fit the bag.  Leaving it loose inside the booth, did not look like a good option.  Bag is removable.

 

It is attached to the table by two Velcro Strips and can be taken out if necessary.
The bag has 5 pockets of different sizes: Left to right:

1] Mini Mic stand,

2] Miniboom,

3] Script Holder,

4] Pop Filter ( 6 inch),

5] Goose Neck pocket.

To Open the VOMO place it on a table, unzip the top compartment.  Reach inside and  Pull on the base strap.   Stop at approximately the level of the Side Velcro holds.  If you pull the base strap too much out, the top will be collapsing back.  Ideally the arches should form an upside-down even sided triangle.   The side Velcro holds designed to help keeping the arches spread apart. But it is optional.

Here is an example of the COVB feature that some people might not be aware of.

Surround Sound hood for Portable Vocal Booth- flipped back onto the booth
Surround Sound hood -folded onto the COVB

If for a voice actor the acoustic environment must be absolutely dead,  meaning no reflections and no room tone,  For singers some reflections may be beneficial.  The side panels of the COVB may be opened up and the top pushed back to open the mic to some liveliness of the room.

I think this is another benefit of the COVB that no other product can offer. (I was going to say in this class. But isn’t the COVB is in a class of its own? J )

VOMO with SSH open - front view
VOMO with SSH open – front view

Side Velcro Holds designed to close over the arches to keep them open. When closing make sure to “push the Velcro in between the arches so it sticks not only on the sides, but also in between.

 

To feed cords into the booth there is about 5 inch opening in each corner of the booth.

 

The Base strap Buckle. Provides smooth operation and assures that the sides are not damaged.

 

The buckle supports the arches allowing them rotated in fold/unfold position.   Buckle also designed to be connected to a strap without stitching.

Mic Mounting Bracket. The only one left inside the booth.

LIGHT.
The light  is very cute, flexible neck, nice bright ( but not too bright)  white light.

You need to touch that  little star to turn it on and it is a little slow to turn on/ off  ( LED has its own problems).  So if you do not drumming your finger on that star – it will turn on the first time.  Battery holds power for about 4 hrs.

It also has a little on/off switch on the back.. so it does not accidentally turn on in the bag and waste battery.

 

LED light for VOMO in the booth
LED light for VOMO shown in the booth

 

As I mentioned earlier you can clip it anywhere, but I thought the best way is to clip to the base strap:

 

 

SSH. The HOOD!

Folds nice and flat

When unfolded the Support rods must be on the inside.

 

Stabilizer strap.

 

SSH attached to the COVB 3.0.   table top.

As you can see the SSH completely covers the speaker from all sides.

And the lamp produces plenty of light. That generates no noise and practically no heat.

When SSH is not needed you can simply fold it back onto the COVB.

It actually will triple the layer of blanket on the sides and the top, and you can still record that way too.  It actually might provide better  reductions of noise coming from that direction

 

 

The COVB 3.0 can be used on a mic stand just like the COVB 2.0.

 

If SSH placed on COVB 3.0 on mic stand  SSH tilts the booth too much the front.   Using stabilizer strap allows to correct that and to straighten the booth position.

Technical details:

Support Rod Channels.

Booth structure the canopy and the hood are held in shape by fiberglass support rods.  In normal operations there is no need to take them out, but the booth covers must be washed, then the metal arches and support rods must be removed.

In Atlanta Georgia we were invited to a local High School to help find a solution for doing Voice over for their Video/Audio class. Currently they were trying to refurbish a janitor;s closet into a vocal booth by sticking some foam to the walls.  It did not work too well.

We presented the AVB33 – Acoustic Vocal Booth 3 x 3, that delivered great sound right there in the Video room. In this video we also quickly touch on WHY do you need to have your room acoustically treated.

Before the actual product was available we sent a prototype sample to industry experts.

See what they have to say:

 

Sean Sorrentino won’t ever again have to sit on a borrowed hotel luggage rack converted to a comforter-covered tent to get a good audio recording. Today, Sean, a podcaster, uses the Carry-On Vocal Booth Pro when he travels for his day job and needs to record on the road. Like many podcasters, Sean creates podcasts as a hobby. But a serious one. He and his friend, Adam, are the show hosts and five friends contribute to it. They have podcasted weekly for more than 85 weeks on topics that appeal to people who are interested in firearms.

Before he bought the Carry-On Vocal Booth Pro, and when he was not on the road, Sean recorded in a 10 x 11-foot office he shared with his wife, who was often relegated to sit on the sofa to work on her computer. He was fortunate, he says, because there are lots of books lining the office walls, so there was “accidental” decent audio quality.  

None of the podcast team live near one another, yet they all submit audio to Sean, who edits it and puts it together for the show. They all provide him with varying audio quality. After all, as hobbyists, they’re not often inclined to make large investments on expensive professional equipment. In addition, some contributors were “recording in places that were just not conducive to good audio quality,” he says.

Erin, for instance, records a segment on blue collar prepping, seeking the most cost-effective way to perform essential tasks.  She’s also the current worst offender in the bad audio sweepstakes, Sean says with a hint of sarcasm. When she recorded her portions of the podcast, her house, filled with two dogs and two parents who like to watch television with the volume turned up, didn’t cut it. So she went to the office of a nearby church to record. Here, she would “build a little fort out of blankets” —clearly a widespread jerry-rig solution in the industry—to help improve the audio quality. But even with that invention, there was a terrible echo. Sean was trying to figure out how to get Erin out from under the blankets and get good audio from her, too. It was clear they didn’t have $5,000 for an audio booth. And since all the seven people on the podcast live far from one another, they wouldn’t be recording in a central location, anyway, so they’d need multiple expensive pieces of equipment to do it properly.

Sean, who’s buying a new house, stumbled upon VocalBoothToGo when searching for solutions for his new house that would allow him to soundproof the walls without having to use the space for books. He looked at several products, including the tracking booth. He sent a link to Erin and she posted it on Facebook, noting it would be a great gift for her upcoming birthday. A week later, her fans and friends had raised the money for the Pro model, which comes with the microphone stand and another stand that allows her to put her computer tablet with show notes nearby (the podcast is heavily scripted). Once Erin received the Pro, she watched a video on how it works. They’re still tinkering with where she should stand to get the best audio without getting bounce off the back wall or too much noise from the room in which she’s set up.

Once she shared the audio she’d recorded in the Pro, people said they hadn’t noticed the echo she’d had until it was gone.  Sean, however, had noticed it. He listens to every piece of audio at least four times. With the Pro, Sean jokes, it didn’t sound like Erin was recording in a cave in Tora Bora.

When Sean witnessed the audio improvements Erin experienced with the Pro, he brought himself one immediately.

Sean believes the Pro’s portability make it very useful for podcasters who travel, especially at large events where podcasters may be competing for quiet in a large media room, like he, Adam and Erin had to do while sharing a single microphone at a large show last year. He believes in it so much, in fact, the show focused its Plug of the Week on the Carry-On Vocal Booth Pro (http://vocalboothtogo.com/product/carry-on-vocal-booth-pro-6/) and Erin offered a review and a thank you to those who helped her acquire the Pro (http://lurkingrhythmically.blogspot.com/2016/03/vocal-booth-pro-to-go-thank-you-and.html).

 

Summer is just around the corner and for the voice actors, pod-casters, journalist, radio personalities – Even Doctors or lawyers who need to record their notes on the go! We now offer for a limited time 90 DAYS PAYMENT FREE! when you finance any of of Sound Booths from VocalBoothtoGo.Com!

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You will know in minutes if you are approved! After your approved we will ship the booth of your choice to you right away and you make NO payments for 90 days! How cool is that?! Enjoy the summer and have peace of mind knowing that if that spur of the moment inspiration comes or that audition you are hoping to get finally calls you’re ready with your one of kind quality portable sound booth by VocalBoothToGo.Com

 

 

 

 

 

To create good sound insulation, one must utilize the following general principles:

Mass — use heavy materials

Air-tightness — cover the whole enclosure airtight

Flexibility — keep it limp, better to overlap, than stretch tight

Isolation — separate (decouple) from surrounding structure

 

Although each project has to be considered individually, the above principles are relevant in most cases.

MASS:

Massive, heavyweight barriers will block more sound energy than lightweight barriers. (Less noise will go through it.) This is because the high density of heavyweight materials suppresses sound vibrations inside the material, to a degree that the inside wall of a room, vibrates with less movement. Therefore, the amplitude of the sound waves re-radiated into the air inside the room, €œloudness€, is also minimized.

NOTE: Although a reduction in the amplitude of sound waves affects the €˜strength€™ or €˜loudness€™ of a sound, it does not affect the frequency (pitch) of that sound.

Mass Law

The Mass Law states that the sound insulation of a single-layer partition has a linear relationship with the surface density (mass per unit area) of the partition, and increases with the frequency of the sound.

Single-layer construction includes composite barriers such as plastered brickwork, as long as the layers are bonded together.

  • The heavier the barrier, the better the sound reduction.

In theory, for each doubling of mass sound insulation increases by 6 dB.

For example, the average sound reduction of a brick wall increases from 45 dB to 50 dB when the thickness is increased from 4 inch to 8.4 inch. This doubling of mass does not have to be achieved by a doubling of thickness, as the mass of a wall for sound insulation purposes is specified by its surface density measured in lbs per square foot (rather than per cubic foot). Similar sound reduction can be achieved by adding thinner, but heavier materials, like a layer of Mass Loaded Vinyl.

  • The higher the frequency the easier it is to block it.

Sound insulation increases by about 6 dB whenever the frequency is doubled.

Any doubling of frequency is a change of one octave. For example, a brick wall provides about 10 dB more insulation against 400 Hz sounds than against 100 Hz sounds. (100Hz = bass note, 400 Hz = Voice).  This change, from 100 to 200 Hz and then 200 to 400 Hz, is a rise of two octaves.  In extreme cases you might not even hear the sound but can feet the wall vibrating to the touch.
But increasing the mass alone is not enough. If you feel that Mass law does not work in your construction, that is because other factors such as air-tightness, rigidity and isolation have an effect.

AIR-TIGHTNESS:

Areas of reduced insulation or small gaps in the construction of a wall have a far greater effect on overall insulation than you might think. The effective soundproofing of a structure depends on air-tightness and uniformity

For example, if a brick wall contains a hole or crack which in size represents only 0.1 per cent of the total area of the wall, the average sound reduction of that wall is reduced from 50 dB to 30 dB by about 40% (!).

In general, ‘sound leaks’ should be considered as carefully as leaks of water.

Common air gaps: Wall€“floor gaps,  Gaps around doors, Poor window seals, Unsealed pipe runs, Unsealed cable runs, Porous barrier material (Cinder blocks)

Another aspect of soundproofing, that is often overlooked is consistency of the material€™s STC  (Sound Transmission Coefficient) used in construction.  Your construction is only as soundproof as its weakest point. For example, an unsealed door occupying 25 per cent of the area of a half-brick wall reduces the average sound reduction efficiency of that wall from around 45 dB to 23 dB.

MEMBRANE FLEXIBILITY:

Rigidity is a physical property of a partition and depends upon factors such as the elasticity of the materials and the way the partition is installed. High rigidity of the barrier can cause loss of insulation at certain frequencies due to resonances and coincidence effects. These effects diminish the expected results according to the Mass Law.

Resonance

Loss of insulation by resonance occurs if the incident sound waves have the same frequency as the natural frequency of the partition. The increased vibrations that occur in the structure are passed on to the air and so the insulation is lowered. Resonant frequencies are usually low and most likely to cause trouble in the air spaces of cavity construction.

Coincidence

Loss of insulation by coincidence is caused by the bending flexural vibrations, which can occur along the length of a partition. When sound waves reach a partition at angles other than 90°, their transmission can be amplified by the flexing inwards and outwards of the partitions. The sound-wave frequency and the bending-wave frequency coincide at the critical frequency. For several octaves above this critical frequency the sound insulation tends to remain constant and less than that predicted by the Mass Law. Coincidence loss is greatest in double-layer constructions, such as cavity walls or hollow blocks.

Flexible (limp) materials, combined with high mass, are best for high sound insulation. But even if you get the flexible high mass material such as Mass Load Vinyl, it needs to be installed in a way that keeps it limp: for example attached only at the top and allowed to hang freely, or installed in a loose wave-like manner, especially if sandwiched between two rigid surfaces, to keep its limp properties.

ISOLATION:

Sound transfers through any medium air, structural elements of buildings such as floors, walls.  As the sound converts to different wave motions at the junction of different materials, energy is lost and an incremental amount of insulation is gained. This is the principle behind the effectiveness of air cavities in windows, of floating floors, of carpets and of resilient mountings for vibrating machines. Decoupling of elements of construction can be effective in reducing the transmission of sound through a structure. Some broadcasting and concert buildings, and acoustic labs, achieve very high insulation by using completely discontinuous construction of a double structure separated by resilient mountings and rested on a springy support mounts.

Sound isolation can be easily ruined by strong flanking transmissions through rigid links, even by a single nail. Cavity constructions must be sufficiently wide for the air to be flexible, otherwise resonance and coincidence effects can cause the insulation to be reduced at certain frequencies. In small air gaps in conjunction with rigid walls air gaps couples with the walls and separation effect gets lost.

Soundproofing and sound isolation need to be looked at as an integral complex approach where all principals are observed.  Even an incremental increase in sound isolation can have a great effect on how it is being perceived.Because sound levels are measured using a logarithmic scale, a reduction of nine decibels is equivalent to elimination of about 80 percent of the unwanted sound.

With the availability of more compact and less expensive recording gear, available and easy to use software, it becomes very easy to record your gigs at home. 

But despite the fact this gear has definitely become much better, there is a limitation on home voice over recordings.  Most professional magazines talk about latest and most sensitive microphones or software that allows to “filter” the noise and “make you sound better”, yet it still does not sound as good as a recording made in a “professional” recording studio.

The reason is acoustics.  If your room does not sound good – it will be very difficult to produce great sounding results.  This, of course, translates to your ability to get repeat business and eventually make a good living doing what you love.

Acoustics can get intimidatingly complex, but treating tour room acoustically does not have to be difficult, or require hours in front of a calculator. Understanding how sound works in the room and how to apply that to creating your home recording space can get you a long way to sounding your best without major construction work or spending too much money.

Whether you are converting your garage, bedroom or a closet into your voice over recording studio, knowing the basic principles of how the sound works will help you to improve the sound in the room you are making the recording.

 

Acoustics is defined as

  • the science that deals with the production, control, transmission, reception, and effects of sound and
  • the qualities or characteristics of a room, auditorium, stadium, etc., that determine the audibility or fidelity of sounds in it.

 

In most cases improving the acoustics in your room will result in the biggest improvement in the way your recording sounds.

So while the expensive microphones allow you to capture your best sound, it is the room acoustics is what allows you to sound your best.

This is why commercial studios spend tens of thousands of dollars to design and build acoustically optimized spaces.  But you do not have to spend thousands to make your room sound good. For very little money you can make even the worst space sound good. So how?

 

First, we need to define two major aspects of your room treatment:

Acoustics and Sound Isolation

When we talk about the “acoustic room treatment” we are not talking about stopping construction noise from the street getting into your mic.  And we are not talking about your own voice annoying your neighbors.   These are examples of “soundproofing” or rather “sound isolation”  – stopping the transmission of sound from one point to another.  We can talk about this in a different article.

Room acoustics, or the way the sound generated inside the room behaves within the room itself, has very little to do with the ability of the sound to go through the barriers and spread out ( or into) your recording space. The approach is different, the materials are different as well.

People often get this confused, but materials used to “soundproof” your room will do nothing for helping your room acoustically and actually in some cases can make it even worse.

 

So what is Sound?

“Sound”  in most people experience is what we can hear.  In physics, “sound” is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a transmission medium such as air or water.

So basically sound is the energy of vibration, and that energy requires some sort of medium to spread around.  It spreads by agitating/vibrating adjacent molecules in the medium, so it can go through the air, water, steel etc. The denser the medium the faster it travels.  In the absence of a medium, such as in vacuum it ( sound energy) cannot spread so there is no sound in Space.

Since it is the energy of vibration, sound travels in waves. Called “soundwaves”.  Like if you wave your hand in a bathtub water you will create waves.  In this example your “vibrating” hand simulates a sound source and the waves in the water will be like “sound waves” spreading all around the tub.

Now you can wave your hand faster or more slowly and with more force, the resulting waves in the tub will also change the pattern.  That wave pattern is important in understanding of basic characteristics of sound:  Frequency, Wave length, Amplitude and Phase.

Try to vibrate your hand fast and easy – the resulting waves will be shallow, frequent and low in height. It will require very little effort on your part to make them.

Now try to wave your hand wider and more forcefully , this will be much harder to do and the waves will be deeper/higher and then will come not as often, and most probably will splash out of the bathtub because they are so high and strong.

You will also notice that the waves are bouncing back from the walls of the bathtub.  You can stop and watch what happens to the waves after you stopped generating more of them.

What you just did you created a model of how the sound waves work. A model that you can actually see.

Have that image in mind this might make it easier to understand how the sound works.

 

Sound waves and Frequency

Sound travels in waves.  Unlike your bathtub water waves, sound creates area of Dense (wave peak) and Rare (wave valley) pressure, because the sound spreads in all directions at the same time (omnidirectionally).  The frequency of the waves or how fast and how often the waves come, determine the pitch of the sound.  Frequency is measured in Hz (“Hertz”, after Heinrich Hertz, who had described this first). The higher the frequency, the higher the note. 

Human ear generally can hear between 20 to 20 000 Hz.  Sound above 20 000 inaudible to the human ear is called ultrasound.  Ultrasound is used by some animals for echolocation.

Sounds below 20 Hz called Infrasound. Infrasounds used for communication by some animals and also by people for monitoring earthquakes (seismic activity).

But for acoustic purposes we are mostly concerned with the audible range of frequencies.  And the related aspect here is “frequency response” .

 Frequency response refers to the way a microphone responds to different frequencies. It is a characteristic of all microphones that some frequencies are exaggerated and others are attenuated (reduced). For example, a frequency response which favours high frequencies means that the resulting audio output will sound more trebly than the original sound.

Ideally response should be the same for all frequencies or “flat response” .  This is virtually impossible to do, so the goal here is to “smooth things out”.

 

Amplitude of Sound

This is the Volume of sound, that measured in dB.  A decibel is defined as the smallest volume that can be perceived by human ear in isolation.  ( note “in isolation” means without reference to another sound. In reference to another sound trained ear can perceive sound volume changes as low as 1/10th of a decibel). 

A very quiet professional recording studio may have 30 to 40 dB of background noise, while Jet airplane engine can produce 140 dB of noise. This is not that the Jet engine noise is only 4-5 times louder than a professional recording studio, but dB level is measured on a logarithmic scale. In approximation, every 10 dB difference is about a 100 times change in sound energy level.

 

Wavelength

Wavelength is the length of a sound wave.  (did I have to explain that?)  It is related to the frequency of the sound waves. The higher the frequency – the shorter then waves. The lower the frequency the longer the waves.  Think of the bathtub example or the ocean.  On a nice calm day, you can see multiple small shallow waves coming onshore in brief succession.   Or you can see huge long waves crashing against the rocks during a storm.

The wavelength is important in combination with “phase” when dealing with room acoustics.

 

Phase

As the ocean waves have the Peaks and valleys, the sound waves also have the peak and trough. The term “phase” describes the relationship of two waves in time. If two identical waves that are at the different points of their cycle are combined, they may cause problems.

Phase is important in the acoustics and recording because the waves that are out of phase can cancel each other or vice versa reinforce each other resulting in tonal changes.

Phase problems occur when the sound bounces around the room.  Sound reflection is not a characteristic of sound per se, but it plays a major role in the room acoustics.  The reflective waves interfere with each other destructively, causing all sorts of problems.  Sound intensity near the hard surfaces because reflected wave adds to the original sound wave.

So Reflection control will be our next topic.

 

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VocalBoothToGo.com ( VocalBoothToGo.co.uk) specializes in providing effective and inexpensive acoustic room treatment products, such as Producer’s Choice acoustic blankets for sound reflection control, Noise control productsmobile sound booth, portable vocal booths and Vocal booth Rentals.

If you have any questions, contact us!

Many people who are starting to set up their home recording studio often get confused on what is soundproofing, and what is acoustic treatment.The materials and techniques used in soundproofing are very different from what needs to be used foracoustic room treatment. And, when you are preparing to set up your home recording studio, you need to understand the differences before shopping for soundproofing products. Understanding of basic principles of soundproofing will help you make right decisions, save you time and money, and a lot of headache down the road.

Many people who are starting to set up their home recording studio often get confused on what is soundproofing, and what is acoustic treatment.

The materials and techniques used in soundproofing are very different from what needs to be used foracoustic room treatment. And, when you are preparing to set up your home recording studio, you need to understand the differences before shopping for soundproofing products. Understanding of basic principles of soundproofing will help you make right decisions, save you time and money, and a lot of headache down the road.

 

Definition of Soundproofing

In a nut shell, soundproofing means that the sound has to be stopped from leaking in or out of an enclosure. Soundproofing, in essence, is reducing the sound pressure between the source of sound that is generating the actual sound pressure and the receiver of the sound – such as a microphone or human ear.

For example: If a lawn mower or airplane passes by your home, it generates a pressure wave of a certain frequency. That wave travels to your house and will be heard and possibly physically felt, depending on the frequency generated. To keep those sounds out, a recording studio needs to be isolated from the outside world. Sound isolation works the same — both ways — so there’s no difference in the approach of keeping sound in or out.

However, don’t be misled. It is very hard to achieve a 100% sound isolation on a small budget. But, knowing the physics of sound and understanding how sound transmits can help to achieve the best sound isolation possible.

The Science Behind “Sound”

The science of sound might have sounded boring when you had to learn it in school, but now, when you are building your own recording studio, it has a very practical application.

So, what exactly is “sound” ?

Sound is a type of energy made by vibrations. Vibrating objects create a mechanical disturbance in the medium in which it is directly adjacent to. Usually, the medium is air. So sound is actually a pressure wave.

When an object vibrates, it causes movement in the surrounding particles. These particles bump into the particles close to them, which also make them vibrate — causing them to bump into more air particles. The energy of their interaction creates ripples of more dense (higher pressure) to less dense (lower pressure) air molecules, with pressures above and below the normal atmospheric pressure. When the molecules are pushed closer together, it is called compression; when they are pulled apart, it is called rarefaction.

The back and forth oscillation of pressure produces sound waves. The frequency of the waves depends on the frequency of the vibrations. This movement keeps going until it runs out of energy.

The other thing to consider is that a sound wave is a form of a traveling wave, in that the air molecules disturbed by the sound source are unlikely to be the ones hitting your eardrum, but transfer their energy to other neighboring molecules. These mechanical vibrations are able to travel through all forms of matter: gases, liquids, solids. Sound cannot travel through vacuum because there are no particles to transfer the sound energy.

In summary:

  • For sound to be generated and transmitted something must be vibrating;
  • Sound waves travel by passing energy form a particle to a particle;
  • Sound dies out eventually when it loses its energy. (It happens due to friction in the air itself or in trying to move (vibrate) the barriers it encounters. Sound energy does not just disappear, but have to be spent on doing some work and while doing the work it is converted to heat. )
  • Sound can be transmitted through anything that has particles air, wood, concrete etc. (not vacuum).

How to use that knowledge to soundproof a room, a door, sound booth or any type of soundproofing?

1 Since sound is transmitted by air you need to make an air tight enclosure, that does not let the sound waves in or out;

2 Because Sound energy can make particles in your enclosure vibrate and get through this way, you need to make it (a barrier) as heavy as possible. (Construct the barriers (walls) using materials that are hard to move, have a lot of mass and it take a lot of energy to get vibrating);

3 Because the sound waves can be transmitted through existing structural elements of the building ( like wall, floors, ceilings) you need to separate the vocal booth enclosure from other structural elements of the building it adjacent to, which may transmit the sound energy from the outside world.

Is soundproofing that simple?

This sounds pretty simple, isn’t it? In theory. But in practice you have to deal with materials that can achieve the level of isolation you require and the costs of those materials.

Theoretically one may suggest surrounding the room with a layer of vacuum, but that is probably for a Sci-Fi.

In real life you have to use what is available and it gets complicated.

This is where the secret is: What and How of soundproofing. What materials to use? How to install them?

Using mass for soundproofing

Although sound can’t escape directly from an airtight environment, its vibration energy causes the walls of the room to vibrate, and they in turn launch new sound waves. That is why it is important to make walls that would not move. And the heavier the walls, the more energy it requires to get them vibrating. So naturally, the simplest thing that can be done is to add mass to the walls.

But different materials have different sound transmission properties (see What is STC – Sound Transmission Class).

Brick is better than plywood, and then there are loss of materials like sand.

(For example, a given thickness of glass may transmit (let through) more sound energy than the same thickness and mass of sand, because the sand particles tend to lose more energy through friction between the individual particles.)

NOTE: As a rule of thumb, if the mass of a wall doubled (by doubling its thickness, for instance) amount of sound leakage will be reduced by 6 dB.

Using decoupling for soundproofing.

Separating the sound enclosure from structural elements of the building it’s adjacent to, (decoupling) helps to block structure-borne sound. Sound energy travels very efficiently, as mechanical vibrations, through wooden joists or steel girders. Special attention needs to be paid to floor supports as most unwanted energy gets injected into the floor.

NOTE: If sonic vibrations are injected into these components, they’ll bypass all soundproofing.

Sound frequencies and soundproofing.

Another issue that makes soundproofing complicated is that the sound waves have a range of frequencies and the isolation provided by a structure reduces with lower frequency. While high frequencies are easy to keep in or out, low frequencies are far more difficult to contain.

Since different frequencies have different wave length for every frequency above a certain, critical value, there’ll be an angle of incidence for which the wavelength within the material is equal to the wavelength of the sound incident upon the material, and when this occurs the attenuation drops significantly. This is why using layers of materials with different acoustic properties can help to improve soundproofing characteristics of a wall.

NOTE: The rule of thumb here is that for every octave drop in pitch the amount of sound isolation is halved.

Using air gap for cost effective soundproofing.

But, things are even more complex than this. Sheer increase in mass and thickness of the wall is not always feasible or cost effective. The best sound proofing method, which is used by most professional studios, is to build double walls with an air gap between them. The cushion of air between the walls separates energy from one wall to the other, and the wider the air gap, the better the isolation (most noticeable at low frequencies again).

NOTE: Unless the walls are separated by a considerable distance, the cushion of air between the walls couples energy from one wall to the other, reducing the isolation. But double wall structure will invariably perform significantly better than a single-layer barrier of similar mass, even if the air gap is only a few inches wide.

When soundproofing your voice over studio or recording room, combinations of factors must be considered. Doing your homework and understanding the science behind the sound will greatly help you to create a more successful home recording studio.

With many audio editing platforms available today, recording can be done in the comfort of your own home, although it is not as easy as buying a microphone and pressing “Record”.  Room acoustics are paramount. Every professional recording studio is fine-tuned to get the best sound possible.  It requires expertise and costs thousands of dollars to do a proper job in acoustic room treatment.  Yet in-home audio recording studios this often underestimated.  It is much more fun to talk about expensive mics, EQ (equalizers) and latest software that “removes” noise and optimizes your tracks all by itself. (more…)

Acoustic Vocal Booth 3’ x 3’
     Assembly Instructions
Material

  • 16 straight pieces
  • 4 straight connectors
  • 8 3-way corner connectors
  • 2 specially designed wall covers
  • 1 ceiling cover
  • 3 corner sound trap

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Frame Assembly

  1. Assemble a square on the floor using 4 straight pieces and 4 3-way corner connectors, leaving the third prong of the connector facing up.

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  1. Use the 4 straight connectors and 8 straight pieces to make 4 double-long poles, and insert them into the open prongs of the 3-way connectors.

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  1. Make another square using the remaining straight pieces and 3-way corner connectors. Place it on top of the four double-long poles by attaching the open prongs of the 3-way corner connectors to the 4 standing poles. This completes the frame.

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  1. Use the Velcro strips to fit the booth cover over the frame.

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  1. Record and enjoy!

Dean Wendt on the Quality of VocalBoothToGo Products and Customer Service

If there’s one thing Dean Wendt knows—really knows—it’s sound. You may know Dean Wendt as the voice of Barney, the iconic purple dinosaur from Barney & Friends. Yes, the voice that most of us parents remember oh so very well. If your kids were anything like mine we must have watched the shows on a constant loop for most of their pre-k and kindergarten days. That is why I for one was excited in his use of VocalBoothToGo.Com’s products. A voice I had become all too familiar with over the years was using OUR products. How cool is that!

Dean had tried lots of acoustic solutions and portable vocal booths throughout his career. But when he stumbled upon VocalBoothToGo.com he knew he had a winner. He quickly became a huge fan of the Carry-On Vocal Booth to GO series. The carry on was able to rid him of annoying reverberations that were wreaking havoc on his recordings, a problem which he had not been able to find a solution for until now.

“I’ve pretty much bought all the stuff Adil has,” Dean says of VocalBoothToGo’s owner, Adil Aliev (talk about literally putting your money where your mouth is!). “It’s really great stuff.”

Dean had been looking for products he could use to record that would ensure high quality audio that’s when he came upon VocalBoothToGo. Excited to see the line of products we had to offer; but skeptical to their efficiency, Dean decided to start off by renting a Portable Acoustic vocal booth (AVB-33) and used it to do commercial voiceover work for a week while he was on the road. And the rest is history! Blown away by the sound quality and its ease of use and portability Dean became a proud VocalBoothtoGo.Com supporter.

Topping off his order experience Dean praised the customer support he received when placing his order. From all his preorder questions to his feedback after his rental VocalBoothtoGo.Com Owner; Adil, answered all his questions and even got some great ideas on how to improve some of the products that were later implemented in the latest edition “Carry on Vocal Booth 2.o”  which Dean is currently using today.

We are proud to offer such unique and amazing products. Helping the busy, traveling, always on the go voice actor has become our specialty. We offer the BEST in Affordable, PORTABLE acoustic solutions.  And you can always count on us to provide incredible customer service and support provided by REAL people (No computerized voices over here) 7 days a week by contacting Support@VocalBoothToGo.Com

Each year the Tribeca Film Festival in NYC showcases an impressive group of independent features, documentaries and short films. It’s the place where filmmakers, innovators, movie and music enthusiasts, in addition to countless celebrities and artists come together to see what new and exciting advances in technology and film are awaiting in the next year and honor those who have created remarkable films and music throughout the year. That is why we were thrilled when one of the newest additions to the festival showcasing the Virtual Reality experience wanted to use our Producers Choice Blankets in its 2016 exhibit.BBC/VRTOV, an independent digital production studio based out of Melbourne Australia successfully used Producers Choice Acoustic Blankets to create an acoustically treated shelter for its showcase at the festival “The Turning Forest”.  With the Producers Choice blankets on board it quickly became the ULTIMATE virtual reality experience. The exhibit, which was listed as one of Wired Magazine’s favorite VR experiences, received rave reviews and was a hit with attendees of the festival.

Highlighting just one more, of the many; uses of Producers Choice acoustic blankets this exhibit is a groundbreaking and game changing example of how using acoustic blankets can give you an acoustically treated environment ANYTIME, ANYWHERE.

VocalBoothToGo.com was honored to be used in this exhibit. Our products can be found in many places and used in a variety of ways, all designed to improve acoustic quality. This is why VocalBoothtoGo is here to change the way you hear the future.

We are literally “Changing the game”!

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Introducing our new Carry-On Vocal Booth 2.0!

We have seen some portable vocal booths before. All of them based on using acoustic foam. Youtube is full of ” DIY $20 portable vocal booths”.  Some of them look mundane just a show box lined with foam and some are quite peculiar. We have also seen what happens to portable vocal booths made out of acoustic foam after they have been used for some time.  Even professionally made foam based booth gets saggy, skewy and  overall shabby looking. The foam gets soiled and rubbed.

 

We also heard from the users of such booths, professional Voice over actors, unhappy about the boominess and boxiness of the recording. The space inside the booth was very limited, which resulted both in bad acoustics and great inconvenience, because there was no place for the script so actors had to look away at the script, which did not make for comfortable reading.
(NOTE: close proximity of acoustic foam to a microphone can create a severe high frequency depletion in the recorded audio).

 

Encouraged by great success of our Producer’s choice acoustic blanket material, we designed the Carry-on Vocal Booth with strong rigid support, and ample space inside to allow not only to place a script, but also place your laptop or tablet in it.  Most importantly, the larger internal space creates much better acoustics inside the vocal booth.We demonstrated the very first Carry-On Vocal booth and Producer’s choice blankets at Voice Over conference VOICE2012 in Anaheim, CA. Producer’s Choice acoustic blankets This is when our work had actually started.  Voice actors in unison commended the great acoustic quality and spacious interior of the booth, but they wanted some additional features.

 

So we started adding features and accessories:
First we added support table, that made the booth “self supported”;
then we made the booth microphone stand mountable;
then we added base strap for “one step” set up;
then we added a miniboom to provide hookup for a microphone and a pop filter,
then we added specially designed script holder,
then we added a micro mic stand to support miniboom that would support the script holder and/or pop filter without a microphone stand;
then we added a light to illuminate the beauty of the whole assembly and then we came up with a solution to hold that light. (the solution was clumsy and confusing, but it worked);

We wanted to create a complete traveling Vocal recording studio, because we realized that voice actors, want to have a full set up, so they can get to work right away.
And we did all that without increasing the price of the unit! Voice actors, new and experienced, were praising the sound quality of the Carry on Vocal Booth, but as more and more users were working with it, we started getting complaints about, things like – “mounting bracket did not fit all of the microphone stands out there, the table was wobbly, the light was hard to fix, the stitching was a little off”.

 

We also realized that by adding all the additional gear we created clutter, that needed to be organized.

It is prettier, stronger and fitter. It is better organized and it has softer hug on your shoulders. It is practical and very stylish!

On the move it is the thinnest Vocal Booth in the world!

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Each accessory has its own niche and we even made additional holders for microphone and pop filter.
Now you can load the traveling Vocal booth with your gear ready for anything, like a Navy Seal on a mission!
Another change we made is larger front padding, which allows to cover more of the area in front of the microphone.But when it is ready to work – it turns into a spacious recording studio ready to accept all your gear. All additional accessories are now neatly organized and stay in their place until you are ready to use them.

We redesigned the support table. it is now a little thicker to provide more reliable support on a mic stand.
The mounting bracket was redesigned as well to allow for use with thicker mic. stands.
Remember i had mentioned the  awkward light attachment?  so now we offer an easy attachment and we offer two positions for the light.  or you can get an additional light and have more illumination inside your booth.The carry bag was changed dramatically. The first most noticeable change is color. instead of  buttoned down all black, we use playful summer-sky blue color with new logo imprinted.

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The Opening for a mic stand mounting table was changed in a way that it is a solid pocket, and not a weird flap in the middle of the bag.
We also added a shoulder pad for a comfortable carry.

In addition, we added quick-close buckles to the booth. Some of the previous cases also had the quick release buckles, but not all of them.  This feature was added by the request of reporters and journalists, who sometimes have to get going in a hurry and spending extra 15 seconds on zipping up the bag is a luxury they cannot afford.

And lastly, we are adding packaging.  As our brand becomes well known the new Carry-on Vocal Booth will come in a beautiful new box.

Our new Carry-On Vocal Booth 2.0 includes the following:

1.  Carry-on Vocal Booth with nylon case and Support table;
2. Mounting Bracket
3. Miniboom
4. Micro Mic stand.
5. Script holder
6. LED no-noise wireless light (One per unit. Batteries not included)
7.  Special gift: VocalBoothToGo USB pen.

Extremely useful tool for a creative professional. It has an all world ball point smooth pen and 8G USB storage to keep  all your auditions or other digital files handy.

All that for only $375.77! Get one today!

 

Glosssary

VocalBoothToGo No Noise LED Light Instructions

These lights were created with the Voice Over actors in mind to eliminate yet another noise source. If you work with highly sensitive microphones, like professional book narrators do you will appreciate this NO NOISE and NO NONSENSE LED light. Below are the directions to use this. Visit the product page for the No Noise LED Instructions.

 

 

 

Producer’s Choice Sound Blanket Test – Pleated – Measures at 95% Sound Absorption

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