Many people in the home recording industry operate in untreated recording locations. A portable acoustic screen that can alter the recorded sound by preventing undesired room reflections from reaching the microphone is appealing to this market. These “portable vocal booths” are found in hundreds of thousands of homes and recording studios worldwide. However, no credible data regarding their efficacy is available to the public, and they have yet to undergo thorough testing.
Screen tests with prices ranging from less than $100 to about $400 have been presented. They all promise to lessen the audible impact of room reflections on a recording. Several manufacturers also assert that their screens can reduce the amount of outside noise picked up, such as air conditioning hum, computer fan noise, and traffic noise.
The concept is almost always the same: an acoustically absorbent inner material is placed within a rigid outer shell that is curved or inclined to enclose a microphone. The degree of perforation in the rigid shell and the selection of lining materials are two examples of design variations. While screens feature a sophisticated multi-layered construction, many other screens are made of basic acoustic foam, often shaped like wedges. These devices’ dimensions also exhibit a surprisingly high degree of regularity.
The frequency determines how much sound attenuation an absorber can provide. The inner lining of most of these screens is about 2.5 cm thick. Theoretically, this should result in total absorption of sounds with wavelengths of 10 cm or less or frequencies higher than 3.4 kHz. Although absorption will be less effective below this point, it will still be helpful down to 25 cm or 1.36 kHz wavelengths. Therefore, in theory, one would anticipate that these screens would function best at mid- and high-frequency ranges; yet, in designs where the stiff shell is perforated, this should also provide some bass absorption.
Although screens can stop some returning reflections from reaching the microphone, portable vocal booths limit room reflections by absorbing sound before it can escape into the space. However, these screens are only effective at some frequencies. In designs where the shell is not perforated, they will unavoidably reflect part of the source sound back into the microphone. These reflections will appear exceptionally soon after the direct sound since the screens are positioned close to the microphone; as a result, they will be perceived as a coloring of the desired sound rather than as an echo or reverberation. Most displays’ concave design increases the chance of amplifying this effect through acoustic focusing.
Unwanted Sounds
Assessing the assertion that portable vocal booths can muffle noises like computer fans and highway roars, the results indicate that most screens modestly enhance external noise below 400 Hz. The term “insertion losses” refers to the difference between the sound pressure level without the screen and the sound pressure level with the screen present. Positive values show that the screen protects the microphone from outside noise and attenuates it; negative values show that the noise incident on the microphone is growing.
The screens all show the same features. Performance is primarily frequency-independent above 2 kHz, with a possible 2 to 5 dB attenuation. The cause of this is sound shadowing. Further down the spectrum, all these screens amplify undesired noise inside the 200–400 Hz band. The most significant level of attenuation, reaching 8dB in some designs, occurs in the 800Hz–1kHz region. The outcomes’ consistency indicates how comparable the screens’ sizes and shapes were.
In general, screens can reduce noise only in mid- and high-frequency ranges. Alternatively, if most of the outside noise is in the low- and low-mid range, a “portable vocal booth” could record more sounds. This is a serious concern when considering sources like road noise, which frequently have noticeable low-frequency components.
Observation
In the end, though, shielding the microphone from outside noise is only one of these portable vocal booths’ secondary purposes. Their primary design objective is to reduce the number of room reflections from the recorded source.
The average variation in attenuation of room reflections with frequency for each screen demonstrates the frequency-dependent variation of this insertion loss, which is, in this example, averaged over all test screens. The room reflection screening is only effective up to 500 Hz. This makes sense considering the size of the screens and the foam’s thickness; these devices measure roughly 30 to 40 cm in length, and protection is visible from half the wavelength upwards. This aligns with physics’s fundamental principles of how waves interact with objects. The screens are too small to make a noticeable difference in the music at lower frequencies.
The room reflection broadband attenuation that each tested screen was able to achieve. The findings for each screen are displayed as a single attenuation value for the range of 100 Hz to 10 kHz. As you can see, there is a range of about 2.5dB for the least effective broadband attenuation to over 8dB for the most effective.
Whatever materials are utilized to build them, portable vocal booths will always absorb and reflect sound. Furthermore, a large portion of this reflected sound will probably be directed toward the microphone due to its proximity to the screen.
Any effects will be perceived as comb filtering rather than echo or reverberation due to the brief delay between the direct and reflected sound. As stated otherwise, the tone of the source sound will unintentionally shift due to these reflections. Specs for every screen that was put to the test. These spectra should be flat; however, none of the test screens reach this state. Comb filtering produces unique peak patterns in all traces, albeit some introduce more coloration than others. Those with a definite, regular peak pattern will likely alter the timbre in the most troublesome ways.
Even though the screen accomplishes its aim perfectly, a portable vocal booth should enable the anechoic recording to be ideally recovered. However, some artifacts resulting from the singer’s voice being passed through a loudspeaker will persist even after equalization. On the other hand, the effects of each screen on the anechoic singing can be compared, both with one another and with the impulses recorded in the absence of the screens.
When listening through, the impacts of the booths are only audible on specific musical notes. As a result, the screens primarily change the reflected sound’s harmonic (or overtone) intensity. Additionally, if the singing note’s frequencies mix with the comb filtering’s peaks and dips to substantially change the note’s harmonic series, it will determine how audible the comb filtering is. It will only work like this for some notes. The variations seem most noticeable in the lower notes, like the first few syllables of “If my dog was green.”
The performance of the evaluated screens varied in observable and audible ways. It is interesting to note that there is no clear correlation between these variations and the screen costs. The variations are negligible, and occasionally, it is difficult to determine if the sound is better or worse with the screen in place. The design offers a comfortable and regulated acoustic environment; the advantages of the screens might be perceived more strongly to balance their drawbacks. Portable vocal booths can help reduce undesired room reverberation that is recorded if you must record in an unfavorable acoustic situation, but they will not remove it.
At most, the problem of unpleasant room acoustics can be partially solved using a “portable vocal booth.” Other steps are also available if you record in less-than-optimal conditions. First, make sure your microphone has a cardioid pickup pattern. This will be less sensitive to reflected sound coming in from the sides and back of the microphone than an omnidirectional microphone used at the same distance. It will also be more sensitive to direct sound from the vocalist or other sources. The most used microphone type for recording vocals is the large-diaphragm cardioid capacitor.
It can also vary depending on the microphone’s position on the screen. Placing the microphone farther into the screen should attenuate room reflections and increase the audibility of color changes between the better and less-than-excellent panels.
The Ultimate Portable Vocal Booth
Record crystal-clear vocals in your living room, garage, or bedroom without going over budget, as well as singers, producers, and voice actors. The best option for professionally recorded voice-overs at home is the Snap Studio. It is not a soundproof booth, but with a 6’8″ (203cm) internal height and a 6’11” external height, as well as a 33″ x 33″ (84cm) footprint, the 360-degree Acoustic Isolation Shield offers plenty of room in case you get a little excited while recording. It uses appropriate acoustic pads for the walls, which have an 80% noise-reduction coefficient to eliminate echo. These pads are twice as heavy as moving blankets and are made expressly for sound absorption. Professional vocals can be recorded without the trouble or extra cost of hiring studio time.
Fast and Simple Assembly
When ideals come to you at any time of day, Snap Studio protects you. This 5.5-square-foot (0.51-square-meter) portable home recording studio easily accommodates one person and a microphone stand. On a tight budget, singers, producers, and voice actors will find it the ideal travel companion since it disassembles quickly and fits into the Snap Studio duffel bag.
360-degree Room Echo Reduction
Snap Studio provides a 360° acoustically dampened environment, unlike conventional voice-over studios that sound boxy and “vocal shields” that only cover the back of the microphone (while the front needs more protection!). Vocals are dry and straightforward as they effectively absorb room sound from all directions, giving an elemental absorption of outside disturbances. Although not soundproof, it lessens unwanted resonance. You may now consistently receive professional sound quality!
Included Accessories
The Snap Studio Recording Booth is fully equipped with high-quality add-ons for musicians and voice actors looking to record high-quality vocals effortlessly.
- Versatile Device Mount: Easily peruse scripts or lyrics from any device without using your hands!
- Hang the wireless LED lightbulb and watch it go! You’re prepared to leave.
- Duffel bag with diamond stitching: Constructed from robust, rip-stop fabric for protection.
Doc T Elliott’s Summation
The Snap Studio Voice Booth is one of the few portable “full body” booths. Its soft setup can fit singers up to 6’8″ tall while offering 5.5 square feet of comfortable space. You can even remove the acoustic Pro Sound Pad insulation blankets and use them on the walls of your studio (or double up with an extra set to make the booth super quiet). The frame is robust but lightweight and easy to install.
All in all, it’s incredible how easily a booth this size can fold up, be carried, and then be assembled anywhere you’d like. This is also an excellent solution for small apartments or spaces with little space. Just store it after your session is over. It has an integrated LED light that is controlled by a single switch. This also comes with a duffel bag for convenient carrying and a mount for your phone or tablet.
While not soundproof, the Snap Studio Voice Booth may significantly reduce undesired outside noise and reverb. The product is flawlessly dry and clean vocals that will optimize the sound quality of your finished recordings without requiring you to pay for studio time or invest thousands of dollars in expensive, high-end equipment.