Have you ever wondered why the picture on some TV and monitor screens seems particularly deep and “lively,” while on others it seems flat? This is partly due to the surface layer of the screen, and perforated (or micro-perforated) screens are one of the most interesting technologies in this area.
In essence, these are screens with thousands of tiny holes invisible to the eye. Why are they needed? Their main task is to hide the “hardware.” These micro-holes allow components such as the front camera, light sensors, or an IR port for the remote control to be placed behind the screen itself, without cutting rough “bangs” or cutouts on the front panel for them. This gives us an almost frameless, seamless display.
But this is where the main compromise lies. These holes, even though they are microscopic, represent a physical barrier to the light coming from the matrix. This can slightly “steal” brightness, and in some cases, slightly affect image clarity, creating a subtle “grid effect” on solid colors if you look closely. The difference between different perforated screens lies precisely in the size and density of these holes, as well as in how skillfully manufacturers have managed to balance the aesthetics of display integrity and impeccable image quality.
Experience and methodology for evaluating perforated screens
“Which is better?” is the most popular topic in magazines and online articles. When computers or cars are compared on their pages, everything is simpler and more straightforward. However, the perception of cinema is quite different.
This is a criterion of “taste and color,” the accurate assessment of which depends on a large group of diverse indicators. As mathematicians say, this value is not always determined. As for perforated screens, only certain aspects can be determined.
It is necessary to determine and study:
— The concept of screen “resolution”
— Contrast — local and across the entire field
— Brightness and light loss
— Brightness uniformity across the field
— Color saturation of the screen image
— The effect of stray light
— The concept of acoustic transparency of perforated screens.
These factors do not simply interact with each other: it is necessary to find the optimal values that give us that very combination of “good picture and clear sound” — which is what we are striving for.
The question is: why are perforated screens needed at all, and what do they offer? In public movie theaters, they work in conjunction with speakers installed behind the screen surface. The goal is to localize speech and other sounds in the corresponding areas of the image to enhance the sense of immersion and realism. In recent years, everyone has been trying to replicate the public cinema experience in home theaters. Supposedly, home theaters offer a more immersive experience than public cinemas because of the proximity of viewers to their screens.
Due to the growing demand for perforated screens, the question of how screens with “holes” are made is very relevant. Even a novice understands that there must be a happy medium between acoustic transparency, reflected light loss, and the type of perforation. The magic lies in the compromise between conflicting elements and achieving a stable viewing experience at much closer distances than in a traditional movie theater.
The optimal viewing distance for an acoustically transparent screen depends on the type of perforation and, to a lesser extent, on the surface illumination provided by the projector. For example, in a typical movie theater with a nominal brightness of 12 fL on a standard Stewart Cinema Screen, the perforation is not visible from a distance of 15 feet, while for Stewart MicroPerf, this distance is less than 12 feet.
The SMPTE 196M standard requires a peak image brightness of 12–22 fL for a darkened room. However, modern viewers, forgetting the teachings of the Lumière brothers, for some reason do not follow the concept of a completely darkened room and prefer a partially darkened one, compensating for this with the brightness of white on the screen — 25–50 fL. As the brightness increases, the perforations become more visible, especially up close, so it is important to analyze the viewing distance: the viewing area must be adjusted so that the perforations are not visible, without sacrificing the viewing angle.
The problem of brightness degradation on a perforated screen, coupled with the desire to watch movies in a slightly lit theater rather than in complete darkness, can be solved by a competent combination of projector and screen. Sometimes in our tests, some screens required doubling the projector's light output to satisfy the viewer! In addition, some screens did not have the ability to absorb lateral stray light (ALR) — for example, from walls and ceilings — which further degraded the image.
Moaru — no!
But we've been talking about perforation and screen properties, and haven't said a word about moiré yet. And that's a shame… Moiré, in terms that physicists would understand, is an interference pattern between periodic brightness structures. Now, let's explain it for regular folks.
The image of the projector's pixel grid is a series of white squares with dark pixel borders, and the screen fabric is also a periodic structure of micro-irregularities (after all, the pattern is “mechanical,” since the fabric is manufactured by a machine according to certain rules). Add to this the periodic pattern of perforations or the texture of the fabric itself.
All this overlaps like two or more sinusoids, creating local peaks of brightness and dark areas. There are “checkerboard” patterns, alternating lines, or more intricate geometric designs. This is moiré. But we didn't order it.
Stewart Filmscreen is perhaps the only company that has freed consumers from marketing “noise” and actually tackled the problem of moiré. Stewart's reputation in the screen industry is very strong and sometimes unquestionable among professionals: based on a scientific approach, Stewart employees know how to deliver a brilliant viewing experience, skillfully circumventing current technical limitations.
6. Gryphon Mephisto Stereo (2025)
5. Audio Note (Kondo) KAGURA (2025)
A good amplifier is not just a box with buttons, but the heart of your music. It determines how clear the notes sound, how the bass feels, and how lively the entire musical range sounds. In this review, we have compiled a list of 50 amplifiers that are truly worth your attention — from affordable models for beginners to top-of-the-line solutions for audiophiles. The main thing is that they all have one thing in common: each of them makes music clear, voluminous, and real. Continuing the best traditions of Gryphon: pure class A, 175 watts per channel into 8 ohms (with peaks up to 6,000 watts into 0.5 ohms), 108 (!) kg in weight. The circuitry is a full dual mono design with no interaction between channels—all power supplies, rectifiers, controls, and amplifier channels are differentiated. The output impedance is negligible – 0.025 ohms. The sound of the Gryphon Mephisto Stereo seems like a real “iron fist in a velvet glove” – it provides phenomenal volume and holography along with bone-crushing bass and exceptional dynamic bursts.
Today, there are many LCD projectors with optical units that use additional filters that effectively “hide” the pixel grid so that it does not conflict with the perforation, forming moiré. In addition, LCoS projectors have an excellent pixel fill factor (the ratio of the useful pixel area to the border area) and produce virtually no moiré. The closer to 1080p resolution (the higher, the better), the less chance of moiré.
In the broad segment of inexpensive DLP projectors, there are plenty of models that produce moiré patterns on perforated screens. This is a consequence of the interaction between the aforementioned fill factor (matrix efficiency) and the color wheel in single-chip projectors. In three-chip DLP projectors, the moiré effect is extremely rare.
The moiré problem is unexpectedly solved by rotating the perforation pattern at a small angle, depending on the image width. For small images, from 72 to 80 inches, the correction is approximately 8° to 26°. The angle correction decreases as the image width increases.
As a rule, the image of virtually any DLP will be completely free of moiré at any angle, starting with an image width of 107 inches or more. Some DLP projectors with anamorphic lenses will still require correction to increase the width, because anamorphic optics stretch both the pixel grid and the content itself across the width.
As mentioned earlier, new high-resolution projectors do not pose any problems, but even for supposedly “hopeless” older generation matrices, the “golden mean” can be achieved by simply rotating the projector relative to the perforation pattern. No correction is required for images with a diagonal of more than 123 inches. As the width (and diagonal) of the image decreases, a correction of 8° to a maximum of 26° is appropriate. These values depend on both the type of optical unit and the size of the image.
This data was obtained by Stewart Filmscreen. If its engineers find gaps in their data, they order the necessary projector or go to the manufacturer to examine the image on screens of different sizes. This company always welcomes the solution of particularly difficult problems.
Contrast ratio “without a mask”
Now we come to our favorite specification: contrast ratio. The amount of misinformation on this topic for displays and projectors of all types is incredible. Before continuing, let's remember that contrast ratio is a constant part of specifications. It is usually presented in the form of the popular “On/Off” ratio, which will always be greatly exaggerated in relation to any other estimates of real contrast ratio.
Why? It benefits the manufacturer. One of the tasks of a cinema projector or TV is to ensure that there is no light in areas of the frame that should appear black. Determining the real (effective) contrast of a projection system involves taking into account the conditions in the room and the properties of the screen and projector. Therefore, we measure real contrast using the ANSI checkerboard test pattern, which consists of 50% white and 50% black squares.
While researching perforated screens, we decided to conduct a series of scientific experiments that would clearly show the differences in screen characteristics—their materials and types. We settled on comparing traditional non-woven fabrics and woven (woven) materials.
We started with a key question: why does video of any resolution look blurry, dull, and unsaturated on woven fabrics compared to images on solid white Lambertian, micro-perforated with reinforcement, or contrasting woven fabrics with micro-perforation?
We found that many answers can be found in the criteria for hardware contrast measurement. The human eye can easily see the difference, but measurement and quantitative assessment provide more—an understanding of what we are observing.
Using a Sim2 C3x DLP projector and 84-inch screens as our working setup, we measured ANSI contrast under various conditions. The wall behind the screen was completely black and non-reflective. To measure contrast, we fed the projector a checkerboard ANSI test pattern with black and white squares.
In a completely darkened room, using a Minolta LS-100 sensor set to measure at an angle of 1° (standard colorimetric observer), we verified that the projector had sufficient on/off contrast to achieve a black level of 0.5 fL or lower. This was confirmed by a certified Lambertian standard.
We then used the ANSI Checkerboard test pattern under various conditions to measure the actual characteristics of the screen. In a completely darkened optical lab with flat black walls, ceiling, and floor, the dark field reading of the ANSI checkerboard on the reflective standard was <0.5 fL.
The projector's light source power supply was unfiltered, and light flux fluctuations were minimal. We then checked the brightness readings in fL for maximum white and minimum black in similar locations on each test screen. Measurements were taken through a window at a 45° angle. Below is a table of the measurement results.
Designations:
Black Level — black level;
Screen Brightness — brightness on the screen;
Contrast Ratio — contrast ratio along the measurement axis;
Dark Environment — dark room;
MGC03 Reflectance Standard — a reflective standard based on magnesium compounds
Let's compare the contrast for these test conditions. In a “black room” — supposedly the best environment for woven acoustically transparent fabric — it falls short of industry standards for reflectance by 28.2% in brightness and 14% in contrast. Woven fabric (even if it is white) never approaches the brightness of the reflectance standard, regardless of how far the viewer deviates from the normal to the screen.
The woven fabric is 38% less bright and 12% less contrasty than the perforated Stewart Studiotek 130. Studiotek remains brighter at a 45° deviation from the axis — that is, outside the viewing area for DC.
Woven fabric also loses out to perforated Stewart Firehawk by 28% in contrast and 36% in brightness. To achieve the same brightness as Firehawk, the projector will require an additional 56% of light output. The viewer must deviate from the axis by more than 30° before the brightness on the fabric becomes equal to that of the Firehawk. Even in a completely darkened room, the Firehawk's black level is 7% lower.
Why do Lambert fabrics provide lower contrast? The dynamic range of available brightness in the axial direction is reduced in Lambert fabrics because the uniform angular distribution pattern causes a large amount of light to escape to the sides, outside the viewing area.
In addition, this light often returns to the screen surface in the form of parasitic light, worsening the already subpar black projection level. Woven fabrics have an additional disadvantage in that they cannot block reflected light from the speaker area: a black backing (also fabric) is required between the screen and the speakers.
Of course, this is another barrier to acoustics, but, as they say, between two evils… And without a backing, parasitic light from the wall is like a shot in the back: it saturates the working layer of the canvas with unnecessary lumens, naturally “killing” the black level.
About parasitic light
What will happen if a designer with a superficial understanding of the principles of home theaters decides to make the interior more cheerful, in the sense of brighter? Alas, such an “upgrade” will not add to the mood of the home theater owner and viewers.
In this test, there was parasitic light leakage — to a reasonable extent. We started with a modest 1.3 fL, measured against the standard with the projector turned off. The light leakage was generated using precisely controlled incandescent lamps, taking into account dispersion. The laboratory was completely darkened, so there was not much light leakage overall. The projector's own contrast ratio, of course, helped the black level on the ANSI checkerboard.
The data shows that the properties of Lambertian fabric are not entirely suitable for conditions where the walls and ceiling do not perfectly absorb light. However, it is a good environment for using gray fabrics of neutral density.
Here are the measurement results:
— The contrast of the Stewart Firehawk gray screen is 77% higher than that of a woven screen.
Ever since the days of jesters and the first puppet shows in town squares, it has been believed that only toys and holy fools can speak freely about truly serious matters. The animated series South Park is an example of how provocatively garish cartoon characters raise the most complex issues and, if they don't solve the world's problems, at least bring them to the attention of viewers, albeit in a somewhat unusual manner. It's a cruel, cynical, funny, unrestrained, and at times bloody series in which Kenny is always killed. Bastards!
— The Stewart Firehawk gray canvas is 36% higher in contrast than the benchmark
An additional question arises when evaluating perforated tapes: what is the role of light that penetrates the tape, reflects off the back wall, and returns to the back of the tape? This is a mathematical problem—and the solution is not obvious. We decided to measure it.
The main character of the show ends up in prison for a crime she committed long ago and had already forgotten about. The sudden change in her life forces her to learn to live in new circumstances and look for ways to make life easier for herself and her new friends. Never before have prison cells attracted so many viewers. 23 seasons
The same measurement protocol showed that the perforated MicroPerf sample lost 0.72 fL to the Lambertian cloth. Interested in where the light goes if not directly into the viewing area, we took additional measurements.
It is difficult to obtain a direct measurement along the axis due to the frontal light from the projector, and we had to deviate from the normal by several degrees. In white light, a direct measurement (the sensor axis is offset by 2° from the normal, the sensor itself is located 1 m behind the screen) gave 0.33 fL on the MicroPerf perforated screen and 4.11 fL on the woven screen. It is clear that there is quite a lot of parasitic light passing through the back side of the woven screen.
System dynamic range
The first comparison was between woven (but with Lambertian diffusion) and non-woven gain fabrics. Since Stewart Filmscreen is one of the world's largest manufacturers of both Lambertian and gain screens, we decided to get their opinion on the matter and conduct independent comprehensive testing. After all, Stewart offers unique perforated fabrics with a gain range from 0.7 to 3, including woven fabrics.
During the tests, we found that various woven screens currently on the market have a gain factor of less than one, and none of them are capable of effectively blocking parasitic light. The sellers of these fabrics try their best to convince us that all non-woven models are outdated technology. They claim that a Lambertian surface is suitable for any viewing. This is clearly untrue.
Lambertian fabric is not always the most suitable option for… most situations. In our tests, we found that woven fabrics are not very good for bright scenes (HDR) and, of course, are very vulnerable to stray light, which negatively affects the overall visual contrast of the image.
Stewart Filmscreen offers its screens based on the criterion of “optimal specifications.” They found that at a gain of 1.3, there is a pleasant “synergy” in viewing perception, thanks to the microstructure of the angular reflective particles of the gain screen.
Although such a screen, with some limitations, generally corresponds well to the properties of a Lambertian surface. The main thing is that a screen with medium gain is clearly more sensitive to light falling normally, unlike a Lambertian screen, which simply reacts to light coming from all sides. The result for screens with a gain of 1.3 is the best “pure” ANSI contrast in our cinema.
Amplification increases the overall dynamic range of the cinema image. In our tests, such screens provide a true and vivid image in the upper IRE range (meaning bright scenes, i.e., HDR), while preserving details in shadows at low IRE levels (the term “preserve” is conditional here, since gain affects the entire brightness range — from black to peak white).
Remember that reducing the influence of parasitic light is a necessary condition for good dynamic range. And dynamic range — the main parameter of a cinema image — is what distinguishes the charm of realistic cinema from useless manipulations with color gamut and resolution in the absence of decent real image contrast.
The second important advantage of amplification is the ability to turn on the average power of the projector lamp (laser) (this is better suited for Cinema-type presets). Not everyone knows this, but it is the average power of the light source that produces the best projector image, including image contrast.
We constructed a unique tunnel to accurately measure the reflected useful light flux that enters the viewer's field of vision. We filtered out the direct frontal light from the projector and were able to measure only the secondary light, i.e., behind the screen—reflected from the white surface of the back wall.
This light first passed through the front layer of the screen, then reflected off the wall and, again, from the back, penetrated through the rear surface, combining with the main light — initially reflected from the front layer of the screen. The result: ANSI contrast degradation. We were able to measure the components of this process. Stewart MicroPerf fabric re-emits 0.08 fL; woven material re-emits as much as 0.33 fL under identical test conditions.
The role of screen resolution
We have talked a lot about contrast. The difference in the values obtained affects the cinematic realism of the image — it is no coincidence that calibration begins with tuning the black and white levels. If the light flux does not reach the viewer, it is either absorbed or lost. We can assess the impact of the screen on visual clarity by analyzing the relative resolution of two types of screens.
Let us remind you that visual clarity, or detail, is a function of contrast and, in fact, the resolution of the canvas. Therefore, where light is lost, detail is also lost. Where light is noticeably absorbed, detail may be lost. This is a qualitative approach, and further objective evaluation will provide more accurate justification. Let's take a look at these images and think about which of the canvases are optimal for conveying the resolution of the new generation of projectors — 1080P and above — to the viewer.
We had previously determined and measured the light flux passing through the screen. Now we understand the essence of the phenomenon. In this macro photograph, you can clearly see that the light disorder is caused by approximately 20 significant voids and countless wavy “yarn” surfaces that chaotically distribute light, sometimes transmitting it and sometimes scattering it.
Now let's look at another macro photo: the perforated sample at the same magnification has only voids — holes that make up exactly 10.2% of the surface area and have a much smaller effect on the useful reflected light.
The miracle of the ugly duckling turning into a beautiful swan will leave no one indifferent. Despite its unassuming appearance, the Musica Int-200 amplifier simply needs to be given a chance and plugged in. You won't want to turn it off afterwards. The timbres are simply magnificent — far beyond its price.
Price: 90,200 rubles.
Sugden A21al Series 2
Unfortunately, this company's devices appear in our tests much less often than we would like. However, this English company, named after its founder, produces very interesting and musical components that consistently deliver high-quality sound. The amplifier we are dealing with today has a very long history — its predecessor was Sugden's very first product in 1964.
When choosing a perforated surface, several important sound properties should be taken into account. The problem is that sound waves are transmitted through the medium (screen material). Unlike the nearly transparent fabric of speaker grilles, which minimally colors the sound, depending on the type of perforated screen, some fabrics cause a noticeable attenuation of -2 dB.
In addition to this, some manufacturers use a black backing on the rear surface of the screen to block reflected light from the rear wall, which causes additional losses. There is a lot of marketing hype about this all the time.
Based on original THX tests, Stewart Filmscreen engineers came up with an elegant but simple solution to somehow circumvent the laws of physics. They took into account that the frequency response of drivers located behind the fabric would be distorted at frequencies above 10 kHz. In collaboration with Tomlinson Holman, a key figure in professional acoustics, Stewart developed and implemented the active Cinemasonic Processor, which restores losses in the 10-20 kHz range.
Condition: for optimal performance, the speakers behind the screen must be at least 12 inches away from the rear surface. If the speakers are closer to the screen, so-called combined comb filtering may occur due to nonlinear interaction with the rear surface. However, when installed according to specifications, attenuation is minimal and the sound is quite transparent.
Ratings
Passport data:
The frequency response of the Musica Int-200 amplifier shows a drop of -4.3 dB at 80 kHz, and the unevenness in the audible frequency range is 0.41 dB (Fig. 1). The damping factor is far from the worst in the test — 57 units. The interchannel signal leakage level is very stable across the entire audible frequency range and is 54 dB (Fig. 2). Testing revealed the rather modest power characteristics of this model, as well as a slightly higher THD level compared to other participants. However, it is necessary to take into account the design features that distinguish this amplifier in our selection. The maximum output power at an 8-ohm load is 13 W and does not differ much for other resistance values. The amplifier stage operates with a low-impedance load, although this results in an increase in the level of nonlinear distortion across the entire low and mid-frequency range (Fig. 3).
Clear, confident, and voluminous sound, excellent timbre texture, accurate recording scale, absolute genre versatility Name – Musica Int-200 | Output power (at 8 ohms), W – 25 x 2 | Frequency response, Hz – 1–40,000 (at –3 dB) | Harmonic distortion, % – 0.1 | Signal-to-noise ratio, dB – no data | Audio inputs – RCA stereo pairs (3) | Audio outputs – none | Power consumption, W – no data | Dimensions, cm – 21.7 x 6.8 x 26 | Weight, kg – no data
Ergonomics beyond good and evil, minor issues with low bass. Conclusion:
We contacted Harman International, a leading supplier of loudspeakers with extensive experience in the field of audio. The company has impeccable measuring equipment and testing methods. Mr. Alan Devantier, Test Manager, developed a comprehensive test cycle for their anechoic chamber. MicroPerf products were tested, as well as conventional products with “cinema perforation” and woven screens.
Loudspeakers of various sizes and configurations were tested on and off the center axis, and the differences and characteristics were analyzed using the Fast Fourier Transform (FFT) method and MLSSA systems. In other words, the drivers were tested quantitatively and mathematically, and therefore impartially. Efforts were made to obtain the most accurate results possible for each product, regardless of manufacturer.
The results are very interesting. All products performed better when the speaker was placed 12 inches from the rear surface of the screen. All products also performed well with slight deviations — when the speaker was moved closer to the screen surface. Of course, comb filtering was observed for all products when the speakers were placed close to the screen (2–6 inches), regardless of the type of speaker: two-way, built-in wall, or open horn type.
— Stewart Firehawk gray fabric is 21% more contrasty than Studiotek.
— Stewart Firehawk gray fabric is 77% higher in contrast than woven fabric.
We started with a Sony VPL-VW50 projector and an 84-inch screen diagonal. The projector produced 13.72 lm on the reflective standard. Placing the standard one meter behind each test screen, we found that the woven screen achieved 0.87 fL of brightness on the standard, as measured by our 1-degree spot sensor. An additional question that arises when evaluating perforated screens is: what is the role of light that penetrates the screen, reflects off the rear wall, and returns to the back of the screen? This is a mathematical problem, and the solution is not obvious. We decided to measure it. — Stewart Firehawk gray fabric is 36% higher in contrast than the reference.
The same measurement protocol showed that the perforated MicroPerf sample lost 0.72 fL to the Lambertian screen. Interested in where the light goes if not directly into the viewing area, we conducted additional measurements.
The following graph shows the results for MicroPerf under the same test conditions: a 6-inch two-way speaker located 12 inches behind the panel, with a 10° convergence. Here, the red curve is the frequency response averaged for the same 30° listening angle range. The blue curve shows the result for MicroPerf, but with Cinemasonic correction. It can be seen that there is some attenuation of the high frequencies in the uppermost octave: between 10 and 15 kHz there is a loss of 0.5 to 1 dB.
Please note that the “pure, unabsorbed sound” promised by sellers of woven screens is not what you will hear in reality. A black backing is required for the “woven screen” to soften the rear parasitic light. It acts as a broadband filter, unevenly attenuating high and low sound frequencies.
In tests, the Stewart MicroPerf screen performed as advertised, so Stewart's efforts to correct attenuation should be considered successful. These tests were in no way used to “discredit” competitors. It's up to you to decide: you can accept a slight reduction in contrast and dynamic range of the “fabric” without a backing, and the sound will be quite acceptable (see graph).
It's a different matter if you are more of a videophile and value contrast in the image (which accounts for a significant portion of the projector's price). In that case, if you have an acoustic woven screen, you will definitely need a black backing. Of course, the dynamics of your home theater “surround sound” will be weakened by 2 dB or more — you will have to correct this yourself.
In the end, perforations in acoustic screens aren't just holes for speakers. They're a carefully calculated compromise. Sound passes through these holes, but they also slightly “steal” the clarity of the picture. So, the choice always depends on what's most important to you.
If you are primarily a movie lover and appreciate deep, rich sound with a fully immersive effect, then massive perforation is the right choice for you. It allows powerful speakers to be placed directly behind the screen fabric. The picture will remain excellent, especially if you sit at a sufficient distance.
If you are a fan of games or sports broadcasts, where perfect detail is important, or your room does not allow you to sit far from the screen, you should consider micro-perforation. It is virtually indistinguishable from a smooth canvas, keeping the image crystal clear, albeit with some limitations on sound.
The main point is to find your balance between “hearing” and “seeing.” And now, knowing the difference, you can make an informed choice that is ideal for your system and your habits.
