Gregg Loewen(THX视频培训首席讲师、Lion AV顾问公司创始人):

An excellent question that could warrant an entire article of response (ie: The question of screen selection). Due to design limitations, a particular model of projector will only allow for a certain amount of light output. The larger the screen size the dimmer the image. There are many light output calculators that will assist you in making educated decision in regard to this question. The parameters of: lightout, size screen, screen color, and screen gain, while considering the ability to control ambient light and also needing to consider room reflectivity (is the room painted white or black) need to be considered.



Gregg Loewen先生



Gregg Loewen(THX视频培训首席讲师、Lion AV顾问公司创始人):

The challenge with 3D is the lack of light output as the use of 3D glasses can decrease the amount of light output by up to 75%.  The minimal goal of light output for a 3D projected image should be 4.5 fL. If the projector and screen combination cannot achieve this target then the screen gain will need to be increase to meet the light output target. Also, remember that as the gain is increased the viewing angle is decreased.  Other options include changing to a projector with more light output and getting a smaller screen size. Lastly, ambient light control is critical when viewing 3D.


哪一个4K投影机技术是最好的?TI UHD 4K, JVC 4K D-ILA 还是Sony SXRD? HDR功能重要吗?

Gerry Lemay(THX视频培训首席讲师、Lion AV顾问公司创始人):

There are many factors involved in the perception of image fidelity and only one them is the native resolution of the imaging chip.  Far more important is the absolute black level followed closely by the contrast ratio. Seating distance, screen size and material, and lense quality also factor into this perception of image fidelity, so there is no best technology but rather the best technology for a given situation should be considered.

HDR is an exciting development in the home theater market. To enjoy HDR the viewer not only needs to have an HDR capable PJ (meaning accepts an HDR signal) but also needs to have a PJ that is able to process at 10 bits, have increased color gamut, and have increased light output of 2 to 3 times the SDR light output value. On a side note, generally speaking the ability to have a good black level is essential when trying to achieve a great HDR image.    




Gerry Lemay(HAA家庭声学联盟创始人与主席 ):

The answer to this question should be based upon the specific room.  For example, in a small room adding more surround speakers can complicate seating layout.  This is because speakers that are too close to any listener can disrupt and even collapse the surround field.  We call this the “exit door effect” since localizing a nearby speaker makes you aware of the speaker and you lose the illusion of the movie created by the sound track… just like someone interrupting the movie by flooding the room with light by opening the exit door.  In such rooms, you might be better minimizing the surround channels so you can place them farther away from your listeners.  As you say a 5.1 system can be very good, however adding more channels can create a better sense of envelopment and immersion.  In most cases, I would add ceiling speakers to fully enjoy Dolby Atmos or DTS:X.  In rooms will tall ceilings (3 meters or higher), you could easily add ceiling speakers, but in lesser height rooms Dolby Atmos Enabled speakers which reflect sound off of the ceiling might be a better choice.  Larger rooms give you more options but you still must avoid having speakers too close to listeners.

这个问题的答案要以具体的房间为基础。例如,一个添加太多环绕音箱的小房间会使座位布局复杂化。这是因为离任何聆听者太近的音箱会破坏甚至使整个环绕声场崩溃。我们将这种现象称为“出口效应”。因为你离旁边的音箱太近,导致你只意识到那只音箱,而失去电影所营造出来的声音幻象。就像有些人突然打开门照亮房间而打断你看电影。在这样的房间中,你可能最好还是减少环绕通道的数量,这样你可以将它们摆放得离聆听者更远。就像你所说的,一个5.1声道可以非常好了。然而,增加更多的声道可以创造更好的包围和沉浸感。在大部分的案例中,我会增加天花音箱来享受完整的杜比全景声或DTS:X效果。在一些有着3米或更高天花板的房间中,你可以轻松增加天花板音箱,但在天花板高度更低的房间中,选择能将声音反射到天花板的 Dolby Atmos Enabled 音箱会更好。更大的房间给你更多的选择,但你仍然必须避免让音箱离聆听者太近。



 Gerry Lemay先生


Gerry Lemay(HAA家庭声学联盟创始人与主席 ):

There are two problems with irregular rooms: 1) Depending on the shape of the room, it may be difficult to properly place speakers. 2) This makes predicting low frequency modes much more difficult to deal with.  As you might understand, the ability to solve either of these problems depends on the shape of the room.  In the case of low frequency modes, we try to predict where these modal resonances cancel bass and avoid placing seats there.  If you don’t have the ability to predict such things, the best solution is to use an audio generator playing a sine wave to find the lowest mode frequencies by changing frequency until the tone becomes very loud.  You then can find the cancellation points and avoid them when placing seats.  This process is taught in the THX-HAA Advanced class and is much easier if you also have a high resolution RTA to use.