How Big Should My Screen Be?
A simple answer might be “how much money do you have?”, but that would ignore the root problem. And it’s not about money, but satisfaction with the result anyway.
The choice of a screen size is actually driven by emotional response. The single most popular screen size in the market today is 42”. That’s where the best prices are, and the 42” set doesn’t demand much from the owner in terms of mounting, or placing on a piece of furniture. In that scenario, the choice is driven only by price and physical size (or lack of it). And that’s the emotion we’re talking about…price and the stress of spending a lot of money on a new TV. That said, it’s funny how many 42” TV owners we hear saying “I wish I’d bought the larger one” though. A 42” screen, as hard as it may be to believe, can have the visual impact of a postage stamp in many homes. In fact, if you’re watching standard TV, an old 4x3 TV will end up with a bigger image on it than the same picture centered on a new 16x9 wide screen 42” TV!
We can separate video screen viewing into two categories: Home Entertainment (casual viewing), and Home Theater (approximate the large, involving image of a theater). Both uses are completely valid, but will result in very different choices.
Home Entertainment screens can be smaller for a couple of reasons. The most obvious is that with this type of use, the viewer doesn’t care about filling his peripheral vision with image, and may not desire to be that involved with the program content. Having a smaller screen separates the view from the content, and isolates him from the “suspension of disbelief” goal of the feature movie maker. Also, smaller screens allow more positional flexibility. You can put smaller screens in a wider variety of places, hang them on smaller mounts, and place them on furniture. So long as we realize the use dictates the size, the Home Entertainment use screen can be 42”, even if the viewer sits 12 feet away.
But that’s not going to work for our other category, Home Theater. If you remove the “Home” qualification from the category title, “Theater” is what remains, and that’s what drives the screen size choice in this world. There are many charts, calculators, and graphs available on web sites that help simplify the process (some are linked below). There has been quite a bit of research into this application, and organizations like SMPTE, THX, and others have specifications that are based on viewing angle with the goal to filling a significant portion of your peripheral vision with picture. We also like to add a resolution parameter to this, since filling your vision with a low resolution image doesn’t do anything to support suspended disbelief.
So the first factor to consider is viewing angle. THX recommends a 36 degree viewing angle, and a minimum of 26 degrees, while SMPTE recommends 30 degrees. For a 50” diagonal screen, that works out to be a viewing distance of 5.6 feet for the recommended THX angle, and 7.9 feet for the THX minimum viewing angle.
Now, let’s look at the same TV from a standpoint of resolution. Assuming a 1080p display, the THX recommended distance will always be slightly closer than the point at which a person with 20/20 vision can no longer see individual pixels. This is because the THX standard is weighted towards favoring peripheral vision rather than resolution, and is actually a pretty smart tradeoff, weighting the entertainment power of a large picture over invisible pixels. (See the post: Can I See 1080p?)
But, as you might begin to see, most TVs purchased are way too small for THX specs. So as you consider screen size and your application, run these numbers to see if you’re in the THX ballpark: Take the screen width (not the diagonal measurement!) and multiply by 1.54. The result is the distance at which you’d need to sit for the optimal THX 36 degree viewing angle. Multiply the screen width by 5, and that’s the maximum recommended viewing distance.
As a closing thought, all of this assumes you are working with a screen aspect ratio of 16x9. These days, that's no longer always true. Technology exists that permits projection of a full 2.35:1 true wide screen image...well beyond this half-baked, slightly narrower than 1.85:1, 16x9 stuff. Oh, don't get me started! But we'll right on that subject soon too.
As always, a professional home theater consultant will be able to optimize your home theater floor plan for screen size and seat position, as well as optimize performance of both your picture and sound.
Links to screen size charts and calculators:
A screen size chart based on resolution
A very nice screen size calculator
Carlton Bale addresses screen size and 1080p
Wednesday, 18 July 2007
Audyssey MultEQ – Fixing room problems other equalizers don’t even know are there
If you’ve been around the Home Theater scene for a while, you’ve no doubt run into the concept of equalization. Simply, and equalizer attempts to compensate for a frequency response problem by pre-filtering the audio with the inverse characteristic. If you have a 200Hz bass peak, an equalizer will create a complimentary dip to compensate for it, with the intended result being smooth, flat response.
Ah, if only we lived in an that ideal world. Or an anechoic chamber. But such is not the case. In reality, our home theaters or multi-purpose home entertainment rooms are far from perfect acoustic spaces. There is a different set of room-imposed flaws in each one of them, and within each room, a different set of flaws for each listening position, making even measuring such problems a very imprecise process. Usually, a technician will make a lot of response measurements over a large area and somehow average them together. That’s a great way to avoid “chasing” a nasty problem for one seat while ignoring a different problem in another…you just average them all out and apply whatever equalization more or less works for every seat. Or rather, doesn’t work for any seat.
What if we could custom equalize out response problems for each seat individually? What if we went even farther and worked not only on frequency response issues, but looked at time-domain problems too, like sound reflections from walls, or physical speaker misalignment? What if we did all of this by making a series of test measurements, then let some highly sophisticated math from another galaxy do the work, and create a custom digital filter for each speaker in the room that addresses problems caused by that room for each seat? Too cool, you say?
Yup, that’s for sure. That’s also, in simple terms, what the Audyssey process does. Audyssey MultEQ XT, MultEQ, 2EQ, and EQ all use variations on the process, to differing levels of sophistication. The most elaborate implementation is found in the Audyssey MultEQ XT system, which a custom installer makes use of a computer and software to make the necessary measurements and calculations to cover the most demanding installations. MultEQ XT can also be found in high-end receivers, and is the most powerful version yet released.
Below that, MultEQ, 2EQ and EQ vary in processing and measurement power, with the EQ version being a preset system tuned for HTiB systems and TV sound systems. And yes, the automotive sound industry may soon benefit from Audyssey processing too.
So you ask, “Who are these guys?” And well you should. From the Audyssey web site’s ‘about us’ page,: Audyssey Laboratories was conceived at the prestigious Immersive Audio Laboratory at the University of Southern California in Los Angeles, California. Dr. Sunil Bharitkar, Philip Hilmes, Prof. Tomlinson Holman, and Prof. Chris Kyriakakis were all involved in conceiving and creating the technology that was the basis for "spinning out" the company in July, 2002.
In late 1996, after a fierce competition among 117 universities, the National Science Foundation established a unique research center at USC that focused on immersive technologies. A key component of the Integrated Media Systems Center (IMSC) is the Immersive Audio Laboratory that was founded by Chris Kyriakakis and Tomlinson Holman. Over the past 10 years Tom and Chris have conducted research in audio signal processing, acoustics, and psychoacoustics. The results of their interdisciplinary research have been published in more than 100 technical journals and several books. One of the most challenging problems that they addressed was the comprehensive understanding of the negative effects of room acoustics on sound reproduction. It took 5 years of intense research and experimentation and more than $5M in research funds to fully understand and solve this intricate problem. No other facility in the world had the scientific expertise and the resources to fundamentally examine and solve this problem.
Sharp eyed readers may have picked up the name of Tomlinson Holman. Yes, the “T H” of “THX” fame, inventor of THX theater sound systems, home THX, and the founder of the entire THX program at Lucasfilm. That Tom Holman. For more about Tom, see the “THX” and “TMH” links at www.platinumhometheaters.com
We have been using Audyssey processing for over a year now with great results, and now recommend it to our clients, if built into receivers by Denon, Marantz, and Onkyo, or in high end component systems using the Audyssey Sound Equalizer product custom calibrated to the space.
For information on how you can get Audyssey MultEQ in your home theater, contact us at Platinum Home Theaters.
Ah, if only we lived in an that ideal world. Or an anechoic chamber. But such is not the case. In reality, our home theaters or multi-purpose home entertainment rooms are far from perfect acoustic spaces. There is a different set of room-imposed flaws in each one of them, and within each room, a different set of flaws for each listening position, making even measuring such problems a very imprecise process. Usually, a technician will make a lot of response measurements over a large area and somehow average them together. That’s a great way to avoid “chasing” a nasty problem for one seat while ignoring a different problem in another…you just average them all out and apply whatever equalization more or less works for every seat. Or rather, doesn’t work for any seat.
What if we could custom equalize out response problems for each seat individually? What if we went even farther and worked not only on frequency response issues, but looked at time-domain problems too, like sound reflections from walls, or physical speaker misalignment? What if we did all of this by making a series of test measurements, then let some highly sophisticated math from another galaxy do the work, and create a custom digital filter for each speaker in the room that addresses problems caused by that room for each seat? Too cool, you say?
Yup, that’s for sure. That’s also, in simple terms, what the Audyssey process does. Audyssey MultEQ XT, MultEQ, 2EQ, and EQ all use variations on the process, to differing levels of sophistication. The most elaborate implementation is found in the Audyssey MultEQ XT system, which a custom installer makes use of a computer and software to make the necessary measurements and calculations to cover the most demanding installations. MultEQ XT can also be found in high-end receivers, and is the most powerful version yet released.
Below that, MultEQ, 2EQ and EQ vary in processing and measurement power, with the EQ version being a preset system tuned for HTiB systems and TV sound systems. And yes, the automotive sound industry may soon benefit from Audyssey processing too.
So you ask, “Who are these guys?” And well you should. From the Audyssey web site’s ‘about us’ page,: Audyssey Laboratories was conceived at the prestigious Immersive Audio Laboratory at the University of Southern California in Los Angeles, California. Dr. Sunil Bharitkar, Philip Hilmes, Prof. Tomlinson Holman, and Prof. Chris Kyriakakis were all involved in conceiving and creating the technology that was the basis for "spinning out" the company in July, 2002.
In late 1996, after a fierce competition among 117 universities, the National Science Foundation established a unique research center at USC that focused on immersive technologies. A key component of the Integrated Media Systems Center (IMSC) is the Immersive Audio Laboratory that was founded by Chris Kyriakakis and Tomlinson Holman. Over the past 10 years Tom and Chris have conducted research in audio signal processing, acoustics, and psychoacoustics. The results of their interdisciplinary research have been published in more than 100 technical journals and several books. One of the most challenging problems that they addressed was the comprehensive understanding of the negative effects of room acoustics on sound reproduction. It took 5 years of intense research and experimentation and more than $5M in research funds to fully understand and solve this intricate problem. No other facility in the world had the scientific expertise and the resources to fundamentally examine and solve this problem.
Sharp eyed readers may have picked up the name of Tomlinson Holman. Yes, the “T H” of “THX” fame, inventor of THX theater sound systems, home THX, and the founder of the entire THX program at Lucasfilm. That Tom Holman. For more about Tom, see the “THX” and “TMH” links at www.platinumhometheaters.com
We have been using Audyssey processing for over a year now with great results, and now recommend it to our clients, if built into receivers by Denon, Marantz, and Onkyo, or in high end component systems using the Audyssey Sound Equalizer product custom calibrated to the space.
For information on how you can get Audyssey MultEQ in your home theater, contact us at Platinum Home Theaters.
Tuesday, 17 July 2007
Visual Acuity…or Can I See 1080p?
Here’s the set up: you fork over a king’s ransom for that new 1080p screen (projector, plasma, LCD, it doesn’t matter for this discussion). You place it in your home theater room, sit back, relax, and enjoy the fuits of your labor. But wait. There’s this nagging voice in the back of your mind that says “How come this doesn’t look better, or different than my old screen?” Let’s extend this question to, “Can I See the 1080p I just paid for?” The answer is a definite “maybe”.
If you are in your 20s, and have 20/20 vision, you can see better than most people in the world, and can see things as small as 1/60th of a degree of arc wide. What that means is, if your place a protractor at your pupil (figuratively!!!) and look at how wide 1 degree is, then divide by 60, that’s how small an object you can see. Anything smaller gets mushed into whatever is next to it and becomes indistinct. In order to see the pixels of a 1080p screen, they have to be at least 1/60 of a degree of your visionary arc wide. Simple math, right? It's all based on visual acuity. In fact, we don’t want to see pixels, so we want to sit just far enough away from our screen so as to have one 1080p pixel mush into the next creating a smooth pixel-free image. So just how far away is that? Here’s an example.
If you have a 42” 1080p plasma TV hanging on your wall, you’d need to sit at least 5.5 feet from it to blend those 1920 pixels into a smooth image. As you move farther, some that 1080p resolution is wasted. Any closer and you’ll see the dots. Again, that's assuming 20/20 vision. How many of you sit 5.5 feet from your TV? I didn’t think so. Most are more like 8 feet or farther. With your eagle eyes at 8 feet, the pixels mush together, even with the lowly 720p screen.
Let’s do the same calculations for a 50” screen. For a 1080p screen, plunk your chair at 6.5ft or more to just blur the pixels. At 720p, try a tad under 10 feet. Yes, 1080p is wasted on you for a 50” set at 10’. You just can’t see that well. And if you don’t have 20/20 vision (yea, me neither) these distances get shorter real fast.
Now, before we start getting all upset about how we think we can spot 720p over 1080i on broadcast TV stations, there’s a lot more at work than just the pixel count. We’re talking about display screens only here. Source material is a whole other discussion that includes the resolution of origination formats, how TV stations process images prior to air, bit rates, and much more. But broadcast HDTV is free to those with antennas, HDTVs are not. As a consumer, you owe it to yourself to know if spending more on your picture for higher than necessary resolution is smart, or just obsessive compulsive behavior. For smart consumers, we offer our consulting services to help you pick the perfect picture. For those with OCD, we recommend buying the highest resolution screen you can at any size and price. It’s probably cheaper than therapy.
Coming soon: How big a screen should you get?
If you are in your 20s, and have 20/20 vision, you can see better than most people in the world, and can see things as small as 1/60th of a degree of arc wide. What that means is, if your place a protractor at your pupil (figuratively!!!) and look at how wide 1 degree is, then divide by 60, that’s how small an object you can see. Anything smaller gets mushed into whatever is next to it and becomes indistinct. In order to see the pixels of a 1080p screen, they have to be at least 1/60 of a degree of your visionary arc wide. Simple math, right? It's all based on visual acuity. In fact, we don’t want to see pixels, so we want to sit just far enough away from our screen so as to have one 1080p pixel mush into the next creating a smooth pixel-free image. So just how far away is that? Here’s an example.
If you have a 42” 1080p plasma TV hanging on your wall, you’d need to sit at least 5.5 feet from it to blend those 1920 pixels into a smooth image. As you move farther, some that 1080p resolution is wasted. Any closer and you’ll see the dots. Again, that's assuming 20/20 vision. How many of you sit 5.5 feet from your TV? I didn’t think so. Most are more like 8 feet or farther. With your eagle eyes at 8 feet, the pixels mush together, even with the lowly 720p screen.
Let’s do the same calculations for a 50” screen. For a 1080p screen, plunk your chair at 6.5ft or more to just blur the pixels. At 720p, try a tad under 10 feet. Yes, 1080p is wasted on you for a 50” set at 10’. You just can’t see that well. And if you don’t have 20/20 vision (yea, me neither) these distances get shorter real fast.
Now, before we start getting all upset about how we think we can spot 720p over 1080i on broadcast TV stations, there’s a lot more at work than just the pixel count. We’re talking about display screens only here. Source material is a whole other discussion that includes the resolution of origination formats, how TV stations process images prior to air, bit rates, and much more. But broadcast HDTV is free to those with antennas, HDTVs are not. As a consumer, you owe it to yourself to know if spending more on your picture for higher than necessary resolution is smart, or just obsessive compulsive behavior. For smart consumers, we offer our consulting services to help you pick the perfect picture. For those with OCD, we recommend buying the highest resolution screen you can at any size and price. It’s probably cheaper than therapy.
Coming soon: How big a screen should you get?
HTIAB…make room for the Ensemble 1080 Home Cinema
HTIAB – that stands for Home Theater In A Box…a concept that usually means a “get everything in a box a cheaply as possible”, has a new big brother, the Home Cinema System. The concept comes from Epson and Atlantic Technology and takes the form of the Ensemble 1080 touted as the “first complete home cinema system designed for the consumer market”. It begs the question, “who were you designing for before?”…but let’s move on…
Ensemble 1080 starts with a 1080p 3 LCD front projector and adds a special 100” front projection screen with built-in LCR speakers and a special ceiling mounted surround speaker assembly. It’s all controlled from console with an up-converting DVD player and subwoofer with integrated amplifiers. The system has an HDMI port for external Blu-ray disc players. Speaking of HDMI, the console connects to the front speakers via an HDMI cable making hookup and cable management simpler. Add some remote control finesse (they claim no multiple remotes…hmm…) and you’re into Home Cinema for 7 grand. And just in case that’s a bit steep for you, their 720P version comes in at 5 grand. (See our discussion elsewhere about if you really need 1080p, or will 720 do youo just fine). But don’t run out to Tweeter (even if they are under new ownership) or Best Buy to find it. The system will be sold only via the custom installer channel (that’s us, folks!).
Here are the links, but as of this post, there's nothing on the Epson or Atlantic Tech sites about this yet...
Epson Home Entertainment
Ensemble 1080 starts with a 1080p 3 LCD front projector and adds a special 100” front projection screen with built-in LCR speakers and a special ceiling mounted surround speaker assembly. It’s all controlled from console with an up-converting DVD player and subwoofer with integrated amplifiers. The system has an HDMI port for external Blu-ray disc players. Speaking of HDMI, the console connects to the front speakers via an HDMI cable making hookup and cable management simpler. Add some remote control finesse (they claim no multiple remotes…hmm…) and you’re into Home Cinema for 7 grand. And just in case that’s a bit steep for you, their 720P version comes in at 5 grand. (See our discussion elsewhere about if you really need 1080p, or will 720 do youo just fine). But don’t run out to Tweeter (even if they are under new ownership) or Best Buy to find it. The system will be sold only via the custom installer channel (that’s us, folks!).
Here are the links, but as of this post, there's nothing on the Epson or Atlantic Tech sites about this yet...
Epson Home Entertainment
Samsung introduces LED based LCD 1080p TVs
It’s a world of contrasts, and Samsung apparently knows it. They recently announced their new 71 and 81 series TVs feature not only elegant gloss-black slim bezels and 1080p resolution, HDMI 1.3 inputs, and more, but hit big new numbers in the dynamic contrast zone…are you sitting down for this…100,000:1! Room light will be the issue for sure from now on.
If you like big numbers attached to your 1080p TVs, then here’s another: how about 80,000 hours on the LED-based backlighting? That’s more than 27 years of 8 hour a day TV viewing. Now THAT’s a lot of TV!
The new LED backlight system uses a process Samsung calls “local dimming”, coupled with Samsung’s Auto Motion PulsLED will be offered in sets from 40” to 58”. If you don’t like HDMI (and who really does?) how about connecting your Blu-ray player without wires? The new Samsung TV’s have built-in 802.11n wireless routers that are meant to talk to nearby Blu-ray players, satellite boxes, etc. Oh, and by “near by” we mean within 200 feet. Sure, it will cost a bit more, but how cool is that?
We’ll be keeping more than one eye on Samsung! The new products should ship by the holidays.
If you like big numbers attached to your 1080p TVs, then here’s another: how about 80,000 hours on the LED-based backlighting? That’s more than 27 years of 8 hour a day TV viewing. Now THAT’s a lot of TV!
The new LED backlight system uses a process Samsung calls “local dimming”, coupled with Samsung’s Auto Motion PulsLED will be offered in sets from 40” to 58”. If you don’t like HDMI (and who really does?) how about connecting your Blu-ray player without wires? The new Samsung TV’s have built-in 802.11n wireless routers that are meant to talk to nearby Blu-ray players, satellite boxes, etc. Oh, and by “near by” we mean within 200 feet. Sure, it will cost a bit more, but how cool is that?
We’ll be keeping more than one eye on Samsung! The new products should ship by the holidays.
Welcome to Platinum Home Theater Blogs!
We're trying out the Blogger system in hopes of streamlining our Home Theater Blogs. If you wish to read our old blogs from before 7/17/07, go to www.platinumhometheaters.com and find the Archives link.
Thanks for joining us!
Thanks for joining us!
Sunday, 17 September 2006
Converting Your DVD Player to Region Free
When hunting for your region free solution online the best rule (as with most things) is not to part with your hard earned money. In this article the webmaster of DVD-Unlock briefly looks over the options available.
Region Free Solution 1 - Remote Control / Key Sequence
Many low to mid-range DVD players have secret menus or "back doors", these methods can let you change things such as:
- The current region setting on your particular model (In most cases this is were the Region Free setting can be set)
- Switch between PAL and NTSC
- Modify the Macrovision setting
- Enable VCD and sometimes MP3 playback
Access to these secret menus normally requires the user to enter a sequence via the remote control, codes for particular players can be found all over the net on both free or a "paid for" basis.
Personally I would avoid subscription, one off payment or "required donation" sites because they will normally contain the same information that the free sites have.
Region Free Solution 2 - Upgrading or downgrading your players firmware
This method involves changing the software installed on your model and normally involves downloading the update from the Internet. Once the download is complete the update can be burned to a disk, (quite often in a certain way depending on your DVD model) the disk is then placed in the DVD player.
This method is one of those things that if it works, it works great. If it fails on the other hand you could be looking at a dead player.
Region Free Solution 3 - Chipped Remotes
This is a method I have never performed, but have been made very aware of.
Many sites now are offing chipped remote control units, these units are supposed to be pre-programmed to unlock your particular player normally by the touch of a button. On the face of it this seems like a great solution for DVD players that would not normally be unlocked. In reality the cost of these remotes can cost around the same price as a brand new region free DVD player. I have also been made aware of numerous sites which basically take your money and don't deliver, have poor customer support, don't answer emails, etc.
Now I am sure there are lots of reputable chipped remote dealers out there on the net, I just don't know of anyone who's found one; to be honest I could not justify the cost anyway.
Region Free Solution 4 - Purchase a Region Free Player
If you cannot find a free unlock code for your player I seriously think the best option would be to purchase a cheap region free player, you can normally pick them up locally plus take them back if you get any problems.
Tim Day
http://www.dvd-unlock.co.uk/
Subscribe to:
Posts (Atom)