Vince Maskeeper
Senior HTF Member
- Joined
- Jan 18, 1999
- Messages
- 6,500
People often ask what a calibration DVD is, whether they need it and which kind they should buy. I thought I would take a crack at offering a basic piece of information on these discs both in concept and in specifics:
AN INTRODUCTION TO TEST & CALIBRATION DVDS
aka "Why the hell do I need one of these things?"
As Jay mentioned in his excellent post here-- a major part of enjoyment of the Home Theater hobby comes from accurate reproduction of the intended look, sound and feel of a film. Respect for film and moviemaking as an ART is taken seriously around here, and thus respect for the INTENT of the artist is a closely protected concept.
When films are conceptualized and shot, a good deal of time and energy goes into color palette choices, lighting, production design and film stock -- all decisions, it is hoped, that help to subtly (and sometimes not so subtly) influence the viewer's mood: enhancing the emotional impact of the scene.
When film is processed and printed, again, much care is taken to ensure the intended color scheme and look are maintained to express the visual message of the person(s) creating the imagery and the overall visual style.
When a soundtrack is mixed and finalized, great care is taken with relative levels of music and effects- of the impact of bass and LFE, and with the volume and presence of surround information.
Finally in the DVD stage, the film masters are once again scrutinized to ensure that the intended color and look of the film is maintained-- sound masters are checked to ensure the proper levels and audio information is conveyed. Technicians and artisans work for hours on specially calibrated display and sound devices to tweak nearly every subtle hue, shade and frequency-- to present the most accurate and proper reproduction of the original artistic vision.
When that disc gets to your home- it is only natural to want to continue this chain of correct reproduction. Without doing so, all the previous work and effort that went into maintaining the specific look and sound of the film would be wasted.
By calibrating your system to the same standard the creators and technicians used, you ensure that the intended presentation is maintained in your home. You can see what they saw, exactly as they intended you to see it!
There are VERY talented people working on many of these films, and the fruit of their labor is often impressive-- and even more so when viewed, heard and EXPERIENCED as close to the original intent as possible.
It is with this goal in mind that we seek to conform our home equipment to the identical standards (or as close as budget allows) as were used in the creation of the material in the first place. We WANT to see what they saw-- To do so, we need some sort of calibration tool...
THE TOOLS WE HAVE AT OUR DISPOSAL
aka "All I want for Christmas is a color comparator!"
There are really two levels of "calibration" that exist:
1) "User" calibration, using basic user menus and picture/sound adjustments (Brightness, Contrast, Sharpness, Speaker Level, etc) to conform to standards using test patterns and basic measuring devices and filters.
2) "Professional" calibration, using service menus and physical adjustment/repair of the internal workings of the display device to conform to standards using advanced test patterns, expensive professional equipment and a professional eye.
The various calibration and test DVDs on the market operate, for the most part, at level one: User calibration. While all of them have test patterns that would be useful in attempting a professional calibration- all the "on screen guides" and instructions contained on these DVDs stick with using the user level controls and menus.
They use various test patterns, along with some colored filters and some fun instructions that allow you to make adjustments to your set's controls to get your test material to display properly.
Higher-end "professional" calibration is also an option (and an excellent investment!)
Organizations such as the Imaging Science Foundation (ISF) train technicians to calibrate and service display devices to ensure visual accuracy. Some of the better calibrators actually tour the US and beyond doing full calibration and setup.
This service runs into the hundreds of dollars, and while being well worth the money, getting your set in the "ballpark" is often as easy as buying a calibration DVD and sitting down with it for the evening. Nothing substitutes for a professional calibration (just do some searching here for testimonials)-- but a calibration DVD is a GIANT step forward in presenting and maintaining a proper system. Even after professional calibration, a test DVD is an essential element of keeping your display looking its best.
THE APPEAL OF THESE DVDs BEYOND SIMPLE CALIBRATION
aka "Don't answer yet, just see what else you get in this spectacular offer..."
One of the bigger complaints I see on these boards by new people looking for a calibration DVD is the cost. I can't count the number of posts I've seen that say "I don't wanna pay $50 for something I will use once."
First and foremost it's silly to think you will use this disc only once. I own three different discs and all of them get a spin a couple times a year at my place- not to mention the half dozen pals I help out with basic calibration. These discs will be used every time you change equipment (and if you are into this hobby, the upgrade bug will bite as often as the wife and wallet allow), every time you unplug or move your equipment, and probably a few hours before you have guests over- just to make sure your stuff is operating at peak!
And a very important additional element to note, beyond calibration and test patterns... these DVDs really do offer an excellent overview of video and audio technology, terminology and pitfalls.
My first big "learning" moment in the hobby of home theater was when I rented VIDEO ESSENTIALS from a local video store and sat down with it for the afternoon.
The information contained on the original Video Essentials (which I will refer to from this point onward as "VE") walked me through how a display device works, how light level and color in the room affected my perception of the display, how signal was carried, etc. It covered basic wiring, concepts on how surround formats worked, and even went through an introduction of why calibration and accuracy was important-- giving examples and visual aids-- all before we got to even the first test pattern setup.
I learned more about home theater in that one afternoon than I knew to that point, and I can't say I ever learned more in a single day since...
So, aside from test patterns and the raw utilitarian value of these discs, it is important to take into consideration the added value and importance of these discs as learning tools. If you're interested in home theater, these discs will supply some excellent background info- and you'll soon be the "expert" among your friends.
If I had a nickel for all the people who complained about the cost of Avia or VE, only to come back and proclaim that it was the best investment they made in their Home Theater-- well, I would have enough nickels to buy a ccalibration disc for each and every one of you! Trust me, it's the best $50 you'll spend on your home theater.
THE DIFFERENT DISCS AND THEIR ATTRIBUTES
aka "I'm sold, which one do I buy??"
The big three are Digital Video Essentials, Avia, and Sound & Vision Tune Up -- I'm going to stick with these three.
Digital Video Essentials
Digital Video Essentials (DVE) is the recently released sequel to Video Essentials, which originally appeared on Laserdisc many years ago. VE was the standard for Laserdisc calibration, and VE continued to be the popular solution for DVD for the first few years of the format. It wasn't until the birth of Avia that VE got its first real competition.
Video Essentials and the new DVE are the product of JOE KANE, one of the main guys behind the Imaging Science Foundation (ISF, the guys I mentioned above that certify TV calibration technicians).
DVE PROS: DVE’s strongest point is the sheer amount of material and test patterns it offers. DVE is designed to guide the novice through basic tests as well as to supply professional level test patterns and added refrence-quality film and video clips. DVE is the most recent calibration disc on the market, so it has the most modern mastering and authoring (without getting too technical, it was created in high definition component digital, and ported to standard definition NTSC or PAL for the DVD releases). It's the most up-to-date in terms of test patterns, information and authoring technology.
Bottom line, it is the latest and greatest, the heavy hitter in the tradition of the most popular calibration disc ever released. It's got the pedigree and the chops to back it up...
DVE CONS: Like its predecessor, DVE has been criticized for being difficult to navigate. DVE (like VE) was obviously designed with the more "technical" user in mind and includes a wide variet of test patterns. As a result, the navigation and simplicity suffers.
I have also read that the sub calibration tones on this disc are incorrect, or at the very least are 2db different in level from the previous VE release. I not familiar with why it happened- but anecdotal evidence states that the tones on DVE are 2db louder, resulting in a lower level when you calibrate. A quick solution would be to simply calibrate to 2db higher readout on your sound pressure meter.
Information on this possible error available here on this forum in the DVE discussion thread.
With its numerous testing capabilities, DVE feels more techy, which some users might find a turn off (I'm a nerd, so I like techy).
Release date: September 2003
List price: $24.99
Reviews:
http://www.dvdfile.com/software/revi...sentials.html
http://www.dvd.reviewer.co.uk/review...=3605&User=203
http://shop.store.yahoo.com/dvdinter...iesdvdtar.html
AVIA
Produced by Ovation software and written by Sound & Vision Magazine's technical editor, David Ranada-- it offers some very good explanations of HT concepts and expansive tests. Ovation's main test designer Dr. Guy Kuo is a respected member of this forum, and a regular contributor to the discussions in our hardware section (both on the topic of Avia and others).
Here is a post from Dr. Kuo outlining the tests on Avia.
AVIA PROS: Avia is the middle ground of these three calibration discs- not including as many test patterns as DVE, but is easier to navigate and understand. Its strength is in it's ease of use and excellent narration. Avia does a very nice job of presenting an "infomercial" style overview of HT technology and methodology.
I took this disc to the in-laws years ago to set up their home theater. They both (in their 50's with no real techno passion) enjoyed sitting and watching the explanation of audio and video concepts. They both said it explained the audio and video components far better than their instruction manuals.
Avia also has some interesting test patterns not featured on other discs and Avia test patterns are easy to find in the menu system. Overall it represents the middle ground between user friendliness and power.
AVIA CONS: Avia is the oldest of the group mentioned here (not including the original Video Essentials of course). As a result, it lacks any DTS audio test (although one could argue its necessity) or any information on 6.1 audio.
Avia also has a subwoofer calibration issue - without getting into too much technical detail- the main test pattern for subwoofer calibration actually puts the test signal in the main channels, and must be rerouted by bass management in your receiver. If you use your speakers set to "large", this test will not work for subwoofer level in your system. There is also a weird sub test that is incorrect (although most people don't use it anyway)-- I have authored and posted alternate test signals for anyone interested, just search on posts from me and LFE TEST TONE.
Avia has released and updated version known as AVIA PRO- but it is LITERALLY a professional package, consisting of seven discs and costing four hundred dollars. As of now, the only consumer update to Avia is the S&V disc (discussed below), which is abbreviated in comparison to the original Avia.
Release date: June 1999
List price: $49.99
Reviews:
http://www.hometheaterhifi.com/volume_6_2/aviadvd.html
http://dvd.reviewindex.com/reviews/630551982X.html
Sound & Vision Home Theater Tune-Up
The Sound & Vision disc is made by Ovation, the people who brought us Avia. Targeted at the HT beginner, S&V was designed to be sold to the budget-conscious dabbler looking to run basic system tests without investing in a full $40-50 disc. Very simple, many of the tests of Avia are removed, easy navigation, simple instructions- but lacking in more advanced tests and calibration tools.
It's important to note that S&V came out well after Avia, and has newer tests Avia does not offer such as 6.1 related tests.
It is cheaper, it is less in depth, and it is easy to navigate. It does have some basic information about HT methodology, like Avia it is well written and easy to understand!
S&V PROS: S&V is cheaper and easier to navigate. Some higher-end and redundant tests of Avia have been removed in favor of simplified navigation and basic tests targeted at the average user. It really is the opposite of DVE in terms of scope and audience- and as a result ends up with a much more "average user" feel than DVE offers.
It's made by the same people who did Avia, so it is well laid out and well explained-- and the tests are accurate.
S&V CONS: Like most things, when you add user friendliness, you sacrifice power. S&V is very simple, has only the basic video and audio tests and only limited HT discussion and information. It really should be seen as Avia-Lite (slightly updated due to more recent release of course).
Release date: January 2002
List price: $19.99
Reviews:
http://www.dvdtalk.com/reviews/read.php?ID=3354
http://dvd.reviewindex.com/reviews/B0000CGECF.html
A WORD ABOUT THX OPTIMIZER AND INTERNAL TONES
aka "A note to cheapskates who want to get off without buying a calibration disc..."
With the release of Star Wars Episode One on DVD, THX began including an "optimizer" program with THX certified DVDs. The basic optimizer tests were supposed to serve as a calibration tool with basic audio and video test patterns for speaker level, phase, and picture settings like brightness.
Unfortunately, these tests have proved to be inconsistent and criticized by everyone from the average HT dabbler to professional technicians. There are large differences from optimizer to optimizer (the one on Ep1 vs. the one on Ep2 for example) causing some debate to be made that each test is catered specifically for the disc it is placed on-- however the reality is a set of baseline standards are necessary for accuracy- and no one wants to have to recalibrate for each disc.
In the end, the THX optimizer serves as a good starting point, and for those people who would never buy a calibration disc (and will never discover this forum)- it's a passable substitute-- if nothing else it makes them understand that there are guidelines and target ideals for equipment settings. If you're serious about getting the most performance out of your home theater system, you should look beyond optimizer.
If you're looking for evidence pointing to the use of Avia or DVE over Optimizer, just look at THX's own site, where they give information on optimizer, followed immediately by links directly to Avia and DVE.
As far as internal tones are concerned: most receivers have their own internal test tone generator which you can use to set speaker level. Most people, unfortunately, attempt to set the level by ear- instead of using a sound pressure level (SPL) meter. This will not result in accurate calibration... it is important to note, whether you use a calibration disc or the internal tone, a measuring device like a SPL meter is a MUST!
There are two schools of thought when it comes to using the internal tones versus disc tones:
1) The internal tones are preferred. This comes from some rather important people, like the folks at Dolby Labs.
2) The tones generated by a good test disc are preferred. This is a more popular opinion around here, and one I subscribe to.
In my estimation, the DVD player will be the source for the actual movie playback, so eliminating it from the calibration chain (by using receiver tones) seems incorrect. Any variations introduced by the player will not be reflected in using the internal tones-- so it seems better to use the entire intended playback chain when calibrating.
I’m not sure why Dolby Labs prefers internal tones, but one could theorize that the chips that produce these tones are based on their specifications, and thus they would side with the internal tones...
In the end, there is absolutely no substitute for one of these discs and a SPL meter. Your system will provide the best possible ACCURATE representation of the material...
See also:
Home Theater Means Accuracy & Calibration! by Jay Mitchosky
A Quick Overview of Home Theater Calibration by Vince Maskeeper
AN INTRODUCTION TO TEST & CALIBRATION DVDS
aka "Why the hell do I need one of these things?"
As Jay mentioned in his excellent post here-- a major part of enjoyment of the Home Theater hobby comes from accurate reproduction of the intended look, sound and feel of a film. Respect for film and moviemaking as an ART is taken seriously around here, and thus respect for the INTENT of the artist is a closely protected concept.
When films are conceptualized and shot, a good deal of time and energy goes into color palette choices, lighting, production design and film stock -- all decisions, it is hoped, that help to subtly (and sometimes not so subtly) influence the viewer's mood: enhancing the emotional impact of the scene.
When film is processed and printed, again, much care is taken to ensure the intended color scheme and look are maintained to express the visual message of the person(s) creating the imagery and the overall visual style.
When a soundtrack is mixed and finalized, great care is taken with relative levels of music and effects- of the impact of bass and LFE, and with the volume and presence of surround information.
Finally in the DVD stage, the film masters are once again scrutinized to ensure that the intended color and look of the film is maintained-- sound masters are checked to ensure the proper levels and audio information is conveyed. Technicians and artisans work for hours on specially calibrated display and sound devices to tweak nearly every subtle hue, shade and frequency-- to present the most accurate and proper reproduction of the original artistic vision.
When that disc gets to your home- it is only natural to want to continue this chain of correct reproduction. Without doing so, all the previous work and effort that went into maintaining the specific look and sound of the film would be wasted.
By calibrating your system to the same standard the creators and technicians used, you ensure that the intended presentation is maintained in your home. You can see what they saw, exactly as they intended you to see it!
There are VERY talented people working on many of these films, and the fruit of their labor is often impressive-- and even more so when viewed, heard and EXPERIENCED as close to the original intent as possible.
It is with this goal in mind that we seek to conform our home equipment to the identical standards (or as close as budget allows) as were used in the creation of the material in the first place. We WANT to see what they saw-- To do so, we need some sort of calibration tool...
THE TOOLS WE HAVE AT OUR DISPOSAL
aka "All I want for Christmas is a color comparator!"
There are really two levels of "calibration" that exist:
1) "User" calibration, using basic user menus and picture/sound adjustments (Brightness, Contrast, Sharpness, Speaker Level, etc) to conform to standards using test patterns and basic measuring devices and filters.
2) "Professional" calibration, using service menus and physical adjustment/repair of the internal workings of the display device to conform to standards using advanced test patterns, expensive professional equipment and a professional eye.
The various calibration and test DVDs on the market operate, for the most part, at level one: User calibration. While all of them have test patterns that would be useful in attempting a professional calibration- all the "on screen guides" and instructions contained on these DVDs stick with using the user level controls and menus.
They use various test patterns, along with some colored filters and some fun instructions that allow you to make adjustments to your set's controls to get your test material to display properly.
Higher-end "professional" calibration is also an option (and an excellent investment!)
Organizations such as the Imaging Science Foundation (ISF) train technicians to calibrate and service display devices to ensure visual accuracy. Some of the better calibrators actually tour the US and beyond doing full calibration and setup.
This service runs into the hundreds of dollars, and while being well worth the money, getting your set in the "ballpark" is often as easy as buying a calibration DVD and sitting down with it for the evening. Nothing substitutes for a professional calibration (just do some searching here for testimonials)-- but a calibration DVD is a GIANT step forward in presenting and maintaining a proper system. Even after professional calibration, a test DVD is an essential element of keeping your display looking its best.
THE APPEAL OF THESE DVDs BEYOND SIMPLE CALIBRATION
aka "Don't answer yet, just see what else you get in this spectacular offer..."
One of the bigger complaints I see on these boards by new people looking for a calibration DVD is the cost. I can't count the number of posts I've seen that say "I don't wanna pay $50 for something I will use once."
First and foremost it's silly to think you will use this disc only once. I own three different discs and all of them get a spin a couple times a year at my place- not to mention the half dozen pals I help out with basic calibration. These discs will be used every time you change equipment (and if you are into this hobby, the upgrade bug will bite as often as the wife and wallet allow), every time you unplug or move your equipment, and probably a few hours before you have guests over- just to make sure your stuff is operating at peak!
And a very important additional element to note, beyond calibration and test patterns... these DVDs really do offer an excellent overview of video and audio technology, terminology and pitfalls.
My first big "learning" moment in the hobby of home theater was when I rented VIDEO ESSENTIALS from a local video store and sat down with it for the afternoon.
The information contained on the original Video Essentials (which I will refer to from this point onward as "VE") walked me through how a display device works, how light level and color in the room affected my perception of the display, how signal was carried, etc. It covered basic wiring, concepts on how surround formats worked, and even went through an introduction of why calibration and accuracy was important-- giving examples and visual aids-- all before we got to even the first test pattern setup.
I learned more about home theater in that one afternoon than I knew to that point, and I can't say I ever learned more in a single day since...
So, aside from test patterns and the raw utilitarian value of these discs, it is important to take into consideration the added value and importance of these discs as learning tools. If you're interested in home theater, these discs will supply some excellent background info- and you'll soon be the "expert" among your friends.
If I had a nickel for all the people who complained about the cost of Avia or VE, only to come back and proclaim that it was the best investment they made in their Home Theater-- well, I would have enough nickels to buy a ccalibration disc for each and every one of you! Trust me, it's the best $50 you'll spend on your home theater.
THE DIFFERENT DISCS AND THEIR ATTRIBUTES
aka "I'm sold, which one do I buy??"
The big three are Digital Video Essentials, Avia, and Sound & Vision Tune Up -- I'm going to stick with these three.
Digital Video Essentials
Digital Video Essentials (DVE) is the recently released sequel to Video Essentials, which originally appeared on Laserdisc many years ago. VE was the standard for Laserdisc calibration, and VE continued to be the popular solution for DVD for the first few years of the format. It wasn't until the birth of Avia that VE got its first real competition.
Video Essentials and the new DVE are the product of JOE KANE, one of the main guys behind the Imaging Science Foundation (ISF, the guys I mentioned above that certify TV calibration technicians).
DVE PROS: DVE’s strongest point is the sheer amount of material and test patterns it offers. DVE is designed to guide the novice through basic tests as well as to supply professional level test patterns and added refrence-quality film and video clips. DVE is the most recent calibration disc on the market, so it has the most modern mastering and authoring (without getting too technical, it was created in high definition component digital, and ported to standard definition NTSC or PAL for the DVD releases). It's the most up-to-date in terms of test patterns, information and authoring technology.
Bottom line, it is the latest and greatest, the heavy hitter in the tradition of the most popular calibration disc ever released. It's got the pedigree and the chops to back it up...
DVE CONS: Like its predecessor, DVE has been criticized for being difficult to navigate. DVE (like VE) was obviously designed with the more "technical" user in mind and includes a wide variet of test patterns. As a result, the navigation and simplicity suffers.
I have also read that the sub calibration tones on this disc are incorrect, or at the very least are 2db different in level from the previous VE release. I not familiar with why it happened- but anecdotal evidence states that the tones on DVE are 2db louder, resulting in a lower level when you calibrate. A quick solution would be to simply calibrate to 2db higher readout on your sound pressure meter.
Information on this possible error available here on this forum in the DVE discussion thread.
With its numerous testing capabilities, DVE feels more techy, which some users might find a turn off (I'm a nerd, so I like techy).
Release date: September 2003
List price: $24.99
Reviews:
http://www.dvdfile.com/software/revi...sentials.html
http://www.dvd.reviewer.co.uk/review...=3605&User=203
http://shop.store.yahoo.com/dvdinter...iesdvdtar.html
AVIA
Produced by Ovation software and written by Sound & Vision Magazine's technical editor, David Ranada-- it offers some very good explanations of HT concepts and expansive tests. Ovation's main test designer Dr. Guy Kuo is a respected member of this forum, and a regular contributor to the discussions in our hardware section (both on the topic of Avia and others).
Here is a post from Dr. Kuo outlining the tests on Avia.
AVIA PROS: Avia is the middle ground of these three calibration discs- not including as many test patterns as DVE, but is easier to navigate and understand. Its strength is in it's ease of use and excellent narration. Avia does a very nice job of presenting an "infomercial" style overview of HT technology and methodology.
I took this disc to the in-laws years ago to set up their home theater. They both (in their 50's with no real techno passion) enjoyed sitting and watching the explanation of audio and video concepts. They both said it explained the audio and video components far better than their instruction manuals.
Avia also has some interesting test patterns not featured on other discs and Avia test patterns are easy to find in the menu system. Overall it represents the middle ground between user friendliness and power.
AVIA CONS: Avia is the oldest of the group mentioned here (not including the original Video Essentials of course). As a result, it lacks any DTS audio test (although one could argue its necessity) or any information on 6.1 audio.
Avia also has a subwoofer calibration issue - without getting into too much technical detail- the main test pattern for subwoofer calibration actually puts the test signal in the main channels, and must be rerouted by bass management in your receiver. If you use your speakers set to "large", this test will not work for subwoofer level in your system. There is also a weird sub test that is incorrect (although most people don't use it anyway)-- I have authored and posted alternate test signals for anyone interested, just search on posts from me and LFE TEST TONE.
Avia has released and updated version known as AVIA PRO- but it is LITERALLY a professional package, consisting of seven discs and costing four hundred dollars. As of now, the only consumer update to Avia is the S&V disc (discussed below), which is abbreviated in comparison to the original Avia.
Release date: June 1999
List price: $49.99
Reviews:
http://www.hometheaterhifi.com/volume_6_2/aviadvd.html
http://dvd.reviewindex.com/reviews/630551982X.html
Sound & Vision Home Theater Tune-Up
The Sound & Vision disc is made by Ovation, the people who brought us Avia. Targeted at the HT beginner, S&V was designed to be sold to the budget-conscious dabbler looking to run basic system tests without investing in a full $40-50 disc. Very simple, many of the tests of Avia are removed, easy navigation, simple instructions- but lacking in more advanced tests and calibration tools.
It's important to note that S&V came out well after Avia, and has newer tests Avia does not offer such as 6.1 related tests.
It is cheaper, it is less in depth, and it is easy to navigate. It does have some basic information about HT methodology, like Avia it is well written and easy to understand!
S&V PROS: S&V is cheaper and easier to navigate. Some higher-end and redundant tests of Avia have been removed in favor of simplified navigation and basic tests targeted at the average user. It really is the opposite of DVE in terms of scope and audience- and as a result ends up with a much more "average user" feel than DVE offers.
It's made by the same people who did Avia, so it is well laid out and well explained-- and the tests are accurate.
S&V CONS: Like most things, when you add user friendliness, you sacrifice power. S&V is very simple, has only the basic video and audio tests and only limited HT discussion and information. It really should be seen as Avia-Lite (slightly updated due to more recent release of course).
Release date: January 2002
List price: $19.99
Reviews:
http://www.dvdtalk.com/reviews/read.php?ID=3354
http://dvd.reviewindex.com/reviews/B0000CGECF.html
A WORD ABOUT THX OPTIMIZER AND INTERNAL TONES
aka "A note to cheapskates who want to get off without buying a calibration disc..."
With the release of Star Wars Episode One on DVD, THX began including an "optimizer" program with THX certified DVDs. The basic optimizer tests were supposed to serve as a calibration tool with basic audio and video test patterns for speaker level, phase, and picture settings like brightness.
Unfortunately, these tests have proved to be inconsistent and criticized by everyone from the average HT dabbler to professional technicians. There are large differences from optimizer to optimizer (the one on Ep1 vs. the one on Ep2 for example) causing some debate to be made that each test is catered specifically for the disc it is placed on-- however the reality is a set of baseline standards are necessary for accuracy- and no one wants to have to recalibrate for each disc.
In the end, the THX optimizer serves as a good starting point, and for those people who would never buy a calibration disc (and will never discover this forum)- it's a passable substitute-- if nothing else it makes them understand that there are guidelines and target ideals for equipment settings. If you're serious about getting the most performance out of your home theater system, you should look beyond optimizer.
If you're looking for evidence pointing to the use of Avia or DVE over Optimizer, just look at THX's own site, where they give information on optimizer, followed immediately by links directly to Avia and DVE.
As far as internal tones are concerned: most receivers have their own internal test tone generator which you can use to set speaker level. Most people, unfortunately, attempt to set the level by ear- instead of using a sound pressure level (SPL) meter. This will not result in accurate calibration... it is important to note, whether you use a calibration disc or the internal tone, a measuring device like a SPL meter is a MUST!
There are two schools of thought when it comes to using the internal tones versus disc tones:
1) The internal tones are preferred. This comes from some rather important people, like the folks at Dolby Labs.
2) The tones generated by a good test disc are preferred. This is a more popular opinion around here, and one I subscribe to.
In my estimation, the DVD player will be the source for the actual movie playback, so eliminating it from the calibration chain (by using receiver tones) seems incorrect. Any variations introduced by the player will not be reflected in using the internal tones-- so it seems better to use the entire intended playback chain when calibrating.
I’m not sure why Dolby Labs prefers internal tones, but one could theorize that the chips that produce these tones are based on their specifications, and thus they would side with the internal tones...
In the end, there is absolutely no substitute for one of these discs and a SPL meter. Your system will provide the best possible ACCURATE representation of the material...
See also:
Home Theater Means Accuracy & Calibration! by Jay Mitchosky
A Quick Overview of Home Theater Calibration by Vince Maskeeper
