***Official Digital Video Essentials Discussion Thread*** (1 Viewer)

[Dave H]

What kind of pattern(s) does DVE use to calibrate brightness or black level? Avia uses the two moving bars as a core testing pattern. How does this compare?

 

[Vince Maskeeper]

Hey guys,

In response to posts in basics asking about DVE vs Avia vs S&V, I wrote this:
http://www.hometheaterforum.com/htfo...hreadid=178509

You should read it over and tell me what you think (email or just reply to the test post, don't post it here).

Let me know if you think anything is missing - or if I should add/clarify anything. thanks!
-Vince

 

[RyanBoyce]

I tried using the DVE 2003 disc to tune my Sound stage. I used a tripod and a Digital SPL meter with all the settings correct. I am disappointed that when I try to bring a channel up to the recommended 75db readout that I am only maxing out the every single one of my gains. When I started I used a main volume control and set it to about 30 on the DVD display readout. That is where I could finally get any reading from the meter. My system is a Samsung HTSK5 5.1 with Klipsch speakers.

I found that my DVD player has a center gain, a sub gain and a rear gain, then front and rear balance. Am I missing something? Can I even tune the system at all???

Ryan

 

[Thomas Smailus]

Your dvd player has controls for adjusting the output levels? I take it you are not running the multichannel sound to an amp via digital interconnect, then, right?


The reference levels that they ask you to set things at are not required, first off. The only reason to set your volume to a reference standard is so that you can compare and contrast with other systems/person's settings. What IS important is setting the output volumes of your various channels (speakers) properly relative to each other. The benefit of a very loud referencse signal to do that is that output overpowers any ambient sounds in your listening room from the environment (a/c, outside noises, the kids in the other rooms, what have you). However, its not required that you set our amplified output to the reference level - just getting it close or at a working level is enough to set your individual system up. Also, you never really listen to anything at reference level as its too loud and will cause you hearing damage from prolonged exposure.

To set to reference, you adjust up the main volume on your amp to get it at or near the reference and then you tweek each individual channel with the individual channel outputs. Your main volume knob should be set 'very high' at reference level.

However, in your case, as you repeatedly refer to adjusting things on your dvd player, I'll let someone else speak on things as that sort of adjustment is not familiar to me.

 

[Grady Hollums]

Ok I have read through this entire thread and I was wondering if I can get some help.


I would love to have a web site that explains what I should be seeing and maybe some arrows pointing it out for the video calibration aspect of the disk. I have used Avia and VE, but even when the speaker is telling me what I should be looking for sometimes I am still not sure.

For example:

When it come to the overscan of my TV I am not sure what I should be seeing, and if I need to change the geometry of of my TV to make sure the over scan is correct. (I have gone into my service menu and done the 56 point convergance, and I think it would just take me playing with that for a few hours to get the over scan correct. But I am just not sure what it should look like.

Has anyone ever thought about creating an online DVE for dummies guide for people like me that know only enough to be dangerous? I would give someone some flowers if they could help me find something like this for DVE.

Thank you for your help in advance and I hope your all doing well.

 

[Thomas Smailus]

You and me both.

There is too much 'description of what you should see' that uses terminology that experts and folks in the know believe would be 'obvious', but they are anything but. If you have never seen an effect, it does not matter what you call it - its not going to make sense.

Example is when you are setting your 'sharpness' or other basic settings and the instructions indicated 'look at the edge enhancement'. That doesn't mean squat if I've never seen it - you can write a book on it and it will not be as usefull as 2 small GIFS ! (NOT JPEG for obvious reasons) that show 'little edge enhancement' and 'lots of edge enhancement'.

Obviously, this would need to be distributed with the various software tools as PRINTED booklets and could not be put on the disc as things to pull up (as the settings of your display would naturally corrupt the intended reference picture, right?)

 

[Nils Luehrmann]

Of all of the consumer level HT calibration software currently available, DVE is certainly designed more for advanced users than any of the others.

Of the most common calibration software available, here is how I would rank them according to the level of complexity and content, starting with the most basic:



1) THX Optimizer (found on most THX certified DVDs)
Released: May 2000 (has been updated twice since then)


2) Sound & Vision Home Theater Tune-Up
Released: January 2002


3) AVIA Guide to Home Theater
Released: June 1999


4) DVE
Released: July 2003

 

[Jeremy Anderson]

For anyone interested, I've done a quickie digital comparison of the DVE and Avia subwoofer tones in this thread:

http://www.hometheaterforum.com/htfo...=&pagenumber=3

 

[Jeremy Anderson]

To summarize what we found with DVE, for those interested (and for Vince's FAQ on the matter): DVE's subwoofer tone is digitally incorrect, without a doubt. I extracted the 5.1 audio off of both Avia and DVE and broke the streams down into their 6 component monaural .wav files. Then, I analyzed each for total output, compensated for C-weighting and averaged. This was all done digitally, so no gear or room response issues can be claimed. Here are the results for both Avia and DVE, comparing the speaker calibration tones to the sub tones:

Avia:
Front left, -20.15 (or 84.85dBC)
Front left sub tone, -22.39 (or 82.61dBC)
Therefore, with Avia you should be setting each channel to 85dB on your meter and the subwoofer to between 82-83dB. In other words, these are accurate tones if you account for C-weighting (which has been common knowledge here on the forum).

DVE:
Front left, -31.06 (or 73.94dBC)
LFE tone, -35.11 (or 79.89dBC, since LFE's max value is 115dB, not 105dB like the other channels)

According to Dolby Labs' 5.1 Channel Production Guidelines, the 10dB boost seen on a RTA for the LFE channel should show as a 6dB boost on a C-weighted meter. DVE's subwoofer tone is digitally ~6dB higher than its speaker tones. Basically, Joe Kane & Co. didn't account for the fact that the LFE channel gets a 10dB boost over the other channels. To further test this theory, Edward JM dragged his SVS out into a backyard for some ground plane tests, which gave similar results. After equalization for flat response in my room, I also get a ~6dB difference with DVE, whereas I get 85/83 with Avia as I should.

In other words, if you're using DVE to calibrate to reference level, set speakers to 74dB and subwoofer to 80dB. However, this assumes that you have equalized for flat response from your subwoofer. Since DVE's subwoofer tones are not 40-80Hz limited as listed (and in fact have strong energy down to 5Hz, if you look at the charts in the thread listed above), room acoustics can cause a major increase in SPL.

Furthermore, DVE's test tones for the individual speakers that are "band-limited" actually range from 30Hz to over 10kHz, whereas Avia's tones range from about 280Hz to about 4kHz. Because it has significant energy below most systems' crossover point, DVE may be problematic for anyone who has an individual speaker that doesn't quite match up in phase with the subwoofer (meaning that cancellation of mid-bass due to slight phase discrepancies with the sub can make that speaker read slightly lower on the SPL meter, which means it will be too loud when calibrated that way).

I defended DVE for a while because the acoustics of my room made it appear correct, until Edward JM and I set out to get the hard data on it. In my opinion, all of the above objective data gives me the opinion that though DVE has some useful tests, it is essentially worthless for the average consumer to adjust either speaker or subwoofer levels.

 

[Edward J M]

Great wrap-up Jeremy. It was fun working with you on this project. To summarize for the lay user:

1) DVE is mastered 10 dB too hot on the subwoofer calibration tone.

2) Outside ground plane it will measure 8 dB too hot with a C-weighted meter, and 10 dB too hot with an unweighted mic.

3) Since the DVE sub tone is wide bandwidth (down to 15 Hz strong), it will measure anywhere from 11-13 dB hot with a C-weighted meter in a moderate size room due to room gain. The deeper your sub can play and the smaller the room, the more room gain you will experience.

4) If your room exhibits a flat response (or you equalize out room gain for a flat response), the DVE sub tone will read 8 dB too hot in-room with a C-weighted meter.

 

[Jeremy Anderson]

Well, it reads 8dB hotter in comparison to Avia, that is, since Avia's tone should be used at 83dB to reach reference (because there's no pre-compensation for C-weighting). The sub tone on DVE should read 6dB hotter than its own speaker tones on a system with flat response. Regardless, the average user who hasn't equalized is never going to know how close or far away he is from reference level with DVE.

And again, Edward, it was a fun ride figuring all this out! I'd love to see Joe Kane's reaction to the frequency analysis.

 

[Mitch Stevens]

4) If your room exhibits a flat response (or you equalize out room gain for a flat response), the DVE sub tone will read 8 dB too hot in-room with a C-weighted meter.

What what if you DON'T have a flat response? I very much doubt that more than 10% of the people here have flat response in their rooms. How much will it read then?

I have a B4+ and I just calibrated all speakers to 75 dBs, and the subwoofer to 86 dB. I know I'm running it VERY hot, but the B4+ can more than handle it. It doesn't even break a sweat, even in the loudest movies, (ie LOTR, Haunting DTS & Toy Story 2).

I also should mention that I have two of the ports on the B4+ plugged. So only two are left open.

 

[Jeremy Anderson]

There's no way to predict what it will read, because your room gain may be greater than someone else's. The best anyone can tell you is what it should be with flat response. Avia's tone isn't AS susceptible to this problem since it is a 40-80Hz band-limited tone, though it is still susceptible if you have a peak or null between 40-80Hz. The only way to really determine what your room gain would be is to chart the in-room frequency response of your subwoofer.

If you have a sub as nice as the B4+, it's almost a crime not to equalize for room response. If you look around here on the forum, there should be test tones available for you to check in-room response using your SPL meter, as well as a chart that will show you the frequency curve. At that point, you'll know whether you need an EQ to reduce any major peaks. And if you do find that you have a huge room-induced peak, the slight expense of an EQ is definitely worth it.

Regardless, reference level is just that: a reference. If you like it set the way you have it, then that's the correct setting for you.

 

[Edward J M]

What what if you DON'T have a flat response? I very much doubt that more than 10% of the people here have flat response in their rooms. How much will it read then?

See #3 in my post. In MY room, here's what I get (all at the same Master Volume and subwoofer level setting):

Avia Surround Channels: 85 dB
Avia Subwoofer Tone: 82 dB (average of all channels)

DVE Surround Channels: 76 dB
DVE Subwoofer Calibration Tone: 88 dB

So in my room (with my acoustics and subwoofer), DVE is about 12 dB too hot.

YMMV but that's not a bad guideline. Jeremy got the same thing in his room (with his PEQ disabled, thus allowing room gain):

Avia Surround Channels: 85 dB
Avia Subwoofer Tone: 83 dB

DVE Surround Channels: 74 dB
DVE Subwoofer Calibration Tone: 86 dB

What I've been telling people who own only DVE (and have no other disc for comparison purposes) is to try 75 speaker/87-88 sub and see how it sounds. That should be close to a flat calibration using Avia.

 

[Mitch Stevens]

What I've been telling people who own only DVE (and have no other disc for comparison purposes) is to try 75 speaker/87-88 sub and see how it sounds. That should be close to a flat calibration using Avia.

That's basically the way I have it now. 75 Speakers/86 Sub. It sounds "perfect." Not too loud, and not too soft. However, at "reference" level my room literally starts to fall apart (with the B4+). The textures from my ceiling start falling down everywhere, the walls begin to shake so hard, you could almost hear them crack, etc.

But then again, I almost never listen to movies at reference. I always listen to them at -15 all the way up to -10 dB.

I used to have Video Essentials (regular) but I sold it 3 months before DVE came out, because I thought that DVE was going to be the "ultimate" calibration disc.

 

[George_W_K]

It sounds like it's a good thing I never bought this disc. Thanks for researching this guys!

 

[Jeremy Anderson]

Edward, if I ever find out that Joe Kane "quietly" fixed the errors in any future release of DVE, you know I'll be leading the charge to have my disc swapped out. I'm sure a lot of others would as well. I seriously doubt he'll ever fix it though, as he seems to be focusing on hi-def instead of DVD.

Honestly, I'd use internal tones to calibrate before I'd use DVE. DVE has some useful tests (especially speaker tones centered between channels, which helps with delay and phase adjustments), but the speaker and sub tones are just unfortunate.

 

[Joe6pack99]

Well guys last night i calibrated DVE vs the old VE and like many here saw the flaws and was initially confused. Like many the sub tones were off but I also had major changes in the rears. The were off by over 5 db's. I think i am going to stick with my VE and Avia settings.

 

[Matt`L]

Hey guys, just a quick one.

I was just wondering if I were to calibrate my tv (brightness, etc.) with NTSC digital video essentials, would it also be calibrated for PAL? Or does PAL require different brightness and contrast levels, as examples?

Hopefully that makes sense.

Thanks .

 

[Leo Kerr]

Okay, lets throw a little more fat into the fire...

A couple of night ago (was it Monday? Yesh, it's been a wierd week!) I finally got DVE. I've had AVS since I've had laserdisc and then VE when it came out for DVD.

Going through the 'programmed directions,' where the video test patterns are interspersed with the directions on how to set them, I had a lot of trouble getting the calibrations dialed in.

Then, later, out of a sense of perversity, I went to the pattern reference section toward the end of the disc, where... the test patterns were different! Those patterns at the end gave me no troubles in getting the display calibrated!

Has anyone else seen this, or was I really just imagining things, being mildly sleep-deprived when I did this?

Leo Kerr