Camelot Dragon 5.1 DTS/DD Surround Enhancer Blind Test

Discussion in 'Archived Threads 2001-2004' started by David Proud, Jan 24, 2002.

  1. David Proud

    David Proud Stunt Coordinator

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    Ok guys, I have purchased the camelot dragon 5.1 Surround Enhancer deJitter device with 30 days to try it out.

    I wanna conduct a blind test on this item.

    I thought I would do the following, before I ever listen to it have a friend goto the back of the dvd player and change the inputs randomly on me.

    next I will listen to a loop of a DTS movie, DD Movie, and PCM music file. as I listen to the loop he will change the input randomly to use the dejitter device and to not use it. I will record my results.

    last but not least I will play the same loops for my girlfriend and another friend who has no idea what the test is about and I will change the inputs on them and have them record there results.

    Now here is where I would like to get some input from you guys. What kinda questions should I put on the test.

    like does this sound better than the first one, about the same, or worse, etc.

    Once I have concluded with the blind testing I will post my results here and give everyone a report.

    There seems to be a lot of mis information about jitter out there. there is one group that says, DD and DTS are not subjected to Jitter b/c the clock is in the packetized data. Well another group says that in fact there is a clock outside the packetized data.

    So the only way to really find out if Jitter effects DD and DTS sources is to conduct a blind test with this device that claims to correct it and without this device. Any help would be much appreciated and if you live in the atlanta area and would like to help me out, come on over..

    Thanks,

    David
     
  2. David Proud

    David Proud Stunt Coordinator

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    I will also be testing the Microsoft Xbox connected to it. Unfortunatly I do not have a HTPC but the Xbox should be a good comparision since I would imagine would dump out a lot of Jitter, since it is coming from a noisy device with a hard disk,etc.. I would imagine since the xbox has the power supply built in it and has a noisy hard drive that it would throw off its clock signal that instructs the digital

    to analog converters when to execute the conversion. If the timing of thisclock signal is off by only a tiny increment it can degrade sound quality.

    This may be a good device for folks who use a HTPC or nfource board with DD output and are not happy with the DD and DTS coming from there HTPC.

    Lets see how it test out.
     
  3. David Proud

    David Proud Stunt Coordinator

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    I just got off the phone with Camelot Technology maker of this device. This devices technology is built into the infamous Camelot Roundtable DVD player.

    Things I was told to listen for improvement in audio in 5.1 where.

    Cleaner Center dialog

    Cleaner Bass response

    Smoothness of highs more detailed

    Better Separation from channel to channel
     
  4. chris c

    chris c Stunt Coordinator

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    I remember someone mentioning that 5.1 information cannot have jitter, and that this device is a hoax (can't correct something that isn't there in the first place). I honestly don't remember who said it or if it is true, but I do remember the person was extremely knowledgeable. Anyone have any ideas on this?
     
  5. Joe Casey

    Joe Casey Stunt Coordinator

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    Two additional things to be considered:
    1. The folks involved in the test have to have the ability to discern minute deatils in the presentation. IMO, the ability to hear differences (if they exist) between minor changes in a systems signal chain is a learned skill.
    2. System transparency. Some systems have much more resolving power in being able to make minor changes in the signal chain audible.
    This of course assumes:
    1. That 5.1 does indeed have jitter, and if it does the Dragon reduces it (not knowing the answers to these questions myself).
    2. If 5.1 does indeed have jitter, the difference that the Dragon will introduce will be next to inaudible because of the nature of the 6 compressed audio channles (5.1 is not a hi-resolution format).
    And finally, IMO, if there is a 'day and night' difference, somethin' ain't right!
    (Don't take this as a knock on Camelot, as I used to own both the Morganna 24 CDP and Uther DAC)[​IMG]
     
  6. Kevin C Brown

    Kevin C Brown Producer

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    You also have to make sure that levels at the listening position when switching back and forth are maintained within +/- 0.1 dB. Or else the results are meaningless.
     
  7. David Proud

    David Proud Stunt Coordinator

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    Good considerations.

    I will have myself listening, while another friend changes the inputs on me without looking, so I will not know if the dragon dejitter device is on or not.

    While I am no audiophile I am pretty picky and if I can't hear a difference in my test, then I really don't need this device anyway. I am sure I will hear a difference in PCM , my real question is will it make a difference in 5.1. I will test both PCM music,

    This is what I intend to do for my test...

    1) use an spl meter before each persons test with avia to verify signal is consistent with the dejitter device connected and without it to maintain the same spl level with the dejitter device and without it.

    2) The test

    A) Intro scene to saving private Ryan played at the exact same time positions in the track.

    B) Rain scene in saving private Ryan payed at the exact same time and pisitions in the track.

    C) PCM music from country CD.

    D) DTS demo disc Ultimate Guide to Home theater, DTS

    Demo rain test

    E) PCM music from JAZZ

    F) DD Final Fantasy opening where dialog in front and deep bass.

    3) TESTERS AND CONTROLLING TEST...

    A) there will be me blind listening and a friend changing inputs on me randomly for each section of the test A-E test.

    For example, he will have the choice of selecting the Dragon filter for the intro to saving private ryan test. after the saving private ryan has been played and looped, it will be played back a 2nd time and my friend will have the choice to select the Dragon Filter device or not the 2nd time around. This will process will repeat for steps B, C, D, E and F.

    B) I will have 3 friends, which none of them really have an ear for audio. I think they are good subjects b/c if they consistently notice a better sound in all the test it would show that this device made a difference even for the common Home theater listener.

    C) I will take this device to another friends house, who has a lower end system than I do. I have no high end system by any means. Just a Denon AVR-4800 and Toshiba SD5109 DVD player and Definitive technology Pro Tower 400 Speakers. I will blind test it on subjects in his enviorement as well with his lower end stuff. IF you are in the Atlanta area and would like me to take this by your house for a test, let me know. I have 30 days to try it out.

    D) I will seek to take this device out and try it out on other type devices/systems, I wanna conduct the test with my microsoft Xbox and suspect that it has a bunch of jitter as well in its DD path. If anyone has a HTPC I would love to take this device to your house as well as I think HTPC emmit lots of Jitter in the signal path.

    Any other suggestions? I should have the device Monday.
     
  8. Kevin C Brown

    Kevin C Brown Producer

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    David- Wow!

    Let us know how the tests come out.

    Oh, I have heard that the PlayStation 2 has very bad jitter numbers (upwards of 10,000 ps). If you could get a hold of one of those, might be an interesting comparison.
     
  9. David Proud

    David Proud Stunt Coordinator

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    Here are my testing results. On Eagles Hell Freezes Over, I was able to notice a difference two out of four times in PCM mode. In Dolby Digital mode, I could not tell a difference between the two. In the Saving Private Ryan, I passed one time out of four tests.

    It is my belief that although I got two out of four blind tests right for PCM Eagles Hell Freezes Over that there is no dramatic difference (or should I say $450.00 difference) for this device. My friend in a listening test confirmed that without the device hooked up, when playing back PCM music, he could hear a difference in the lower end. He claimed that PCM music actually sounded better to him without the dragon device filter.

    From the tests, I have concluded that either my system is not audio file grade enough to notice differences and/or dd and dts are not affected by jitter. I will attempt to use this device and blind test it on another system with the cheapest dvd player with coaxial out. If you have any question please email me.
     
  10. RicP

    RicP Screenwriter

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  11. Kevin C Brown

    Kevin C Brown Producer

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    David: great info.
    Don't tell Camelot what you found... [​IMG]
     
  12. Andriy Zolotoiy

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    Since PCM is the only questionable source wouldn't it be better just to get one of those NAD CD players with buffered SPDIF output?
     
  13. Saurav

    Saurav Cinematographer

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    Some thoughts:
    * If you put someone else to the test, the only question you ask them is "Do you hear a difference". No questions about preference or anything along those lines. All you're trying to establish is, can a difference be heard.
    * If you want to adhere more closely to the ABX/DBT methodology, you'll need to modify your test a little, and I think this is a good idea. What you do is, you are allowed to ask your friend to play the input with or without the Dragon. The idea is, you are allowed to hear both A and B, which is sighted, so you know which is which. Then, you listen to X, which is blind, and you have to tell if that was A or B. You're allowed to switch back and forth between the known/sighted A and B as many times as you like. IMO this is better than playing a whole track through with one and then the other, because any differences should be more easily audible, you're not relying on your memory of what it sounded like the last time. To eliminate some bias and differences in the time taken to change inputs, your friend should do something like change to an unused input and then change to the requested input. That way, it'll take him the same amount of time to switch inputs if X is the same as the last input you were listening to.
    So, first, your friend tosses a coin 20 odd times and writes down the outcome - heads for A, tails for B. Then, your friend sits with the remote, and you sit so that you cannot see him (so that eye contact/body language don't enter into it). You ask him "play A" or "play B". Every time he changes inputs, he first selects an unused input, then selects the input you requested. You are also allowed to ask him to rewind the track as many times as you want. Finally, you say "play X", and he plays whatever he has on his list - A or B, depending on the coin toss. You are allowed to go back and forth between A, B and X as many times as you want. Once you have formed an opinion, you write it down, and go on to the next test, with a different track, and use the next coin toss result for deciding whether your friend plays A or B when you ask for X.
    I hope that makes some sense [​IMG]
     

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