How does Lexicon's Logic 7 Modify DD5.1 and DTS Soundtracks?

Discussion in 'Archived Threads 2001-2004' started by Scott-C, Feb 9, 2002.

  1. Scott-C

    Scott-C Supporting Actor

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    I've heard so many good things about Lexicon's Logic 7 processing, and in a conceptual sort of way I always thought I understood it. But lately, as I think about it in more detail in the context of an impending processor purchase decision, I want to make sure I understand the details of how it works. I've done a little searching on some forums but wasn't able to uncover a good explanation.

    This is probably a "softball" question for you Lex afficianados out there, but I just wanted to make sure I understood Logic 7 processing correctly. So, my question is can someone explain what is happening to a movie soundtrack when Logic 7 is applied to it?

    Take Dolby Digital 5.1, for example. If I select Dolby Digital 5.1 as my surround track option, and apply Logic 7 to it, my uninformed guess is that the front soundstage stays exactly as it would with no Logic 7 processing. Is this correct so far? Do the side surround channels produce the same information regardless of whether Logic 7 is used? To put this question another way, does Logic 7 modify what comes out of the side surrounds? As for the rear surrounds, is the surround information "taken" from the side surrounds and matrixed into the rears? If so, does it leave the side surround information exactly as it would be with no Logic 7 or is the side surround information also modified in some way with Logic 7?

    I have the same questions relating to DTS 5.1 and DTS ES 6.1 Discrete formats.

    Thanks for the help in clearing up my questions?
     
  2. Shawn Fogg

    Shawn Fogg Stunt Coordinator

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    " my uninformed guess is that the front soundstage stays exactly as it would with no Logic 7 processing. Is this correct so far?"

    Not always. There are options in 5.1 L7 (that is DD/DTS w/ L7 processing) that can effect the front speakers.

    For example Vocal Enhance is a selective EQ that boosts the vocal portion of the center channel. It is not just a center channel boost as that would throw of imaging... it just boosts vocals.

    " Do the side surround channels produce the same information regardless of whether Logic 7 is used?"

    No, the surround channels are modified as part of the matrixing to four surrounds. Steering is applied along with a sort of sliding EQ which changes the apparent source location. That helps to widen the sweet spot. If you only have 5 speakers L7 can also simulate rears with HRTF using '5 Speaker Enhance.' Depending upon the setup Bass Enhance may modify the bass portion of the signal.

    "I have the same questions relating to DTS 5.1 and DTS ES 6.1 Discrete formats. "

    DTS 5.1 is similiar. Only the MC-12 supports DTS ES 6.1 Discrete. It there can apply processing to turn the mono back channel into stereo rears.

    Shawn
     
  3. Scott-C

    Scott-C Supporting Actor

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    Shawn,

    Thanks for the explanation. So one thing that separates Lexicon's processors apart from so many other processors is its ability to effectively build algorithms to logically steer and manipulate the soundtrack to give the illusion of discrete sound coming from 7 speakers? This must help explain why so many people think a good setup using Logic 7 is so much better than plain old DD5.1 or DTS.

    I would also think that applying Logic 7 to a DTS ES Discrete track yields cool results too.
     
  4. Scott-C

    Scott-C Supporting Actor

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    One other question: what type of speakers does Lexicon recommend for the 4 surrounds in a Logic 7 setup? Bipolars for the side surrounds and monopoles (direct radiating) for the rears?
     
  5. Shawn Fogg

    Shawn Fogg Stunt Coordinator

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    Scott,
    " to give the illusion of discrete sound coming from 7 speakers?"
    Yes, it is very effective. It works even on 2 channel material. You can literally get pans that go from right to side right to rear right to rear left to side left to left. Very impressive and they have been doing it since '95.
    Also, having 4 surrounds makes for a much more continuous enveloping/spacious rear soundstage.
    The Lexicon's do a lot of other subtle things that help all the time too. Things like the Loudness control which is calibrated around the SPL at the listener position so the curve is proper for the level the music is playing at. DD has compression built into it for night time viewing. Most processors that is an on/off sort of thing or a few different levels. The Lexicon's can automatically vary the compression based on SPL at the listening position.
    "I would also think that applying Logic 7 to a DTS ES Discrete track yields cool results too. "
    You need the MC-12 to do that but it has a similiar effect as L7 on regular 5.1 DD/DTS.
    "what type of speakers does Lexicon recommend for the 4 surrounds in a Logic 7 setup?"
    They don't say there is any hard and fast recommendation as that is influenced by personal preference. I know Lex owners with pretty much every combination out there and they all have their pluses and minuses.
    If you haven't read it already I'd suggest going to:
    http://www.lexicon.com/downloads/mc1_downloads.asp
    and reading the 'Theory And Design Booklet.' It gives a lot of good info into the thinking behind the processing the Lexicon performs and also deals with things like speaker/room setup.
    Shawn
     
  6. Scott-C

    Scott-C Supporting Actor

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  7. ling_w

    ling_w Second Unit

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    The Meridian products are great. They might not have all the add-ons like the latest pre/pro (things like component switching, or any video switching at all in some cases,) but their sound quality is top notch.

    Many of the better processors out there like the AVM-20 might have better DACs, high bandwidth component switching or flexible bass management. But they are basically are decoding the surround modes with generic off the shelf decoder. Even some pretty expensive pre/proc basically goes that same route.

    Meridian (along with Lexicon) custom rewrites their own surround codes. Plus Meridian has some music modes (specifically Trifield) that is true to the recording without the sounding gimmicky that is common in many music surround modes.

    The Meridian would be preferred if you gear toward music, the Lexicon if you are geared toward HT.

    A used Meridian 565 7.1 would run you no more than $2k (audio/video switching module 562v extra.) It might not have the latest DAC and such, but the custom surround codes makes 10x the difference compared to 24bit DACs. If you want upgradability, a used 568 might run you $4k (video switching extra,) and that has a long life ahead of it. Then it just goes up from there, to the 861 with 9.3 capability that will cost new over $20k when fully loaded. If you want to go full out, then there is the Meridian digital speakers with digital crossover, different types of DAC for woofer/mid/tweeter & seperate amplifications for each driver itself. Then there is the 800 DVD-A player that provides digital output of DVD-A to the 861 so the 861 or digital speaker could decode it. But I am getting ahead of myself.

    The guys at hometheaterhifi has used the Meridian as their processor for ages.
     
  8. Shawn Fogg

    Shawn Fogg Stunt Coordinator

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    Scott,

    " I need to decide if I should buy an MC-1, which I don't believe has quite as many features as some of today's newer processors, but may sound better nonetheless, or go with one of the newer, "

    If you buy a used MC-1 find out if the unit has been used in a trade in toward the MC-12. If it hasn't been traded in it should be eligible for trade in toward the upcoming processor Lexicon is putting out in a year or so. That will be sort of a baby MC-12 as it is based on its design. You can call Lexicon with the serial number of the MC-1 and they will tell you if it was traded in or not.

    "(i.e. who needs DTS ES 6.1 discrete if Logic 7 does just as good or a better job with DTS 5.1 soundtracks?)."

    And L7 will work on all DTS 5.1 soundtracks. DTS ES 6.1 Discrete has a handfull of titles available. Having ES 6.1 Discrete decoding does nothing to improve the sound of all the other DTS 5.1 soudtracks.

    "But on the other hand, there may be other processors out there that come so, so close to the sound quality of the Lexicon and have more options, and in some cases are even a little less money."

    None of them have L7 though which improves just about everything you watch/listen to vs. the standard off the shelf decoders.

    Shawn
     
  9. Scott-C

    Scott-C Supporting Actor

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    Thanks guys, you make good points.

    Shawn, great point about getting a used MC-1 that hasn't been traded in and then upgrading to the "baby" MC-12 when it's available. I'll give that some serious thought.
     
  10. Jeff H

    Jeff H Stunt Coordinator

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    Scott, over the last year, I have had different combinations of preamps/receivers. I started with a Denon receiver as a preamp. Then a Fosgate 3a preamp, then a Citation 7.0 preamp, then a HK Sig 2.0, and finally a Lexicon dc-2. I am overwhelmed by the Lex. The next best was the Citation, which has 6-axis, somewhat similer to Logic 7. Then the Fosgate, HK, and Denon. If you want a 7.1 setup, buy the Lexicon or Meridian. Don't even think twice. Just do it! Good Luck
     
  11. Scott-C

    Scott-C Supporting Actor

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    Jeff,

    I'm leaning in that direction! The prices of new MC-1s on eBay are looking pretty good right now...although I don't know if these units have been traded in, which would diminish their utility. Seems like you can get one in the mid $2K range which isn't bad.
     
  12. Ricky T

    Ricky T Supporting Actor

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    In the past 2 years, I've had: Angstrom 200/205, Sherwood 9080, Nakamichi AV10, HK Sig 2.0, Onkyo 989, and several ac3/dts decoders. And now....I've had my MC1 for four days and love it! See my thread on MC1 vs Onkyo 989. Logic 7 is heaven [​IMG]
     
  13. Scott-C

    Scott-C Supporting Actor

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    Ricky T,

    Thanks - just read that thread. Congrats on the Lex and I'm glad you like it so much! With all of this Outlaw 950 news, I'm still not sure what I'll do but one thing is for sure - the Lex must be a winner.
     
  14. James Mudler

    James Mudler Stunt Coordinator

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    If the budget is tight and $2k is not a option, don't forget about a DC-2. Ive seen DC-2's go for around $1100-1200 loaded. No trade in value, and limited future support but still a great unit.
     
  15. Jeff H

    Jeff H Stunt Coordinator

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    James, I hope you are wrong about the trade in of DC-2's. Over at SMR the thinking is the MC-1 and the DC-2 will be allowed for the trade in program for the baby 12. I bought one that was not a trade in for that very reason.
     

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