are my speakers compatable with dolby dig

Discussion in 'Speakers' started by Mike F, Jan 17, 2004.

  1. Mike F

    Mike F Extra

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    A reviewer wrote the folloing.

    klipsch ksb-s1 surrounds "These are excellent for Dolby Pro Logic surrounds. However, they are NOT for Dolby Digital due to the limited frequency response. And, if I ever upgrade, what the heck am I gonna do with speakers that only
    reproduce 120Hz-8kHz?"

    Is this true ?
    And if so what are the frequency requirements for speakers to reproduce dolby digital and is that the same for all channels ?
     
  2. Mike F

    Mike F Extra

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    A reviewer wrote the folloing.

    klipsch ksb-s1 surrounds "These are excellent for Dolby Pro Logic surrounds. However, they are NOT for Dolby Digital due to the limited frequency response. And, if I ever upgrade, what the heck am I gonna do with speakers that only
    reproduce 120Hz-8kHz?"

    Is this true ?
    And if so what are the frequency requirements for speakers to reproduce dolby digital and is that the same for all channels ?
     
  3. AndrewErickson

    AndrewErickson Stunt Coordinator

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    If I had speakers that have a response from 120Hz to 8kHz I would throw them in the trash. That's horrible! The human ear can detect sound up to 20kHz. Get new speakers! They should be able to reproduce frequencies from 80 Hz to > 20 kHz and the sub takes over below 80.
     
  4. John Garcia

    John Garcia Executive Producer

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    120Hz is relatively high, and will lack some realism in the lower midrange. This will require a very high crossover as well, either resulting in a frequency gap or requiring the sub to play far too high into the lower midrange. The 8kHz top end is simply unacceptable - sounds like something Bose would make.
     
  5. Tim K

    Tim K Second Unit

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    Its not as if they won't "work". I think what the reviewer was getting at is that those speakers are not the "full range" speakers that would be ideal for Dolby Digital reproduction. Ideally, you would have 5 identical full range speakers so that when sounds panned from left to right or front to rear the transition would be seamless. However, 5 identical full range speakers is impractical for most home theater usage, so we compromise.

    The surrounds, while used more in DD soundtracks than in Prologic, don't really need to be full range. Most soundtracks do not have a tremendous amount of sound coming from the rear channels. Mostly ambient sounds and the occasional truck or airplane go by. Many people use much smaller surrounds than their fronts because more often than not they are wall mounted (or they need spouse-approved speakers).

    My surrounds are only 125Hz-22kHz yet they work just fine for me (mains are 46Hz-20kHz). They key is timbre matching (meaning all of your speakers produce the same sound). This is easily achieved by having speakers from the same line because more often than not, they will use the same tweeters and same woofers.

    I wouldn't worry too much about it right now...but eventually you will want to upgrade. While you don't need FULL-Range surrounds, there are some minimums you'll want to meet.
     
  6. Ed Moxley

    Ed Moxley Cinematographer

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    Just look at all those tiny little speakers that come with HTIBs that work!
     
  7. ChrisWiggles

    ChrisWiggles Producer

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    Yeah, I wouldn't worry *too* much about it, but do consider upgrading.

    They will work just fine, there isn't any "compatability" problems.

    However, back in the days of Pro-logic, you'll notice that PL surrounds were bandwidth limited, so speaker manufacturers didn't bother making speakers with response that went really high, or really low. Now, though DD can provide full-range to those surrounds, so you'll want to use full-range speakers if possible.
     
  8. Bob McElfresh

    Bob McElfresh Producer

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    Your reciever has something called "Bass Management". Part of this is that you can define your speakers as LARGE or SMALL.

    If you tell your reciever that your speakers are SMALL, it will not try and send sounds below about XXX hz to any small speakers. Instead it will:

    -Route those sounds to a nearby LARGE speaker
    -Route those sounds to the subwoofer

    Here is why the reviewer did not like the Klipsch for Dolby Digital: Many recievers have a fixed crossover of .... (I am going to get this wrong I just know it [​IMG] ) 100 hz for the cut-off for small speakers.

    Ideally, you would have speakers that are rated to something like 10/20 hz below this value so you have some overlap.

    For these Klipsch speakers - there is a gap. The reciever will send sounds to the rear speakers above 100 hz, but the speakers want sounds above 125 - a gap in the 100-125 hz range.

    In truth, those speakers WILL produce sounds in the 100 hz-125 hz range. But it wont be as loud as the sounds above 125.

    One of the keys here is to check your reciever. Some of them have adjustable crossovers. If you can set your reciever to 130 hz, putting speakers that go down to 125 hz is fine.


    I have to disagree a bit that 'full-range' all around are the best.

    I have just setup a system with 5 monitor-style speakers (M&K K5's - $47 each at a scratch-and-dent sale) and a Home Theater Direct 3 subwoofer. This $450 speaker system is really, really good.

    My main system (DefTech 2000TL's, SVS Subwoofer) is more impressive, but NOT ten-times as impressive as the price would indicate.

    While we love our tower (full-range speakers) a set of identical monitor-style speakers is actually a superior setup. Here are some of my reasons:
    • Identical speakers are naturally tone-matched. Sounds do not change as they swirl arround providing a better immersive experience.
    • Monitor style speakers reduce the power demands on your electronics. (The low-frequency sounds of a "LARGE" speaker eat watts). This frees up power for the system as a whole which improves the sound. (Note: If you have a mix of tower and small speakers with a external sub - try setting all your speakers to SMALL. People who have done this have commented on the improved sound.)
    • Monitor speakers DO sometimes need stands, but this makes it easier to get the tweeters on all the speakers at the same level to improve the surround experience.
    • The monitor-style speakers are a lot cheaper than tower speakers, even when they have the identical drivers and crossovers.
    • Monitor speakers dont encroach into the room like tower speakers. (Imagine a 7.1 system with all towers)
    • Monitor speakers have a better SAF (Spousal Acceptance Factor).
    • It's usually easier to buy 5 monitor speakers, then later add 1-2 more for Ex or 7.1.

    So small speakers all around - cheaper, better, more flexiable.
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    I *totally* agree with you Bob, but the issue in this post are bandwidth limited speakers designed for an old pro-logic system. It's not just an issue of no/little bass capabilities, as certainly bass management takes care of this. I am a firm beleiver in the smaller, but superior monitors, over big floorstanders with more bass but inferior sound quality for the same $.

    However, in *this* instance, these speakers are SEVERELY lopped off at the highs as well. There is no way to retrieve these high freq that are lost in the surrounds, nor would you even want to have some kind of "high-freq management" anyway. When I said "full range" I misspoke, but what I mean is not "pro-logic range" or whatever you'd want to call it. You want regular speakers that extend fully through the high frequencies. The bass capabilities are less important, because of the very good explanation that Bob gave (which i totally agree with).

    I think you missed the high-freq lop off though, which was what I was getting at.
     
  10. ChrisWiggles

    ChrisWiggles Producer

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    As for the last question as well:

    "And if so what are the frequency requirements for speakers to reproduce dolby digital and is that the same for all channels ? "

    "regular" speakers are what you need for DD, just as you would with ANY normal source. Sometimes I see speakers listed as being "dolby digital ready" or "digital compatible" or whatnot. This is totally bizarre, as the speaker has nothing to do with Digital decoding or any of that. Regular speakers are what you are looking for. Again, back in the days of pro-logic, it was unneccesary to have surrounds that extended past the high and loq freq limits of the surround channel in pro-logic. I don't know of any speakers still made today with these limitations. IMO, they would be marginally ok in some second system or radio or something, but other than that, bandwidth limited speakers designed for PL systems are pretty usless nowadays.

    Hope that helps! [​IMG]
     
  11. Michael Reuben

    Michael Reuben Studio Mogul

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    Yes. That's one of the advantages of the digital multi-channel formats -- all channels are capable of reproducing the full audible spectrum.

    M.
     
  12. Cees Alons

    Cees Alons Moderator
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    Mike,

    To summarize the conclusions: (1) your speakers can be used in a DD 5.1 system; (2) your home theater experience will dramatically improve soundwise (compared to your current Pro Logic); (3) you can take your time to find speakers that go all the way to 20kHz - starting with the fronts (and center) first if you cannot replace all at once.

    Cees
     
  13. Michael Reuben

    Michael Reuben Studio Mogul

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    You've started three threads in two different forums asking the same question. I've consolidated all the replies here, in the Speakers forum.

    Please do not post multiple threads on the same topic. If you want a thread moved from one forum to another, contact a moderator.

    M.
     
  14. Jonathan Dagmar

    Jonathan Dagmar Supporting Actor

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    Frequency responce is not entirely dependent on the size of the speaker (although it is certainly a factor). For instance, my speakers are small satellites all around, but they have a frequency response that starts at 70hz. With a subwoofer crossed over at 100hz, this provides more than adequate sound in my small room.

    I would much prefer to have larger bookshelves that went to 50hz or so, but space is at a premium and I simply do not have room for bookshelf speakers all around (which would be my preferred setup.) nor can I afford them just now.
     
  15. Mike F

    Mike F Extra

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    Hey thanks for all the input guys .
    Sorry about the multiple threads.
     

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