Is 80 hz the best crossover?

Discussion in 'Beginners, General Questions' started by Mike:K, Jan 7, 2004.

  1. Mike:K

    Mike:K Auditioning

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    I have my speakers calibrated to 75db and my sub is calibrated to 83db or so. My main L/R speakers are set to small. According to my manual, my unit directs signals that are 90hz and below to the subwoofer when those speakers are set to small. If that's the case, what (in theory anyway) is the preferred crossover setting? 90hz? 80hz?

    My mind is spinning reading all of the crossover threads, but I'm getting the impression that most prefer 80hz. Given the facts above, would 80hz still be preferable (again, in theory)?

    Also, does changing the crossover at any given time affect the amount of db's the sub is calibrated to?

    Thanks in advance for your replies!
     
  2. ChrisWiggles

    ChrisWiggles Producer

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    The short answer is: it depends on your setup.

    So the best way is to try other crossover setting on your receiver, if available, recalibrate, and see which sounds best.
     
  3. Brian L

    Brian L Cinematographer

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    The lower the crossover, the less likely you will be to be able to localize the sub. That said, I would wager that in a listening test, 80 Hz and 90 Hz would sound about the same.

    It is felt that 80 Hz is about the point where you will no longer be able to localize the sub. THX has standardized on 80 Hz, but there are some users that argue for a lower value. I personally run 80 Hz and do not feel that I can localize my sub.

    The point about not being able to localize the sub is this: Since the common arrangement is to sum the bass from all main channels below the crossover and send it to the sub, you would not want bass that is associated with a given channel to sound like its coming from the sub location; if the blend is done right, it will sound like its coming from the channel in question.

    Putting that aside, it does depend on the capabilities of your gear. If you have a speaker that can play down to only 120 Hz (that would be a pretty small speaker), you don't want a crossover of 80 Hz; you would loose everything below what the speaker could do, up until the sub picks up the chase.

    Now, its usually OK to have the crossover cut in ABOVE what you speakers can do (and in some cases, its an advantage to do so), but NEVER below.

    Some users suggest a crossover that is a full octave above what the speaker can handle. I don't agree with that, but at least doing so you will not loose anything in the crossover region.

    BGL
     
  4. Justin_D

    Justin_D Stunt Coordinator

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    I can't localize 80hz by way of sound, but I can fell where its coming from in the floor. I do not feel that this is enough to detract from the surround experience though.
     
  5. Bryan_Bortz

    Bryan_Bortz Stunt Coordinator

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    hmm, thanks for the explanation of cross over and localizing.

    -Owl
     
  6. Jonathan Dagmar

    Jonathan Dagmar Supporting Actor

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    If you can feel where you sub is, then you may want to try relocating your sub.

    I myself run my crossover at 100hz, and am not able to localize my sub. I'll go out on a limb here as say that MOST people will not be able to localize bass under 120hz. If you have a sub/ small sattelite system (satelites defined as small cube type speakers, not bookshelf speaker used for all channles), then you may find that using a crossover closer to 100hz to be an advantage, just because your satelites CAN reporduce an 80hz frequency doesn't mean they can do it WELL.

    Some reciever allow you to set the corossover as high as 250hz. At that point you are getting pretty ridiculous.
     
  7. Oachalon

    Oachalon Stunt Coordinator

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    that is my problem i can localize a sub crossovered at 80hz. Its a gift and a problem at the same time. Usually not a good thing.
     
  8. John Garcia

    John Garcia Executive Producer

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    Oachalon - If you can localize it, placement and settings (volume is too high) are the problem. Have you calibrated your system with an SPL meter?

    I agree with Brian L, most people would not be able to tell the difference between an 80hz and 90hz x-over.

    Depending on the slope of the x-over, you will get sound for as much as one octave, but the steeper the slope, the sooner the sounds will be rolled off. That means that one full octave is not necessary in all cases, but you need to account for about 2/3 or so of that frequency range below the x-over.
     
  9. Oachalon

    Oachalon Stunt Coordinator

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    i have put my sub in every place and it doesnt make a difference. I can still localize it. My system was calibrated with my yamaha rx-v1400 using its calibration. After that i tested things with a piece of crap spl meter and everything came out pretty close. Every room ive listened to i can tell where the sub is. I can tell where the sub is in my car unless i put the crossover at 63hz then i cant tell. What really helps me is setting my front speakers to large and letting them get some bass. That helps a lot for me.
     
  10. Jonathan Dagmar

    Jonathan Dagmar Supporting Actor

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    You must have remarkable hearing, Oachalon.
     
  11. Oachalon

    Oachalon Stunt Coordinator

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    yeah it pisses me off sometimes lol. My friends also say how i can hear certain things. Im also actually able to hear 20-20,000hz. When i get older i will probably lose the ability to localize the sub since i am only 18 years old.
     
  12. David Hoffman

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    Oachalon,

    Are you setting your speakers to "large" now for home theater, or music, or both?

    As I understand it, when your speakers are set to large, the crossover is ignored for those speakers (ie, the "crossover" is set at 0 Hz). Are your main speakers able to yield a flat response at 25 Hz?

    If not, then movie soundtrack 25Hz sounds for, say, the Front Right channel will be sent to your front right speaker, and that speaker will try to reproduce them, at which it will fail, while distorting the upper base and mids that it's much better at reproducing.

    Also if you're using 63Hz as a crossover (for speakers set to "small", then you should make sure those speakers can extend well below that.
     
  13. Oachalon

    Oachalon Stunt Coordinator

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    when i listen to music i have the front speakers set to large. When i watch movies i usually have the fronts at small and at the 80hz or 63hz crossover. I have axiom audio m60s in the front so they can go below 63hz with no problem if i needed them to. In my car though the crossover is pretty much most of the time at 63hz for my sub and i think 60 for my component set i dont remember. My component set does a good job with it. Im happy with the sound in my car with those settings.
     
  14. Cees Alons

    Cees Alons Moderator
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    When you can still locate a sub that's set to a crossover of 80Hz, it's most probably harmonics, i.e. distortion.

    Unless your ears are more than 20" apart....


    Cees
     
  15. Oachalon

    Oachalon Stunt Coordinator

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    I can locate the sub when its pretty low in volume. I dont think my diy tempest in a 7.8cubic ft box tuned at 15.4hz adires 215L box design is distorting at a low power. Lol my ears arent 20inches apart.
     

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