Crossover explanation wanted.

Discussion in 'Archived Threads 2001-2004' started by Andrew*W*S, Jan 4, 2003.

  1. Andrew*W*S

    Andrew*W*S Auditioning

    Joined:
    Dec 6, 2002
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    0
    How exactly does the crossover work on a receiver? I know that if it's set to 80hz then only those signals above 80hz will be sent to the satellites, but what about the sub? Are frequencies above 80hz not sent to the sub? Is there a 'grey area' around the crossover so that the sats and sub can blend?

    The reason I ask is that my sub (Acoustic Research HC6) has it's own adjustable crossover. If the receiver is not sending signals above 80hz (as an example), then why would the sub have an adjustable crossover to 150hz?
     
  2. Steve Schaffer

    Steve Schaffer Producer

    Joined:
    Apr 15, 1999
    Messages:
    3,756
    Likes Received:
    1
    Trophy Points:
    0
    Andrew,

    Although there is a "gray area" as you describe it, not much above the crossover point is sent to the sub--the gray area is a bit below the crossover point.

    The reason the adjustment knob on the back of the sub goes up to 150hz is that many recievers have adjustable crossover that can be set anywhere from 50hz up to 150 or even higher in some cases. This varies by mfr and receiver model.

    If your receiver has a fixed crossover at 80hz (and that's the THX spec btw) it won't hurt anything to leave that crossover knob on the sub set at 150. That will insure that the "gray area" is covered.
     
  3. Andrew*W*S

    Andrew*W*S Auditioning

    Joined:
    Dec 6, 2002
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    0
    Thanks for the explanation.
     
  4. StephenL

    StephenL Second Unit

    Joined:
    Nov 21, 2000
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
  5. Chris Huber

    Chris Huber Second Unit

    Joined:
    Jan 2, 2003
    Messages:
    416
    Likes Received:
    0
    Trophy Points:
    0
    Ok, by what you guys are saying is this... If I have 10 inch floor standing FL and FRs, then I should set the reciever to 100hz(pioneer) and set the sub knob to 150hz?

    Right now they are set at reviever 150hz and sub 75hz. Is there a prob with that setup?
     
  6. Steve Schaffer

    Steve Schaffer Producer

    Joined:
    Apr 15, 1999
    Messages:
    3,756
    Likes Received:
    1
    Trophy Points:
    0
    Chris,
    You want the crossover setting on the receiver to be lower than the one on the sub, regardless of the specific setting you choose.

    The receiver won't put out anything above the crossover setting to the sub, and the sub won't produce any sound over it's crossover setting.

    So if you set the crossover on the receiver to 150hz and the crossover on the sub to 75hz, the frequencies between 75 and 150hz won't be reproduced by the sub.

    I'd suggest setting the receiver's crossover to 100hz or below, maybe 80hz if that's one of the choices, and the sub's crossover at 150 so there's plenty of overlap.
     
  7. Chris Huber

    Chris Huber Second Unit

    Joined:
    Jan 2, 2003
    Messages:
    416
    Likes Received:
    0
    Trophy Points:
    0
    Ok Steve, that makes sense. Thank you.
     
  8. Chris Huber

    Chris Huber Second Unit

    Joined:
    Jan 2, 2003
    Messages:
    416
    Likes Received:
    0
    Trophy Points:
    0
    one more thing... Even though I have 10 inch floor standings, you'd still set the reciever for 100hz?
     
  9. ChrisAG

    ChrisAG Supporting Actor

    Joined:
    Aug 26, 2001
    Messages:
    503
    Likes Received:
    0
    Trophy Points:
    0
    With my receiver's crossover at 100Hz and the sub's crossover maxed out at 150, deeper male voices on certain DVDs could be heard from the sub, which was very distracting. Setting the sub crossover to 100 solved this problem.
     
  10. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    25
    Trophy Points:
    0
    Location:
    NorCal
    Real Name:
    John
     
  11. Clinton McClure

    Clinton McClure Casual Enthusiast
    Supporter

    Joined:
    Jun 28, 1999
    Messages:
    4,370
    Likes Received:
    401
    Trophy Points:
    4,110
    Location:
    Central Arkansas
    Real Name:
    Clint
    As an example to add to John's explanation, my receiver has a hard x-over setting of 80Hz meaning I cannot adjust it. My sub has an adjustable x-over which runs from about 140 or 150Hz down to around 40Hz. I keep the sub's x-over set on the maximum setting (150Hz I think it is). This way, with the slope of both crossovers taken into account, I am not losing any information on the sub channel. My sub's x-over cannot be turned off or deactivated so this is a good work-around and yields the same results.
     
  12. Steve Schaffer

    Steve Schaffer Producer

    Joined:
    Apr 15, 1999
    Messages:
    3,756
    Likes Received:
    1
    Trophy Points:
    0
    I was aware of the slopes, just wanted to try to keep things simple but ended up being innacurate--sorry.

    One can experiment with different crossover settings, there's no hard and fast rule as a lot depends on your speaker's frequency response characteristics.

    One other consideration is that the lower frequencies require the most power to reproduce. Because of this it is often desirable to set main speakers as small even if they do have big woofers
    capable of deep bass response. This releives the receiver of having to produce the power for this deep bass, passing the load to the powered sub. Of course this is more of a factor to consider with lower powered receivers than with flagship models in the 1.5k range.
     
  13. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    25
    Trophy Points:
    0
    Location:
    NorCal
    Real Name:
    John
     
  14. Phil_Lunar

    Phil_Lunar Stunt Coordinator

    Joined:
    Jul 11, 2002
    Messages:
    61
    Likes Received:
    0
    Trophy Points:
    0
    this is interesting, I was making some test yesterday on my receiver and sub and I was left with a lot of questions... now some of them are now answered thanks to this tread but is still got a few...

    Having quite small speakers, I've always run my speakers setting to small, also, I got a Passive sub powered by a dedicated amp(I am running the LFE pre-out on it) but with no crossover at all. I got a receiver Kenwood VR-410 and I always though he have a cross over point around 80Hz-100Hz.

    but I made some test with my Avia Guide DVD ans Blade II and I got some interesting result :

    with the front and center speakers set to small, when I use the test tone of Avia chapter 7 that goes from 200Hz down to 20Hz , I've discovered that My sub produce sound even a 200Hz! So the Crossover can't possibly be at 80Hz I suppose?
    I also noted that on my front speakers, the tone still produce sound at 40Hz(very low sound and die at like 35Hz) but they have small woofer(3.5" or 4") so I suposse It has nothing to doe with Crossover, and they simply can't produce lower frenquency right?

    Now after that, I've decided to set my Front speakers to Large just to see :

    Now, I was not able to test with the Avia Tone because the Way Avia is made, it send the signal to 1 of the 5 speakers only(nothing on the LFE output), and it is my receiver that send bass to my sub when I set speakers to "small". and the other test tone on the LFE only run front 100Hz to 20Hz, so of course I heard sound at 100Hz(but since there must be a slope, I can't conclude anything out of this)

    So I've decided to try this with a movie just to see(Blade II)

    I've started the House of Pain chapter and compare the sound shifting my speaker front "Large" to "Small".

    What a difference! Of course, I was expecting this difference since my front are small speakers, so I now understand that in a Movie sound track there is low HZ info send to all the speakers and not only on the LFE.(by the way, is the a standard fixed crossover point that studio use when mixing soundtrack? like anything bellow 50Hz are not send to main speaker but only on the .1 LFE channel?)

    Now , when set to Large , I got quite less bass since my small speaker can't produce much bass, also, I only got something comming out of my sub with DD 5.1 or DTS anything else that does not have a not a .1(DD 2.0, or TV analog sound) does not send info on the LFE.

    this help me quite understand how all of this work.

    So I suppose I shoud buy a External Crossover for my sub so I can cut frequency above 80 or 100Hz right? or is it normal that my sub still produce some sound at 200Hz even if there is a crossover on my receiver?
     
  15. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    25
    Trophy Points:
    0
    Location:
    NorCal
    Real Name:
    John
    Phil - what receiver? What sub settings are available to you, and do you have a sub out as well as LFE out or LFE only?

    Without knowing what your receiver's x-over slope is, I can only say that it is highly likely that you will get some sound at 200Hz with a 6dB slope. Your room, and placement of the sub within it, can be a factor as well, as it may accentuate the 200Hz range. With your main speakers set to small, the x-over will be applied to your sub as well.

    I don't know if there is an industry standard for x-over during studio mixing, but for THX mastering it is 80Hz.
     
  16. Phil_Lunar

    Phil_Lunar Stunt Coordinator

    Joined:
    Jul 11, 2002
    Messages:
    61
    Likes Received:
    0
    Trophy Points:
    0
     
  17. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    25
    Trophy Points:
    0
    Location:
    NorCal
    Real Name:
    John
     
  18. Phil_Lunar

    Phil_Lunar Stunt Coordinator

    Joined:
    Jul 11, 2002
    Messages:
    61
    Likes Received:
    0
    Trophy Points:
    0
    well, thanks for all the info!
     
  19. Greg Kolinski

    Greg Kolinski Second Unit

    Joined:
    Oct 13, 2002
    Messages:
    331
    Likes Received:
    0
    Trophy Points:
    0
    I had experimented with my HK 520,I am using Acoustic Research TSW 510's in the front,older but really GREAT speakers.I set my crossover to the "large plus LFE" and set crossover at 60.Then ran it that way for about a week,with various DVD's.I seemed to be losing some low end.I then put it back to "small" at 80.,and it sounded much better
    just my experience[​IMG]
     

Share This Page