Advantages of using a higher x-over point?

Discussion in 'Speakers' started by Vaughan Odendaal, Oct 30, 2005.

  1. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    Hi there,

    Over the weekend, I was experimenting with my equipment. I have an SVS PB-10 ISD and I have Whalfdale Diamond 8.4 front speakers, center and Diamond 8.1's for rears. I know, they are quite old speakers, but I think they still sound great.

    Now, since I've had my SVS subwoofer, my bass has gone through certain phases. At first, the bass droned on and on and there was a lot of overhang. I didn't know what was causing this. Two months later, I found out that I had the phase set on my reciever as "reverse" instead of normal.

    I changed it to normal and the bass was more in sync with the mains, with less obvious bass overhang. But the bass was still a bit "thick". Now I know that the room contributes towards the sound in a big way and I have no treatment to speak of.

    However, this morning I changed my crossover point from 80hz to 60hz. All of a sudden, the bass firmed up. There was almost no overhang to speak of. No lag. But there was slightly less bass (not as boomy as it was before).

    The bass sounds precise and "quick" now. With films, I'm still getting the same very deep bass that I feel with films (I don't think I'm missing anything at all), and when there is music, the bass just sounds precise.

    I also noticed that if I change the x-over point from 60hz to 80hz, there are more high frequencies.

    Can someone please explain to me what I'm experiencing here. Why I am getting less overhang with a lower crossover point and why there is less boom?

    I don't know if the high frequencies sound better at 80hz or 60hz, I honestly don't know because I have no frame of reference in which to judge. But the bass sounds absolutely wonderful with the 60hz x-over point (arguably better than with the 80hz x-over point).

    Your thoughts?

    --Sincerely
     
  2. SethH

    SethH Cinematographer

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    I can't explain it. At first I thought you might be losing the frequencies between 60 and 80 when you dropped the crossover, but according to the Wharfedale website, the 8.4's are good down to 30. It may be that you had a large peak somewhere between 60 and 80 and that by dropping your crossover point your speakers are sloped lower at that peak frequency, thus reducing the peak -- but I could be completely wrong.

    Anyway, the key is that you should use what sounds better to you. If you can set your crossover between 60 and 80 then play with it more. If you can't, then leave it at 60.
     
  3. Wayne A. Pflughaupt

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    In lieu of “before and after” room response curves, we can only speculate. A good place to start is that you had a peak in response in the 60 Hz region that crossing over there helped smooth out. If your mains have weaker output at 60 Hz than at 80 Hz, that would also help this theory along.

    Regards,
    Wayne A. Pflughaupt
     
  4. Jacob C

    Jacob C Second Unit

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    another issue could be the location of the mains vs. the sub. Similar to moving your sub around in your room. It sounds different at different locations.
     
  5. MikeyWeitz

    MikeyWeitz Supporting Actor

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    Yep, as soon as I read you post, a peak @ the 70-80hz range is what 1st came to my mind.
     
  6. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    Thanks for the responses, guys. You know, I've tried placement. You don't even want to go there.[​IMG]

    But if I leave the subwoofer in it's present location and change the x-over point from 80hz to 60hz, the bass is just so precise sounding. There is no bass lag.

    At 80hz, the bass sounds a little bit muddy with music. Now I know this shouldn't be used as a reference but I'm using satellite as an example. I've got around 50 or so dedicated music channels. It sounds great, but obviously not 100% cd quality.

    I tried the Foo Fighters cd (latest album), and with an 80hz x-over point, the bass sounds like it's dragging on just a little bit. But if I change the x-over point, the bass is more agile, sounds more precise, but there is slightly less apparent bass.

    I never thought that I might have a peak in my response at 80hz. So lowering the x-over point would help with peaks?

    And I just would like some input from those of you who have tried the same x-over point. Have you guys also noticed an improvement in bass articulation by lowering the x-over point from 80hz and down?

    I'm sorry I can't give you more in-depth information about my room response but I have no SPL meter at present.

    Thanks a bunch.

    --Sincerely,
     
  7. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    Sorry, I just wanted to add that I have my speakers all set to small on the receiver.

    --Sincerely,
     
  8. SethH

    SethH Cinematographer

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    It would only reduce peaks if they fall between 60Hz and 80Hz.

    I'm pretty sure you've got a continuously variable phase knob on that sub. You might try setting your x-over back to 80Hz and playing with the phase to see if that cleans things up at all. If not, I'd set it on 60Hz and enjoy it.
     
  9. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    A question: is the 60-80hz bass region the most critical when it comes to music? Would that region cause a "thick" sounding bass if there were peaks in the response?

    The thing is, I don't know if I'm getting peaks because I can't measure it, but if someone could let me know what the effect would be if there were peaks it might help me understand what is going on.

    In other words, do my observations correlate with a peaky response in the 60-80hz bass region?

    With regards to phase, I've played around with it for a long, long time and I've found the best position for it while playing a music dvd (Eric Clapton Live in Hyde Park), so that is sorted out.

    Thanks for helping.

    --Sincerely,
     
  10. SethH

    SethH Cinematographer

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    I wouldn't say it's the most critical, but when you're listening to listening to anything other than R&B or rap, it's probably the lower region of what you're hearing. For instance, on a 4-string bass guitar, the lowest note (an E) is 41.3Hz, so unless there are some computer-generated effects in the music, that's about as low as you'll go. The lowest note on a regular guitar (also an E) is 83Hz, so the bass and kick-drum are about the only things below 80Hz.
     
  11. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    So then a peak in the 80hz bass region would not cause a boomy bass or a thick sounding (I hate that term "thick"[​IMG] ) bass?

    Thank you very much for the information. Much appreciated.

    --Sincerely,
     
  12. Mike-G-H

    Mike-G-H Auditioning

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    I'm completely new to this so please bear with me guys.


    I read Vaughan's post and decided to give it a try on my system as well. I was listening to some music and felt the bass to be way muddy and slow. I switched the x-over to 60 from 80 and it is much better.I must have some kind of peak in that range also.

    Next I used the THX calibration setup on my Phantom Menace dvd. Using my spl meter and the frequency sweep test, the level started out around 80, pegged in the middle of the sweep and then went back to around 80 at the end of the sweep. I'm guessing there's a pretty big peak there somewhere?? Would an equalizer help even this out or is there some other route to take?

    Mike
     
  13. Scott Simonian

    Scott Simonian Screenwriter

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    Most of us would figure this much since we're discussing lowering a xover point from 80hz to 60hz. [​IMG]

    Try em [rant]LARGE[/rant] next. [​IMG]
     
  14. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    Heh. Sorry, I wasn't thinking clearly. I have tried the large setting but with mixed results.

    I'm glad to hear that at least one member has noticed an audible improvement lowering the x-over point, which is nice.

    --Sincerely,
     
  15. GregBe

    GregBe Second Unit

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    I think that is right in the area where a peak can cause boominess. I had a peak at 65 that I reduced, and the bass tightened up considerably.
     

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