OK - EQ's for sub and test CD - which ones?

Discussion in 'Archived Threads 2001-2004' started by Bryan Acevedo, Dec 13, 2001.

  1. Bryan Acevedo

    Bryan Acevedo Second Unit

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    I have been reading all of the posts about sub eq'ing, and I think I need it in my room. I have the Velodyne SPL 1200, and I am pretty sure I have some peaks down in the 30 to 40 Hz region. My deep bass is just overpowering compared to the mid bass. If I turn down the sub, then the rest of the bass is non existant. I have my sub at like 2 out of 12, and the deep bass is still really loud! My receiver's trim control is set to 0.

    So, which CD is it that everyone uses for the test tones? I have seen the Stryke Test CD mentioned. Is everyone using the Volume 1 CD? They have it on sale for like $10.95 plus a $1 for shipping. That is cheap, but I am not sure if this is the same one everyone is talking about.

    What do I use to measure it? Do I just use my Radio Shack SPL Meter? Do I basically just play the test tones at 1/6 octave starting at 20 Hz, and record the SPL for each one? I have seen mention of the Spectra software. Do you just basically use this with the RS SPL Meter plugged into your sound card mic input (using a 1/8" jack converter)? Do I use the analog output on the DVD player or is Digital mode ok?

    Which EQ is the best? I have seen mention of the Behringer Feedback Destroyer (DSP1124P), but what about the PEQ 2200 5 Band Parametric EQ? Is that just not enough bands to tame a sub? Is that why people like the BFD - 12 bands should be enough I would think. But would 5? How big are these - would it be too big to put on top of the sub? Would the vibration from the sub effect it? I have my sub in a custom built media niche, so putting this on top of the sub would be easier - I can hide it behind the grill cloth covering the niche. I can put it in the rack if I need to, but it is also a custom niche, and I don't have unlimited room in it.

    How hard is it to hook up the BFD - you just have to get the RCA to 1/4" converters. Does this degrade sound quality at all? Pick up any hum? People spend $200 on a sub cable, and then put a Radio Shack 1/4" converter on it - seems kind of pointless. What about ground hum? Do I HAVE to get a cheater plug? Has anyone had ground hum without it? I will have everything plugged into a Monster Power Conditioner (HTS 1000) if that helps.

    Once I have the measurements, how hard is it to adjust the BFD? Would the software download help with this?

    Thanks for all the help in advance.

    Bryan

    P.S. The receiver is a Denon 3802, and the other speakers are all Klipsch Reference series, crossed over at 80 Hz.
     
  2. Bryan Acevedo

    Bryan Acevedo Second Unit

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    ^^^^ And up we go ^^^^

    (For now anyway)
     
  3. Greg_R

    Greg_R Screenwriter

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  4. BruceD

    BruceD Screenwriter

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    Typically there are a few benefits with the BFD, for bass only, over other parametric EQ devices.

    1) The BFD allows you to control the center filter frequency to as fine as 1/60 of an octave. As an example, the octave from 40Hz to 80Hz in 1Hz increments would be 1/40 of an octave.

    2) The BFD allows you to control how narrow or wide the EQ filter bandwidth is - this is called "Q". I can't remember, but think it is either 1/30 or 1/60 of an octave (much finer than many other EQs).

    3) The BFD allows for 12 individual filters per L&R channel.

    IMO this is just info, buy whatever you think works best for you.

    Bruce
     
  5. Bryan Acevedo

    Bryan Acevedo Second Unit

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    The reason I was confused about the CD was that I have seen people say that they use 1/6 octave pink noise. I thought you just used tones. So I wanted to make sure I got the right disc.

    Thanks!

    Bryan
     
  6. Wayne A. Pflughaupt

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    FYI, Bruce, the 1/40, 1/60 etc. octave thing refers only to bandwidth (or “Q”), not incremental frequencies. The number of individual frequencies doubles with each ascending octave.
    Otherwise, assuming the BFD operates the full frequency spectrum, you would be dealing with 1/10,000 octave between 10-20kHz... ??!
    Get the picture?
    By the way, the BFD’s super-tight 1/30 or 1/60 octave bandwidth capability is more useful for its intended purpose (controlling frequency-specific feedback in live audio situations) than for home theater use. No one has nulls or peaks that narrow! I’ve personally never seen a response peak wider than 1/6 octave (which audibly-speaking, is pretty narrow – practically a one-note situation).
    Not that you need it, but it’s still cool that the BFD can do this.
    This is just “trivial pursuit,” by the way. Has nothing to do with the decisions Bryan is trying to make. [​IMG]
    Happy Holidays,
    Wayne A. Pflughaupt
     
  7. David Judah

    David Judah Screenwriter

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    I would definitely use an RTA. I tried the SPL and test tone route and it was time consuming and not as accurate as using Spectra Plus(free demo download).

    As far as EQs go, I don't think it matters as long as you have enough flexibilty to tame the peaks in your particular room. The BFD is extremely flexible, so that is why it is favored by many here. It's not hard to use after you spend a little time messing around with it, and since many here own one, you can always get help.

    Good luck,

    DJ
     
  8. Bryan Acevedo

    Bryan Acevedo Second Unit

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    David - if you use Spectra Plus - is that the RTA? What mic do you use for it? Just any PC mic?

    I just don't know what I would need for a real RTA analysis. I am not afraid of computers and the hardware (I am a software engineer) so you can get as technical as you want. I just have never used an RTA, so I wasn't sure if I need a seperate piece of hardware (the RTA) or if your PC with a mic becomes the RTA with the Spectra Plus software.

    Thanks,

    Bryan
     
  9. Sonnie Parker

    Sonnie Parker Second Unit

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    Never mind.
     
  10. David Judah

    David Judah Screenwriter

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    Download the demo program. http://www.telebyte.com/pioneer/
    You can use your SPL meter by plugging it into your mic input on your PC(with an eigth inch adapter), and then run the program with some kind of test tones for an analysis of the room.
    There is mic compensation for the Radio Shack spl meter at Terry C's site(scroll down a bit on that page).http://members.tripod.com/~terrycthe...um/page12.html
    Extract the file and put it in the miccomp folder(SPECPLUS/miccomp)of the program and then after you run Spectra plus goto the Options menu and click Scaling. At the bottom you will see Microphone compensation. Click Select and it will take you to the miccomp folder where you can click on the file you downloaded and placed there.
    DJ
     
  11. BruceD

    BruceD Screenwriter

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    David,

    I think you meant: plug the RS SPL meter's RCA output connection (which is a line level signal not a microphone signal) into the LINE-IN on your PC and not the mic input didn't you?

    When I used the mic from the SPL meter, I routed it to the PC's LINE-IN port with my RTA PC software - which is ETF5, although I now have a separate calibrated mic and preamp.

    Bruce
     
  12. David Judah

    David Judah Screenwriter

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    Yes, you are right, Bruce.

    DJ
     

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