need some test tones...

Discussion in 'Archived Threads 2001-2004' started by John Doran, Feb 3, 2003.

  1. John Doran

    John Doran Screenwriter

    Joined:
    Jan 24, 2002
    Messages:
    1,330
    Likes Received:
    6
    Trophy Points:
    110
    does anyone have any links to downloadable test-tones for calibrating and EQ'ing subs?

    i'm hoping for tones from 1-100hz in 1hz increments, but i'll take whatever i can get.

    thanks for the help.

    - jd
     
  2. Bill_D

    Bill_D Supporting Actor

    Joined:
    Dec 10, 2001
    Messages:
    755
    Likes Received:
    0
    Trophy Points:
    0
  3. John Doran

    John Doran Screenwriter

    Joined:
    Jan 24, 2002
    Messages:
    1,330
    Likes Received:
    6
    Trophy Points:
    110
    thanks for the great link.

    i'm wondering: there are momentary breaks during some of the tones i listened to - will those harm my sub if i play them fairly loudly?

    thanks for the help.

    - jd
     
  4. Bill_D

    Bill_D Supporting Actor

    Joined:
    Dec 10, 2001
    Messages:
    755
    Likes Received:
    0
    Trophy Points:
    0
    I did not use them in 1hz increments but I did use major octaves at pretty insane levels to set my BFD up with no harm done to the subs.
     
  5. PaulT

    PaulT Supporting Actor

    Joined:
    Oct 28, 2002
    Messages:
    932
    Likes Received:
    0
    Trophy Points:
    0
    John, if you have a CD burner or access to one, try this freeware program to generate your own tones:
    http://www.nch.com.au/tonegen/index.html

    I have burned numerous discs for different applications ie. One for Sub test (like you want) 10 - 100Hz in 1Hz steps, 1/12th Octave, 1/6th Octave, etc etc.
     
  6. John Doran

    John Doran Screenwriter

    Joined:
    Jan 24, 2002
    Messages:
    1,330
    Likes Received:
    6
    Trophy Points:
    110
    thanks for all the help, guys - i really appreciate it.

    - jd
     
  7. Ned

    Ned Supporting Actor

    Joined:
    Feb 20, 2000
    Messages:
    838
    Likes Received:
    0
    Trophy Points:
    0
    john-

    I sent you an email at your listed Sympatico address. Did you receive?
     
  8. Mark Shannon

    Mark Shannon Screenwriter

    Joined:
    May 27, 2002
    Messages:
    1,991
    Likes Received:
    0
    Trophy Points:
    0
    ok, ok.... NOOB alert!(when it come to this)

    when it comes to these test tones, I have no idea what you people are talking about.... is there an online guide/thread that I can read in order to use these properly? I'd like to calibrate my system as best I can (without Avia)
     
  9. Justin Ward

    Justin Ward Supporting Actor

    Joined:
    Jun 6, 2002
    Messages:
    673
    Likes Received:
    0
    Trophy Points:
    0
     
  10. Justin Ward

    Justin Ward Supporting Actor

    Joined:
    Jun 6, 2002
    Messages:
    673
    Likes Received:
    0
    Trophy Points:
    0
    Ok guys I have some questions too. I downloaded the tone generator and using sine waves I can only hear from about 35hz to 14khz?
    But using triangular I can hear from about 16hz to 20500hz, is this right? Which one is more accurate? I am listening though headphones if it matters.
     
  11. Edward J M

    Edward J M Cinematographer

    Joined:
    Sep 22, 2002
    Messages:
    2,031
    Likes Received:
    0
    Trophy Points:
    0
    John:

    I have found 10-100 in 1/12 octave increments works best for me. It gives plenty of resolution without going overboard with single Hz increments. Also, I see no reason to go below 10 Hz. I use 80 Hz as my filtering point, so at 100 Hz almost the entire signal is being handled by the mains. A test tone sweep is a good way not only to plot the overall FR of the sub, but also to evaluate the filtering transition from the sub to the mains.

    In my sweep, there are 41 tones, each 10 seconds long, and it gives plenty of time to read and record the SPL reading. There isn't much of a break between test tones - just long enough for your DVD player to switch to the next track. It is essentially a 410 second continuous sweep. So yes, if you play it too loud, you can fry the VC - in your case the 4 VC's [​IMG].

    With your B4, you can probably push it pretty hard without fear of damage, but all subs have their limits. Personally, I ran my sweep off a gentle 80 dB reference point at 100 Hz just to plot the in-room FR, not to determine max output.

    If you want to check max safe output at any given frequency, just select that particular track and play it. As for how long and how loud your sub is safely capable of playing any given frequency in your HT room - I would go straight to the horses mouth and ask Tom V. He knows the characteristics of the TC Sounds dB-12 driver better than anyone. With that said, most people with trained ears can detect a worsening of the bass tonal quality and character at around 10% THD. I would certainly never push the sub to the point of obvious audible distress regardless.

    Anyway, there are software programs that can plot your FR, or you can do it in Word or Excel. I developed a custom Excel spread sheet which plots the SPL against the frequency. There are different data columns and charts for different states of tune and phase settings. You could certainly add to these since you have 4 ports. You could even add a feature which automatically adds the approximate RS Correction Factor if you are using that meter.

    If you want the spreadsheet, just send me a PM, and I'll email it to you.

    Regards,

    Ed
     
  12. PaulT

    PaulT Supporting Actor

    Joined:
    Oct 28, 2002
    Messages:
    932
    Likes Received:
    0
    Trophy Points:
    0
    Mark, don't want to hijack this thread, but Justin is correct. The Sine Waves are for measuring the Frequency Response (generally using low freq for Subs) using typically a Radio Shack SPL meter. Some may use them just for measuring (guess we had nothing else to do that day [​IMG]), others use EQ (a unit called a BFD, do a Forum Search) to adjust their Sub to flatten peaks/dips caused by reflections in their listening room.

    Without Avia you could burn some Pink Noise tracks for Level Calibrations but they would be mono or stereo only. Avia goes from Channel to Channel. As per Justins post, you would be better off using your receivers tones until you had Avia or Sound&Visions version of the Disc.

    Justin, depending on the quality of your headphones, I would think 35Hz - 14kHz sine waves would be reasonable for you to hear albeit a tad low on the high freq side. Don't use the triangular waves. Sine for Response, Pink Noise for level Cal as per your post.
     
  13. Mat_M

    Mat_M Stunt Coordinator

    Joined:
    Jan 3, 2003
    Messages:
    225
    Likes Received:
    0
    Trophy Points:
    0


    Justin, when you're listening to a sine wave at a particular frequency, you're hearing one exact frequency. A triangle wave is composed of multiple frequencies summed together. So when you have the program output a 16Hz triangle wave, you're hearing a sum of frequencies that extend far below and far above 16Hz. The same goes for the 20.5kHz you setup. If you want I can extend this further with a Fourier transform explanation.
     
  14. a little late, but if you click below in my sig file, I have liked some 1/12th octave test tones and my PEQ program (for mapping out the responce and seeing the influence of the BFD)
     
  15. PaulT

    PaulT Supporting Actor

    Joined:
    Oct 28, 2002
    Messages:
    932
    Likes Received:
    0
    Trophy Points:
    0
    Anthony, and what a great program the PEQ is to use, thank you.[​IMG]
     
  16. Edward J M

    Edward J M Cinematographer

    Joined:
    Sep 22, 2002
    Messages:
    2,031
    Likes Received:
    0
    Trophy Points:
    0
    Anthony:

    First I would like to thank you for hosting the 1/12 octave test tones. These are the ones I have been using all along for plotting my FR.

    Second, I keep getting "page not found" error messages when I try to link to your PEQ page(s). What am I doing wrong?

    Thanks,

    Ed
     
  17. John Doran

    John Doran Screenwriter

    Joined:
    Jan 24, 2002
    Messages:
    1,330
    Likes Received:
    6
    Trophy Points:
    110
    edward,

    i tried to PM you, but it said you don't accept PM's...

    anyway, i'd love to see that spreadsheet if you wouldn't mind sending it to me: [email protected]

    i was only wondering about the test-tones at reasonable volumes - 80db or 85db; it occurred to me that maybe there was something in the occasional breaks in the tones on that web-site that might stress the drivers too much even at those levels...

    but i've used the other tone-generator, anyway, which makes pure, uninterrupted tones.

    i figure i'll probably test every 3 or 5hz...

    thanks,

    - jd
     
  18. Glad you like it. Since tripod has bandwidth limitations, I created many mirrors upon the release of the program (opening an account for mirror use is a violation of Tripod membership) and they closed most of the accounts after about the 1st week. I believe 2 are still working. I will try and update the page today by removing the dead links.

    Those Test tones were created by me, but are actually hosted by another HTF member, Mark Fitzsimmon [​IMG]
     
  19. Edward J M

    Edward J M Cinematographer

    Joined:
    Sep 22, 2002
    Messages:
    2,031
    Likes Received:
    0
    Trophy Points:
    0
    John:

    You've got mail. Sorry about that. I was getting PM regularly, and then the settings spontaneously changed.

    Ed
     

Share This Page