What's the point of having a powerful subwoofer if....

Discussion in 'Archived Threads 2001-2004' started by LaMarcus, Feb 10, 2003.

  1. LaMarcus

    LaMarcus Screenwriter

    Joined:
    Mar 7, 2002
    Messages:
    1,619
    Likes Received:
    0
    Trophy Points:
    0
    it's going to be so low that it doesn't make a difference what kind it is? I see people getting SVS and etc, but if your going to have it calibrated to the same level as the rest of your speakers, what difference does it make?

    When calibrating the speaker levels, I get them all to the same level, then when it's time for the sub, the meter goes off the chart. I would have to actually turn the power level on the sub down for it to match the rest of the speakers. I have never listened to the sub set at the same level as the rest of the speakers. Is there enough bass with it being that low? I can only imagine how much of a lack of bass there is if it's on the same level as all the speakers.

    Am I wrong, does the type of sub really make a difference at such a low level? It seems like you will barely scratch the surface of the subs potential with it being so low. I adjust my sub by ear, I like to hear the rumble. But if this is inaccurate, I will have to consider doing it differently.
     
  2. RayJK

    RayJK Stunt Coordinator

    Joined:
    Nov 25, 2002
    Messages:
    131
    Likes Received:
    0
    Trophy Points:
    0
    Your hearing isn’t as efficient at lower frequencies as it is in the midrange. Setting up the sub so that it has the same level as your other speakers is the correct way to do it. The difference in brands is in the quality and quantity of the bass they produce.
     
  3. CurtisC

    CurtisC Second Unit

    Joined:
    Jan 7, 2003
    Messages:
    369
    Likes Received:
    0
    Trophy Points:
    0
    The first rule is if it sounds ok to you,that's all that matters.To your ?,more power usually gives less distortion, more speed,and a flatter freq response below 30hz down to teens.Low power usually fails at below 30hz level and comprimises above 30hz.This is another,you get what you pay for dealy.
     
  4. Steve_Ma

    Steve_Ma Second Unit

    Joined:
    May 7, 2001
    Messages:
    420
    Likes Received:
    0
    Trophy Points:
    0
    After properly calibrating my sub inline with the rest of my speakers, I (personally) can't really tolerate it any other way.

    That being said: I know plenty of people who want their sub to do alittle more and crank it up. For many, a flatter type of response is too subtle when it comes to the bass and they want more. I say have at it, but I usually advise newcomers to the hobby to try it calibrated the proper way first to get adjusted and to help establish your personal baseline.

    --Steve
     
  5. Ryan Schnacke

    Ryan Schnacke Supporting Actor

    Joined:
    Feb 5, 2001
    Messages:
    876
    Likes Received:
    0
    Trophy Points:
    0
    Well, some receiver's internal test tones are pretty poor. My Onkyo's subwoofer test tone is 10dB louder than the speaker tones. So unless you're using a good calibration disk, you may never know where "flat" really is.

    And when you have a sub that plays flat to 20Hz you need to move LOTS of air to get anywhere near reference levels.
     
  6. Mitch Stevens

    Mitch Stevens Supporting Actor

    Joined:
    Apr 27, 2002
    Messages:
    581
    Likes Received:
    0
    Trophy Points:
    0
    I think that LaMarcus, is calibrating with a calibration disc with his speakers set to large. I think the bass coming from the large speakers is what is causing him to turn the sub almost completely off.

    LaMarcus, try setting your mains to small, and then calibrate your sub again, you'll see it was just your mains that play the bass too loud. The sub should be somewhere with the gain half way up...not almost completely off.
     
  7. LaMarcus

    LaMarcus Screenwriter

    Joined:
    Mar 7, 2002
    Messages:
    1,619
    Likes Received:
    0
    Trophy Points:
    0
    Actually, I am using Video Essentials to calibrate my speakers. Have em all set to small, have the radio shack meter set right and every thing. I get all my speakers to hit the 70db mark from the test tones off the disk. It does the surrounds, then finally it's time for the sub. I promise it makes me giggle every time the sub test signal comes on because my room starts shaking and the spl meter sky rockets. I can turn the receiver db level totally down and it wont make a difference. I would have to turn the level on the subwoofer down for it to be equal with the rest of the speakers.

    But alllllright, I'm going to try it you guys way and see if I like it. But if I can't feel Sauron walking up to hit home runs, or Sauron's explosion in my back when he dies, it's gonna be trouble.[​IMG]
     
  8. Mitch Stevens

    Mitch Stevens Supporting Actor

    Joined:
    Apr 27, 2002
    Messages:
    581
    Likes Received:
    0
    Trophy Points:
    0
    you need to calibrate to 75dBs not, 70. Hmmm...maybe it doesn't make a difference.
     
  9. RichardH

    RichardH Supporting Actor

    Joined:
    Nov 28, 2000
    Messages:
    742
    Likes Received:
    0
    Trophy Points:
    0
     
  10. LaMarcus

    LaMarcus Screenwriter

    Joined:
    Mar 7, 2002
    Messages:
    1,619
    Likes Received:
    0
    Trophy Points:
    0
    Hmmm, the sub I have is rather shitty, that's why I turned in into sort-of-a diy sub. I have a sony 8" powered sub think it's 50 (maybe 100) watts. But what I did was I opened up the sub so I could use the amp inside to power my 15" competition sub together with the 8" at the same time. It actually sounds really good. I like to have two powered subs going at the same time.
     
  11. Bob McElfresh

    Bob McElfresh Producer

    Joined:
    May 22, 1999
    Messages:
    5,182
    Likes Received:
    0
    Trophy Points:
    0
    Remember something: the SPL meter only shows you the LOUDEST frequency. When you corner-load a subwoofer, you get a lot of sound from wall-reflections. If a wall gives you a very efficent reflection at say ... 50 hz, your meter will go off the scale even if the sounds from 20-40 and 60-120 are too low.

    You can do some things to test this:

    - Buy a test-tone CD with single frequency tones for the sub assigned to particular tracks.

    - Download a copy of NCH Tone (a shareware tone-generator) and this will let you save tones as wave files and burn your own test-tone CD.

    Setup your SPL meter and get the .. 100 hz tone going and adjust the volume level to .. 80 db (it's easy to see in the middle of the dial). Now with a piece of paper, start going down the frequencies 90, 80, 70, ... 10 hz and note how loud your ROOM is at each frequency.

    (Yes, your room is having a big effect here).

    You are doing a crude real-time analysis of your room response. You are likely to find some really loud frequency, then some sudden drop off's.

    You can tame peaks by moving your sub along a wall to the 3/5 position or even 1/3. It may not solve everything, but it can give a smoother/closer to the same volume across all frequencies.

    Once you tame your worst peaks, my guess is you will now have to turn up the over-all volume on the sub to match the rest of the speakers.

    Seach for "House Curve" in this fourm for lots of discussion/graphs of what other people have done.

    PS: With Video Essentials, if you set your main speakers to 75 db, you must then adjust your sub to 85 db to match. The subwoofer test-tones on the VE disk are made 10 db below the other tones on purpose. You can search other posts for the reasons.

    Hope this helps.
     
  12. Chris Tsutsui

    Chris Tsutsui Screenwriter

    Joined:
    Feb 1, 2002
    Messages:
    1,865
    Likes Received:
    0
    Trophy Points:
    0
     
  13. Tim_S

    Tim_S Stunt Coordinator

    Joined:
    Oct 2, 2000
    Messages:
    80
    Likes Received:
    0
    Trophy Points:
    0
     
  14. James Bergeron

    James Bergeron Supporting Actor

    Joined:
    Oct 9, 2001
    Messages:
    831
    Likes Received:
    1
    Trophy Points:
    0
    A better sub will go lower flatter, so that you'll get all the frequencies at the same volume, your little 8" most probably just can't do it.

    I CANNOT boost my sub more than the level of my speakers, it would be WAY too loud, I even have it down a few dB's, when I get in the 20hz-30hz range the entire room presurizes and you wouldn't want it louder.
     
  15. Jack Keck

    Jack Keck Second Unit

    Joined:
    Nov 23, 2001
    Messages:
    269
    Likes Received:
    0
    Trophy Points:
    0
    Remember that the Radio Shack SPL meter becomes less accurate at lower frequencies. the lower ther frequency, the more the meter is off. there are tables posted somewhere to tell you how to correct for this. Suffice it tosay that it reads lower than the actual output in the low bass.
     
  16. Mark Zimmer

    Mark Zimmer Producer

    Joined:
    Jun 30, 1997
    Messages:
    4,300
    Likes Received:
    40
    Trophy Points:
    0
     
  17. Phil Iturralde

    Phil Iturralde Screenwriter

    Joined:
    Oct 7, 1998
    Messages:
    1,867
    Likes Received:
    0
    Trophy Points:
    0
     
  18. LaMarcus

    LaMarcus Screenwriter

    Joined:
    Mar 7, 2002
    Messages:
    1,619
    Likes Received:
    0
    Trophy Points:
    0
    Wow. Leave it to Phil to give you a information overload.[​IMG]

    Tim you and James I think really hit the nail on the head, you gave me the answer I needed to understand "why".

    All of you guys were helpful, you really make this hobby more work than play [​IMG] .

    But DAMN YOU ALL for making me have to get a SVS sub, because no way am I going to be able to enjoy my theater knowing that I have an inaccuracy.[​IMG] Ignorance is bliss. [​IMG]

    I thought I was finished buying HT stuff for this year, bought the whole S-series (jbl) bought a new receiver (D811s), now I gotta get a new sub too, sheesh. [​IMG]
     
  19. Bob McElfresh

    Bob McElfresh Producer

    Joined:
    May 22, 1999
    Messages:
    5,182
    Likes Received:
    0
    Trophy Points:
    0
     
  20. jeff lam

    jeff lam Screenwriter

    Joined:
    Jun 4, 2001
    Messages:
    1,798
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    San Jose, CA
    Real Name:
    Jeff Lam
    To answer your original question... You simply don't need a huge, powerful sub if you won't be asking much of it. If all you need of it is to produce 10dB below reference level then you won't need the massive powerful sub. But you still want to have a flat frequency responce all the way down to the low 20's or maybe even lower. This simply can't be done by a cheap little sub, even at really low levels. If what you need is 10dB below reference flat all the way down to the 20's in a normal room, I would say the minimum you would need is a single 25-31PCi. If you want clean, full reference flat down to the 20's in a normal sized room, I would say the minimum you would need to get even close is a pair of 20-39PC+'s.

    A paremetric EQ would really help flatten out your frequency responce. Look into it.
     

Share This Page