HSU VTF-2 --- bumpy response. help

Discussion in 'Archived Threads 2001-2004' started by Cramer_A, Dec 26, 2002.

  1. Cramer_A

    Cramer_A Auditioning

    Joined:
    Dec 15, 2002
    Messages:
    13
    Likes Received:
    0
    Trophy Points:
    0
    In an effort to achieve near-flat response from my sub (HSU VTF-2), I purchased a RS SPL meter. To my surprise, the db levels are much different from 35-125 hz.

    To measure this, I'm using my receiver's (Yamaha HTR-5280) LFE test tone from 35-125 hz and setting the sub at 75 db (matched to my main speakers).

    Right around 50-70hz my sub goes up +8 decibels and then it goes back down. Is this normal? Will moving the sub to a new location help this bump? Currently the sub is located in the front right corner (the room is a rectangle).

    Do I need to change something with my reciever crossover settings?

    Thanks for the help.

    -Adam
     
  2. Zack_R

    Zack_R Stunt Coordinator

    Joined:
    Nov 4, 2002
    Messages:
    220
    Likes Received:
    0
    Trophy Points:
    0
    There could be many reasons. It could be the room or the crossover between your mains and your sub. Around the range of the crossover you could have several speakers producing a frequency in phase which could amplify those frequencies.

    If your receiver has a polarity setting for the sub where you can reverse it, I would suggest you try that and take a measurment without making any other changes. You may find it flattens out the 50-70 hz region without affecting the 20-50 hz sounds. Or then again it could sound awful. Either way its an easy thing to try.

    This worked wonders on my SVS Ultra as I had a 5-6 db dip from 63-100. I reversed the polarity and now my response is very flat from 20 - 200. I cross my sub at 80 but I like to take the signal well on through the crossover to ensure my mains are picking up the frequency properly. Correcting for the radio shack meter, the response is + / - 2 db. For 80% of the range I'd say it is pretty close to + / - 1 db.

    BTW, am I correct in assuming you are using your receiver to make the crossover rather than the sub?
     
  3. RichardH

    RichardH Supporting Actor

    Joined:
    Nov 28, 2000
    Messages:
    742
    Likes Received:
    0
    Trophy Points:
    0
    More than likely it is because of your room and can't really be helped. You could EQ the bump out if you like, and that would give you flatter response. Alternatively and more complicated, you could buy/make some bass traps to take that bump out.
    Actually a little bump in the 50-60Hz range probably sounds good on a lot of music! [​IMG] Like kick drum and bass!
     
  4. Cramer_A

    Cramer_A Auditioning

    Joined:
    Dec 15, 2002
    Messages:
    13
    Likes Received:
    0
    Trophy Points:
    0
     

Share This Page