Will I damage my speakers by running w/o a HPF

Discussion in 'Archived Threads 2001-2004' started by Tony Gibbons, Jul 28, 2002.

  1. Tony Gibbons

    Tony Gibbons Auditioning

    Joined:
    Jul 28, 2002
    Messages:
    6
    Likes Received:
    0
    I have a pair of Infinity IL40s as my main speakers. My reciever has an HPF at 80Hz. The frequency range of the speakers goes down to ~40Hz, so I assume that the ported frequency is about 40Hz. I know that drivers become underdamped or something like that below the ported frequency. So in home speakers do they usually have an HPF built in to avoid playing frequencies below their range or do I have to make sure that frequencies below the range aren't sent to the speaker by enabling the crossover on the reciever? Sorry for my ignorance...don't know much about home audio. I'd really like to run them without the crossover but don't want to damage them when I play movies with a lot of LFE
     
  2. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    Welcome to HTF [​IMG]
    Your speakers have a passive x-over to divide frequencies between the drivers, but it does not have anything to manage the low end rolloff. Just don't turn it up to the volume to the point of distortion, and they should be fine.
    A x-over is not a stake in the ground, but rather there is a roll off of frequencies above or below it, depending on whether it is an HP of LP. Most likely, your receiver is still passing a percentage of the frequencies between 40Hz and 80Hz (one octave), rolling off throughout that octave.
    Movies will be MUCH better with the LFE handled by a sub, since your mains cannot really handle true LFE, but music may sound better with them set to large with no sub. You will only damage your speakers if you drive them to distortion.
    What receiver?
     
  3. Tony Gibbons

    Tony Gibbons Auditioning

    Joined:
    Jul 28, 2002
    Messages:
    6
    Likes Received:
    0
    Thanks for the info. I am going to build a sub sooner or later. Till then I'll just keep the x-over enabled. Right now I am using an ~7 year old Technics THX reciever. I'll probably get a Denon 3802 sooner or later. My dad has one and I really like the sound. I have to build a sub first though.
     
  4. Mark Tranchant

    Mark Tranchant Stunt Coordinator

    Joined:
    May 9, 2002
    Messages:
    126
    Likes Received:
    0
    I'd suggest you don't do that. By enabling the crossover but not running a sub, you are missing out on the entire LFE channel as well as the low bass.

    Unless you drive your speakers to distortion (you will hear this, we're not talking 0.1% here!) you are unlikely to damage them. Watch the woofer cones - they are designed to move in and out a few mm with no problem.

    You're right, the driver in a ported box is unloaded below resonance: it's running as if sitting on the table outside the box. This isn't a real problem unless you play action movies at very high volume.
     

Share This Page