Amplifier gain control, etc., questions ->>

Discussion in 'Archived Threads 2001-2004' started by Zach M, Feb 28, 2001.

  1. Zach M

    Zach M Auditioning

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    I finally got my amplifier and hooked it up, but it is really quiet! [​IMG] I have to turn the gain controls all of the way up and turn the sub level to +10 on my receiver just to get a moderate volume. What is going on? [​IMG] I split the receiver's sub output, used RCA -> 1/4" unbalanced connectors. The speaker cables are hooked up with bananas (Not a very 'tight' fit[?]) They play but just not loud at all. I turned off all of the hz filters on the amp, set the clip control to 'on'. What am I missing? Please help I want my bass!
    Thanks
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  2. Patrick Sun

    Patrick Sun Moderator
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    More details, please. Like, what's kind of make/model of amp are you using? Is it a pro-gear amp which may require a "hotter" input level than a home-gear amp?
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    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  3. Zach M

    Zach M Auditioning

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    Thanks for replying Patrick. It is a QSC RMX 1450 amp (pro style, 450 watts per channel 4 ohm). What do you mean by hotter input level? How would I acheive that? It is powering my dual Tempests and gets its signal from my Kenwood receiver. Any other ideas?
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  4. Patrick Sun

    Patrick Sun Moderator
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    Well, you've got a pro amp, and it expects to see a certain input level (sometimes you can get away with it) like +4dbu for pro gear, but the home gear puts out -10dbv and there's a level mismatch. I think the home gear is lower in output, so it would sound lower in volume. But it could be your Kenwood might not be putting out enough voltage to drive your amp's input. Do you have access to another receiver?
    Here's the only thread I could find that talks about this input voltage level "gap" by mixing pro and home gear. I've read others, but they must have fallen off the server by now. Vince Maskeeper knows about this stuff, so perhaps you could message/email him for more ideas.
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  5. Zach M

    Zach M Auditioning

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    Thanks again P@. Do you think it would be alright to run the amp at 85% full gain and my receiver's sub level at +5 all the time? Also, when I turn it up really loud, the amp's red 'clip' lights flash. I don't want this right???? Have I depleted the amp's 450 watt headroom? When I saw those lights, I turned it down immediatley, which is what I should have done, right (or is is ok to have them flash a little with clip protection on?)?
    Thanks
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    My Home Theater
     
  6. Patrick Sun

    Patrick Sun Moderator
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    Do you have a SPL meter? You need to record the SPLs when the amp's red lights are flashing.
    Normally, you should turn up the amp 100%, and then then the receiver's LFE/sub adjustment (pad) to control how much juice it sent to the sub.
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  7. Vince Maskeeper

    Vince Maskeeper Producer

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  8. Zach M

    Zach M Auditioning

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    Vince,
    Thanks to your help I have gotten the subs in perfect working condition! I had trouble finding the time to write this because I've been listening to the subs with a silly grin on my face, replaying most DVDs for the "first time." Anyway, I turned the gains all of the way up and I think that made a huge difference. With Avia, the sub registered at 75 on the dot at -10 on the Kenwood. So its working! The clip light never came on except when I watched that scene from The Haunting really loud. My hair was trying to jump off of my head! I am completely satisfied.
    Thanks for all of your help and going above and beyond for a fellow enthusiast. You too, Patrick. There is no way I could have done any of this without your webpages and personal help. I think I speak for all HTF members when I say you guys are some of the most valuable assets to the forum.
    One more question: I should have the clip limiter off all of the time?
    -Zach
    P.S. pics up soon!
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  9. Vince Maskeeper

    Vince Maskeeper Producer

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  10. Patrick Sun

    Patrick Sun Moderator
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