Help needed with sub pre out

Discussion in 'Archived Threads 2001-2004' started by Joenco, Jan 3, 2003.

  1. Joenco

    Joenco Auditioning

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    Hello all,

    It looks like I have no luck in the receiver department so I try it here.

    I have just bougth a very cheap kenwood home theater

    receiver.
    It's a krf-v5060d.
    It has a pre out for hooking up an active subwoofer.
    The specs for this output are.
    output level 1.5 V
    impedantie 2.2 kOhm

    I do not have an active subwoofer but I do have very powerfull speakers
    (8ohm nominal input) and a hifi amplifier with input for tuner, tape, aux
    and phono.

    What can I do to fabricate a subwoofer with the amplifier and the speaker?
    Which input should I use? Do I need something else?
    Is it possible to amplify the sub pre out with a normal hifi amplifier?

    Thank you
     
  2. John Spicer

    John Spicer Agent

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    I dont know what you mean by powerful speakers since speakers consume power not produce it [​IMG] I would assume
    that you could just interconnect the sub out of the reciever with one of the inputs on the hi fi and use your "powerful" speakers as the sub. The reciever should do the crossover for you. Ill say however that it could really sound good or bad depending on what the speakers are that you are using. I would suggest that if it doesnt have at least an 8" woofer in it the effort would be wasted. More information would be nice.
    -- John
     
  3. Joenco

    Joenco Auditioning

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    Hey,

    I have a reply.
    Thank you,
    The speakers I'm talking about are RCF monitor 8 300W.
    I also have some turbosound subwoofers but those are a bit to big for my living room. You see I'm newbie to home cinema but I'm a professional musician.

    What was my question
    If I connect the pre out off my kenwood reciever to the Phone input of my hifi amplifier the signal is too hot so I have to put volume of my amp almost to zero. If I use aux, tape or tuner as input I get almost no signal. What kind of input should I use? The spec of my subwoofer pre out on the kenwood is 1.5V and 2.2Kohms imp.

    Thenk you,
     
  4. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    Joenco,

    I'm not sure which of 2 situations your in. Are you using the RCF as your mains, or are there other mains and you want to use the RCF only as a sub. The answer is different depending. If the RCF monitor 8 300W are your main speakers, then you want to ignore the sub out jack and find the setup directive on the kenwood receiver to tell it there is no subwoofer in the system. The receiver will then direct all the deep bas signal and route it to the mains.

    If on the other hand you want to use the RCF only as your sub, this can be done with your stuff. DO NOT USE THE PHONO INPUT ON THE STEREO RECEIVER. This is an ultra sensitive input intended for the very feeble signal output of a phono cartridge. Aux, tuner or tape will all work. You found a weak signal doing this, so some trouble shooting is needed. Make sure the Kenwood setup is told that a sub is present. Bring up the sub trim on the setup. Test the system with a DVD with strong LFE, not a stereo CD. Start with just one, and turn the stereo receiver's balance all the way over. That should get you going.
     
  5. Joenco

    Joenco Auditioning

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    Brian and others,

    Here is the complete situation.

    I use the kenwood receiver in its 6 channel mode.
    So i have.

    Front main L and R (RCF monitor 8 300 W)
    Center (Monitor 5 175 W)
    Surround L and R (Monitor 5 175 W)

    After testing a bit with a film I'm missing the deep rumble
    bas effects so I tried to hook up a (RCF monitor 8 300 W) as
    dedicated subwoofer. I have no test CD but there is a test signal in the receiver with I think some white noise.

    If I test the sub pre out on the dedicated pioneer Hifi Amp
    I found out that I can only uise the Phono input to create the effect I'm looking for. I know the phono input is very sensitive but I tried it because I get almost no signal on the other inputs. ( tuner, aux and tape).

    Should I use an pre-amp to pump up the signal?
    Is this normal?
    The specs for this output are.
    output level 1.5 V
    impedantie 2.2 kOhm

    Thank you,
     
  6. Guy Usher

    Guy Usher Supporting Actor

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    An output level of 1.5 volts should drive any comercial home amp to its full potential, do you have the input specs on the amp? Is the pioneer HiFi amp a home amp or a pro type amp? Could be a big difference in input sensitivity.
    If you continue to use the Phono input you will overload it and you will destroy it.
    Configure it the "normal" way then it the sound is not load enough we need to determine if inpit sensitivity of the amp is suitable for your 2.2K 1.5v signal. There are EQs etc that have gain where you can boost this output.
    See if you can find the amps specs? Have you used this amp for music? Also check to see if all your speakers are set to "small" on your KW. . .
    The RCF-M8 I am thinking of is a Sound reinforcement speaker w/8" woofer rated down to 50hz but the truth is it is already down 3db @ 70hz so it is not practicle to use it for a sub. With good 10inch powered subs available now under $100 you may be better served with one of those, by the time you are done buying necessary equipment to do what you want you may be over that 1buck mark anyway. If everything you are using is home audio gear I am suspect of your KWs sub output. . . .
     
  7. Joenco

    Joenco Auditioning

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    Thanks for your help

    I will try another amp instead of the old pioneer.
    I have no input specs.

    Thank you again
     

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