Need some help with crossover points please

Discussion in 'Room Acoustics, System Layout & Setup' started by pjoseph, Feb 11, 2013.

  1. pjoseph Full Audioholic

    pjoseph
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    <o:p> </o:p>
    My setup: Onkyo 709 as my main receiver which powers my center channel, & mids/highs of my polk RTI 12’s. Pre outs of the receiver go to a DCX2496, two of the DCX outputs go to a Marantz SR4001 & another going to behringer ep2500.
    I wired the qty (3) 7” drivers in the RTI 12’s in series which gives me close to 8 ohms total, these are connected to my Marantz SR 4001
    polk audio lists the following for crossover freq:
    Woofer/mid 120Hz, mid/tweeter 1.8kHz
    My sub is a JL Audio 13.5 W1 in a ported enclosure which is powered using the ep2500.
    I am looking for some input on what I should set the crossover points at for the 7” woofer/mid of the RTI 12’s as well as for the JL Audio 13.5

    Thanks
    Last edited by a moderator: Oct 19, 2014
  2. pjoseph Full Audioholic

    pjoseph
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    Anyone have any input?
  3. hyghwayman Audioholic

    hyghwayman
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    Some members may not be able to read the OP, try increasing the FONT SIZE.
    • Like Like x 1
  4. pjoseph Full Audioholic

    pjoseph
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    hmmm font it looks like its same size as your reply at least on my computer....this is font 3 now
    My setup: Onkyo 709 as my main receiver which powers my center channel, & mids/highs of my polk RTI 12’s. Pre outs of the receiver go to a DCX2496, two of the DCX outputs go to a Marantz SR4001 & another going to behringer ep2500.
    I wired the qty (3) 7” drivers in the RTI 12’s in series which gives me close to 8 ohms total, these are connected to my Marantz SR 4001
    polk audio lists the following for crossover freq:
    Woofer/mid 120Hz, mid/tweeter 1.8kHz
    My sub is a JL Audio 13.5 W1 in a ported enclosure which is powered using the ep2500.
    I am looking for some input on what I should set the crossover points at for the 7” woofer/mid of the RTI 12’s as well as for the JL Audio 13.5

    Thanks
    Last edited by a moderator: Oct 19, 2014
  5. pjoseph Full Audioholic

    pjoseph
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    Does the font look bigger on my repost?

    Just an update I ran Audyssey last night and it set the my fronts to 150hz (mid & tweeter of RTI12's Only)

    I am guessing I would set the 7" dirvers a little higher so there is some overlap maybe 200hz?

    and for the JL i was thinking around 80 or 100hz and below

    So the range for the 7" dirvers 60 or 80hz to 200hz?


    just looking for a starting point here any input would be appreciated!

  6. avengineer Banned

    avengineer
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    I suggest running Audyssey and taking the crossover point it picks for you.
    Last edited by a moderator: Oct 19, 2014
  7. Grador Audioholic Field Marshall

    Grador
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    Wait, what are you trying to accomplish here? It almost sounds like you're trying to use the receivers bass management to active biamp your speakers, which will not work.
  8. fuzz092888 Audioholic Warlord

    fuzz092888
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    First of all you're trying to basically turn a passive crossover into an active one. Second of all you're doing it wrong. Third, it's been discussed before, but using a receiver as an amp isn't advisable for quite a few reasons.

    Most importantly, as Grador said, what you're trying to do is impossible. Get rid of the SR4001 from the audio chain and either use the Behringer for sub EQ (although I guess you could bypass audyssey and use it to EQ your mains) or get rid of it altogether and just use Audyssey.

    If you really want to actively cross the towers you have you'll have to open them up, take out the passive crossover, add a third set of binding posts, rewire everything, measure each driver to figure out what the optimal crossover point would be, model everything, factor in the cabinet to your modeling, buy an active crossover (miniDSP, behringer, etc) and then invest in some external amplifiers. Unless you plan on doing all of this, stop what you're doing and just enjoy the towers and 709 and focus on bass management with the 2496.
  9. pjoseph Full Audioholic

    pjoseph
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    Nothing has changed since my previous posts, but to clarify I did open up the speakers and I removed the crossover for the 7" woofers I did not touch the crossover for mids/tweeter. I also disconnected the wires connected to the woofers only, I next cut some speaker wire, added the appropriote connector and wired the qty (3) 7" woofers in series giving me close to an 8 ohm load. I did not add any additional terminals I just ran the wire out of the rear port directly to the amp.. I will eventually add another amp which will replace the marantz but until then this is what I have to work with. I decided on the idea because I wanted to mess around with the dcx2496 since it is new to me. I guess i will eventually put it back
  10. TLS Guy Audioholic Overlord

    TLS Guy
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    You have a mess on your hands.

    First off what makes you think those three 7" drivers in series are close to 8 ohm? The impedance is not the DC resistance. I suspect your actual impedance is somewhere between 16 and 24 ohms, most likely nearer 24 ohms.

    Next the Polks are a lousy design, especially for HT with sub, as which ever way you slice it you will have two crossovers far too close together.

    I suspect this system will sound best without the 7'' woofers. The 150 Hz crossover sounds right. I would put your sub in front, and just use the mid and tweeter, and run your sub to 150 Hz.
  11. pjoseph Full Audioholic

    pjoseph
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    Yes, my mistake the DC resistance is close to 8 ohms, I guess I will just throw the 7" drivers in the trash and use the empty portion of the enclosure as storage space.

    Thanks

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