QSC's NEW Powerlight 3 Series . . .

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Mon Feb 09, 2015 6:23 pm

  • Hi guys, I'm fairly new to the sound system game, but i have a basic idea of whats what.

    Here i have a couple questions regarding the above mentioned amps with the drivers i plan on using to start my own sound system.

    PL 325 - 8-ohm - 500w // 4-ohm - 850w // 2-ohm - 1250w
    PL 340 - 8-ohm - 800w // 4-ohm - 1250w // 2-ohm - 2000w
    PL 380 - 8-ohm - 1500w // 4-ohm - 2500w // 2-ohm - 40000w

    I'm planning on getting some locally built line array cabinets [built to specs] and the drivers I'm thinking about using for the LF and MF
    are the RCF L10 750YK rated at [350 W AES Power Handling Capacity, 700 W AES Program Power, 70 Hz - 3000 Hz].

    I'm thinking about starting off with four cabinets, so that i can run them two left and two right @ 4 ohms, but my main question is really this :
    If i decide to run them as one stack of four, will the PL340 @ 2 ohms handle them efficiently, seeing that the Power Handling would fall somewhere around 1400 W, 600 W short of the 2000 W 2ohm rated amp supply.

    The same would apply for the Subs, two [2] dual 18's with the PL380 at 2ohms using around 3200W per channel, haven't decided on the drivers as yet though...but it should be around that wattage.

    I'm just trying to get the most out of the amps without creating chaos.......

    Thanks in advance.
    mjlive868@icloud.com
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  • Are the RCF drivers you mentioned 8 ohms (that's as essential as the power rating)?
    Bob Lee
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  • Bob Lee wrote:Are the RCF drivers you mentioned 8 ohms (that's as essential as the power rating)?


    Yes, they are all 8 ohm drivers. There isnt anyone here using those specific amps, so i'm just gathering technical info at the moment
    mjlive868@icloud.com
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  • When I say "here" I meant here in Trinidad & Tobago where I live. There may be some around but I haven't picked up on it. But I know the QSC brand is a well respected one as well, especially the RMX series, I'm just looking for lighter stuff.
    mjlive868@icloud.com
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  • OK, 700 watts program power in an 8-ohm driver comes to about 75 V rms. That suggests the PL340 as the optimum power match.
    Bob Lee
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  • Thanks Bob for your replies.....

    Just a few follow up questions

    1. If I wanted to run four (4) RCF L10 750YK 8ohms drivers rated at 350 AES Power Handling / 700 Program Power,
    at 2 OHMS STEREO , should i go with the PL340 or the PL380 ? (although I know the 2ohm load shouldn't be an option)

    2. How stable is the PL380 at 2.7 OHMS ?
    mjlive868@icloud.com
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  • The PL340 would work. The PL380 would allow some more headroom.

    The PL380 is OK for 2Ω loads, so logically it's even more OK for 2.7Ω loads.
    Bob Lee
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  • Bob Lee wrote:The PL340 would work. The PL380 would allow some more headroom.

    The PL380 is OK for 2Ω loads, so logically it's even more OK for 2.7Ω loads.


    Good looking out Bob, thanks again !!!
    mjlive868@icloud.com
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  • I just got my 1st Pl380 what a beast this thing runs a pair of SRX728 subs without breaking a sweat no need to push it, more than enough power
    topdj
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  • I would highly recommend using the PL380's...I've just aquired 5 PL380's myself to run a bottom rig that consists of 30 single 18 subwoofers.The drivers are rated for 8 ohms...But when I put my meter across them i'm getting a reading of only 6 ohms!Now I have a question for Bob Lee...I'm feeding the PL380's a good source current of 30amps/120V.I'm putting 3 cabinets per channel,so 6 Bins per amp.Calculated out to be 2ohms per channel.From the measured value of 6 ohms.Would the PL380's handle a load lower than 2 ohms?I.E.if I were to add one more sub per channel...which in turn would bring the impedance down to 1.5ohms?Please note that i'm not going by the value stated on the speakers (8 ohm.)...but my own meter measurement(6 ohm)...Also asking before i attempt this hook-up.Your answer would be greatly appreciated...Thanks
    Phil Dubrock
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  • Did you use an actual impedance meter to measure the subs? I would disregard resistance measurements with an ohmmeter; that's not quite the same as impedance. If they're labeled 8Ω, that's probably a reasonable description of their impedance.
    Bob Lee
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