Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

QSC power amps: RMX vs. PLX

Discussion in 'Amps and Cabs [BG]' started by toddtodd, Oct 18, 2005.


  1. RMX vs. PLX

    the PLX are more money per watt.
    what does this get you?

    thanks!
     
  2. Dan1099

    Dan1099 Dumbing My Process Down

    Aug 7, 2004
    Michigan
    A lot less weight.
     
  3. Templar

    Templar Supporting Member

    And a quieter fan.
     
  4. There are no sonic benifits to the PLX over the RMX. If half the weight is worth twice the money then the PLX is for you.
     
  5. Metal Mitch

    Metal Mitch

    Jul 14, 2003
    NJ
    One of the things that kept me away from the PLX is the amperage draw. I've played a lot of places where it would be a "Really Bad Idea(tm)" for me to be drawing 8-12 amps while 2 big guitar amps and a PA are trying to suck down juice from the same 15 amp line!

    Very very few small bars/clubs have adequate, properly grounded electrical wiring. If you're playing on medium/large rock club stages, chances are much better they will have adequate power supplied to the stage.
     
  6. bigtexashonk

    bigtexashonk Supporting Member

    Less weight and better quality in my opinion. The RMX is a lot of power for the $, but I have heard they can thermally cycle easier than the PLX. Aren't the RMX's assembled in China?
     
  7. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    That's a bit of an overreaction. My PLX3002 only draws between 2 and 3 amps when driven loudly, according the the ammeter on my rack, and that's WITH my preamp, rack tuner, and pedalboard.

    Only if you max out the power amp and max out the imput voltage would you ever get anywhere near the rated amp draw, and I guarantee you that ANY speaker would blow way before that happened.
     
  8. I've had both, and the PLX is just great.

    Doesn't weigh a ton, and has lots of power.
     
  9. brooklynbassguy

    brooklynbassguy Supporting Member

    Feb 8, 2004
    maplewood, nj, usa
    Isn't the PLX made in the USA, and RMX made in China?
     
  10. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    That is correct.

    The PLX is a little cleaner in terms of audio performance--noise and THD--but the differences are quite small to begin with. The PLX has a quieter fan, is easier to bridge, and weighs less.
     
  11. Unchain

    Unchain I've seen footage.

    Jun 20, 2005
    Tucson, AZ
    I think I'm just going to settle for the RMX, I'm a strong young man. ;)
     
  12. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    I can tell you this: at one time I settled on a Carvin DCM2000, three rack spaces and HEAVY, but cheap. Performed very well, but after awhile the added weight became a pain in the #$%^. Especially after a gig when your tired, been drinking a little, and a bit tight and sore the next day when you empty your vehicle in the garage. It gets old.

    I dumped the Carvin and got a used PLX 3002, save one rack space so I could use a 6 space rack instead of an 8, and saved TONS of weight on the amp itself. My rack is no longer the piece of gear I dread lugging to and from my van.

    If you can handle the little extra price, I really think you will thank yourself later if you spend the extra change and get the PLX. QSC's are also built very well, and their service is impeccable in my experience, so you might want to consider buying used. I'm certain you can get a gently used PLX for the same price as a new RMX, if not even cheaper.
     
  13. brooklynbassguy

    brooklynbassguy Supporting Member

    Feb 8, 2004
    maplewood, nj, usa
    PLXs can be found at very reasonable prices these days, and they are bullet-proof. The weightier amps do wear on one after so many load outs...
     
  14. millard

    millard

    Jul 27, 2004
    SoCal
    I had an RMX in my rack box for a while, but it was just too heavy for the number of times it had to be moved each week and the number of stairs and doorways that had to be negotiated with it.

    I put a comparable PLX in (bought used, here I think) and I couldn't be happier. I'm neither old, nor weak and I'm still thankful for the lighter box. The RMX is now in the wheeled PA cart.

    Hit your local music store, do the 12-month same as cash financing thing and buy a new PLX. Last time I looked, QSC was still doing a 6-year warranty to the original owner.

    Millard
     
  15. Metal Mitch

    Metal Mitch

    Jul 14, 2003
    NJ
    Nope and nope.

    I don't have an ampmeter but I can tell you in medium/large rehearsal studios and live gigs I'm always running at max power before clipping. The speakers don't blow because I match up the power ratings and don't let it clip.

    Granted, max power on one side of the amp should only draw half the maximum rated amps. I got tired of running 2 4 ohm cabs on one side, so on our last show I tried a single 8 ohm high power 410 in mono mode. Still had to go max power and still wasn't loud enough. That time, I let it clip. So I'm sure it's drawing quite a bit.

    And you didn't mention/consider the situation I described in your typical dive bar where everything is running off a single 15 amp line.
     
  16. Templar

    Templar Supporting Member

    My (former) RMX 1850 was made in China. That thing could run all day and never even get warm, honestly.

    To save weight, I now have a PLX 2402 in the rack instead. I can't hear any sonic difference, except the PLX fan is noticably quieter.
     
  17. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    I understand what you're saying, but just because you run the amp with its gain knobs "full up" does NOT mean you are running the amp at full power. To really run at full power, you have to have the amp's gain at full AND have the input signal at its rated voltage, which is pretty high. I really doubt you are feeding it that strong of a signal if you have the amp up full and haven't destroyed something . . .

    As for putting a full band on one 15 amp outlet, yeah, that's a problem no matter how you look at it. Its normally best to spead the band's gear around to a few different circuits.
     
  18. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    No, you can hit full power with the gain controls turned down and a correspondingly hotter input signal going in.
     
  19. Ryan L.

    Ryan L. Moderator Staff Member Supporting Member

    Aug 7, 2000
    West Fargo, ND
    We use PLX's in our PA amp rack. We are running 2 3402's to power our JBL subs, and (I believe) 2 3002's to run our tops. FWIW, we have (4) 2x18 SRX subs, and (4) 2x15+horn SRX tops. The amps are super reliable, have all the power we need to do any gig, and with all of them in one rack, come in a package that doesn't break backs.

    Deals on the PLX's pop up on ebay all the time. We got a couple of ours NIB with full warranty for much less than we could have gotten them through a store.
     
  20. Metal Mitch

    Metal Mitch

    Jul 14, 2003
    NJ
    Ok, first off they are not "gain knobs". Gain is on your preamp. These are attenuators. Meaning they cut down the input gain from your preamp going into the power amp. They don't boost anything.

    The maximum rated power is before clipping. A power amp will exceed it's maximum rated power while clipping. I've never run it with the attenuators full up because it clips. Usually I set it in the range of 12:00 to 2:00. If I'm reading the RMX 1850HD specs correctly, the amp requires 1.16v to drive it to full rated power. The SVP-PRO puts out up to 2.0v. Believe me, with this pre it's VERY easy to drive the amp to full power. :D With a strong enough input signal it can and will clip with the attenuators on low settings.

    I DO in fact enjoy destroying things, but my speakers aren't one of those things. I hope you understand it's ok to run at full rated power without clipping, speakers are rated in RMS and the peak power they can handle is normally double the RMS rating. So no worries about blown speakers unless you're clipping.

    Absolutely. But in the real world sh*t happens. I used to have a regular gig at a club where the entire band (including PA) was plugged into the same 15 amp line and we had to share it with a beer cooler. Care to guess how many amps one of those draws?