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Pre-Amp with Amp vs Full Bass Amp????

Discussion in 'Amps and Cabs [BG]' started by martybernal, Jun 29, 2007.

  1. I heard something today that I'd never heard before. My QSC PLX 1804 is currently having a rattle problem fixed. The tech told me that I should be aware that placing my QSC amp on top of my 2 X 12 cabinet is not a good idea. The tech said due to the vibration and thumping bass frequencys that the components internal to the amp would not withstand it for long. And overall performance could be compromised and future failures may occur. The suggestion was made to me to move the rack my QSC is in from the top of the speaker cabinet to the floor. As many of you know, stage size and space will not always accomodate additional space to move components to the floor. Much less I like my components up to a level that I can review and adjust them as neccessary. So my question is has anyone had any issues over the years with components sitting on top of the speaker cabinet? Should I be looking to buy a full traditional bass amp? I really like the sound of my Epifani Quest Pre-amp with the QSC 1804. Thank you for reading. Marty
  2. Crabby


    Dec 22, 2004
    Just get a pice of rubber matting material and cut it to fit the top of your cab. This placed between your cab and your rack will pretty much take care of any vibration issues
  3. Hey pal, I eventually did move all my goodies to a rack that sits on wheels next to my cab, I personally love that setup since there's a good bit there and it's a B$^%@ to move. But while I still had everything ontop of my cab I had good luck using an auralex Gramma to decouple the amp from the cab.


    I never experienced the type of damage to my amp that you did, but I did notice that something inside my amp was rattling a bit with from the cab and that was a traditional bass head.. so I tried the gramma and the rattling stopped had that in use for like 2 years no prob and my amp's perfectly fine

    the pad's intended to decouple your cab from any structure. With certain stages it'd help to bump up your volume to hearable levels without all the low frequency sound energy being trasfered through the stage.

    I use it at home and I can turn up a lot louder when I have one under my cabinet than when I don't. it's absolutely noticeable IMO.

    Yeah but in your case of decoupling cab from amp it may be worth a shot, plus you don't have to rig anything it's all set right there out the box

    IMO I don't see this being a pre and poweramp vs traditional bass head issue I see it as physics. If you like your setup.. keep it!! give these suggestions a shot there's little to loose ya know.
  4. Hey man on a side note how you like your QSC 1804? I was thinkin bout one of those.
  5. Nagan60


    Jan 15, 2005
    Roanoke, VA
    Very interesting post.....I could see how a poweramp, or any amp for that matter sitting on top of a bass cabinet could rattle a loose the inside of an amp. It would seem to me that it wouldn't matter if it were a power amp, or a traditional amp. Putting some type of rubber under the power/traditional amp seems like it would work. The auralex also seems like a great idea.....I was thinking of getting one, now I might have to get two of them.

    On another note, the QSC 1604 is a great power amp so the 1804 should be equally as good. I am interested in the PLX2 power amps........they are lighter than the original PLX's but I'm unsure of the quality.
  6. I place my rack on one of those amp stands that allows the amp to lean back a bit.. but I did shorten the two upright bars to allow for the banana plugs and the power cord to the Crown amp. It is nice.. with the rack facing up just a bit, it is easy to see the racked gear.

  7. bassman10096

    bassman10096 Supporting Member

    Jul 30, 2004
    Only the 1104s and 1804s appear to be lighter than the original PLX series. Up from there, both the PLX and PLX2s weigh 21 lbs. I have a PLX 2402 that's been the best. It's lighter than most PA amps at 21 lbs so my rack is not a boat anchor; it performs beatifully and has never overheated or shut down; I absolutely can't complain. I'm interested in the PLX2s as well. I would risk to say that every QSC product I've used has been top flight, so I'd expect no quality problems from the PLX2s.
  8. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

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