1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Crest CA4 vs. QSC PLX1202

Discussion in 'Amps and Cabs [BG]' started by pnutz, Aug 6, 2012.

  1. pnutz

    pnutz Supporting Member

    just picked up a swr megoliath (1200w bridged at 4 ohms). now i need a power amp to match. been checking out the threads here and the crest amp and qsc amp have been smiled upon greatly.

    don't think i can go wrong with either amp. so was wondering if anyone here a/b'd these particular amps and heard any difference. does one sound more 'musical' than the other? does one 'color' the sound more than the other or are they basically both flat?

    or if you have run into (or own) a particular power amp in the 1200w range that rises above these two contenders, i'd be interested in your feedback.

  2. johnpbass


    Feb 18, 2008
    Glen Mills, PA
    I've used a Crest CA4 - ran it with both a Demeter VTBP 201 preamp and Sansamp RBI. The Crest was super clean, no added color that I could hear, very fast response.

    I've heard similarly great things about the QSC's so, IMO, you can't go wrong with either.
  3. wcriley


    Apr 5, 2010
    Western PA
    No well designed power amp should "color the sound" or be more "musical" than another. A power amp should be very "sterile" and reproduce exactly what it's fed.

    Curious as to why feel the need for "a power amp to match".
  4. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA
    They sound exactly the same as long as you don't drive them into clipping.

    I'd strongly recommend getting one of the many great high power micro heads you can get now instead. They make pre/power setups totally irrelevant IMHO.

    Shuttlemax 9.2 for example.
  5. Session1969


    Dec 2, 2010
    I've used a CA-6 AND A CA-9 at times. Best yet for me, but I got tired of lugging it for the gigs I do now. I play small places.
  6. pnutz

    pnutz Supporting Member

    started the thread to make sure that the amps in question do not introduce anything to the sound. want to make sure that the tone from the preamp of choice is the only thing present.

    i need a power amp to match the 1200w that the cab can take. the megoliath is rated at 1200w rms so would like the power amp to match that rating. the ca4 puts out 1100w and the qsc puts out 1200w.
  7. I'm using a crown XTI 2000 poweramp for 3 years now with an Avalon U5 as a pre. It gives a VERY clean sound with rich detail of the basses I play. It may not be the choice of a player who likes some warm coloration or tube grit but that is mainly choice of preamp.

    Although my XTI puts out 2x 800 watts at 4 ohms, I really never turn up past 11 o clock playing one 2x15 cabinet rated 1000 watts (homemade, Eminence drivers) and 2 aggie db112's (rated 600 watts).
    My personal experience is that you would never need all that power and I still think that when a dedicated power amp puts out, say 500 watts, it is more you will ever need and more than most lightweight bass amps put out using "smart" techniques which boost the perceived loudness of a amp, but I may be wrong!

    Both the Crest and QSC won't let you down, only your back!

  8. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    Just keep in mind that the cab more than likely can't take that amount of power.

    I've got a CA4 that is a great amp, but I don't gig with it. It's huge and heavy. If you wanted to rack it you'd need a full depth rack.
  9. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    The PLX would be decently light, and it has little switches on the back you can set for low-end filtering (very important) and clip limiting.
  10. Bassist30

    Bassist30 Supporting Member

    Mar 19, 2004
    Years ago I wanted a power amp. I wanted something lite. At the store - I wont name - had and a/b me a 1602 and a crest CA6. I took the crest. I don't believe all power amps are the same. Crest CA series is a great power amp. Needless to say it wasnt light but it sounded so good.
  11. Jeffrey Wash

    Jeffrey Wash Supporting Member

    Jan 2, 2011
    Santa Cruz
    Just last year I A/B'd Crest CA9 with Crown XLS 1500, QSC GX7, QSC 1220, 1450 and 1650, Fender MB-1200 and several others I can't remember at the moment. Also used several different preamps to see how much of a difference that made within the range of amps I had to choose from. I regret to report that the Crest sounded better (I say regret because it's so dang heavy). Especially noticeable when playing fast and low - a song like Teen Town, for instance, with those staccato notes in first position. The lightweight Crown's and QSC's didn't have the punch. Even at it's lowest setting - with the volume at first click so that the fan noise (which is pretty minimal) was louder than the actual instrument level, the Crest had noticeably more punch and fundamental content than the SMPS amps did at any volume.

    I firmly believe that someday soon there will come a lighter weight alternative and I'm really looking forward to that day. But for now, IME & IMHO, the engineering simply hasn't caught up with the marketing and the hype.

    I encourage anyone who's truly curious to A/B these amps for themselves. It's really not that hard, if you know a soundman or two who'll loan a couple of amps, maybe another bass player, owner's of local studios, etc. Lots of used amps out there to borrow if you're a trustworthy person. Most of the big music stores have generous return policies and in my experience if you're up front with a salesperson, let em know that you want to buy an amp, try it and compare, then bring it back and try something else, well I've had nothing but cooperation in that regard. It helps if you are a fastidious person (like me), return things in mint condition and keep everything above board.

    These TB threads are helpful to a point - lots of opinions and attitudes on both sides of every issue - but IMHO there's nothing better than using one's own ears to judge.
  12. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA
    If you A/B power amps you need to match the gains (not the attenuators positions). If you do and you test blind all the differences will disappear. Until I did that all of my ABs has results where one sounded better than another. After, no difference at all.

    It was sure more fun the other way though. Makes you feel like you've got an amazing amp instead of the boring old truth that all the good ones sound the same.
  13. Jeffrey Wash

    Jeffrey Wash Supporting Member

    Jan 2, 2011
    Santa Cruz
    Pickles, I have read that many times before. In my admittedly unscientific test, I thought i was allowing for the gain matching factor by having tried at least a half dozen different preamps with each power amp, all of which sounded about the same in the lighter weight Crown's and QSC's and all of which sounded significantly better through the Crest.

    Can I infer from your post that you have in fact played bass through the Crest and other amps in side by side comparison? If so, I'd like to know the methodology you used for gain matching. I'm not going to undertake a huge experiment like I did last year again - lotta work and time and some $$ too - but it'd be easy enough for me to borrow another Crown or QSC and test the 2 amps. Is there some sort of adjustable converter one would put between the pre and power amps in order to match gains precisely?

    An inquiring mind wants to know: what's the trick?
  14. Bassist30

    Bassist30 Supporting Member

    Mar 19, 2004
    No trick. Its all in the ears. The Crest is a great power amp.
  15. wcriley


    Apr 5, 2010
    Western PA
    The most precise way of "gain matching" two pre/power setups would probably be to measure the voltage going to the speaker cab.
  16. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    I've owned both a CA and PLX...still have the CA-6. You won't be disappointed in either. The PLX offers more in terms of features like user-friendly high pass filters. My older CA-6 is a workhorse but heavy and deeper front-to-back to the point I had to purchase an oversized SKB case to fit. It also only has binding posts so I have to keep a dedicated speaker cable in my gig box.

  17. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA
    Yeah, you need a dummy load. You wire up the amp to the dummy load then measure the voltage across the load as you play. Now, I didn't even get close to perfect because I was using a bass played at a "consistent" level to gain match, a tone generator would be better, but even still the attenuator positions were wildly different to hit the same gain, and one of the amps could not be on a "click" on the control to get matched.

    Then I played a CA6 and PLX2402 through Aguilar 1x12s and found that my two identical cabinets sounded WAY more different from each other than the two amps sounded different (I compared all 4 combos).

    Blew my mind, it was kinda depressing.
  18. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Unless you're doing a tube amp you really don't need a dummy load for matching gain. The difference in voltage between loaded and open-load is negligible.

    You need just an audio signal generator that can put out a continuous tone, and an AC voltmeter that covers audio frequencies well.
  19. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA
    I honestly don't think you even need the tone generator, the gain difference between these amps is huge, if you even get close it'll change your mind on there being a difference in tone.
  20. Jeffrey Wash

    Jeffrey Wash Supporting Member

    Jan 2, 2011
    Santa Cruz
    I was under the impression that the 'gain matching' component of comparative listening tests had to do with matching the signals going into the power amps from the preamp. I thought it had something to do with impedance and the input sensitivities of the amps. Am I completely wrong about that?

Share This Page