power amp question

Discussion in 'Amps and Cabs [BG]' started by harryhood, Jun 27, 2004.

  1. harryhood


    Jun 25, 2004
    right now i have an ADA Mb1 preamp and am looking to get an SWR goliath 4x10. Im looking for any suggestions as to what kind of power amp i should get to fill in the blank. Also would a 4 or 8 ohm cabinet be better??
  2. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    There are a lot of good power amps out there. I have a QSC PLX2402 and I've been very happy with it. It takes up two rack spaces, puts out up to 2400 watts bridged into 4 ohms yet weighs just 21 lbs. Many other TalkBass members use them too..and Bob Lee (QSC) is an active member.

    As for cabinet impedance, it depends on what you ultimately want to do. Amps generally don't double their output power when the impedance is halved so going with a 4 ohm Goliath won't really be any louder with the same amp as an 8 ohm cabinet. And if it was, it wouldn't be by much.

    Having written that, I'd recommend going with an 8 ohm Goliath, any pro quality power amp will bridge into 8 ohms, not all into 4 so you'll be able to get maximum power into the cabinet.

    If you'll add another Goliath, a SOB or even a Big Ben later, having a two channel amp that has enough power output at 8 ohms is important.

    I may draw some fire, but I'd look for a power amp that has 1.5 to 2 times the Goliath's power rating into 8 ohms per channel.

    Have fun!!!
  3. Chapbass


    Dec 11, 2003
    Chicago, IL
    There is a whole ton of Power amp manufacturers that can suit your needs.

    Immediately (im gonna have to look that word up sometime...did i spell it right?) coming to mind is:

    Peavey (yeah yeah, i know, but they do have a 1000 watt power amp in 1 rack space...thats pretty cool stuff if your low on space...)
    I think SWR has a power amp too...

    Anyway i know theres more. Id say my personal favorites are QSC (because of the weight) and Carvin (because of the price/performance).

    As far as ohms...It depends on what your going to do. 8ohm cabinets are a LITTLE quieter than 4 ohm, but not much. I believe its stated that double the watts = 3 more DB, which i suppose would be noticible, but nothing thatll make you go wow...

    8ohm cabs are a better bet if your looking for expandability. If in the future you need to run a second 8 ohm cab in parallel, youll find that a lot more amps can run 4 ohms than 2 ohms (some can, just not as many). Or perhaps you might never run em in parallel, but someone else might. Good for resale value...
  4. Chapbass


    Dec 11, 2003
    Chicago, IL
    Yeah billy, id say that 1.5-2x wattage rating is a pretty good guess.

    I would lean more towards the 1.5x wattage if your trying to decide between two amps, especially if the one with 2x is a bit more...

    However, like i said in my above post, if your planning on expanding, that extra power might be good for the second cab, especially if your using bigger (15, 18, 21) inch speakers...
  5. harryhood


    Jun 25, 2004
    ok the goliath 8 ohm has a 750 watt RMS power rating. So when you say it should be 2x per channel does that mean i should look for a power amp with 1500 watts at 8ohms bridged? that would mean id only be getting 425 watts at 8 ohms per channel if i were to run 2 cabinets at 8 ohms in parallel. Or would both cabinets with 8ohms running in parallel cause the impendence to drop to 4 ohms per channel? im still a little confused about the power requirements needed for something bridged and somethings running parallel through the amp. ALso while im at it it looks like carvin amps have the most bang for the buck. Are they quality products or does it seem to good to be true??
  6. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    How about a nice Stewart 2.1? 2100 watts bridged into 4 ohms, around 1500 into 8. Weighs all of 17 pounds. I use these to drive the subs for outdoor gigs. Great little amps.
  7. Chapbass


    Dec 11, 2003
    Chicago, IL
    Though there might be some that disagree with me, carvin amps are definitely quality products. Arguably the best thing they make (And i know someone is going to bash me/carvin about that comment too, but whatever, everyones enabled to their opinion.)

    I'll see if i can post stuff about the rest of your questions tomorrow when im not so tired.