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What are those specs about?

Discussion in 'Amps and Cabs [BG]' started by leomilani, Nov 22, 2002.


  1. hello f3ll4z!
    I'm looking for a new amp/cab, but I have no idea what all those ohms and rms are about, of course, I could just go to some shops and test every amp I see, but thoose salesman are really tricky, so i wish you could give me some tips before I start wasting my parent's money
    :D

    thanks
    danke
    obrigado
    merci
     
  2. noone? :(

    up for me! :rolleyes:
     
  3. Before someone else does it...A few questions need to be answered...
    What kind of style(s) and Music do you play?
    What kind of bass do you play, 4-5-6 String?
    Brands can be picked through your favorite bands and the sound/brand of their bassist....
    How much money are you looking to spend?
    Do you want to practice?Or to play a full production arena show?
    What kind of guitarists' amps would/will you be up against?
     
  4. i play some Nirvana, Foo Fighters, Green Day and Incubus with my band, it is basicaly for that (tough i play some jazz and other stuff at home)
    i have a 5 string bass, and my current amp can't quite take it :(
    i'm looking to do some gigs, but not very big...
    i'll be fighting against a Marshall of about 200w...
    I still don't have a fixed budget, because I can wait for some more cash to fill my pockets till i can buy something decent... but im asking in the case I buy a amp + cab, what should I know before I do that (how to make good combinations and know what those specifications like ohms and rms watts are about)
    thanks!
     
  5. Being a former punker myself, I know Mike Drint uses custom made Mesas with 6x10's(JIC you didn't know...1 cab, 6 10" spks) and 1x18's(1 18" spk)

    Most amp heads are tested for 4 ohm operation(Minimum of 4 ohms) and can handle 1 8 Ohm cab, 2 8 ohm cabs or 1 4 ohm cab....

    Others(peavey Firebass, some tube amps) are rated 2 ohms stable, which would handle 1-4 8Ohm cabs OR 1-2 4ohm cabs...or 1 8 and 1 4Ohm cab...

    If it was me, I'd go bigger than I did...I went with a Hartke 3500, which is plenty enough for most situations, my brother used it for a small outdoor gig with a 4x10 and an 18, fighting with a Marshall 1993 reissue of the 1960s JCM(300 TUBE WATTS) and it held it's own....
    Nevermind that...I'd go with something versatile
    Hartke or Peavey for the budgetly challenged, SWR, Ampeg, or Eden for the richer folks(OK, maybe not rich, but richer than me...)

    For Punk, the usual cab sizes are larger than I'd carry(6x10, 8x10)...But I'd go with a 4x10 if you're planning on playing small-medium sized clubs...with at least 300W @ 8Ohms and if you're planning on playing larger clubs or Outdoor gigs, 4x10 and 1x18(I don't like 15's, they don't give me enough THUMP) with at least, oh, 600W at 4ohms...

    Now that I think about it...a Carvin R600/R1000 ($500-600)with an Avatar 4x10(if you have little money) or a used Eden 4x10($350-$400)

    That's a chunk'a change...But it'd get you something fairly good...

    MY $.02
     
  6. thanks for all that! it'll be really usefull
    but i still don't know what ohms or RMS watts are about
     
  7. FretNoMore

    FretNoMore * Cooking with GAS *

    Jan 25, 2002
    The frozen north
    To simplify:
    - ohms denotes the resistance (impedance to use the correct term) to the current you feed the cabinet
    - RMS watts is the maximum average power a cabinet can handle, which says something about how loud it can get

    The ohm value is important as you need to make sure you don't use a speaker with a lower value than the amp is designed for. When you use more than one speaker you also need to calculate the resulting ohm value. You often see different power values for the same amp at different speaker impedances, for instance 400W at 4 ohms, and perhaps 250W at 8 ohms. What this means is you get almost twice the power with the same amp if you use a 4 ohm speaker (or two 8 ohm speakers which combines to 4 ohms).

    Hope that helps.
     
  8. thanks!
    but if is that so, what is the advantage of having a 8 ohm amp if I can have a 4 ohm that will make me much louder?? is there a huge diference in the sound?
     
  9. FretNoMore

    FretNoMore * Cooking with GAS *

    Jan 25, 2002
    The frozen north
    No difference in sound really, the main idea is to match the impedance of the speakers with the amp. Lower ohm value means the speaker draws more current from the amp, and there's only that much the amp can deliver before breaking. If the amp can only go down to 4 ohms and you want to use two cabinets (for instance a 4x10 + a 1x15) you need to get 8 ohm cabs as the resulting impedance is 4 ohms. But if you know you'll only use one cab you will get more volume by using a 4 ohm speaker. Some manufacturers can deliver their speaker cabinets in 2, 4, 8 or 16 ohms so you can mix and match to the correct value. 4 and 8 are the most common ones though.