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building a bass rig - for dumbies ?

Discussion in 'Amps and Cabs [BG]' started by Matthew Bryson, Mar 13, 2003.

  1. Matthew Bryson

    Matthew Bryson Guest

    Jul 30, 2001
    Can anybody point me to a thread, article or web site that will explain the basics of putting together a rig? I have recently decided that my little combo isn’t going to meet my needs much longer so I’ve begun trying to educate myself about amplification. I don't know anything about this stuff. The first thing that I have learned is that it will be expensive so, being poor white trash, I’d better get to saving. Eventually I’ll be shopping around for some used gear so I need to understand how to match up the watts and ohms and head and cabs and such. I think that what I’d like to have is about a 400 watt head and a 410 cab and if possible the option to add a 115 extension cab at some point in the future.
  2. Lackey


    May 10, 2002
    Los Angeles
    Start by getting 1000 watts, you never know when it will come in handy.

    If I were putting together a pre/power + cab(s) setup, I would try and go used for the pre (epifani,demeter,aguilar,kern,eden,ampeg,swr,sansamp etc.) new for the power (carvin or qsc), and new or slightly used with the cab.

    Also, heads from Mesa Boogie, Gallien Krueger, and Ampeg have my approval.

    There's a veritable cornucopia of tonal landscapes that can be achieved these days by mixing bass gear (unlike the guitarists standby, Mesa/Marshall stack).

    As far as Ohm's go, the higher the impedence, the more power you get (I believe). An amp running into a 4ohm 410 cab will produce more volume than running into an 8ohm cab. If you are using two cabs, add their impedence together and divide by 4. For example, two 8ohm cabs would be a 4ohm load. Two 4ohm cabs would be a 2ohm load. An 8ohm cab and a 4ohm cab would be a 3ohm load.

    I believe it's perfectly safe to run 4ohms of power into an 8ohm cab, it just won't be as efficient as a 4ohm cab would be. BUT, you can add another 8ohm cab and blast a hole in the wall if you need to.

    For wattage, If a cab is rated at 1000 watts continuous, you could theoretically run a 1000 watt amp thru it no problem. Clipping occurs when you aren't loud enough, so you compensate by turning your volume and gain to 10. Then the flux capdiCotscxlsjdoisdj[iposdjoij AND I'll let an expert take over from here. Hey, I just play bass.

    NOTE: All the above info could be very wrong, I suggest you consult with an electrical impulse genius before you finalize your thought patterns.

    P.S. This note shouldn't even really be here, it just took me so long to type it that I would feel a sense of despair if I didn't post it. Thank you.
  3. Reefer

    Reefer Guest

    Mar 9, 2003
    For God sake, please don't try to make any sense of this and seek professional help!!!
  4. Petebass


    Dec 22, 2002
    QLD Australia
    For everything you'll ever need to know about speakers, click here .

    My advice is to take your time learning the science side of it, then apply that to your own personal needs.

    Good luck, let us know how you go.
  5. Or click on the TalkBass TechTalk link in my signature.
  6. RichBriere

    RichBriere Guest

    Jan 1, 2003
    Upstate NY
    Hey Brother....there's nothing dumb" about asking questions. There IS something dumb about NOT asking them. :^>)

    I use a 60 (sixty) watt Sunn 200S tube head and a "very efficient" 2x15 JBL D-140 speaker cabinet. It's quite capable of blowing ones brains out OR being the tone monster that it was meant to be. I ALWAYS choose the latter.

    You can find previously-owned amps like these for $400, complete, and you'll be able to keep up with your wealthy, power hungry friends with NO problem.

    The constant quest for "wattage" is, IMHO, quite silly. The power is in YOUR music, not in how big your rig is.

  7. Velkov


    Jan 17, 2001
    Lansdowne, Ontario
    Wow. Where did you hear that one? There is laws of physics that in most cases are a little more complicated than "add and divide by 4". I mean 4 is not that magic of a number.

    Anyway, when connecting speakers in parallel, the inverse of the total impedance equals the sum of the inverses of the impedance of the speakers:

    1/R = 1/R1 + 1/R2 + ....
  8. SRSiegel

    SRSiegel Guest

    Sep 17, 2001
    Ann Arbor, Michigan
    the scary thing is that the "divide by 4" method actually is a decent approximation in most cases involving speakers. but the actual values of two cabs hooked together in parallel are as follows:


    Don't ever hook a combination of cabinets to a head if the impedance of the combined cabinets is lower than the minimum that is listed on the back of the head. You would be running the risk of overheating and melting down the head.
  9. BassPulsar


    Oct 16, 2002

    Has you can tell by the post subject, what I would like to know is somebody prefers a rig setup with a separated pre-amp and a power-amp (e.g., QSC) and others use a bass head (pre and power in one place...!!).
    What are the advantages and disadvantages of both setups?

    Thank you all!!