What do I need?

Discussion in 'Amps and Cabs [BG]' started by LiL BaSS DuDe, Nov 23, 2001.

  1. LiL BaSS DuDe

    LiL BaSS DuDe Guest

    May 15, 2001
    Just curious...

    What kind of rig would I need to play a gig. Just say about 200 people MAX.

    1st question; Can someone explain to me about CABs and how they are set up??

    2nd why have different sizes? Tone? Loudness?

    I have a Peavey 50 watt Microbass with a jack to add a speaker. Would it be possible to hook up more than one?

    I'm thinking of getting something around 100WATT or maybe 150 for Crimbo.. Just have to wait and see.

    Thanks in advance.
  2. monkeyfinger

    monkeyfinger Moderator Staff Member

    This is a difficult question to answer, but I will give it a try. First I am going to assume you play in a rock band with a drummer and at least one guitarist. (You should tell us otherwise.)

    About cabs: cabs move air. The more air a cab moves, the louder it is. Think of it like this: Sound is waves of compressed air. The larger the wave the louder the sound. The faster the wave the higher the frequency. So if you move more air you get more sound. Some cabs move a lot of air, or at least have the potential too. My SWR Megaliath has 8 - 10" speakers and 4 ports. It moves a ton of air. The ability to move air is related to two things, the surface area of the cone, and the amount of energy it can use to push the air. This energy comes from the amp. The speaker converts the amps energy to a push of air. There is always some loss of energy in the conversion. The less energy lossed, the more efficient the speaker is. This ability to convert energy efficiently is also related to the frequency. In general it is very difficult to push low frequencies efficiently. This is why guitar players can be very loud with a small amp and speaker, and a bass player needs a large speaker and amplifier. (This is a generalization. There are other factors.)

    Several small speakers have a similar effect as one large speaker. There are some differences though. Which I will explain.

    Speakers have mass. When an amp pushes energy to the speaker, the speaker also pushes back on the amp. How much it pushes back depends a great deal on the weight of the speaker. Small speakers push back less because they weigh less. The amp is less disrupted by the push-back of the speaker. (Sort of like getting punched in the nose by a gnat.) This relates to how tight the speaker sounds. A smaller speaker has more punch.

    A large speaker takes all the energy from an amp and pushes a lot of air by itself. This is generally inefficient. A group of small speakers take a little part of the total energy from the amp and each moves a little air. All together they move as much air as the big speaker. So why not use little speakers? Well, lots of small speakers are more popular now than one large speaker. However, little speakers move low frequencies less efficiently than large speakers. On the other hand large speakers more high frequencies less efficiently than small speakers.

    To make a cab with a lot of small speakers handle the low frequencies like a large speaker, the cabinet designers add ports to the cab. These are holes, usually about 4" in diameter, or slots in the cab. The very lowest frequencies come from these ports.

    Other elements of the cabs structure effect how efficient and loud it is. To handle the very highest frequencies, some cabs add a horn. This is a special high frequency speaker. The cabs size and shape also effect it's design. How much the walls of the cab absorb the energy of the speaker rather than project it out effects its sound and efficiency.

    Finally, some speakers can take more power from the amp than others. The ability for a speaker to handle a lot of power is partly the design of the speaker and partly the design of the cab. A poorly designed cab will cause the speaker to vibrate abnormally because the cab shakes the speaker in a unwanted manner. (Like trying to talk while running a jack-hammer.)

    So, what speaker should you buy? I would recommend a 4x10 with horn. You will likely need at least 250 watts. Welcome to the world of bass. Please have your wallets ready. :) Peavey, and Carvin make good inexpensive cabs. I wouldn't recommend a combo. You will be replacing gear a lot as you can afford better stuff. This is easier with a component system.
  3. LiL BaSS DuDe

    LiL BaSS DuDe Guest

    May 15, 2001
    Thank God my guitarist will be starting off with a 10watt amp. ;)

    No gigs until he gets a new one for his birthday.. Need to see what he gets..

    Yeah - 3-piece band, guitarist, bassist and drummer.