I've got a few questions

Discussion in 'Amps and Cabs [BG]' started by BassMisfit, Dec 11, 2001.

  1. BassMisfit


    Dec 31, 2000
    Irwin, PA
    Well I have a few questions that may seem amusing, but i'll ask them anyways. First off, is there any way you can you run a speaker cabinet off of a Sans Amp bass driver D.I.? If an amp is rated at 400 watts does that mean at 8ohms/4ohms, or what?Also if you have an 8 ohm speaker in your amp and you change it with a 4 ohm speaker will that double yor volume, or at least make you louder? What makes an amp ported? And finally, lets say an amp pulls 400 watts of power and only gives out like 150 or so, when they rate an amp in Musicians Friend do they give the actual watts of sound, or just what it takes in electricity to run (ie:400watts=150 in actual sound). I'd appreciate answers to any of these questions.
  2. kirbywrx

    kirbywrx formerly James Hetfield

    Jul 27, 2000
    Melbourne, Australia.
    Uhh...I know im not a mod but doesnt this belong in Amps?
  3. Oysterman


    Mar 30, 2000
    I am almost certain that the power rating in amp specs tells us what's fed into the speakers, not what's drawn from the socket. There are amp gurus on this BBS who know exactly what's going on... perhaps toss a question in the Amps forum? :)
  4. Oysterman


    Mar 30, 2000
    Report it! Report it! :D
  5. beermonkey


    Sep 26, 2001
    Seattle, WA
    If you mean plug your bass directly into the DI box and then the DI box directly into a speaker cab, the answer is "no". The DI box doesn't have enough power to drive the speaker(s) in the cab.

    It depends on the amp as to how much power you get at 8/4/2/whatever ohms. The amp should state on it what it's power rating is at a certain load. In theory, going from 8ohm speakers to 4ohm speakers is going to double your power. You should not just rush out and replace your speakers or re-wire them internally to get a lower ohm load however. You will most definately want to be sure that your amp can handle running at 4ohms/2ohms or else your amp will have a very short life. :)

    Amps are not ported, the speaker cabs are. The really, really simple answer to this question is this: when you look at the speaker cab, is it completely sealed, or is there a hole somewhere in it? The hole will be the port(s).

    I believe you're asking about usable power here. A lot of this will depend on the efficiency of the amp and the speakers. A really efficient amp can sound better/louder than a lousy amp that has a higher rated power output.
  6. lo-end


    Jun 15, 2001
    Yes, these are all amp questions. This should be moved so Joris and Bob Lee and those guys can pick at it. :)

    No, the DI is made to be plugged into a mixing board or PA system, you cant just plug it into a cab because the signal isnt amplified yet.

    Usually the manufacturer says in their specs. If you're reading this from somewhere like Musiciansfriend and they dont tell you how many ohms it is, assume 4. But you should really know the specs of an amp before you buy it. You can usually get them when you go to that manufacturers website.

    Yes it will make it louder, but it will probably change the cabinets sound for the worse. Cabinets are tuned a certain way to sound the best way for the speakers they have inside. If you change the speakers, you will probably have a negative effect, unless they are the same type and everything. And amps dont have speakers, cabs do ;)

    First of all, amps aren.t ported. Cabs are. :D

    There are holes or "ports" in the cabinet which allow the air to move in and out of the cab as the speakers move. For example, when a speaker goes forwards, (I think this is called excursion) air is sucked in. This porting allows for better bass response and deeper notes, which is good for funk or jazz or if you're looking for a bassy sound. If you play with a pick or want a punchier tone, then you want a sealed enclousure with no ports.

    Do you really need to know? :p Watts are usually used to give you some indication of how loud an amp is. They are actually a measure of something other than volume, which would be dB, but are a good indication of how powerful your amp is.

    Heres some terminology:

    The "amp" or the "head" is the thing that amplifies your signal. The "cab" or "enclosure" or "speaker cabinet" or "speaker enclosure" is the thing with speakers in it that you hook up a head to so you can hear your bass. You can also have a head and cab in one box, which can be referred to as a "combo amp". These usually dont go much more powerful than 200 watts though, so they're only useful to small time bassists.
  7. embellisher

    embellisher Holy Ghost filled Bass Player Staff Member Supporting Member

    Off to Amps with this one.
  8. BassMisfit


    Dec 31, 2000
    Irwin, PA
    Thanks alot for all the replies. At least now I have a better understanding of my equipment.