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New Empty Cabinet....Know what???

Discussion in 'Amps and Cabs [BG]' started by Gintaras, Jan 8, 2005.


  1. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    I have a scorpion 12" bass speaker laying around and wanted to put it into an extension cabinet. I bought a Steelsound 12" cabinet with tweeter. Know for all of the things that I don't know!!!

    1) The cabinet came with a grill with 4 clamps and screws. Is this all that is necessary to hold the speaker in? It seems to work but not sure for how long.
    2) I have read that there should be some acoustic insulation. What kind and how much?
    3) It came with a tweeter and a double jack. right know I just have the speaker wired to single jack. How does the tweeter fit in? What do I use for a crossover and how is it wired? Does wiring the tweeter parallel change the OHM's? Presently the Scorpion is 8 ohms. :meh:

    This is just a fun project and I plan to eventually give it to my aspiring 9 year old bass playing son!!!!
     
  2. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Not to rain on your parade, but odds are that speaker is terribly mismatched to the dimensions and porting of the cab you bought. Insulation should be the least of your concerns.

    At the very least you need to find the T/S parameters of that speaker, then the tuning frequency of the cab, then adjust the port tuning accordingly. Failure to do so will result in some notes booming radically over others, and potential creasing and physical damage to the speaker itself, even under low power conditions.
     
  3. jondog

    jondog

    Mar 14, 2002
    NYC metro area
    IMO, T/S do make a difference, but I personally would not worry about an imprecise cab size causing radical booming or damaging the speaker in a project cab for a 9 year old. It's sort of like your car - will it be more efficient if you use high octane gas? Yes. Will it still work if you just use regular? Definitely. Just stick it in there, if it sounds good it is good. If it sounds funny, like some notes being noticably louder than others, then go ahead and look up the T/S parameters in bgavin's spread sheet and mess w/ the porting. Does it even have ports? Sealed cabs are supposed to be more forgiving. If you want to do some insulation (you don't have to), you can buy the real stuff from Parts Express or you can just use some stuff around the house - I used one of those foam sleeping pads w/ good effect once. Use wood screws (or bolts if you're going all out) to attach the speaker to the cab - the clamps are just to hold the grill on.

    I'm pretty sure piezo tweeters don't need a xover and don't change impedance, but I'm not positive so wait for someone else to confirm on your wiring questions.
     
  4. Gintaras

    Gintaras Supporting Member

    Dec 11, 2004
    Kent Island, Md.
    Thanks for the replies and cabinet sounds fairly good already and this is a fun experiment and a learning experience. I plugged this in the external speaker port of my son's Peavey microbass which disables the internal speaker. The sound was fuller but the distortion was about the same on my the B string of my LB75. The volume was about the same. This cabinet has an 8 ohm speaker and the internal on the microbass is 4 ohm.

    The more info is 17 x 15 x 10 size. Has a 3x5 port and is made of 3/4" maple plywood. I will try putting in some foam and hook up the tweeter and see what happens. (in case I didn't mention, the scorpion was free)