Pulling tweeters

Discussion in 'Amps and Cabs [BG]' started by Moo, Nov 29, 2004.

  1. Moo

    Moo Banned

    Dec 14, 2002
    Oakland, CA
    Hi, I never use tweeters and was thinking of pulling it out of my Eden D210T to save a pound or two. It's not much but if I lose 3 pounds I'll feel happier.

    What specifically would be the expected change in tone and volume if I left the hole open as another port? Bgavin, you out there? It won't be too hard to plug and seal the hole but I'm curious as to what cabinet theory says.

    This is the model.


  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    pulling the tweeter also means you're going to have to remove the crossover and rexire the cabinet. Leaving the hole open will screw with your cabinets tuning dramatically and sealing it will be a major pain. Don't do it, you're being silly. 3 lbs isnt that much.
  3. wildsponge


    Oct 21, 2004
    Novato, CA
    What he said. Benefit-to-pain in the a$$ ratio is not worth it. 3lbs is NOTHING. Just turn it off and leave it there. Besides, if you ever decide to take up slap, eden makes some pretty tasty tweeters.
  4. Moo

    Moo Banned

    Dec 14, 2002
    Oakland, CA
    Instead of just telling me what I want is wrong I was hoping someone can answer the questions in the post? I already stated it's not much but it's worth it to me.

    The wiring is a piece of cake, it's not silly it's a 5% weight reduction and I've been slapping for more than 20 years.
  5. Here's what I would suggest trying:

    1) Download WinISD, it's free.

    2) Play around with Win ISD to find out where the cab dimension section is.

    3) Measure your cab and enter that into WinISD. Also enter your existing port size and enter that into the vents. Now you can find out what frequency your box is tuned to now.

    4) Change the vent sizes or numbers and you can see what the new box tuning frequency will be.

    Disconnecting the tweeter from the crossover will have no effect on the woofers as far as the crossover is concerned.(I'm assuming this is a parallel crossover network) You just have to make sure the disconnected wires don't short out together or to something else, so a little tape will fix that.
  6. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    It will likely drastically change the tuning of the cab having a big open hole there. Lots of effort to correct, since modifying the shelf porting is much harder to do than simply modifying a round port. Odds are, you'll have to dissect the cab to do it properly. Major surgery for about ONE pound difference, I highly doubt that tweeter is three pounds.
  7. Moo

    Moo Banned

    Dec 14, 2002
    Oakland, CA
    nashvillebill, that was helpful :) While I couldn't get the graph to change by changing port sizes the help files had some interesting info. It seems bigger ports will lower the tuning, but it also says I'd need to put a tube at least 3 inches long in the hole and that will reduce internal volume. A simple plate to cover the hole using the existing screw holes might be the best choice.

    Eric, I'm making a guess on the weight savings from the Bergantino specs showing the EX112 is 3 pounds lighter than the HT112 without the tweet and x-over. I've pulled the cones from this cab before so I've seen the inside and the mod will be pretty easy.

    I wonder how much the carpet covering weighs ;)
  8. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Hmm...I wouldn't get involved, except this has come up with our products also. (insert general "we don't authorize mods" disclaimer here).

    If you just gotta pull your tweeter, you SHOULD in general disconnect the tweeter crossover....

    A very simple type of crossover would not need that, but any of the types which have coils AND capacitors may cause an impedance problem at the crossover frequency if the tweeter is not there to load them.

    That CAN (but may not) lead to amp problems or smoke from the speaker.

    The attenuator, if any, might or might not be enough load to avoid the problem. You should turn it to minimum and leave it there, at least.

    I cannot speak for Eden, but on other speakers at least, including ours, there is a real possibility of a problem if the tweeter is not there, due to the multi-pole crossover.

    As far as tuning, on most any cabinet, if you block the tweeter hole, you would be done. The volume of the tweeter and its baffle hole is usually way too small to make any difference that you could even measure reliably.

    On that cabinet, with a "shelf port", an open tweeter hole would clearly act as a secondary port, with a much shorter length than the "shelf port".

    Most design programs won't give a good answer, or any answer, if you want to use multiple ports of different lengths. But I would say the tuning frequency would be likely to go up, as the net effect will be to increase port area, and decrease length. How much? Dunno without calculating based on data that isn't given.