Digital Pro Audio SLT 2.8 Speakers???

Discussion in 'OT Technology' started by rudeboy, Aug 29, 2002.

  1. rudeboy

    rudeboy Guest

  2. 04

    04 Guest

    :ugh: :ugh: :ugh: :ugh: :ugh:

    I don't want to hear them. It probably sounds like utter shit, and looks like one of the White Van brands.

    Most of the time, when you have not heard of a brand before, it sucks. Although that is ABSOLUTLY NOT ALWAYS THE CASE. Just by the pictures it looks like those speakers are worth around 75 to 100 dollars a pair. They probably sound rather poor. If you can get them for 75 dollars, that might be a decent price? :dunno:

    What's scary is that the cabinets look similar to those on my bookshelf speakers. :ugh:
  3. Grouch

    Grouch Guest

    well i fell for the scam. I bought 2 of the towers for $220 for the pair. the tweeter sucks so bad. the 8" mid is ok and seems to take good power. (took a while to blow them up anyways) the cabnets are ok. i am now planing to replace the drivers with some good stuff.
  4. 04

    04 Guest

    Thats not adviseable, because just throwing a bunch of random drivers in a box is going to sound just as bad or worse than the stuff that is already in there. If you take the time to get a properly designed crossover, only then would your efforts be worth it.
  5. Grouch

    Grouch Guest

    uhhhh its a generic inclosure just like the ones from Partsexpress. there is already a passive x-over in there. Droping in some Audax or vifa drivers will be fine, so long as i get an 8 ohm load.
  6. 04

    04 Guest

    No it really won't be fine. And quite frankly you would be wasting your money if you did that. A passive crossover has to be specifically designed for the components being used. You cant just get a textbook butterworth filter and slap it in a box and expect great sound quality. There are other factors to worry about such as cone breakup, driver inductance, phase, baffle step compensation, tweeter mounting, etc etc etc.

    Sure you can do that, and it may sound fine to you, but it will not be an accurate speaker. If you ever wanted to sell them no one would buy them unless they wanted a poorly designed loudspeaker.

    Sorry to sound so harsh, but you would really be making a mistake by doing that...
  7. Grouch

    Grouch Guest

    if you switch a 12 db per octave x-over (say at 3000 htz) with any other 12 db per octave x-over at the same feq. there will be neglegable differance. passive alpines and passive JBL are going to sound about the same. speaking from my car audio knowlege.

    cone breakup again means almost nothing if the x-over is at the aproptiarte feq. phaseing on a passive x-over is and easy fix, for every 12 db you reverse it. tweeter mounting and baffle step are both problems that you will run into using any prefab box. we are talking a 200$ set up, not a 20K martin logan or thile speaker.
  8. 04

    04 Guest

    Ok, first I never said two butterworth filters of the EXACT same value wont sound the same, but you are missing the whole point, that is a bad idea. A prespecificed crossover slope does not usually turn out properly.

    That is a link to a very budget loudspeaker, with a lot cheaper components used than you are thinking about using. Notice how the simple textbook crossover does not work properly?

    Also, comparing two equal order filters just based on their textbook rolloff is not correct due to the driver being used's inductance as well as DCR values being used by the inductor.

    Phasing on a passive xover is NOT EASY TO FIX. If you use a butterworth filter, then yes, a 180degree phase shift is introduced, but you have to take into account the phase shift accounted by the driver, as well as the other driver you are crossing over to. The phase of a driver does not stay constant over its linear operating range.

    Cone breakup can still be a problem, because if you have a large peak and a shallow filter, you can still have peaking from the driver dependant on the magnitude of the peak.

    Baffle step can be accounted for by room placement or a filter network, the dimensions of the front baffle do play a crucial role, but they can be adjusted by the above tweeks.

    If you are going to spend 200 on drivers, you SERIOUSLY should think about doing a proper crossover, and not some prefab POS.
  9. Grouch

    Grouch Guest

    nice link.

    sure it can be. and if it sucks then guess what? I make a new one.

    all problems you are going to face in ANY system.

    again can happen in any system.

    thank you for the post, but in all reality you stated nothing of which is not a stadard problem for any diy'er, prefab or not. Or any loud speaker for that matter.

    if i dont like the x-over I can build or buy a new one. simple. you dont have to get in a huff about it.


    how do you plan on designing your crossover if you do a new one when you realize it sounds like anus?
  11. Grouch

    Grouch Guest

    prolly fallow similar steps as the link he posted. Change the xover points. Use winisd (i think has one) or anyother online crossover calculator other then that i wont know until I try out the one i have already. then its all about what my ears like.


    so what are you going to use to get your impedance curves and all the fun info on the drivers to use and input into the xover program ;)
  13. 04

    04 Guest


    Dude, we are not trying to belittle you or anything. We are trying to help you from EXPERIENCE. Trust me, I have done what you are trying to do, and it ended up with a poor sounding loudspeaker.

    If you are really serious about designing your own crossover, get a copy of the loudspeaker design cookbook by vance dickason.
  14. Grouch

    Grouch Guest

    multimeter, test tones

    <bad speeling>

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