Announcement

Collapse

Columbus Day Sale

Extended One More Day! Columbus Day Sale at Parts Express! 10/15/19 Click the Parts Express Logo at the top left of this page.
See more
See less

Nd91-8 and Nd16fa-6

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Nd91-8 and Nd16fa-6

    Hi everybody, I want to make a speaker that is small but can as low as 80 hz. I want to use them as satelite speakers in a 2.1 setup. I know there are some designs like scott's helium wich use the nd91-4. Can somebody help me with the crossover. Below 70 hz -- 65 hz Xmax is gonna be to high, so I tought a highpass at 70 hz maybe 65 hz( I don't know If other designs have a highpass to avoid reaching Xmax)





  • #2
    I assume you mean a passive high pass. They're almost never used between subs and satellites because they're prohibitively expensive. The inductors would probably exceed the cost of the drivers, and the high value caps wouldn't come cheap either.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

    Comment


    • #3
      Yes I mean a passive highpass. There is no crossover filter on my amplifier so I have to do it this way (active won't work on my amplifier).

      Comment


      • #4
        Just put a fairly large electrolytic cap in series. Cost will be just a few dollars. We went in detail about this in an older thread. I will see if I can find the thread when I have a chance.
        Don't worry, if your parachute fails, you have the rest of your life to fix it.

        If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

        Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

        Comment


        • #5
          For the price of four 13mH coils and four 400uF caps you can buy a 5.1 receiver. The cost of the same components for the sub low pass would pay for a sub amp.
          Just put a fairly large electrolytic cap in series.
          A first order filter will have almost no effect. Even second order would be marginal, excursion rises much too fast.
          www.billfitzmaurice.com
          www.billfitzmaurice.info/forum

          Comment


          • #6
            Don't know what your box model looks like, but in 0.05 cf w/a 1"id x 13" long port, they'll take 28wRMS (over 95dB) down below 50Hz before breaching Xmax, AND (IPST) their Xmech is appreciably greater.

            Comment


            • #7
              Thanks guys, I had some struggle with the amp choice. The sub I use is tuned to 30 hz and most of the amps don't go flat to 30 hz. So now I have a amp that will go down to 30 hz but have no highpass on the satelite.

              Comment


              • #8
                Originally posted by Chris Roemer View Post
                Don't know what your box model looks like, but in 0.05 cf w/a 1"id x 13" long port, they'll take 28wRMS (over 95dB) down below 50Hz before breaching Xmax, AND (IPST) their Xmech is appreciably greater.
                The box is 1.5 liters tuned to 75 hz with a 0.8" by 4" port. With bass heavy music or movies they will be in trouble(I think).

                Comment


                • #9
                  https://www.parts-express.com/lepai-...3118--310-4002

                  if I buy this one I have a built in highpass but the rest of the amp I know nothing about. I want to give the sub 50 clean watts RMS and this amp only have 60 watt RMS. Also it will only accept a max of 22 V wich isn't 60 watt RMS

                  Comment


                  • #10
                    Check out post #236. Scott has modeled a 8ohm Helium xo

                    http://techtalk.parts-express.com/fo...monitor/page16

                    Comment


                    • #11
                      Also, not sure if you are interested in buying an amp...but this amp has a high pass for the satellites and is pretty stinkin' cheap right now

                      https://www.parts-express.com/dayton...ifier--300-771

                      Comment


                      • #12
                        So... our boxes are the same size (pretty much) but my lower tuning goes 16Hz lower before Xmax.
                        You can also control overexcursion by using the "volume" knob.
                        If you don't like my port length, substitute a PR.

                        Comment


                        • #13
                          Originally posted by Jeff F. View Post
                          Check out post #236. Scott has modeled a 8ohm Helium xo

                          http://techtalk.parts-express.com/fo...monitor/page16
                          Hi Jeff, the amp I use now is 8 ohm for the satelites, so it depends on wich amp I gonna choose. My first option a while ago was the dayton 2.1 amp, but it falls of at 40 hz, While my sub goes down to 30 hz.

                          the problem I have is that I need a highpass, but most amp I see with a highpass don't go low enough.

                          now I have a tpa3116d2 2.1 amp that start to roll of at 32 hz but don't have a built in highpass.

                          the Lepai LP210PA seems good with a highpass at 100 hz but lack a bit on power, but maybe the way to go...

                          Comment


                          • #14
                            Originally posted by Jeff F. View Post
                            Also, not sure if you are interested in buying an amp...but this amp has a high pass for the satellites and is pretty stinkin' cheap right now

                            https://www.parts-express.com/dayton...ifier--300-771
                            maybe I gonna buy this amp but for other projects, I live in the netherlands and this amp cost a 160 dollars over here 🤔😅

                            Comment


                            • #15
                              Originally posted by Chris Roemer View Post
                              So... our boxes are the same size (pretty much) but my lower tuning goes 16Hz lower before Xmax.
                              You can also control overexcursion by using the "volume" knob.
                              If you don't like my port length, substitute a PR.
                              With 25 watt rms I can integrate it with my sub, I think I go for a amp with built in highpass.
                              thanks for the responce Chris!

                              Comment

                              Working...
                              X