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Building my first crossover. Seeking advice.

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  • Building my first crossover. Seeking advice.

    i recently purchased 4x AuraSound NS3-193-8 drivers and 2x Dayton Audio ND20FB-4 Tweeters to build either a pair of bookshelf speakers or a BT speaker box. Either way, im looking for suggestions as to where to start with designing a crossover and whether i should build or buy one. I downloaded Xsim but haven't yet familiarized myself with the program. Would building one give me that much more over just buying one premade? Given the two driver/twtrs that i am using can anyone link to a PE crossover that would work for this setup? Any resources or video tutorials that anyone can recommend for a beginner speaker builder?

  • #2
    "SpeakerBuilding 201" by Ray Alden
    (also, don't skip all the "stickies" at the beginning of this forum)
    A pre-made 4kHz XO won't work like this one -v (at all).

    2nd order high pass (tweeter) w/"L-pad" (for -18dB of attenuation, which the pre-made won't have ANY of !)
    4uF series cap, 0.25mH shunt coil (to ground), L-pad: (series resistor) SR = 6ohms / PR = 1ohm
    (reverse polarity is indicated on the tweeter)

    2nd order LP (woofer): 2.0mH low DCR (iron core) series coil, 3uF shunt cap
    Put these in about a 0.15cf vented box (rear ported is best).

    74dB, crosses near 4kHz, nearly full BSC (+5dB), 8ohm amp is fine (or 4ohm)

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    • #3
      Shouldn't you be closer to 80dB since this is an MTM? 80dB each +6 for parallel pair, and then -6dB for BSC.
      Methinks you modeled with a single woofer.
      Wolf
      "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
      "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
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      http://techtalk.parts-express.com/blog.php?u=4102

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      • #4
        Yup. This is just a TM.

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        • #5
          For an MTM I'd use a 0.30 cf vented box (2"id x 6" long rear vent):
          HP - just change the L-pad: SR=5n(ohms) / PR=2n (parallel resistor)
          LP: 1.0mH coil (#18 or #15 air core OK), and a 6uF shunt cap (to gnd).
          80dB (full BSC), 8n amp STILL okay. 20w RMS to 50Hz @ 100dB.

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          • #6
            Thxs Chris for the book recommendation and the tech specs.

            Comment


            • #7
              Click image for larger version

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              So here it is, or rather here they are. i built a pair of X/O's's according to Chris Roemer's specs. Thxs Chris. I drew a schematic and than plotted a layout that would fit within the perf-board. I used some euro terminal blocks for input and output connections, hot glue and zip ties. However when i hooked them up to my speakers i got two different ohm readings. 5.1 and 5.7. Is it normal to have two different values for the exact same components? And i guess this would be seen as a 6 ohm load to the amp?
              Attached Files

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              • #8
                Did you ever ohm out each driver separately?

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                • #9
                  djg
                  3 of the 4 drivers are 8.1 and the fourth is 7.9.
                  the tweets are 3.6 and 3.6

                  Comment


                  • #10
                    Originally posted by Chris Roemer View Post
                    "SpeakerBuilding 201" by Ray Alden
                    (also, don't skip all the "stickies" at the beginning of this forum)
                    A pre-made 4kHz XO won't work like this one -v (at all).

                    2nd order high pass (tweeter) w/"L-pad" (for -18dB of attenuation, which the pre-made won't have ANY of !)
                    4uF series cap, 0.25mH shunt coil (to ground), L-pad: (series resistor) SR = 6ohms / PR = 1ohm
                    (reverse polarity is indicated on the tweeter)

                    2nd order LP (woofer): 2.0mH low DCR (iron core) series coil, 3uF shunt cap
                    Put these in about a 0.15cf vented box (rear ported is best).

                    74dB, crosses near 4kHz, nearly full BSC (+5dB), 8ohm amp is fine (or 4ohm)
                    Chris,

                    I don't have any NS3''s but I have some Dayton ND90-8's, could they also be used with this same tweeter and crossover?

                    Comment


                    • #11
                      Probably close enough...

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                      • #12
                        Ok, thanks Chris!

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