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Fountek Neo CD3.0 Fc ~2.6kHz?

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  • Fountek Neo CD3.0 Fc ~2.6kHz?

    I'm working on a TM monitor design with a HiVi M5a and Fountek Neo CD3.0. The current design has a XO point of ~2.3kHz, but the tweeter response mostly follows a BW 3rd order at 2.6kHz. Frequency response is reasonably flat and phase is good. On Paul C's Speedster, he said many were recommending a minimum XO frequency of 5kHz for the Neo CD1.0 and he found 3kHz still worked well, defying those recommendations he received. Fountek at the time Paul designed the Speedsters recommended a 2nd order XO at 3kHz, which they've revised to 3rd order at 3.5kHz. For the CD3.0, Fountek recommends a 3rd order at 3kHz. Since Paul was able to squeeze a bit lower than recommended by both Fountek and other DIYers, I was hoping to do the same with the CD3.0 going down to the mid 2000s in frequency without problems, especially since the advantage of the larger CD3.0 over the CD1.0 is supposedly a lower XO frequency.

    Now, I recently saw some test results for the CD3.0 showing energy storage at 2kHz and recommendations of not going below 3.2kHz and closer to 4khz. I'm wondering if anyone has designed/built anything with the CD3.0 that crosses lower than the recommended (as Paul did with the CD1.0) and still get great results. I've not been able to find any CSD/waterfall data or distortion data for the CD1.0, but I'm wondering whether it too may have some energy storage issues at a frequency close to the 3kHz used in the Speedsters, which may indicate that the CD3.0 may also be able to cross closer to the 2kHz point than many predict.

    I'm hoping the similarities are there between the CD1.0 and CD3.0 that even though it looks like a bad idea based on CSD and distortion data, it will still sound great when crossed a bit lower than what the test numbers would indicate. So far, I think Paul's used one of these ribbons at the lowest Fc, a whole 2kHz lower than what others recommend. So I'm hoping I can go from the 4kHz recommendation for the CD3.0 to the 2.6kHz of my design.

    Additional note: I did do another simulation with the XO point of ~2.8kHz and the tweeter following a BW 3rd order at 3.2kHz. FR isn't as flat and phase, while still good, isn't as good as before. A peak in the woofer response also went up 3dB. I'd prefer the original design if possible.
    Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
    Digger8 - Small compact 8" sub with F3 = 20Hz
    Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
    Jeffrey - Tang Band W5-704D + Beston RT003C
    Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

  • #2
    Re: Fountek Neo CD3.0 Fc ~2.6kHz?

    I don't know the answer for the Tweeter part of the equation but I'm wondering why you'd choose a metal coned driver to try to pair up with the tweeter? From everything I've read my impression is a paper cones breakup isn't as offensive as a metal driver breakup so if I were going to push the limits of a woofer in an effort to get it to pair up with a tweeter I'd look for a similar sized paper coned driver.

    Silver Flute, NS6, Sbacoustics etc...

    Take it easy
    Jay
    "I like Brewski's threads, they always end up being hybrid beer/speaker threads based on the name of his newest creation." - Greywarden

    Breakfast Stout - HiVi RT2 II/Aurasound NS6
    Imperial Russian Stout - Vifa DX25/Fountek FW146/(2) Fountek FW168s - Built by Fastbike
    Ruination 2.5 way - Vifa DX25/Fountek FW168
    Levitation TM
    - Vifa BC25SG15/Fountek FW168

    Comment


    • #3
      Re: Fountek Neo CD3.0 Fc ~2.6kHz?

      I'm retrofitting an existing speaker, so I'm limited in size due to the cutouts and recess. With the preferred design, it's within the well operating area of the woofer and breakups shouldn't be a problem. Acoustic slope is about LR4 at 2.3-2.4kHz. Also, from what I've read, the M5a has a non-metal character to it. Based on the woofer size limitations and volume, the M5a seems to be the best option for a nice compromise of low end extension, clarity and fit (and I like the way it looks). Another contender is also a metal cone, though I don't know how that one would fair at this frequency. Another option was the DS135, but having read the reviews of the DS175, I didn't put too much effort into a design with it. The Silver Flute is close to fitting, about 3mm too big...could maybe sand the recess diameter a bit by hand, but it didn't model to give much low end extension in the box.
      Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
      Digger8 - Small compact 8" sub with F3 = 20Hz
      Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
      Jeffrey - Tang Band W5-704D + Beston RT003C
      Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

      Comment


      • #4
        Re: Fountek Neo CD3.0 Fc ~2.6kHz?

        The crossover frequency Paul C. used in his Speedsters was not 3 kHz, it was more like 4.1 kHz according to the response graphs he published. That worked out pretty well according to my ears, but crossing even higher, say near 4 kHz is even better with the NeoCD1.0.
        Paul K.

        Comment


        • #5
          Re: Fountek Neo CD3.0 Fc ~2.6kHz?

          Darn. I can't see images at work so just read what Paul wrote. Looks like the design I have is a no go. I could possibly use the DS135, but not sure how that one sounds or whether theres breakup fairly low in frequency like the larger DS175. Back to the drawing board. Is like to use the CD3.0 in this speaker and already have the tweeters. Just need to find a suitable woofer.
          Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
          Digger8 - Small compact 8" sub with F3 = 20Hz
          Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
          Jeffrey - Tang Band W5-704D + Beston RT003C
          Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

          Comment


          • #6
            Re: Fountek Neo CD3.0 Fc ~2.6kHz?

            Originally posted by jsr View Post
            I'm retrofitting an existing speaker, so I'm limited in size due to the cutouts and recess. With the preferred design, it's within the well operating area of the woofer and breakups shouldn't be a problem. Acoustic slope is about LR4 at 2.3-2.4kHz. Also, from what I've read, the M5a has a non-metal character to it. Based on the woofer size limitations and volume, the M5a seems to be the best option for a nice compromise of low end extension, clarity and fit (and I like the way it looks). Another contender is also a metal cone, though I don't know how that one would fair at this frequency. Another option was the DS135, but having read the reviews of the DS175, I didn't put too much effort into a design with it. The Silver Flute is close to fitting, about 3mm too big...could maybe sand the recess diameter a bit by hand, but it didn't model to give much low end extension in the box.
            You have yourself a difficult challenge in the crossover design. M5a has a cone resonance fairly low. Not sure how non-metalic the sound is.
            Let me run this idea. How about small Fountek mid woofers or ZA14? Drivers are very similar and have cone resonance higher in the F range.
            As far as the electrical order of the crossover goes and a crossover points, it's all relative. Like I've sad before: The soup is in the tails.
            http://www.diy-ny.com/

            Comment


            • #7
              Re: Fountek Neo CD3.0 Fc ~2.6kHz?

              I've really wanted to try the Fountek FW146, but the recess outer diameter is about 7mm too small. The cabs look really move and I'd hate to uglify them with my horrible wood working handiwork. Not even sure how I'd open the recess diameter aside from sanding which may turn out bad considering my skills and tools.
              I think the ZA14 wools fit, but for the price, I'd like to try the FW146 (no real reason side from I like the way the FW looks). How about the 55-3870? Is that breakup high enough to use?
              I'd greatly appreciate any help you can offer r-carpenter and any designs you may come up with.
              Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
              Digger8 - Small compact 8" sub with F3 = 20Hz
              Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
              Jeffrey - Tang Band W5-704D + Beston RT003C
              Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

              Comment


              • #8
                Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                Originally posted by r-carpenter View Post
                You have yourself a difficult challenge in the crossover design. M5a has a cone resonance fairly low. Not sure how non-metalic the sound is.
                Let me run this idea. How about small Fountek mid woofers or ZA14? Drivers are very similar and have cone resonance higher in the F range.
                As far as the electrical order of the crossover goes and a crossover points, it's all relative. Like I've sad before: The soup is in the tails.
                That might work... an all fountek three way a really difficult to resist I think my wallet is rooting against it ;).

                JSR - I'd plan on making a baffle like I did for the levs so you'd not be locked into drivers that would fit into the original baffle. Trying to only use what would fit is just too limiting.
                "I like Brewski's threads, they always end up being hybrid beer/speaker threads based on the name of his newest creation." - Greywarden

                Breakfast Stout - HiVi RT2 II/Aurasound NS6
                Imperial Russian Stout - Vifa DX25/Fountek FW146/(2) Fountek FW168s - Built by Fastbike
                Ruination 2.5 way - Vifa DX25/Fountek FW168
                Levitation TM
                - Vifa BC25SG15/Fountek FW168

                Comment


                • #9
                  Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                  MCM will break up between 7k and 8k. May be another break up around 12k. That gives you enough room to tail the passband of the woofer. It's actually very similar to ZA-14.
                  As far as helping with the design, I can give you general suggestions, but the reality is, it has to be measured and verified.
                  I think, Jay's suggestion about new baffle is a very good one.
                  http://www.diy-ny.com/

                  Comment


                  • #10
                    Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                    Unfortunately i don't have the tools/equipment to make a new baffle. Even to put in front of the original one would be difficult as the sides are curved and the curvature extends through the baffle. I'll try modeling the 55-3870 tomorrow based on zaphs graphs. The FR looks very close to the ZA14 with the ZA14 having better distortion. I honestly don't think I have good enough ears to hear the distortion difference, so the only benefits for me with the ZA are a bit more excursion and nicer appearance, not sure thats enough for me to justify the cost difference. I'll let you guys know how the sims look tomorrow. Thanks.
                    Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
                    Digger8 - Small compact 8" sub with F3 = 20Hz
                    Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
                    Jeffrey - Tang Band W5-704D + Beston RT003C
                    Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

                    Comment


                    • #11
                      Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                      if the TS of the driver will work in the exiting box, sure go for it.
                      http://www.diy-ny.com/

                      Comment


                      • #12
                        Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                        I simmed the 55-3870 with the Neo CD3.0. Got a -6dB crossover point of ~2.8-2.9kHz. The tweeter follows a 3rd order BW at 3.5kHz. Is that enough?
                        I couldn't stretch the woofer further while keeping phase well aligned and the XO started to get complicated.

                        Attached are the PCD simulations.

                        I also did a sim with the W4-1720 (if it becomes available again). XO is just past 3kHz, but the tweeter slope isn't as steep as the 55-3870 design, so the response is higher at 2kHz with the 1720 than the 55-3870.

                        Thanks.
                        Attached Files
                        Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
                        Digger8 - Small compact 8" sub with F3 = 20Hz
                        Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
                        Jeffrey - Tang Band W5-704D + Beston RT003C
                        Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

                        Comment


                        • #13
                          Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                          Originally posted by jsr View Post
                          I simmed the 55-3870 with the Neo CD3.0. Got a -6dB crossover point of ~2.8-2.9kHz. The tweeter follows a 3rd order BW at 3.5kHz. Is that enough?
                          I couldn't stretch the woofer further while keeping phase well aligned and the XO started to get complicated.

                          Attached are the PCD simulations.

                          I also did a sim with the W4-1720 (if it becomes available again). XO is just past 3kHz, but the tweeter slope isn't as steep as the 55-3870 design, so the response is higher at 2kHz with the 1720 than the 55-3870.

                          Thanks.
                          I'd probably change the z offset to .2 rather than .1 other than that it looks really nice.
                          Note: Pos or Neg will depend on flavor of PCD)

                          Take it easy
                          Jay
                          "I like Brewski's threads, they always end up being hybrid beer/speaker threads based on the name of his newest creation." - Greywarden

                          Breakfast Stout - HiVi RT2 II/Aurasound NS6
                          Imperial Russian Stout - Vifa DX25/Fountek FW146/(2) Fountek FW168s - Built by Fastbike
                          Ruination 2.5 way - Vifa DX25/Fountek FW168
                          Levitation TM
                          - Vifa BC25SG15/Fountek FW168

                          Comment


                          • #14
                            Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                            Originally posted by jsr View Post
                            Unfortunately i don't have the tools/equipment to make a new baffle.
                            In that case this is just an "Oh , nevermind" But just so you know, the NeoCD2 is on sale for about $25 more.
                            Its actually the bigger 5" model ( strange naming system they've got)

                            http://www.madisoundspeakerstore.com...-flange-black/

                            Its "recommended" down to 2000 vs 2500. mighta been a good solution for you.
                            BEER: Proof that God loves us and wants us to be happy

                            I've measured many things I cannot hear; and heard things I cannot measure...

                            Comment


                            • #15
                              Re: Fountek Neo CD3.0 Fc ~2.6kHz?

                              Thanks Jay.

                              I thought the ribbon was decently recessed, so only put 0.01m for offset. I'll look again. Just need to adjust the second cap on the filter to pull the phase back together (0.015 or 0.02 offset is easy to adjust for). Hopefully that frequency is enough for the CD3.0. Looking forward to opinions from those who have used/tested the CD3.0.
                              Nichikuros - Peerless 831735 Nomex + Vifa NE25VTA
                              Digger8 - Small compact 8" sub with F3 = 20Hz
                              Madison-D and Madison-R - Tang Band W4-1720 + Vifa BC25SC06 or Beston RT003C (TM and MTM)
                              Jeffrey - Tang Band W5-704D + Beston RT003C
                              Jasmine - Fountek FW146 + Fountek NeoCD3.0 Ribbon in Pioneer BS21 Cabinet

                              Comment

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