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  • Starting a New Horizons Build

    apparently i'm on a quest to build every small, inexpensive design out there. i have always been attracted to many smaller projects, over a single larger one. i think it keeps my ADD at bay or something. also in keeping with my usual style, i tend to start 1000 projects before finishing any projects. in this case, i've got a pair of overnight sensations that i'm breaking in while i test different paints and painting methods, a pair of dragon foals that i'm still deciding on a stain for, and now yesterday i went and picked up everything needed for some new horizons (see below). i decided to do these because i already had a pair of nd105-4's with no intended use, that i picked up back when they first went on sale, not knowing how long they'd be on sale.

    here was yesterdays BOM:


    i pm'ed michael when i first started thinking about this project and asked him for his thoughts on using NPE's for the woofer caps, to keep cost as low as possible. he said he thought it would be fine and suggested bypassing them with poly's as a compromise. so thats the reason for the undersized NPE's, and hoard of 1uf poly's. i actually intended for the 16uf tweeter cap to be a 15uf poly and 1uf poly, but accidentally got 15uf NPE instead. hopefully it won't make an audible difference. the 47uf NPE's measured a good bit higher than spec (50.5uf and 52.5uf), so i think i'm going to leave off the 1uf bypass in their case. again, i'm hoping it won't make an audible difference. feel free to chime in if you think it will.

    i never saw anything specifying inductor gauge for this design, so i went with 18ga. for both. since there's no jantzen .55mh 18ga., i went with the .56mh and unwound it to .55mh.

    hopefully i won't work too fast, and i'll be able to keep this thread updated as i go. i meant to do that with my OS build and it just never happened. also, i don't have the most experienced ear out there, but none-the-less, i intend to do an a/b comparison of these and the sensations, once i have these together.

  • #2
    Re: Starting a New Horizons Build

    Smaller projects can be fun, and the assembly goes faster too!
    I'm a bit of a fan of those as well- their EASY!









    Have fun!! :D:D
    Wolf
    "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
    "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
    "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
    "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

    *InDIYana event website*

    Photobucket pages:
    https://app.photobucket.com/u/wolf_teeth_speaker

    My blog/writeups/thoughts here at PE:
    http://techtalk.parts-express.com/blog.php?u=4102

    Comment


    • #3
      Re: Starting a New Horizons Build

      Originally posted by absolootbs View Post
      apparently i'm on a quest to build every small, inexpensive design out there.

      i actually intended for the 16uf tweeter cap to be a 15uf poly and 1uf poly, but accidentally got 15uf NPE instead. hopefully it won't make an audible difference.


      the 47uf NPE's measured a good bit higher than spec (50.5uf and 52.5uf), so i think i'm going to leave off the 1uf bypass in their case. again, i'm hoping it won't make an audible difference. feel free to chime in if you think it will.

      i never saw anything specifying inductor gauge for this design, so i went with 18ga. for both. since there's no jantzen .55mh 18ga., i went with the .56mh and unwound it to .55mh.
      Nothing wrong with small builds, espically as "skill builders". The only way to practice is to do!


      The tweeter cap is less than desirable... But OK. The ND20 is amazing, but I think its "dumb" enough to get past the audible effects of the NPE. If I had any fears it would be the NPE's tolerances which will effect imaging and timbre. Bypassed, you should be fine.

      The 47uF cap being off is not as critical. Add the Bypass, it will do more good than harm.

      18AWG is fine, you are not talking a 18" subwoofer here. Nice on the unwinding. I always do it to get as close of tolerance as I can.

      You will need a generous amount of stuffing (about 4oz per speaker). Something you may want to play with and tune how you like it.

      Most importantly HAVE FUN!!!!
      .

      Comment


      • #4
        Re: Starting a New Horizons Build

        Originally posted by mzisserson View Post
        But OK. The ND20 is amazing, but I think its "dumb" enough to get past the audible effects of the NPE.
        Didn't you use the ND16??
        Wolf
        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

        *InDIYana event website*

        Photobucket pages:
        https://app.photobucket.com/u/wolf_teeth_speaker

        My blog/writeups/thoughts here at PE:
        http://techtalk.parts-express.com/blog.php?u=4102

        Comment


        • #5
          Re: Starting a New Horizons Build

          Originally posted by Wolf View Post
          Didn't you use the ND16??
          Wolf
          i hope so, because thats what i bought. i'm thinking type-o

          Comment


          • #6
            Re: Starting a New Horizons Build

            :o heh heh..... oops. Kid was screamin' dinner was cookin' I was making a mistakin'...

            ND16 it is.

            ADD at its finest as fore-mentioned!
            .

            Comment


            • #7
              Re: Starting a New Horizons Build

              Originally posted by mzisserson View Post
              Nothing wrong with small builds, espically as "skill builders". The only way to practice is to do!


              The tweeter cap is less than desirable... But OK. The ND20 is amazing, but I think its "dumb" enough to get past the audible effects of the NPE. If I had any fears it would be the NPE's tolerances which will effect imaging and timbre. Bypassed, you should be fine.

              The 47uF cap being off is not as critical. Add the Bypass, it will do more good than harm.

              18AWG is fine, you are not talking a 18" subwoofer here. Nice on the unwinding. I always do it to get as close of tolerance as I can.

              You will need a generous amount of stuffing (about 4oz per speaker). Something you may want to play with and tune how you like it.

              Most importantly HAVE FUN!!!!
              Michael, thanks for weighing in on the issues so far. other than the 47uf's, the NPE's actually measured quite well, tolerance-wise. with the bypass caps, i've got 18.4uf and 18.47uf for the 18uf, and 16.36uf and 16.5uf for the 16uf. and of course, thats +/- a couple % to account for meter tolerance. not perfect, but a whole lot closer than the 47uf's that were pushing their 10% limit.

              glad to hear that the 18 ga. is approved of, and will do on keeping the bypass on the 47uf NPE's.

              question on the center to center spacing of the drivers: in the one part of the write-up you say "not to exceed 4", and in a thread where someone commented saying it looked kinda far, you responded by saying something about not being too happy with how it wound up. is it safe to infer then, that a closer spacing would be acceptable... maybe even preferred? i was hoping/planning to push them a little closer together, then do a front port. see below for my proposed baffle layout. thoughts?

              Comment


              • #8
                Re: Starting a New Horizons Build

                Originally posted by absolootbs View Post
                Michael, thanks for weighing in on the issues so far. other than the 47uf's, the NPE's actually measured quite well, tolerance-wise. with the bypass caps, i've got 18.4uf and 18.47uf for the 18uf, and 16.36uf and 16.5uf for the 16uf. and of course, thats +/- a couple % to account for meter tolerance. not perfect, but a whole lot closer than the 47uf's that were pushing their 10% limit.

                glad to hear that the 18 ga. is approved of, and will do on keeping the bypass on the 47uf NPE's.

                question on the center to center spacing of the drivers: in the one part of the write-up you say "not to exceed 4", and in a thread where someone commented saying it looked kinda far, you responded by saying something about not being too happy with how it wound up. is it safe to infer then, that a closer spacing would be acceptable... maybe even preferred? i was hoping/planning to push them a little closer together, then do a front port. see below for my proposed baffle layout. thoughts?
                It was actually Wolf who picked up on my err. My 2nd set of cabs corrected the matter. Within 4" is ok for these. I kept the tolerances wide. 3-1/16 is WELL within one wavelength of the x-over point so you are fine. I am not a big fan of front-porting and would rather see a rear port with these. Given I bottom-ported, I did not account for any reflected mid range through the port. I am not saying it will not work, but thus far it is my only contention.
                .

                Comment


                • #9
                  Re: Starting a New Horizons Build

                  Originally posted by mzisserson View Post
                  It was actually Wolf who picked up on my err. My 2nd set of cabs corrected the matter. Within 4" is ok for these. I kept the tolerances wide. 3-1/16 is WELL within one wavelength of the x-over point so you are fine. I am not a big fan of front-porting and would rather see a rear port with these. Given I bottom-ported, I did not account for any reflected mid range through the port. I am not saying it will not work, but thus far it is my only contention.
                  hmm, i never thought about it before, but when it comes to port placement, the thing that makes the most logical sense seems to conflict with what you almost always hear people say. if i'm correctly understanding the assertion here (and what i've read elsewhere in discussions not necessarily related to port placement), the issue in question is that some midrange can leak out of the port, which can be audible when the port is on the front, and if the effect that that "leakage" has on the response isn't accounted for in the design, it can throw things off. this seems perfectly logical and makes total sense. but why is it then that whenever anyone directly asks about port placement, they're told port placement won't change anything/doesn't make any difference, and that it can go where ever you want to put it, so long as the opening isn't directly behind the back of the woofer? is it, perhaps, that the difference is small and it's just easier to say "doesn't matter", or is there something i'm missing here?

                  Comment


                  • #10
                    Re: Starting a New Horizons Build

                    no one has a comment/opinion on this?

                    Comment


                    • #11
                      Re: Starting a New Horizons Build

                      Originally posted by absolootbs View Post
                      no one has a comment/opinion on this?

                      Let's talk subs. Your electronics (amp's LFE channel, or plate amp's Fc knob) will be rolling your sub ON most likely somewhere between 125 Hz (awful high), 80 Hz (seems to be fairly common), and possibly 50 Hz or even lower. My 8" mains can do 30 Hz, so I've got mine bottomed out (at 50 Hz). Essentially no mids to leak out of a port tube. Still, there's plenty of possibility of "chuffing" (which CAN be a sound that you'd classify as midrange, but it's nothing that's in the recording, IN your box, or even something that you can electronically filter out). It's exacerbated by undersized (too small dia.) vents, large dia. drivers, and prodigious amounts of Xmax. If you aim your vent away from your listening position (rear port), you can somewhat acoustically filter out this effect. YOu can at least reduce its SPL by not aiming your vent at your ears. Some people say there's not too much of a reason to line a vented subwoofer box. I quit a few subs back and never noticed.

                      Let's talk NOT subs. In a 2-way, or even a 3-way, your woofer will be playing well up into the midrange, crossing anywhere from maybe 300 Hz up to nearly 2kHz. These sound waves (mostly emanating off the back of your midbass) are short enough in length that they can bounce around inside your box and exit any convenient opening (like a port). If you line the inside of your vented box with convoluted foam, it will absorb a LOT of this energy. Even so, there's no point in front porting due to the problems of chuffing as outlined above.

                      In sealed boxes (including subs) the internal "stuffing" (polyfill, fiberglass, or even some expensive botique stuffings) will act to absorb these midrang waves that are bouncing around inside your box. Again, a sub may not need this stuffing as the mids are being electronically filtered out via electronics. Still, a side benefit of stuffing a closed box is that the mass of added material can act to make the box SEEM like its about 20% larger to the woofer regarding its rolloff parameters.

                      Chris

                      Comment


                      • #12
                        Re: Starting a New Horizons Build

                        Originally posted by Chris Roemer View Post
                        Let's talk subs. Your electronics (amp's LFE channel, or plate amp's Fc knob) will be rolling your sub ON most likely somewhere between 125 Hz (awful high), 80 Hz (seems to be fairly common), and possibly 50 Hz or even lower. My 8" mains can do 30 Hz, so I've got mine bottomed out (at 50 Hz). Essentially no mids to leak out of a port tube. Still, there's plenty of possibility of "chuffing" (which CAN be a sound that you'd classify as midrange, but it's nothing that's in the recording, IN your box, or even something that you can electronically filter out). It's exacerbated by undersized (too small dia.) vents, large dia. drivers, and prodigious amounts of Xmax. If you aim your vent away from your listening position (rear port), you can somewhat acoustically filter out this effect. YOu can at least reduce its SPL by not aiming your vent at your ears. Some people say there's not too much of a reason to line a vented subwoofer box. I quit a few subs back and never noticed.

                        Let's talk NOT subs. In a 2-way, or even a 3-way, your woofer will be playing well up into the midrange, crossing anywhere from maybe 300 Hz up to nearly 2kHz. These sound waves (mostly emanating off the back of your midbass) are short enough in length that they can bounce around inside your box and exit any convenient opening (like a port). If you line the inside of your vented box with convoluted foam, it will absorb a LOT of this energy. Even so, there's no point in front porting due to the problems of chuffing as outlined above.

                        In sealed boxes (including subs) the internal "stuffing" (polyfill, fiberglass, or even some expensive botique stuffings) will act to absorb these midrang waves that are bouncing around inside your box. Again, a sub may not need this stuffing as the mids are being electronically filtered out via electronics. Still, a side benefit of stuffing a closed box is that the mass of added material can act to make the box SEEM like its about 20% larger to the woofer regarding its rolloff parameters.

                        Chris
                        so let me paraphrase, and see if i'm understanding what you're saying...

                        port placement is only completely irrelevant, as far as leakage is concerned, in a sub, where no midrange is being played in the box in the first place. and it's probably in that context where you mostly hear people saying port placement has no effect on FR. however, port placement can matter to a sub if you've done a sloppy job designing your port and you have a chuffing issue.

                        for a speaker, on the other hand, port placement in regards to uncompensated leakage is relevant, although this relevance can be mitigated through proper lining. chuffing, however, is a non issue for a speaker, since you're probably not moving enough air to create chuffing in the first place.

                        does that sound right? if so, i think we're on the same page here.

                        EDIT: i just realized you didn't say chuffing was a non issue for a speaker, you were saying even if you mitigate leakage, there still could be chuffing, so front porting would still be a bad idea. just so you know where i'm coming from, my reason for wanting to front port is that in situations where i'm not quite sure where a set of speakers is going to end up, i like to avoid a rear port in the event that it's desired for the speakers to be placed in close proximity to a wall behind them, which causes problems if rear ported. and yes, i know that if speakers aren't designed to be placed near/on wall, they shouldn't be placed there anyway, but sometimes thats the breaks, and i would think i'd rather have one problem (BSC) than two (BSC and blocked port). yes? no? thoughts?

                        Comment


                        • #13
                          Re: Starting a New Horizons Build

                          Originally posted by absolootbs View Post
                          so let me paraphrase, and see if i'm understanding what you're saying...

                          port placement is only completely irrelevant, as far as leakage is concerned, in a sub, where no midrange is being played in the box in the first place. and it's probably in that context where you mostly hear people saying port placement has no effect on FR. however, port placement can matter to a sub if you've done a sloppy job designing your port and you have a chuffing issue.

                          for a speaker, on the other hand, port placement in regards to uncompensated leakage is relevant, although this relevance can be mitigated through proper lining. chuffing, however, is a non issue for a speaker, since you're probably not moving enough air to create chuffing in the first place.

                          does that sound right? if so, i think we're on the same page here.

                          EDIT: i just realized you didn't say chuffing was a non issue for a speaker, you were saying even if you mitigate leakage, there still could be chuffing, so front porting would still be a bad idea. just so you know where i'm coming from, my argument in favor of front porting is that in situations where i'm not quite sure where a set of speakers is going to end up, i like to avoid a rear port in the event that it's desired for the speakers to be placed in close proximity to a wall behind them, which causes problems if rear ported. and yes, i know that if speakers aren't designed to be placed near/on wall, they shouldn't be placed there anyway, but sometimes thats the breaks, and i would think i'd rather have one problem (BSC) than two (BSC and blocked port).
                          Hum. Must have gotten buried. I missed this. I have herd some very expensive front-ported speakers that had audible mid-range coming from the port. Not a big fan of it. I am also not convinced you can absorb these 100%. It is also more prevalent in small cabinets than large. The reflections occur sooner, and are stronger. Perhaps the ill effect is negligible, perhaps not. That is my stance on it due in large part to experience. It is why they ended up on spikes/bottom ported.

                          Incidentally, They were designed to work * best * between 1.5 and 2.5 ft from rear and side walls... (all BSC things considered ) Though I have yet to completely stump them from desktops to 5' from walls.
                          .

                          Comment


                          • #14
                            Re: Starting a New Horizons Build

                            Originally posted by mzisserson View Post
                            Hum. Must have gotten buried. I missed this. I have herd some very expensive front-ported speakers that had audible mid-range coming from the port. Not a big fan of it. I am also not convinced you can absorb these 100%. It is also more prevalent in small cabinets than large. The reflections occur sooner, and are stronger. Perhaps the ill effect is negligible, perhaps not. That is my stance on it due in large part to experience. It is why they ended up on spikes/bottom ported.

                            Incidentally, They were designed to work * best * between 1.5 and 2.5 ft from rear and side walls... (all BSC things considered ) Though I have yet to completely stump them from desktops to 5' from walls.
                            thanks for the additional thoughts. also nice to know that you've found this to be a pretty versatile speaker.

                            i know it's extremely unconventional, but what do the experts out there think of a top port? logically, based on the "prevalence" of the top as compared to the other box faces, i would think it would be better than a front port, but not as good as a bottom or back port. maybe a good compromise?

                            here are my thoughts on the different options for this particular application:

                            rear port: precludes placement near/against a wall behind the speaker

                            bottom port: could preclude placement on a lot of speaker stands, where the top of the stand would be smaller than the distance between the spikes on the bottom of the speaker

                            front port: uncompensated midrange leakage and possible port noise

                            side port: impossible due to cabinet width

                            top port: i seriously doubt these will ever be going directly underneath anything. can't possibly be as bad as front port for audible mid leakage and port noise. compromise/winner?

                            Comment


                            • #15
                              Re: Starting a New Horizons Build

                              Top port: almost guaranteed to have foreign objects dropped in. Especially if you have young children. This is what comes to mind in my home atleast.

                              Comment

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