Announcement

Collapse
No announcement yet.

The Summits

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

  • The Summits

    So I decided to tackle my first three way (not counting the ones I made ten years ago with prefab crossovers). It is finally completed and definitely challenged me.

    The design is a three-way bookshelf designed with a set of requirements decided by me:

    1) As compact as I can make them
    2) Adequate bass response for their small size
    3) Utilize a dome mid (just because I've always wanted to use one)
    4) An AMT or Planar tweeter (same reason as above)

    So I chose the Dayton DCS165 for the woofer given it's small box capabilities, durability and reasonable excursion (marketed as a sub), and it looks tough :D. I picked the Dayton AMT Mini8 for the tweeter because it looked interesting being a small budget AMT. Initially I was pretty set on a HiVi dome mid as it looked to be a good value, but ended up choosing the Dayton RS52 because it looked like a nice product, and I thought an all Dayton speaker would be cool.

    The cabinet design and construction was concurrent with a 3-way tower I am working on, so it was to be simple and inexpensive. Menards had some 3/4 birch ply in stock that had a nice (thin, but nice) veneer, high ply count, and relatively few voids for big box store plywood. I used this for the face, and 1/2" MDF for the sides and rear. Two dowel braces connect the sides (would like a third, but the crossover prohibits this). Jumping ahead, that woofer makes a lot of energy in that small box, so If I had to do it again I would definitely use 3/4 all the way around. I used ceramic tiles in the enclosure with adhesive holding them to the wall, which seemed to help the non-braced part of the walls due to it's stiffness.

    For time and simplicity I surface mounted the drivers. This was in addition to my lack of decent router circle jig for making a accurately sized recess. What I have can cut holes but is not accurate enough to make tight-fitting recesses.

    The gross internal volume is .42ft3 and the baffle measures 7.5*15 inches, all drivers centered horizontally. The vent is 1.5d * 7. A larger diameter would be nice but got too long. They will get a little muddy when vented and loud, but I found plugging the port really increases the clean volume limit.

    The cabinet was covered in a heavy and stiff adhesive vinyl (usually used for top coat of signs), covered with gloss black automotive vinyl film. This was my resolution to wanting a gloss black finish without the days of polishing. It is not as nice as a lacquer finish, but perfect for what I wanted. I'm happy with their looks.

    The crossover was relatively involved. I got a lot of help from folks of the forum to point me in the right direction. Since then I also learned more about my measuring and re-measured, getting more accurate acoustic offsets and workable graphs. I had so many revisions my head was spinning, but got a final design ironed out while trying to keep the advice in mind that was given. Thank you to those who took a look and helped me out! I apologize that at the time I did not have the most accurate data to work with..

    The most parts-involved circuit was the mid, with a third order high and low pass and notch filter. The name of this projects was determined while trying to develop the crossover. The response chart provided by Dayton for the AMT had a nasty dip and peak (which didn't appear to actually be there when measured), the RS52 has a significant breakup peak, and the woofer had its own peaks as well. All these peaks looked like mountains, hence the name :D. I was able to iron it reasonably flat, with one noticeable dip in the woofer response. This could be a measurement issue on my part. If not, hopefully it works its way out with break-in. If not, so be it. I did add a zobel on the input to even out the impedance some, as well as a large resistor across the woofer to help flatten things out a little.

    Voicing was a little bit of a chore. The pics of the crossover are before several revisions, so if the parts don't look right, that is why. The walls of the cabinet were lined in a combination of 3/4" fiberglass batting and egg carton foam, with much trial and error for bass response, muddiness, boominess, etc. I may dive back in and add a little more foam on the back wall where there isn't any, but it isn't too bad after dialing that in. The tweeter was also fussy. I found it to be either too quiet or too loud/harsh until dialed in. I tweaked it using a high-value parallel resistor on the tweeter. The value was high enough that it didn't adversely effect the crossover components. I initially had a 47r, which was too quiet, attempted 100r, which was too loud yet, and settled on a 70r, which about nailed it (for my ears)

    In listening after I got things dialed in I am pleased. They don't have a huge stage (update: seems to be opening up nicely with break-in), but I think the vocals sound nice, as does the overall sound. They are to a point that I am happy with them, don't plan to open them back up (aside from adding a little more dampening), and would not be afraid to give them to another person. They are inefficient, 79-80dB, but they play plenty loud for normal 2ch listening in a small to med sized room. The impedance is not for the feint of heart amp, touching 3r and hovering not much above that. That said it is nothing a decent quality amp rated for 4 ohms shouldn't be able to handle. I can run them all day on my 25ish year old NAD 2400 with no issues.

    UPDATE 04-27-16: Crossover was revised and the improved schem is posted below in post 5. Revised because of measurements with new equipment and driver offset recalc.

    Pics to follow. Thanks for looking!
    Last edited by dynamo; 04-27-2016, 02:40 PM. Reason: Took new measurents and revised the crossover because of this.
    Projects:

    transcenD: http://techtalk.parts-express.com/fo...5035-transcend
    Summits: http://techtalk.parts-express.com/sh...75-The-Summits
    References: http://techtalk.parts-express.com/sh...-My-References
    Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

  • #2
    Re: The Summits

    Pics
    Attached Files
    Projects:

    transcenD: http://techtalk.parts-express.com/fo...5035-transcend
    Summits: http://techtalk.parts-express.com/sh...75-The-Summits
    References: http://techtalk.parts-express.com/sh...-My-References
    Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

    Comment


    • #3
      Re: The Summits

      Pics (crossover pic is not current, is of an early version)

      Click image for larger version

Name:	IMG_1064.jpg
Views:	2
Size:	529.1 KB
ID:	1165979Click image for larger version

Name:	IMG_1128.jpg
Views:	1
Size:	591.0 KB
ID:	1165980Click image for larger version

Name:	IMG_1130.jpg
Views:	1
Size:	467.8 KB
ID:	1165981Click image for larger version

Name:	IMG_1141.jpg
Views:	1
Size:	720.4 KB
ID:	1165982Click image for larger version

Name:	IMG_1157.jpg
Views:	1
Size:	762.0 KB
ID:	1165983
      Last edited by dynamo; 04-27-2016, 02:42 PM. Reason: made note that crossover pic is of an earlier revision
      Projects:

      transcenD: http://techtalk.parts-express.com/fo...5035-transcend
      Summits: http://techtalk.parts-express.com/sh...75-The-Summits
      References: http://techtalk.parts-express.com/sh...-My-References
      Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

      Comment


      • #4
        Re: The Summits

        Pics
        Attached Files
        Projects:

        transcenD: http://techtalk.parts-express.com/fo...5035-transcend
        Summits: http://techtalk.parts-express.com/sh...75-The-Summits
        References: http://techtalk.parts-express.com/sh...-My-References
        Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

        Comment


        • #5
          Re: The Summits

          Graphs and schematic. (NEW CROSSOVER REVISION)

          **Update: After running the design through xsim, I updated the 6r to a 20w. Given the inefficient design 20w all around isn't a bad choice for higher volumes.
          Attached Files
          Last edited by dynamo; 10-12-2016, 01:42 PM. Reason: new schem to refelct resistor wattage
          Projects:

          transcenD: http://techtalk.parts-express.com/fo...5035-transcend
          Summits: http://techtalk.parts-express.com/sh...75-The-Summits
          References: http://techtalk.parts-express.com/sh...-My-References
          Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

          Comment


          • #6
            Re: The Summits

            I'm wondering if the tweeter issues you think you heard were not the peak in the RS52 that isn't suppressed enough.

            Can we get a completed pic?
            Wolf

            EDIT: They look nice!
            "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:
            http://photobucket.com/Wolf-Speakers_and_more

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

            Comment


            • #7
              Re: The Summits

              The rest of the crossover pics
              Attached Files
              Projects:

              transcenD: http://techtalk.parts-express.com/fo...5035-transcend
              Summits: http://techtalk.parts-express.com/sh...75-The-Summits
              References: http://techtalk.parts-express.com/sh...-My-References
              Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

              Comment


              • #8
                Re: The Summits

                Originally posted by Wolf View Post
                I'm wondering if the tweeter issues you think you heard were not the peak in the RS52 that isn't suppressed enough.

                Can we get a completed pic?
                Wolf

                EDIT: They look nice!
                Thanks Wolf! They have a (IMO) pretty pleasant sound now. The schematic posted is how the crossover is now (despite the pics). I did the notch instead of a tank on the mid as you suggested, so the peak is shorted. I believe I even ended up with the same values you suggested and used with your RS52, so I'm pretty confident that issue is handled (unless you feel otherwise and have any more advice on it). Also, the annoyance is now gone without touching the mid circuit to do it. I honestly believe it was just the tweeter being a touch hot for my taste. I'm pretty happy with them now that I have them dialed in. I remember I had a similar experience when demoing some of the Martin Logan Motion bookshelfs. I liked them, but just felt they needed to be toned down a notch.
                Projects:

                transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                References: http://techtalk.parts-express.com/sh...-My-References
                Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                Comment


                • #9
                  Re: The Summits

                  Originally posted by dynamo View Post
                  Thanks Wolf! They have a (IMO) pretty pleasant sound now. The schematic posted is how the crossover is now (despite the pics). I did the notch instead of a tank on the mid as you suggested, so the peak is shorted. I believe I even ended up with the same values you suggested and used with your RS52, so I'm pretty confident that issue is handled (unless you feel otherwise and have any more advice on it). Also, the annoyance is now gone without touching the mid circuit to do it. I honestly believe it was just the tweeter being a touch hot for my taste. I'm pretty happy with them now that I have them dialed in. I remember I had a similar experience when demoing some of the Martin Logan Motion bookshelfs. I liked them, but just felt they needed to be toned down a notch.
                  If you're happy- you're happy!
                  I think they look slick....

                  Just one word of advice- If someone were to replicate this, the driver names should likely be labeled on the schematic so that's not called into question.

                  Later,
                  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:
                  http://photobucket.com/Wolf-Speakers_and_more

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

                  Comment


                  • #10
                    Re: The Summits

                    Originally posted by Wolf View Post
                    If you're happy- you're happy!
                    I think they look slick....

                    Just one word of advice- If someone were to replicate this, the driver names should likely be labeled on the schematic so that's not called into question.

                    Later,
                    Wolf
                    Thanks again Wolf. I will add that to the schematic. If you think I could improve the mid circuit reference the resonance, please feel free to let me know your thoughts, whether here or in PM.

                    Thanks!
                    Projects:

                    transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                    Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                    References: http://techtalk.parts-express.com/sh...-My-References
                    Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                    Comment


                    • #11
                      Re: The Summits

                      Nice build, beautiful cabs.

                      Comment


                      • #12
                        Re: The Summits

                        Originally posted by Wolf View Post
                        Just one word of advice- If someone were to replicate this, the driver names should likely be labeled on the schematic so that's not called into question.
                        Done!
                        Projects:

                        transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                        Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                        References: http://techtalk.parts-express.com/sh...-My-References
                        Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                        Comment


                        • #13
                          Re: The Summits

                          Originally posted by BusterIrvine View Post
                          Nice build, beautiful cabs.
                          Thanks! The pics do them a lot of favors though, they aren't perfect when seen up close
                          Projects:

                          transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                          Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                          References: http://techtalk.parts-express.com/sh...-My-References
                          Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                          Comment


                          • #14
                            Re: The Summits

                            A shot of the back
                            Attached Files
                            Projects:

                            transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                            Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                            References: http://techtalk.parts-express.com/sh...-My-References
                            Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

                            Comment


                            • #15
                              Re: The Summits

                              Originally posted by dynamo View Post
                              Graphs and schematic
                              What is the 50 Ohm shunt resistor on the woofer for?
                              Isn't it about time we started answering rhetorical questions?

                              Paul Carmody's DIY Audio Projects
                              Twitter: @undefinition1

                              Comment

                              Working...
                              X