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  • #61
    Originally posted by dlr
    To what would you attribute this? dlr
    Between numerous different topologies, power supplies, quality of parts, etc. I think all have to play roles in sound.
    craigk

    " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

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    • #62
      Originally posted by craigk View Post

      I agree 100 %. i have several good amps that all sound different when listening. so do you have any ideas or thoughts as to what is going on ?

      Ahh, wish I knew, I'd be retired. I agree design decisions make differences but its hard to be predictable. One thing the ncore has going for it is large power and current reserves, but what I'm hearing is also low level detail, organic textures, that sort of thing. Its a great amp when fed great sources.

      At the Ottawa DIYaudio meet in '15, I took two identical (fairly old but good for their time) dacs. One was stock, the other I modded with an OPA627 swap-in. Validated all stability was good, made battery of measures and the usual vanishing noise floor and several zeroes in all distortion numbers. Frequency response and gain were identical.

      I split the digital input so both ran in perfect time synch. The output was fed through a carefully built A/B make before break switcher (grounds switched as well) to a very high quality headphone amp and an excellent set of cans. I then asked listeners to listen as long as they wanted with their source music, and to write down their perceived difference and I collected input. No one discussed with each other, on agreement. Perceived differences were strongly consistent and well above chance. About halfway through the day, I switched A and B in case anyone thought "A" had to be better than "B". IME, standard measures can't tell the tale for electronics unless they're really dirty. I think it would take something like the uncorrelated audio post processing test from Liberty (Audio diffmaker) and years of time and patience to even start to understand this.

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      • #63
        I am a big fan of " no such thing as to much good, clean power." I also agree that lots of amperage is a very good thing. When you get a high quality system there is an "ease" to the music. Like nothing is having to work to make music. I don't know what it is, but i agree that when someone figures it out they will be very wealthy.
        craigk

        " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

        Comment


        • #64
          Sorry to veer a little off topic here, but, the amplifier discussion may be relevant, if we're really trying to make the "ultimate" small speaker, after all?

          Originally posted by craigk View Post

          I agree 100 %. i have several good amps that all sound different when listening. so do you have any ideas or thoughts as to what is going on ?
          I bought a receiver that played louder and cleaner than the others I compared it to at the store. They also did a good job marketing labeling it with phrases such as "WRAT" (Wide Range Amplifier Technology), and, it was a brand that I had liked over the years - ONKYO. It also claimed a much larger bank of power reserve capacitors compared to other receivers in the price range. So I bought it, and I was happy with my purchase - my roomate loaned me some speakers that were capable of easily reproducing "concert level" volumes with this amplifier - the shear raw volume, playing cleanly, was impressive. And it was *excellent* for home theater.

          But, listening to music in stereo it felt somehow "cold", something was missing. Over time I grew to miss my old Dyna 35 watt tube amp more and more - I basically stopped listening to music because it wasn't enjoyable.

          So, on one hand, I agree with DDF and CraigK, on the other hand, I KNOW that in order to be FAIR, we have to do these amp comparisons in BLIND listening tests.
          "...this is not a subwoofer" - Jeff Bagby ;)

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          • #65
            Brian invited me to share pictures here as the build took place. Only got to spend about a half day Sunday working on these due to being sick most of the weekend. The front baffles will be permanent on the enclosures, the rear baffles will be removable. The front and rear baffles will incorporate rear mounted woofers, not an easy feat when the baffle is only 1/4" thick. Here is a thread showing the solution used: http://techtalk.parts-express.com/fo...river-solution

            The following pics show the progress from Sunday. Nothing real exciting yet, just a step by step breakdown. First pic is of a throw away board needed to accommodate the bolts sticking out of the back of baffles.



            Next pic shows the 1/4" Birch with all of the holes required for the two sets of baffles. Driver holes will be routed after Veneer is applied.



            Added nuts to be buried on the outside edges of the front baffles for speaker grill magnets to work with.



            Ground flats on the 16 weld studs required.



            Covered all of the bolts and nuts with Epoxy.



            Board cleaned up and veneer cut to size.



            Veneer applied (heatlock glue).




            Next up will be to cut all of the driver openings. The rear baffles will also have provisions for 4 rca jacks and a 110 volt receptacle. The rear baffles will also have to be flipped for a cut on the back side of them that will hold the 1/8" tube gaskets for the seal.
            My "No-Name" CC Speaker
            Kerry's "Silverbacks"
            Ben's Synchaeta's for Mom
            The Archers
            Rick's "db" Desktop CBT Arrays
            The Gandalf's

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            • #66
              Brian wanted as small a midrange chamber as could be afforded. I offered to Thermoform some for his speakers. These are made from 3/16" ABS. The first couple of videos show the tool being cut and the last two videos show the part being formed and trimmed.

              https://www.youtube.com/playlist?lis...mNQwUfDi3JoB84


              Should have some more stuff on the enclosures to update by the end of the weekend. Here is a picture of the chambers. The pictures make them look huge when in reality one will fit in the palm of my hand.

              Click image for larger version

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              My "No-Name" CC Speaker
              Kerry's "Silverbacks"
              Ben's Synchaeta's for Mom
              The Archers
              Rick's "db" Desktop CBT Arrays
              The Gandalf's

              Comment


              • #67
                Kevin,
                Really cool stuff there. I especially liked the rounded router bit vid where the rough wood block almost instantly looked like a perfect finished product. That thing really dances a graceful ballet. Was that a 1/2" bit? The vacuum forming was neat to see too; don't blink though or it's over. How hot does the plastic need to be before 3/16" of it will just change shape like that? And does it smell very bad getting heated up like that?

                Really Interesting stuff! thanks for posting those, I enjoyed seeing how that was done.

                TomZ

                *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                Comment


                • #68
                  Hey Tom,

                  The first video showed what we call the "rough" cut of the tool. It was done with a two-flute 3/4" Flat End Mill cutter(carbide tipped) and the cut time was about 8 minutes. It was cutting at 250 IPM and stepping down 1/4" steps. It leaves what looks like a pyramid effect. The whole purpose of the first cut is just to make it a little easier on the "Finish" cutter which is what you saw in the second video. Yes, that's a 1/2" Ball cutter in the second one. It's a Solid Carbide 4-flute Spiral cutter. The finish program takes a little longer. On this one, I used a surface finish parallel program. It's running at a 45 degree angle to the tool which helps prevent scallops and it is stepping over .012" per pass. Yes, you read that right, .012 or about the equivalent of three pieces of paper from a "Post it" pad. If you attempt to step over much more with this size cutter, it leaves ridges that would have to be sanded off the tool. The "finish" program was run at 120 IPM and came in at just under 30 minutes.

                  The forming process takes about 4 minutes on 3/16" ABS. It's in the oven for about 2-2.5 minutes and after the vacuum is applied it is cooled for the remainder of the cycle until rigid again. The plastic's core temperature needs to be somewhere between 280-320 degrees. Skin temperature will be anywhere between 350-380 degrees when it comes out of the oven. The infrared heaters we are using in the oven are averaging around 700 degrees. Our oven is antiquated. It's not fully automatic like some others and requires you to slide the blanks into the oven by hand and then pull them out when ready. You don't want to put your arm in the oven for very long or you'll end up with a nice sunburn. There is a smell that comes off the plastic as it is warming up in the oven. I'm probably a little weird and like the smell. It's not a burnt smell if that is what you are wondering. Here is the vacuum portion of the cycle slowed down for a better look.

                  My "No-Name" CC Speaker
                  Kerry's "Silverbacks"
                  Ben's Synchaeta's for Mom
                  The Archers
                  Rick's "db" Desktop CBT Arrays
                  The Gandalf's

                  Comment


                  • #69
                    Wow! The video really brings it to life and just how cool this is! I knew it was going to be great, but this is incredible.

                    Comment


                    • #70
                      Not exactly setting records for build time on these. This weekend was out of my control. Storms came in Saturday and we lost power at the shop. Came back in today and made a little headway but still have a ways to go. Here are the updates.

                      Completed the enclosure bodies this last weekend and applied FatMax to the inner walls. Built the brackets to mount the amps, drilled and tapped the 4-40 holes for the screws and cut some grooves in the nylon spacers on the lathe. Brian has asked if there is room to separate the amps a little more due to heat concerns. I'll have to see what our options are this week, maybe I can buy some longer screws and spacers. Personally, I don't think there will be enough heat radiating off the aluminum plate to create a problem for the other amp but if we can spread them out a little more it certainly can't hurt.




                      Installed the threaded inserts for the rear baffle to be attached with. Not a big fan of these inserts, especially in MDF, but didn't have a lot of options.



                      Here is a cutaway of the midrange chamber. An additional piece of 1/4 birch had to be added to the rear of the front baffle due to the thickness of the tweeter. The additional piece served two purposes, more meat for the tweeter recess and the midrange chamber fit over it. The plastic was epoxied to it.



                      The rear baffles had to be cut from two sides. The back side has a 3/16" wide recess cut into it for the O-ring cord stock that will be used as the seal. I've used this before and had good results.



                      This is where I stopped this evening. The front baffles are glued on both enclosures and the rear baffles are secured with some temporary screws. The final screws for the rear baffles will be black flat head allen screws but I haven't cut the countersinks into the baffles yet. Veneer is cut and the part I'm nervous about comes next, wrapping the enclosures with one piece all the way around. Once it's wrapped, I will trim off the excess and then I'll have to run a razor knife in the seam on the back baffle to separate it from the enclosure again.


                      My "No-Name" CC Speaker
                      Kerry's "Silverbacks"
                      Ben's Synchaeta's for Mom
                      The Archers
                      Rick's "db" Desktop CBT Arrays
                      The Gandalf's

                      Comment


                      • #71
                        Looking forward to more updates Kevin!
                        See my projects on Instagram and Facebook

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                        • #72
                          Can't wait to see more! Really cool to see the details inside the enclosure.

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                          • #73
                            This project has got to be the most intricate and complicated speaker project I think I've ever seen. I can't imagine getting this far without CNC 'help.' Even with the aid of the CNC it looks super-complicated. It sure is fun to watch, though! Kevin..... I wish I could watch you cut the back panel free... I can just imagine me doing that and sweating bullets the whole time. I'm sure it will look perfect when finished, though. Awesome stuff. TomZ
                            *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                            *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                            *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                            Comment


                            • #74
                              Originally posted by tomzarbo View Post
                              This project has got to be the most intricate and complicated speaker project I think I've ever seen. I can't imagine getting this far without CNC 'help.' Even with the aid of the CNC it looks super-complicated. It sure is fun to watch, though! Kevin..... I wish I could watch you cut the back panel free... I can just imagine me doing that and sweating bullets the whole time. I'm sure it will look perfect when finished, though. Awesome stuff. TomZ
                              Thanks Tom. You're right, it's a super-complicated build for such a small speaker. Ever heard the expression "10 pounds of $#@! in a 5 pound bag"? That's exactly what comes to mind here except the components aren't $#@!, it's all quality stuff. There's a whole lot going on in a small space and not a lot of margin for errors in locating the parts. I felt Brian was in over his head when he approached me and this would be extremely challenging to build by hand. The CAD program and CNC certainly helped in making it a little more feasible. Unfortunately, detail takes time even with a CNC, and I think he's having a hard time understanding that. He's been cooking up this speaker in his head for a good while now and just anxious to finally have it in his hands. Can't blame him but I'm only one guy and can only accomplish so much in a given weekend.

                              I have watched your YouTube video on wrapping veneer and creating a perfect seam on the enclosure several times. Really appreciate you sharing those tips and techniques Tom. Will be trying my hand at it tonight on one of the enclosures and if all goes well, the other one the following night. I have an idea on how to make the cut to separate the rear baffle and will share it if everything works out good. Otherwise, probably gonna need a mop for the pool of sweat on the floor afterwards.

                              Brian wanted desperately to be able to share these with you guys this coming weekend in Indiana. It's my fault he'll be showing up empty handed, don't hold it against him. The Array's took their toll on me and I'm having a hard time pushing myself like I normally do and then there's "life" to deal with as well. They will get finished soon and perhaps Brian can make MWAF to show them off.
                              My "No-Name" CC Speaker
                              Kerry's "Silverbacks"
                              Ben's Synchaeta's for Mom
                              The Archers
                              Rick's "db" Desktop CBT Arrays
                              The Gandalf's

                              Comment


                              • #75
                                Note to self: sunk cost and the pursuit of the best are two very slippery slope roads that I'm walking on!

                                Because I don't have any capability to build enclosures, I don't have the luxury that many of you here to do trial and error with speaker building and learning through experience. Building an enclosure is a rare opportunity for me, and therefore I spend an enormous amount of time learning the theory well and simulating and optimizing the design to improve as many aspects as possible before building. In a way this is good, because I know if I had a woodshop I would have built at least 3-4 speakers already, and then they would have all gone to waste as I came up with better designs.

                                Kevin, there is no need to blame yourself for the delay. $hit happens and we have to deal with it. I think throughout the 5 months of working with Kevin I have asked him no less than a dozen times to build a much simpler enclosure because I thought it was too much work for him, but Kevin would always insists on going above and beyond to build something fancy (and I can't thank him enough for everything). Well of course it is going to take a long time then! Maybe the trick to get Kevin to build a simpler enclosure is to ask him a dozen times to build something more complicated?

                                The delay gave me time to find even more ideas on improvements to be made. Who knows, if I got the speaker earlier I might have just stayed in audio nirvana and not worked on any other improvements to the speaker. (and now Kevin is probably thinking of taking a few more months longer "so I can find more improvements"!)

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