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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

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        • #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

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                • #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.

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