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  • New 3way build - no name yet

    Ok, it's time to start this puppy up. I've been working on this one for a while on paper and slowly aquiring the drivers. I's time to bring it out of the closet, litteraly, 'cause I've been hiding them from my wife until the right time. :D It's easier to ask for forgiveness then to ask for permission, right? It's going to be a 3way but I haven't completely decided on the configuration. I'm still on the fence about which way to go. Any input is welcome...

    Here's the TMWW


    and the WTMW


    The drivers I'm going to use are the SB Acoustics SB17NRXC35-4 woofers (2 each, in series), the Morel MDM55 midrange and the new Fountek Neo X 2.0. These will be paired with a CSS SDX10 sub in a 2.5cf, sealed cabinet now driven by the BASH 500 amp. I'll put up a small thread in the Speaker Gallery to show that off in a little bit. I want to make mention of Mark at Meniscus. He went way out of his way to somehow aquire the final 2 woofers as everyone was out of stock and it was going to be months before they became available again. This was over a month ago and they're still out of stock! They're going to sit on stands with the tweeters at listening height, 32-35" depending on the final configuration.

    More to come on why I chose these drivers...

    Last edited by takitaj; 07-05-2012, 04:35 AM.
    Hybrid floor stander build - The Tikki Lau - D8's

    CNC baffle cutting services

  • #2
    Re: New 3way build

    I chose the 2 SB17's because of price to performance ratio plus I prefer the sound of paper vs aluminum and I didn't want to deal with the cone break up. The sensitivity is really good (92db) and they're 4 ohms so I could run them in series and end up with a reasonable Re with good sensitivity in the end. Xmax was on par with the competition, they'll reach down to a solid 40Hz in a < 1.5cf cabinet and I only needed to hit around 50-60Hz to cross to the sub. They're built really, really well.

    I chose the Morel MDM55 due in part to it's reputation, small size, the shape matched the tweeter I wanted to use (this is important too ) and I just like the sound of a well done soft dome mid. A small built-in rear chamber was really the only option to keep the cabinet size as small as possible for high WAF so a cone mid was out of the question. I've tried the DC50 and it was ok but it is physically way too big. The Dayton RS52 was a close second but here again I didn't want aluminum and it's just too big for this build also.

    Now the tweeter is a different story. I've been wanting to try a true ribbon tweeter. I had a backup plan to use the SB26STCN-c000-4's I have if the ribbons didn't work out. I chose the Neo X 2.0. This one was a tough decision because there really isn't any info out there on these guys. Just the factory FR and IMP graf along with the basic T/S params of course. Given it's predecessor's success and that it was supposed to be an improved version of NeoCD's, not to mention the lack of availability of the NeoCD's at the time, I took a chance and went for it. Of course the day after I ordered them the CD's came back in stock. :( It's ok though, so far I don't regret it, they sound awesome. As I mentioned in another thread, even with a thrown together xover sitting on top of the center channel they sounded really nice. Of course now I have to get another one for the center or it's going to sound really dull compared to the mains.

    Box sims to come next...
    Hybrid floor stander build - The Tikki Lau - D8's

    CNC baffle cutting services

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    • #3
      Re: New 3way build - no name yet

      Ok, I had some time to do some more on this project. Given the parameters of my room, the planned height and positioning I decided to go with a TMWW. Using Unibox I come up with about a 40L box tuned to 40Hz with a rear mounted 3" double flared port, about 6" long. All I need to do is put the 2 ends together to get the 6". WinISD pretty much agrees with Unibox giving me an F3 in the low to mid 40's.




      WinISD's prediction


      Now the excusion shows a bit over xmax at the rated power but keep in mind these will never see below 50Hz anyways due to them being crossed to a sub somewhere between 50 and 80Hz.

      And the port speed the same.


      Next will be the cabinet design...
      Hybrid floor stander build - The Tikki Lau - D8's

      CNC baffle cutting services

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      • #4
        Re: New 3way build - no name yet

        I'd guess if you drop the watts in unibox to where the FR was around 100 DB you'd end up being ok on your excursion without a sub. It looks like a fun project keep us posted.

        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

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        • #5
          Re: New 3way build - no name yet

          Yes, this is true. It doesn't take much either. I just wanted to see/show what it would be like at max rated power. I don't think I'll be listening at 110+db too often. :eek:

          The Unibox power field is wierd. It's actually set to 30w. When you use 2 drivers, even though it's set to 2 drivers in series, it doubles whatever you put in that field. So I don't put too much faith in that chart. **edit: When using multiple drivers. WinISD doesn't show excursion but it shows 114+db at 60w, plus it shows the port speed (3"x6") at .12mach. Bassbox shows excursion running out at around 100w. It's all an estimation. The truth will be known when the box is built and I put the fire to it!


          TJ
          Hybrid floor stander build - The Tikki Lau - D8's

          CNC baffle cutting services

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          • #6
            Re: New 3way build - no name yet

            One cabinet is done and measurements have begun. *Just want to note that these are in-box measurements. I'll put up more info on the cabinets later but the basic dimensions are 28" high x 10" wide x 12 3/4" deep. The 3" double flared port is mounted on the back, center 5 1/8" down from the top and is 7 1/2" long giving a tuning of around 35Hz. The walls are lined with poly batting (from Meniscus) and a small folded piece of additional batting approximately 24" high x 24" wide placed directly behind the woofers.

            I also decided on a name....The Ancino's. Named after my grandfather, Angello Cincotta, who just passed away last month. 2 days before his 91st birthday. :( This was the screen name that he used. He was also somewhat into speaker building too. He built his current speakers MANY years ago and was a TV repair man "back in the day". I can't figure out how to change the thread title. You used to be able to do it but I can't find how to do it with the new forum software. If anyone knows how....

            Back on topic ...Measurements were taken semi anechoic at 2m with the cabinet in place on a 16" stand, 12" out from the wall and roughly on the tweeter axis. They were gated to just before the first reflection which was about 7ms. I used Omnimic and WT3 (DATS) to actually take the measurements then imported into Soundeasy and "tailed" using the Hibert-Bode Transform function. The crossover design will be done in Soundeasy and I'll probably plug the values into PCD too as a sanity check. I will update with impedance and distortion, etc. graphs soon as well.

            Upper and lower woofers (SB17NRXC35-4): These guys are pretty nice except for the breakup just below 1K. It's not really audible but it's causing a little trouble with the xover. Originally I wasn't worried about it as I was planning to cross below there but as I'll mention below the midrange is causing me to have to cross right at or just above it. Initial distortion checks were excellent. The dip around 140-150Hz is my room. It's there with every speaker I've tested so far.


            Lower:


            Midrange (Morel MDM-55): I'm not so pleased with this driver. As you can see it has a pretty pronounced "stepped" response at 1.2-1.5K. It is however very smooth and faily flat above that point. Distortion was also pretty good. I think it's going to end up being more of a "filler" taking over around 1.2-1.5K and handing off to the tweeter around 4-5K. Unless I can work out the "step" and preserve enough sensitivity to keep up with the woofers and tweeter. I may be glad I only did one box so far. I'm not leaving out the possibility of replacing this driver with something else. I like the looks of that 3" Vifa or perhaps the RS52, it's just so big though.


            Tweeter (Fountek NeoX 2.0): Ahh, my first experience with a ribbon tweeter. It's different, that's for sure. It measures out pretty close to the mfg graphs. The impedance is wierd lol. It also has a big step in the response but it's going to be a lot easier to deal with this one, especially given it's 94db sensitivity. Distortion on the Neo is really good as long as you stay above 2.5-3K. It's mostly 2nd order and the rest is very low. It is very detailed and revealing. I'm excited to hear how it will sound when finished.


            More to come...

            TJ
            Hybrid floor stander build - The Tikki Lau - D8's

            CNC baffle cutting services

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            • #7
              Re: New 3way build - no name yet

              Interesting project!

              Why not try the little SS10F? Should be enough with a really small chamber.
              "It is only Scrooge McDuck and others with a personality disorder who have money as their goal"

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              • #8
                Re: New 3way build - no name yet

                Don't freak out on that midrange 'step' as you should be able to smooth it out with a simple notch filter. You may want to ask Chris Roemer for help if you struggle with it - Chris is The Man!

                Not sure I would have gone with the Morel, but once you hammer out the x/o issues I'll bet you're a happy dude. Keep us all posted.

                Marty

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                • #9
                  Re: New 3way build - no name yet

                  Not sure that the irregularities in the MDM55 are real or at least inherent in the driver itself. The ones I used in the Blades measured very smooth throughout the range (see below). These were smoothed results, but unsmoothed showed little difference. Also, if you check out Zaph's postd measurements, you will see they don't indicate the step you are showing in the passband.

                  There may be something else affecting your results. Perhaps it is diffraction related, but I didn't see any information about the box. Maybe some large chamfers in the region of the mid would address this. If it is diffraction related, you may find a similar result with other mids.

                  Good Luck!

                  Dan N.

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                  • #10
                    Re: New 3way build - no name yet

                    I measured at 1 inch away just to check for any anomalies and here's the graph. Very little diffraction effects, pretty much as modeled. It actually smooths out further away. I can beat it into submission but the initial intention was a simple smooth integration. I did do my homeworks and I looked at other's measurements, etc. before deciding on these but mine don't seem to measure like the others I've seen. Oh well, I'll just have to deal with it or go in another direction. Thanks!



                    I hadn't posted it yet but here is the plot from the xover I had come up with. Granted it's extremely flat but it takes $300+ in parts to get it there. (see xover pic)

                    FRD Plot *note the db scale :D


                    Xover


                    TJ
                    Hybrid floor stander build - The Tikki Lau - D8's

                    CNC baffle cutting services

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                    • #11
                      Re: New 3way build - no name yet

                      Well I'm no crossover genius but I think I can save you at least eight pieces on the woofers....eliminate everything after C13. The SB17 is a well behaved unit and shouldn't need all that manipulation. As far as your Morel goes, it looks like you have it running well: +/- 1.5 dB is mighty fine stuff!

                      Remember 'Flat ain't always where it's at'. ;)

                      Marty

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                      • #12
                        Re: New 3way build - no name yet

                        The only concern I have is the limited bandwidth of the Morel in your sim. I've seen it used most of the time between 1k and 5k, and sometimes as low as 850-900 Hz. I think you can give it a bit more bandwidth. Even in your case, you should be able to tweak the knee on the HP and make it flatter.

                        As to Unibox, you can select either series or parallel for your combo of drivers, there is a drop list with quite a few selectoins.
                        Later,
                        Wolf
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