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Introducing the "INTIMATES" (high WAF & quality sound)

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  • Introducing the "INTIMATES" (high WAF & quality sound)

    If you're getting a good tax refund this year and are in search of a high quality 'build' mini-monitor project, read on....

    About a year ago I became intrigued with a dated Stereophile review of what turned out to be the very popular Sonus Faber Extrema (SFE) loudspeaker. But it was Martin Colloms' preamble to the actual review that caught my attention. The crossover design, he explained, was extremely simple, but needed special drivers to be as successful as it eventually was. Just a resistor in series with the tweeter and two coils and no capacitor. At the time the xo design was called the "Sine-Cap". The design required a high wattage resistor and the production SFE sported a heat sink on the back of the cabinet. http://www.stereophile.com/standloudspeakers/915

    At the same time I discovered the Acoustic Reality series xo. It also had only 3 parts and again, no capacitor. http://arhifi.dk/store/product.php?id_product=22

    I decided to build (more correctly stated; assemble) two mini-monitors, one with the SFE xo and the other with the AR sxo so I could compare their measurements and sound. Each design resultd in a 1st order elect xo so I knew I needed to find some very good quality drivers that could handle the demands of those xo's. I eventually settled on a SS D2905/970000 tweeter and SS 15W/8530K 01 woofer mid which when coupled with a 1/2 cu. ft. vented box could easily get down to 40 hz. Not wanting to be bothered with constructing boxes, I decided on the attractive PE p/n 302-723 curved sided cherry 'finished' cabinets. The other critical consideration in the driver selection was that each had a relatively smooth extended FR.

    A BB drawing was created and when the cabinets arrived, I had 2 BB's professionally cut so each driver was flush mounted. Next, cabinets were assembled and drivers and wires from each were snaked out the back two holes that come pre-drilled in the cabinets. I set up my virtual xo box and started varying parts until each xo design measured and sounded quite nice. Sorry simmers; no PCD's to display. The xo's were arrived at totally empirically. Off axis response was also excellent (see link below)

    With the SFE design I still had the problem of dealing with the tweeter's series wired resistor and its power challenges and inherent heat dissipation. Then it hit me. I needed to install a vent (ended up 2" dia. X 9" long PE p/n 260-387). So, locating the resistor near the vent's internal mouth would naturally cool it by the air flow thru the vent. I decided on locating it high up on the back side behind the tweeter and selected Mundorf M-resist 20W resistor. They come with a convenient 1/4 in hole thru their center. I cut some 1/4 inch wood doweling and installed two pre-fabed wooden 'nests' on the inside cabinet sides to rest the dowel in a position that suspended the resitor right over the end of the vent tube.

    High quality coils were selected. A 3.0 mH, 15 ga. air coil for the woofer/mid and 14 ga. copper foil coils for the tweeter parallel coil. Being concerned about tweeter protection in the event of a DC surge, I decided to add a totally optional high value cap in series with the tweeter and settled on a 500 uF Bennic which didn't impact the already finalized xo topologies.

    After some extended listening with each xo in my somewhat reverbarent listening room, I decided on the SFE xo with it's small BBC dip response using 15 ohms for the series resistor. If you want a flatter response, you can try a 10 ohm resistor in place of the 15 ohm shown on the schematic. I haven't had much luck with it. Evidently, the 5 ohm reduction in series resistance is just enough to bring on ringing.

    In the meantime my wife saw the finished speakers and said "your keeping those aren't you?" :D So, they now reside in our living room where no speaker system has sat for many years since we first got married and I owned a HK compact stereo. Bass extension with these woofer mids in these vented cabs is surprisingly low and articulate. Reviews from fellow audio society members who've visited for extended listening sessions have been very positive.

    I decided to call these speakers the Intimates because they aren't designed for regular 95+ dB listening. They perform best with acoustic music and vocals from smaller groups. I have them on 26 inch high solid cherry stands located about 1 ft from the wall to take advantage of the vent's reflected output. Being a hugh fan of classical music, I also listen to symphonies with them as well. They hold their own, but obviously don't have the big, complimentary symphony sound you'd get from a much larger multi-driver speaker system.

    Below are a couple of teaser pics of the speakers and some measurements which some of you may have seen posted in other threads. Visit here for more detail pics of the internals, BB dwg and xo schematics. http://s1219.photobucket.com/albums/...ct%20pictures/










    ADd a xsim model of the above design.
    Last edited by carlspeak; 10-12-2015, 08:51 AM. Reason: Added 10 ohm resistor option
    Intimates with AMT tweeters now a parts kit available to DIY'rs.

    Live in Southern N.E.? check out the CT Audio Society web site.

  • #2
    Re: Introducing the "INTIMATES" (high WAF & quality sound)

    Carl,
    Been following these for some time. Great build and a good challange. I doubt they sound any less than wonderful!
    Facebook Page - Ocean State Acoustics

    Comment


    • #3
      Re: Introducing the "INTIMATES" (high WAF & quality sound)

      and his wife likes them.
      " To me, the soundstage presentation is more about phase and distortion and less about size. However, when you talk about bass extension, there's no replacement for displacement". Tyger23. 4.2015

      Quote Originally Posted by hongrn. Oct 2014
      Do you realize that being an American is like winning the biggest jackpot ever??

      http://www.midwestaudioclub.com/spot...owell-simpson/
      http://s413.photobucket.com/albums/pp216/arlis/

      Comment


      • #4
        Re: Introducing the "INTIMATES" (high WAF & quality sound)

        Very nicely done Carl! I see why you were intrigued... Thanks for sharing--now I am intrigued too. Just what I need, another build to add to my already long list :p
        Jason


        "In my opinion, there are more tactful ways to state your opinion."

        Comment


        • #5
          Re: Introducing the "INTIMATES" (high WAF & quality sound)

          I can't quite understand what you did with the dowling /resistor /vent. Pics?

          Comment


          • #6
            Re: Introducing the "INTIMATES" (high WAF & quality sound)

            Originally posted by 2leftthumbs View Post
            I can't quite understand what you did with the dowling /resistor /vent. Pics?
            Go back to my photobucket album link. Double click on the top row middle pic. It will show the dowel being held in little wooden 'nest' blocks I glued to the sides of the cabinet walls. I picked a spot that has the resistor suspended about 1/2-3/4 inches above the mouth of the vent tube, but not too high to intefere with the tweeter magnet. I have a few more pics I could upload if need be.
            Intimates with AMT tweeters now a parts kit available to DIY'rs.

            Live in Southern N.E.? check out the CT Audio Society web site.

            Comment


            • #7
              Re: Introducing the "INTIMATES" (high WAF & quality sound)

              I know I'm going to feel pretty stupid when I see the answer, but what is a BB drawing?

              I really love the look of these, wish I could afford the drivers...


              Nice work!


              Mark
              You go your way, I'll go mine. I don't care if we get there on time.

              ~Pink Floyd

              Comment


              • #8
                Re: Introducing the "INTIMATES" (high WAF & quality sound)

                Originally posted by Mark65 View Post
                I know I'm going to feel pretty stupid when I see the answer, but what is a BB drawing?

                I really love the look of these, wish I could afford the drivers...


                Nice work!


                Mark
                Sorry Mark for being criptic. BB=baffle board.
                Intimates with AMT tweeters now a parts kit available to DIY'rs.

                Live in Southern N.E.? check out the CT Audio Society web site.

                Comment


                • #9
                  Re: Introducing the "INTIMATES" (high WAF & quality sound)

                  Looks reasonable, Carl!

                  I almost did this with the Glucinium Amor MTM I did. I mapped out a sim, but didn't have the guts to try it out.





                  Hope to hear yours one day...
                  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: Introducing the "INTIMATES" (high WAF & quality sound)

                    Originally posted by Wolf View Post
                    Looks reasonable, Carl!

                    Hope to hear yours one day...
                    Wolf
                    Well, if you can make the CT. Audio Society Aug. mtg mini-monitor shoot out, you'll be able to. ;) (www.ctaudio.org)
                    Intimates with AMT tweeters now a parts kit available to DIY'rs.

                    Live in Southern N.E.? check out the CT Audio Society web site.

                    Comment


                    • #11
                      Re: Introducing the "INTIMATES" (high WAF & quality sound)

                      How did you like those Dayton pre-built enclosures? I was contemplating them for my current build. Kind of wish I went with the pre-built enclosures because it's taken me a week just to build the enclosures, not to mention finish them.

                      I decided to build the enclosures to custom fit my entertainment center and to save the $210 the 3x Dayton .50 cu foot enclosures would have cost.

                      Comment


                      • #12
                        Re: Introducing the "INTIMATES" (high WAF & quality sound)

                        Originally posted by carlspeak View Post
                        Well, if you can make the CT. Audio Society Aug. mtg mini-monitor shoot out, you'll be able to. ;) (www.ctaudio.org)
                        Though I'd like to- it's a far journey, and my wife is due that month.

                        Not gonna happen,
                        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


                        • #13
                          Re: Introducing the "INTIMATES" (high WAF & quality sound)

                          Originally posted by lucasa.miller View Post
                          How did you like those Dayton pre-built enclosures? I was contemplating them for my current build. Kind of wish I went with the pre-built enclosures because it's taken me a week just to build the enclosures, not to mention finish them.
                          I like mine alot. The finish is smooth and shiny but not real cherry. There is a brace about 1/2 way front to back. It can be seen in the photos I provided. There was a minor issue with one of the grilles not adhering to the BB reliably due to the BB screws were a bit deep into the BB and the magnets on the grille frame couldn't be as effective. I just installed some small washers under the screw heads to make them flush with the BB face and now all is well.

                          I can vouch for the cabinet's strength. One of the assembled cabinets fell about 3 feet onto a carpeted floor :eek: and there was not damage. Close call though!
                          Intimates with AMT tweeters now a parts kit available to DIY'rs.

                          Live in Southern N.E.? check out the CT Audio Society web site.

                          Comment


                          • #14
                            Re: Introducing the "INTIMATES" (high WAF & quality sound)

                            Nice project! But is that a ferrous screw in the center of the woofer air core inductor? If so it will alter the inductance and likely add non-linearity.

                            Comment


                            • #15
                              Re: Introducing the "INTIMATES" (high WAF & quality sound)

                              Originally posted by sdl2112 View Post
                              Nice project! But is that a ferrous screw in the center of the woofer air core inductor? If so it will alter the inductance and likely add non-linearity.
                              That was changed to a brass one when the whole coil came loose from its moorings.
                              Intimates with AMT tweeters now a parts kit available to DIY'rs.

                              Live in Southern N.E.? check out the CT Audio Society web site.

                              Comment

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