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Javelin - a high end journey into digital active speaker systems

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  • Javelin - a high end journey into digital active speaker systems

    Hey Everyone. Just thought I would create my first project post here and at least create a place holder. As the title implies, this is not a completed project but the beginning of my first serious project in a long time. I have been reading through TechTalk and a handful of other DIY audio forums for about 15 years now, only actively participating here for the last 6 months or so.

    This project reflects my ideas/ideals in a domestic hi-fi project. It is the result of my best amateur thinking along these lines, while I still dream about a few other categories, like my version of the best near-field monitor, studio mains monitor, wave guide tower or ultimate reference listening room system... I am finally going for broke and pressing forward with this particular idea. Having spent so many years thinking about so many possibilities, it is very unnerving to actually start putting stakes in the ground and pushing the "buy" button.

    This thread will eventually be jam packed with pics and a ton of text... so my apologies if you prefer brevity : ) To be honest, this will be a little self-indulgent as I would like to create something to help me look back and reflect on my experience with this exciting project, especially since I probably won't be able to afford the time or money for another project anytime soon. Also, as I have read through hundreds upon hundreds of project threads, I always find myself looking for a little more detail and/or wondering where the owner was coming from regarding context and thinking that led up to his/her decisions. There will be little left to the imagination on this one.

    Right out of the gate I must state that unlike many others around here and other places, I am not a talented engineer with a deep understanding of acoustics and even more so the electrical components and systems that go into a speaker system. I am a very experienced listener and reader however, being obsessed with home hi-fi, music studios and many things audio since I was in junior high school about 35 years ago. I am an enterprise software architect by trade, so I like to think that I have a very good sense of systems and synergies across a variety of topics.

    Over the next few months I will be covering the following:

    1) Introduction (more to follow)
    2) Design Objectives
    3) Design Concepts
    4) Component Selection
    5) System Roadmap
    6) Unboxing
    7) Blueprints
    8) Sawdust
    9) Assembly
    10) Testing
    11) Tweaking
    12) Final Thoughts and Listening

    I hope that you will have some fun following this thing. I will be very honest about the joy and the pain, and the general anxiety of trying not to stray too far in over my head. Please feel free to jump in and offer any type of feedback, positive or negative... I will offer a defense (or perhaps just a poor excuse) of what I am doing, but I am not sensitive and welcome your unvarnished thoughts. There will be opportunities for your input to make a difference at a variety of decision points, so I hope you will offer up whatever you can think of.


    Greg Jensen
    Twin Cities MN
    Last edited by Greggo; 08-31-2014, 02:54 PM.

  • #2
    Re: Javelin - a high end journey into digital active speaker systems

    You should have a chit-chat session with Charlie Laub and Neil Davis, I'm pretty sure they were working out the kinks on a similar design (electronics-wise) and could point you in a good direction like the Cheshire Cat.

    रेतुर्न तो थे स्रोत
    return to the source
    leviathan system thread
    deadhorse thread
    shockwave build thread

    instagram :: greywarden_13

    in war, victory . . . in peace, vigilance . . . in death, sacrifice.


    • #3
      Re: Javelin - a high end journey into digital active speaker systems

      Thanks greywarden. I did a bunch of searching on posts from both of the gentlemen you mention above. Neil does some neat stuff but I am going to go miniDSP 4x10 Hd to start with. Unless a new product is announced in the next two weeks, as I am waiting until the very last minute before I push the buy button on this, it is the only significant component for this project not currently sitting in my basement. Charlie has done some cool stuff in providing advice and tools for setting up digital crossover designs so I will go back and get more familiar with his stuff and reach out to him soon.


      • #4
        Re: Javelin - a high end journey into digital active speaker systems

        Current design, hopefully not subject to change but you never know. Before I dive into a long write up on my background, objectives, and concepts... here is a pic to get things started. Well, actually just a diagram... but someday...

        Click image for larger version

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        • #5
          Re: Javelin - a high end journey into digital active speaker systems

          My Hi-Fi History

          1980 - I am living with my Dad in a suburb of San Francisco and he surprises me with an evening at a stereo show. For the previous 3 or 4 years I have been living on a potato farm in northern Maine with my mom and step dad, reading stereo magazines but never having a chance to hear much beyond Radio Shack models and the Bose speakers my local Radio Shack would carry. Between the two brands, some models were actually pretty good.

          So we go to the show and the following events change my life forever:

          1) Listening to the Infinity IRS - waited around an hour to finally get into a medium sized room with around 16 other people. The majesty and scale of that system was amazing. Of course, I am not a very good listener at this point, but I am forever convinced that bigger is better most of the time and have trouble pulling the trigger on small speakers no matter how impressive, because I am always afraid I am going to wish for more scale and dynamics at some point down the road… so I go without since I can’t afford bigger and better, what a dumb philosophy, still haunts me a bit to this day.

          2) Acoustic Research AR9 - My Dad was in the Air Force and had a pretty nice system he bought while stationed in Japan, big pioneer speakers and their top of the line receiver at the time… We both couldn’t believe how awesome this speaker was. He was tempted a few months later to actually buy a pair at the local stereo shop but decided not to. I was crushed. This is the first time I can actually hear and identify things I read about in printed reviews like imaging across a sound stage further enhanced with a sense of depth and to a lesser degree even some height, midrange that communicates the human voice in such a lifelike manner that it reminds you of sitting in church and hearing someone sing while you feel some goosebumps on your arms, and bass that sounds like real bass, and percussion that is capable of startling you with real dynamics rather than just being loud and hurting your ears. The Infinity IRS captured my imagination, but the AR9 stole my heart.

          3) Shahinian Obelisk - Not sure about exact model, and not sure about the room and various characters, but I think Bud Fried was in there (and I think someone from Heil as well) with Dick and they were gabbing about a bunch of stuff, they notice me and comment on how young I was to be interested in this stuff and after 30 minutes, Dick Shahinian writes down the name of the music I liked after I commented on how I had never found classical music that interesting before. It was Mussorgsky, Pictures At An Exhibition. After vinyl and then CD and a few different versions, one of my favorite discs to this day. Of course, at the time I had no idea who I was hanging out with, but years later when I would read through every page of stereophile magazine, I would often see names/faces/speakers that I would remember from this show. What a gigantic opportunity it turned out to be for me, without a doubt the coolest thing my Dad ever did for me.

          4) Dahlquist DQ-10 - Again, some fuzzy memory here, but for some reason I think these were in the same big room / open area that I saw Shahinian and Fried and a few others. A couple of the sales guys I was talking to pointed to them and said I should wait a few minutes to hear them play some music. I thought it was a joke for a second as I remember thinking that these “things” weren’t really speakers, they didn’t look like impressive speakers to me after all, especially after seeing the IRS, but I eventually heard them and was stunned. Not as thoroughly as I was with the AR9, but I knew I was hearing something special even though I could not readily identify or describe it.

          Overall, it turned out to be a crash course in audiophile systems and culture, and to this day I wish I had followed my heart and pursued a career in this industry even though it has turned out to be a rough ride for many.

          A few months later I was dragged to a dinner party and a young doctor and I were talking about hi-fi and he offered to take me over to his new house to hear his system (he lived just down the street aways). So my Dad said that would be OK and I heard the full Magneplanar tympani system with Phase Linear amp and AR tube preamp. Toto, Hold The Line, a simple song that sounded like a studio session right in front of me. Now I knew what “fast” meant, when reviewers talked about speakers that could immediately let go of the notes and let them just float in front of you. I still smile when I hear that Toto song playing anywhere, the evening of listening to music and being spared the boring dinner party talk now forever etched in my mind. I was 16 years old at this point.

          Snell Type A - The last time my Dad and I listened to high end audio stuff together, this was the speaker. We both looked at each other like we were witnessing something very special. If there was a poster of this speaker, It would have been on my wall instead of the Farrah or Lambo pics of the day.

          Wrapping up my experience, over the next 20 years, through college and my own stint in the Air Force and my work during the height of the IT/dotcom explosion as a consultant... I pursued audio experiences but never really owned anything decent. I don't know why that is to be honest, I was always afraid to commit the dollars to what I liked, even when it was within reasonable financial reach. Every time I traveled, which was often, the first thing I did in my hotel room was to grab the yellow pages and find some stereo shops to visit, this included vacations with my wife in tow as well. I even made a few special trips for RMAF. For about 5 years, she really liked it but eventually became tired of my obsession. Together, we eventually settled on some Audio Physic Tempo II speakers. We really wanted the Virgo, but had to settle for the Tempo. I followed that up with a used Perreaux preamp and power amp of very good quality, a Panasonic DVD player that got rave reviews for CD playback, and a Project turntable with some nice upgrades. This lasted about 5 years and was the nicest system I have ever owned. Even more importantly, for the first few years it was all in a nice dedicated room I had remodeled just for this purpose. It was heaven for a while. Then the dotcom bust, sell the house, and a few years of misery to recover from a very big professional and financial set back.
          Last edited by Greggo; 08-10-2014, 08:34 PM.


          • #6
            Re: Javelin - a high end journey into digital active speaker systems

            My Hi-Fi History...continued

            Up until this point, my wife and I together experienced a few highlights that we still talk about to this day. So here are what I remember as the top 5 audio experiences in the last 20 years, listed in order of how much we thought we could spend the rest of our lives thrilled with the sound we were hearing:

            1) Linn Keltik fully active (mid 90s) - a small shop in San Antonio TX had a room set up to perfection. This is the system my wife still remembers to this day. We were driving a Honda Accord at the time, and briefly considered selling it to finance this system but we didn’t have a house to put it in, just a crappy apartment

            2) Apogee Duetta (early 90s) - sitting on top of subwoofers, and yet so far out of reach...starting to realize this hobby is cruel.

            3) ProAc Response 2 and somewhat later, the Totem Mani-2 - both of these speakers snapped me out of the “bigger is better” mind set. So musical and compact and powerful, made a lasting impression on me.

            4) Harbeth M40.1 - There is something slightly off about these things… but with my music on the importer’s demo system at the time (Fidelis AV in New Hampshire) this is still the most “musical” speaker I have ever heard in my entire life. I don’t know what “musical” really means, it may not actually be as big a compliment as we want it to be, but there is no doubt in my mind that there is a certain quality achieved here that sets a mark most other speaker companies fail to equal.

            5) Dynaudio tower speakers and Studio Mains Monitors - Heard some prime examples of both the same summer, really liked what I heard. Bass and mid-bass really stood out for me, tweeters did a nice job too but I thought the low end was where these things stood out from the pack. Not in depth, and not necessarily even in slam, just life like coherence.

            So how does this all add up? I think I prefer my martinis on the dry side, and despite a couple of two-ways making a big impression on me, I really like 3 or 4 way speaker systems. Yes, they often lack the pure voice of a good 2-way, but I am addicted to the idea of a small cone or dome mid that then hands off to the tweeter. There is a presence or a dimensionality to big multi-way speakers that I just love, and I just don’t get that same sensation from small 2-way designs. And I want a really strong and clean bass to mid-bass transition. I don’t care so much about 30 Hz or 25 Hz or 20 Hz or lower… I just want 30-300 to be as clean and dynamic as possible, with zero strain on the drivers tasked for the job. And finally, I like stuff that looks different… something about being off the main road really appeals to me, and since I look at my speakers even more than I listen to them, industrial design is a big factor for me and I am willing to compromise a bit in order to have the visual aesthetics bring a smile to my face as often as the sonics do.

            I know what you are thinking now... more pics less talk. OK, I will start with some diagrams later this evening, and then move into some actual pics tomorrow. Stay tuned.
            Last edited by Greggo; 08-10-2014, 04:06 PM.


            • #7
              Re: Javelin - a high end journey into digital active speaker systems

              This thread should really be in the Tech Talk Forum section as this section is for completed projects and build details.
              “I cried because I had no shoes until I met a man who had no feet”

              If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

              Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D


              • #8
                Re: Javelin - a high end journey into digital active speaker systems

                Well, obviously I don't have such a strict interpretation. I would find it more out of place in TechTalk because I am not asking for references or help with specific issues in this thread, I am documenting a build that has started with design, component selection, purchases, resources... and will very soon move to sawdust and soon after result in a phase one completion. Since I am already past the point of no return, this is a real project.

                There are plenty examples here of just that, though many have posted from the sawdust stage of the project, but then take weeks or months to arrive at completed state, posting along the way. This is no different. For specific issues I have and will continue to post in TechTalk, but this is in fact a build diary and hopefully one that will at least be enjoyed by a few.


                • #9
                  Re: Javelin - a high end journey into digital active speaker systems


                  Please continue, i must say its one of the most enjoyable thread i ever read in here .

                  I do wonder though why the complexity of the dome mid between satori mid and tweeter?


                  • #10
                    Re: Javelin - a high end journey into digital active speaker systems

                    Henry, thanks so much for the nice feedback. The dome mid was, along with the woofers, a difficult decision for me. Jeff Bagby and Joachim Gerhard have both earned a tremendous amount of respect from many of us. I have only known about Jeff for about a year now but I have been a big fan of Joachim for many years. Comments from both of them and their success with the Satori mid and tweeter was the primary inspiration behind those choices. The addition of the Morel mid dome was kind of a “why not” moment for me, knowing that I was not interested in true subwoofers, at least not yet, and that I had 4 channels to work with from the miniDSP 4x10 Hd. I thought that even though it may in fact be a bit of a thorn in my side to get everything going, that longer term as my skills and DSP resources improve that it would become an asset. More on why I like mid domes will emerge in the following paragraphs.

                    Design Objectives:

                    1) No Strain
                    2) No Bloom

                    It took me a while to figure out what my real priority was here, and this simple description came to me after I was already committed down this path. But I think we all want the same thing for the most part… smooth frequency balance, low distortion, solid bass, good imaging, detailed and high resolution sound, natural voices, crystal clear highs, etc… So what was it about my objectives that would/could possibly explain this particular path I am on? I think it boils down to strain. I hear speakers fall apart all the time. Every time I push a speaker just a little past reasonable SPL in room, I start to hear a very slight change in character. Some of that is the room talking, the reflections may be manageable at one level, but then become more audible at higher levels and have a changing ratio in terms of the direct sound. But as I continue to listen and especially if I start to really push things up, I hear the drivers start to sigh or grunt at best, and flat out start crying at worst.

                    Earl Geddes, and many others, are rolling their eyes at this kind of subjective nonsense. But then again Earl would be the first to tell you that 1 inch domes are terribly inadequate in a number of ways. So if I am not going the waveguide route (and I really wanted to go this route, but things just didn’t come together the way I wanted them to, and then I also lost a little bit of faith in terms of that being the path I really wanted to go down), then how do I ensure that I get the general crossover points and assigned passbands for the drivers to line up the way I want and ensure that every driver is extremely comfortable with it’s assignment? Well, I will start by not pushing the limits on the tweeter and keeping the rest of them well below their upper frequency response limits as well. That’s where the mid dome comes in, and also why I still have a mid-bass rather than just woofers in the equation as well. No Strain. As other’s have pointed out, that is a bit overkill, but for me an important factor.

                    The “No Bloom” thing has two meanings for me… first, nothing ripe or wet or emphasized in the presentation from a direct axis sound perspective. Second, nothing significant in terms of frequency balance from a reflected sound perspective. I want the transition from woofer to tweeter to be assisted by other drivers so that the directivity is consistent. I also want the speed, timbre, etc… to be as consistent as possible between drivers, figuratively speaking of course, I don’t know if these things are real and can be measured but I use these terms to identify a sensation that seems to be consistent with my experiences. There is something about the "character" of a mid dome that I seem to gravitate to. Forget the quick digression on character however, the overwhelming concern I have is directivity and waveform. I have always felt that domes are more effective than cones (at low to medium listening levels), so if I can have two domes instead of one that is great. If they blend well together then my transition to cones happens below 1 kHz rather than above… and I can’t explain this, and it might not even be real, but this matters to me for some unexplainable reason.
                    Last edited by Greggo; 10-04-2014, 10:07 PM.


                    • #11
                      Re: Javelin - a high end journey into digital active speaker systems


                      I am approaching this project as an artist (maybe intuit or empath is a better term as I am not much of an artist in any medium) more so than as an engineer or scientist, I am not depending upon deep study here as much as I am trusting my gut after many years of listening, reading, thinking, comparing… What I really want is a world class mains monitor for a recording studio, but one that will not sound harsh, throw at least a decent image, and look nice in my family room. I think most studio owners/producers want their “mains” to accomplish something a bit different from the nearfields that the audio engineer holds near and dear to his heart. As much as I appreciate the latter, I am landing on the former, and here is my interpretation of the priorities for a mains monitor:

                      1) Look cool, or better yet, look strong and confident, set the expectation with the humans in the room that whatever they are about to ask you to reproduce, you will do so quickly, competently, and with a sense of power and ease that will be awe inspiring. Say whatever you want about form vs function, or looks vs performance, or whatever… but I enjoy this experience personally. I want it all, good audio performance is the central theme, but I want my speaker to “work the room”, to establish a personal space and hold court.

                      2) Deliver the goods… not the audiophile nuance per se (but we will be in search of this), just the meat and potatoes. Honest balance but maybe a tilt towards warmth, and competence at the frequency extremes, and ready to rock all night long, no break, no visible sweat (audible strain), no “could I get a class of water” or “could someone turn on the air conditioner, it’s getting a bit warm in here”... just “Let’s Dance”.

                      Getting back to more tangible objectives, there are a few crucial guidelines that serve as the foundation of this project. I am looking at this project the same way I view a sophisticated computer workstation in some ways. For me:

                      1) The drivers are the monitors, and they are expensive high resolution color calibrated monitors using technology that is probably not going to change significantly anytime soon. And I will need a few of them at least, maybe even a handful or more… So get what you feel will satisfy your needs both today and 5 years from today. Make sure you have all your angles covered, enough viewing space, enough resolution, etc.. I may not use all the monitors all the time (like the mid dome perhaps), it just depends on what I feel gives me the best view for the type of work I am doing. Sure, I may swap a new one in and an old one out, but I would prefer to just set and forget.

                      2) The cabinets are like a desk/chair/mouse/keyboard. They are a pain in the backside to get right, but compared to everything else, it is not really that big a deal to just change them all out for something new and different. So I hope to get it right the first time, but I am not overly concerned about it. For most designs, I don’t think the cabinet matters as much in terms of shape, driver locations, and overall form for the most part, but it does need to be solid, sealed (in this case), and as non-resonant as possible. My own experience has me less concerned about driver spacing, orientation, and diffraction than many other builders, but only to a certain degree as I am quick to admit that all of these things are also capable of ruining the end result.

                      3) The DSP/Amps all go together as the actual workstation, and they are in two parts:

                      3a) Hardware - I am going to start off modestly here, with the miniDSP 4x10 Hd and the Dayton MA1260 (every single driver gets it’s own power amp, albeit a small one). I fully intend to upgrade all of this in the next year or two.. and then use the starting hardware for fun projects (how cool is it to now build other small speakers and never buy crossover components?) or sell it to someone else who wants to go down the digital active path.

                      3b) Software - At the end of the day, this is the most important element, and I think this translates to speaker design as well. How often have we heard about great designers taking a rather mundane collection of drivers in a rather conventional cabinet but making the speaker system sound like magic due to their crossover skills? Well I don’t have those skills, but I am willing to learn software, to experiment, to incorporate new software and techniques at a rapid and agile pace. This is the key to my thinking on this project. I will not achieve the desired results this year. Even if I am thrilled with the results, and I hope that I am, I will be convinced there is much to learn and much more potential to be extracted from this system. I am looking forward to this.

                      Design Objective #3 - Room Tunable - this is also a significant driver to the above points. I know I have a difficult room at the moment, and no idea what my environment will be a few years from now, so I want the option to easily EQ and tune other parameters that change the relationship between the speaker and the room. Better yet, have different profiles of DSP for music, movies, or mood... this is the power of "software" and it brings our hobby into another big part of the galaxy.
                      Last edited by Greggo; 08-10-2014, 04:03 PM.


                      • #12
                        Re: Javelin - a high end journey into digital active speaker systems

                        Nice post Greggo,enjoying the timeline approach to your project,will be following along.


                        • #13
                          Re: Javelin - a high end journey into digital active speaker systems

                          FYI, my current reference is satori 4ohm, raal 70-10d AM and Eminence Kappalite 3012LF. The speakers total sens around 92-92.5db.

                          I have tried different amps with my speakers, from 28w SET to NCORE.

                          None of them have any problem driving my speakers, and they can go louder than i can hear in my room (lossy room, concrete floor around 60m2 net then bleed out to 2nd floor.

                          My speakers xover is @2.8khz, and i have heard other satori speakers with scan d3004 and 15" dayton woofers crossed @1.5khz.

                          None of them showed any strain, and i have never seen my woofers or midrange cone moves :p

                          I usually listen max at 85db continuous level with peak above 100db.

                          Im just not sure whats the role for the dome here, as the satori mid is prettty flexible


                          • #14
                            Re: Javelin - a high end journey into digital active speaker systems

                            Henry, I have little rationale to offer on this I admit. Despite my stated objectives, you are correct in pointing out that there is no evidence that the Satori mid-bass needs any extra help in order to perform well. It is just a mental thing for me, I have always liked small mids and especially mid domes, and I have a mental block about running cone drivers up past 1.2 kHz. There are tons of examples of fantastic speakers that run cones beyond that point so it is really just a personal preference (in concept more so than experienced sound). I want to have the option to someday use very steep crossover slopes and know that the directivity pattern is as close as possible between drivers. So I expect the 2 inch dome to be nearly identical to the 1 inch tweeter at 2kHz for instance, and I expect the 6.5 mid-bass to be nearly identical to the 2 inch dome at 800 Hz. All of my waveguide reading has me completely obsessed with directivity patterns.

                            I hope everyone realizes that there will be nothing presented here as to "points of fact" that could be used to strengthen or weaken the validity of other designs, my goal here is to just find my voice and let all this stuff out of my head and share with others why I am doing what I am doing. I have to live with the notion that when this is all said and done, I may simply look like the village idiot. I may be there already for some of you But I have nothing to lose, so I am just following my gut and letting it all hang out.

                            For me, this is more about the journey than it is about landing on a certain point or proving out a design theory, hence the title. I am just extracting from this process what works for me, what makes me happy and inspires me to press forward. I hope to show up at DIY Iowa, not to show off the superiority of my results, just to enhance the sharing experience and sense of community. I have spent so many years thinking rather than taking action, now I feel like I am finally living again.


                            • #15
                              Re: Javelin - a high end journey into digital active speaker systems

                              Henry, I also should have mentioned that your system sounds quite nice. I have not heard any speaker with the Raal ribbon yet, but I am sure I will check it out at some point. I came very close to using a new AMT tweeter/waveguide combo, but in the end I just like what SB Acoustics has done with their dimple dome designs.