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Micro bluetooth speaker idea (tiny) - Visatron BF37

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  • Micro bluetooth speaker idea (tiny) - Visatron BF37

    Gents, i have 4 of those 1.5 inch drivers coming my way, hopefully by the end of the week. At work today i thought i would have a play around in CAD and float a few ideas just to get an idea of the size comparison to what i have just finished and was a bit suprised how small it was. So far it is modelled as a rectangle, but i may throw a bit old curve in there somewhere to give it a bit of character....

    This is the first concept, downside is i cant model the membranes due to their site not having any T/S parameters, but considering the size of this unit (0.01 cuft each) there isnt a lot of room. I've been led to beleive that if i'm to use stereo and the membranes to work, that i need the enclosures to be indepenent of each other, so marked up in yellow what my thoughts are, either that or convert the signal to mono was something else i've seen recently.

    I'm looking to power this with a PAM amp i have which is quite small and apparently a 2*15w unit @ 12 or 16vs, so will have to be careful not to blow these things, it also will be looked to be powered off a 18650 battery and use a 5v to 12v booster......got the parts, just need to see if the crazy thoughts in my head can be turned from just that to reality. I've been researching Linkwiz transforms and bass boost circuits over the last 12 months and still as confused as ever, taking the advice that the BSC MAY work against me in this case due to the low sensitivity of these drivers and learning other bits and bobs along the way.

    A few of you may recall i've been rabbiting on about making a bose clone or competition to a soundlink mini and realise that bose has the advantage with decades of engineering and digital EQ's and boost etc, but it is something i feel i have to persist with to get it out of my system, also i like the wood working probably more than the speaker components to be honest

    I quite like how small this is and whether or not it needs to be beefed up a bit more will really depend on what timber i can source and its thickness. I'm going to see if there is a 4-6mm option and think 12mm is too thick potentially.

    Option 2 is basically a bigger version, but having a mirrored image on the back (2 drivers, 1 PR membrane), but this would require roughly 0.15 to 0.2 cuft enclosures to get a similar curve to the singular option. not sure what the actual benefit would be have 4 drivers yet and whether or not this would be too big and i would try a micro version again, i really cant say....

    Anyway i would like to hear some opinions from the experienced folks in the forum, just only constraints is i'm pot committed to the 1.5 inch drivers and not looking to go a 2.5 or 3.5inch boombox option.

    also how good are the little surface go with a stylus, i love mine all measurements are metric and in millimeters, i just write in cuft for the north american audience.
    Attached Files

  • #2
    I still don't think you HAVE to go electronically, especially since the XO circuit that robs sensitivity also adds power handling and since you have excessive power, it's not actually a negative in this case to go passive.

    Comment


    • #3
      Pros of more drivers are more max output, even if sensitivity doesn't rise, and more power handling. Cons are size, cost and possibly interference in dispersion causing worse imaging.

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      • #4
        There ARE parms on Visaton's site...
        ( and graphs, too )

        - and if you're driving 2 diff drivers w/2 diff signals (stereo) then the int. volumes need to be separate to function as designed.

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        • #5
          Option 2 was sort of thinking of the BOOMINATOR from the diyaudio site, but instead of ports and large drivers, it would be drivers the size of tweeters and cheapo passive radiators....well I'll call them membranes as they are only a bit of rubber

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          • #6
            Originally posted by Chris Roemer View Post
            There ARE parms on Visaton's site...
            ( and graphs, too )

            - and if you're driving 2 diff drivers w/2 diff signals (stereo) then the int. volumes need to be separate to function as designed.
            I'm not sure if one would notice the difference between stereo or mono in something this size? Either way it's been great counsel in the past so I'll widen the box slightly to compensate for the split chambers.

            Only downside is for all to be tested you really need to airtight the box right? Which I thought would mean almost finishing the unit? I really don't know how these rubber things will go, but YouTube seems to have success at 300mm filming away so what could go wrong I know sarcasm doesn't really translate though typed text but it was intended. Let's just say the shipping cost more than the unit and shipping was almost free

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            • #7
              I like where you are going with this. A friend had one of those tiny Bose bluetooth radios, the one that's like 5 or 6 in wide. Given it's size, the sound was incredible. I think that's what you're going for here?

              I've wanted to do something similar just to see how small you can go while keeping some semblance of bass. You know by now from your experience just how hard it is to squeeze all the stuff in there.

              I'll be watching... do it!

              TomZ

              PS the ND65 passive radiator is on sale for 5 dollars ea if you want to experiment.
              *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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              • #9
                Thats the one Tom, my folks and my sister both have one and i just show them i can do something better well i want to anyway, gives me a sense of acheivement when people say dont do it haha.

                I had a go carving out the inside of some timber the other day, i think i could refine it, but also found 8mm timber, so will be going that as it is the thinnest pine i could find. Im trying to steer clear of ply as the premium stuff i bought last time was too thinly layered and sanding took too much off. ive even contimplated bending the thinner timber to get a similar profile to the bose.

                It is going to be small and fiddly i would assume

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                • #10
                  Mimicking the form factor is not so hard. Trying to mimic the amount of DSP that Bose has going on in that thing is the real challenge. I like the current products coming to market but have yet to find a DIY piece that comes remotely close to what these OEMs have going on.

                  Good luck - have fun.

                  Comment


                  • #11
                    Originally posted by Dukk View Post
                    Mimicking the form factor is not so hard. Trying to mimic the amount of DSP that Bose has going on in that thing is the real challenge. I like the current products coming to market but have yet to find a DIY piece that comes remotely close to what these OEMs have going on.

                    Good luck - have fun.

                    Yup. Without the magic that the DSP supplies, it would sound like it looks... tiny.
                    Plus that one has enough battery inside for 7 or 8 hours of music at a decent volume, kind of amazing.

                    As far as the construction materials; it sounds like you've got a solution that will work. I have parts to make something similar but a bit larger. I plan on using 1/8" HDF as it is fairly rigid for it's size. Two layers glued up makes a nice rigid panel assuming it's fairly small. Add a slight curve to it and it really becomes rigid.

                    What amp are you thinking about for this?

                    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


                    • #12
                      The amp could be the issue, when I got the Bluetooth boards I also picked up a 5 pack of pam8403 5v chips and a 12v Pam8610...let's just say this will be a very cheap electrical build....if the 2*15w board doesn't blow the drivers and if it sounds bad, I'll probably get a 2x3w sure board.

                      I was also thinking a 1s bms/charger and incorporating a 5v to 12v boost chip. All uncharted territory for me.

                      If all fails back to the DA DTA_2 Board haha

                      Comment


                      • #13
                        Originally posted by tomzarbo View Post

                        Yup. Without the magic that the DSP supplies, it would sound like it looks... tiny.
                        Plus that one has enough battery inside for 7 or 8 hours of music at a decent volume, kind of amazing.

                        As far as the construction materials; it sounds like you've got a solution that will work. I have parts to make something similar but a bit larger. I plan on using 1/8" HDF as it is fairly rigid for it's size. Two layers glued up makes a nice rigid panel assuming it's fairly small. Add a slight curve to it and it really becomes rigid.

                        What amp are you thinking about for this?

                        TomZ
                        Hmmm didn't think of using thinner and bending/layering into place.....so many options.

                        I came across this site and have been a bit intimidated by these circuits and the Linkwitz transforms

                        https://electro-dan.co.uk/electronics/bassboost.aspx

                        Comment


                        • #14
                          Wow, I don't know what I was expecting, but let's just say I was taken back at how small these drivers are...I thought the ND65 was a small driver but these take the cake lol. Had to take a pic next to the Nd64 and TEBM65 for scale.

                          They are light and my hole can be drilled with a 35mm forsner bit I have. Just waiting on the piece of rubber to come on the boat from china.
                          Attached Files

                          Comment


                          • #15
                            They are tiny. They look to have a decent little bit of surround for some excursion. It makes most tweeters look like giants. You could really make something tiny with those.

                            Keep us posted, this looks fun.
                            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

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