Announcement

Collapse
No announcement yet.

DIY LCR passive sound bar

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #61
    I tried a few more options with a frame similar to my inspiration pics. The frame can float off the wall by an inch or so to provide enough ventilation for the tv while also giving me the look I prefer. The last concept I shared felt pretty good…I just wasn’t loving it yet. I’m getting much closer with these concepts. I prefer option 2 and will try the black baffle on that one. I can have one or two contact points on the top edge to create the needed strength.
    Attached Files

    Comment


    • #62
      You can visually balance a sideways TM with a port opposite the tweeter. On a black baffle especially. it would look fine. A PE black plastic port and small dia. tweeter would match quite well.

      DIYSG S2000 TM

      Click image for larger version  Name:	IMG_0001 (6).JPG Views:	0 Size:	421.9 KB ID:	1485984

      Comment


      • #63
        I would say that your amp will have absolutely no problem with a high sensitivity 4ohm speaker. So get the speaker sensitivity up around 90dB (or more) with 2.83V/1m and you will be fine.

        The RS150T-8 is just about the same as the RS150-8 but with a different frame. Here's kind of exactly what you are looking for I think - the Abourious. Just use the truncated drivers instead. Fairly low xo point with excellent phase matching at the xo should give very decent off-axis response. It has a lovely flat summed response and it looks like it's designed for on-wall placement. If you are interested, I'd probably want to do a sim of that to double check and maybe also make any small changes that might help due to the very different baffle configuration you are going to use.

        I'd probably go with the Seas 27TDFC out of the tweeter choices. Three of the MTM's sealed is what I'd go with although with the price of the xo components, you might be pushing a little beyond a $600 budget. About 8-9L for each MTM sealed should work fine giving an F3 of about 97Hz. Max SPL will be limited by the power limits of the drivers (40W) and not cone excursion when you cross to the sub at 100Hz. The max SPL of each MTM will be sort of ridiculous up at about 110dB at 1m, which is exactly what you want for HT - it means both your amp and the speakers won't be close to breaking a sweat under normal listening volumes and should be able to handle any full-on bombastic movie moments with ease and clarity.

        One other thing to mention which affects the cabinet design is that some kind of internal damping for the walls can really help when you start getting into better drivers but it will also eat up a little more cabinet volume too. With 1/2" walls, I'd recommend at least 1/8" bitumen sheets or similar almost everywhere except maybe the back panel (since it'll sit up right against the back wall) and maybe a 2nd layer of some smaller pieces here and there too.

        Of your new designs, I think I like #3 best. I like the symmetry but since heat rises, I question the need for ventilation at the sides of the frame at all. The space you are leaving between the tv and frame around the bottom and sides of the tv I would think would be adequate to provide a flow of air in behind the tv as the hot air escapes.

        Comment


        • eavo44
          eavo44 commented
          Editing a comment
          I bet a few of those would sound really nice…I’ll take a closer look into the box sizes. I’ll check out the bitumen product too. With the frame design… it’s hard to know what’s actually needed for ventilation with the tv. I guess the Sony’s require 4” all around…the images are set up to 1.5” space around the tv so opening up the side will help with some of the radiant heat…figured it would get it close to it’s cooling requirements. Thanks for the input.

        • mobius
          mobius commented
          Editing a comment
          Always better to be safe than sorry I guess. I couldn't decide before but now I'm liking the soundbar front baffle better in the walnut as opposed to the black.

      • #64
        Might be a little big for a soundbar, but they sound excellent and would fit nicely in your credenza.

        https://techtalk.parts-express.com/f...jd-s-abourious

        Comment


        • #65
          If you're going to jam 3 MTMs into a soundbar, or an MTM and two TMs, I'd go for the S2000. The MTM is 92db efficient and as remarked upon by many, can play really loud. I really like mine.

          In stock at the moment, not always the case. Same sizes as OS series. And better.

          The way you're designing, you could probably put some of the speaker cab volume behind the TV.

          Comment


          • #66
            I called Harman Kardon yesterday to ask them about running 4ohm speakers on my avr2600. The representative said it was not recommended and that it could damage the amplifier over a period of time. He’s most likely just looking at the specs and saying that it’s not recommended, but it does make me a little apprehensive to purchase 4 ohm speakers. I am sure you guys know your stuff, and math, to figure out that the 4 ohm speakers shouldn’t be an issue but I don’t understand all the math as well. I feel a bit slow sometimes when reading you responses, but I try to read up and get a base line understanding of the topic. I really like the s2000’s cause they look great and the size is right…but I am leaning towards an 8 ohm solution just for a little security. You guys have supplied me with some great links and options and I’ve been checking them out and taking notes. I’m currently looking into the tm version of the Aubourious but I haven’t been able to find the cabinet specs yet. The image of the tm looks to be around 9” wide…but I’d look into the truncated rs150-t and reduce the baffle height as much as possible for the bar...like you where suggesting mobius. If the cabinet size looks doable, I’d be looking at a tm, mtm, tm setup. Can the mtm center have the woofers run in series so it’s an 8 ohm speaker? They may require a larger bar than desired but I’m going to check it out. Thanks again for your assistance and hopefully I can land on a speaker design soon.

            Comment


            • #67
              The manufacturer knows more than anyone.

              Calling a speaker 4 or 8 ohms is a vast oversimplification. The impedance of a speaker varies significantly throughout the frequency range. Some speakers have very low dips in impedance and are considered "difficult" loads on an amp. Others have a smoother impedance curve and are "easy".

              Amps rated for 8 ohms are not built to handle low impedance loads. It really depends on the individual amp and speakers as to how well it will work.

              Last edited by djg; 05-11-2022, 09:05 PM.

              Comment


              • #68
                Audio Science Review writeup of the S2000 TM. Minimum impedance is 3.8 ohms.

                https://www.audiosciencereview.com/f...-review.17507/

                Comment


                • eavo44
                  eavo44 commented
                  Editing a comment
                  So a dip to 3.8 ohms would make the s2000 more of an easy impedance…so it shouldn’t draw as much current as some other 4 ohm speakers? Am I understanding that correctly?

                • djg
                  djg commented
                  Editing a comment
                  I would guess some 4 ohm speakers would be a tougher load. Getting back to where you started, the OS TM is 8 ohms, the OS MTM is 6.

                  To be honest, I never paid much attention to speaker impedance, but I wouldn't want to recommend that approach to someone else, who may experience problems costing them time and money.

              • #69
                Have you considered upgrading your AVR?

                Comment


                • eavo44
                  eavo44 commented
                  Editing a comment
                  It’s a possibility but I’d rather work with what I have. The HK has performed well so far and replacing it just seems like an added cost. It’s been more difficult than expected to find a speaker kit to fit this project…so maybe upgrading my receiver should be a consideration.

              • #70
                I took a look at the Abourious bar setup tonight…looks cool. It has a more serious look with the size increase. The truncated frame on the Dayton looks nice! Still not sure if the cabinet is large enough but I’ll dig into that a bit more later. Also going to spend some time looking more deeply into impedance. Click image for larger version  Name:	9F327085-75B1-4E3A-BA75-840856CE3447.jpeg Views:	14 Size:	364.7 KB ID:	1486147
                Last edited by eavo44; 05-12-2022, 12:56 PM.

                Comment


                • #71
                  The T and standard are different in specifications. These were not designed for the T version.
                  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:
                  https://app.photobucket.com/u/wolf_teeth_speaker

                  My blog/writeups/thoughts here at PE:
                  http://techtalk.parts-express.com/blog.php?u=4102

                  Comment


                  • eavo44
                    eavo44 commented
                    Editing a comment
                    Thanks wolf…I didn’t realize that.

                  • mobius
                    mobius commented
                    Editing a comment
                    Yes likewise from me. I thought they were more similar than they are.

                    Know of any designs using the T version?

                • #72
                  There are plenty of 8 ohm speakers you could use, but you seem particularly hung up on using a MTM for the center purely for the visuals. I've commented on using the port to visually balance the tweeter. Why don't you cook up a rendering or two with this concept in mind? You're very good at that.

                  Tyger 23's Canzonettas. Move that port to the same distance from the woofer as the tweeter, turn it sideways. Paint it black.

                  Click image for larger version  Name:	tyger.jpg Views:	0 Size:	86.4 KB ID:	1486165

                  Comment


                  • mobius
                    mobius commented
                    Editing a comment
                    For me, it's not the visuals driving the MTM recommendations. First it's because MTM's can handle the bombast of HT better than just a TM. Second it's because they are usually higher in sensitivity which means less is being asked from the amp for equivalent SPL. And because third, the OP's amp of 65W into 8ohms isn't exceptionally high. But much of that depends on the max SPL's required which really hasn't been defined yet.

                    Right now I'm thinking the MTM Sopranos, 8ohm and high sensitivity MTM's, either sealed or ported or a combination of both might still be the ticket.

                  • eavo44
                    eavo44 commented
                    Editing a comment
                    Djg…I get hung up on the symmetry of the design for sure, which is why I lean towards the mtm for the center. It seemed that a few people suggested either a tm or a tmm for the left and right in order to reduce comb filtering from those channels. That approach makes sense to me. I think you can graphically balance a port with a tweeter to create the look of symmetry, but i get the feeling it’s going to feel off but I’ll take a look at it. It seems like a tm for all three channels would be a good performer with several speaker kit options that could work…but I feel this would be the last approach for me. I looked at the tritrix at lunch…could be an option. The tm and mtm are rated at 6 ohms. I did a little reading about impedance and am understanding that a little better. One of the articles I read said that most standard/budget receivers can handle a 6 or 8 ohm speaker.

                • #73
                  I had a Tritrix 5.1 suite long ago. They really sounded nice, especially for the price. For you, take a close look at the woofer. It is a bit ugly with a thick black cardboard gasket on the front of the frame, more suited to rear mounting, which of course you could do.

                  Another 8 ohm suite from cjd, who designed the Abourious, is the Ochocincos, with another ugly woofer you could rear mount. Dayton 4 and 8 ohm ND series woofers are great performers.

                  https://www.divine-audio.com/ochocinco/

                  Comment


                  • eavo44
                    eavo44 commented
                    Editing a comment
                    I took a quick look at the woofer and could see what you’re talking about…would definitely look better rear mounted. Thanks for pointing that out. Any issues with rear mounting? Seems like I only see rear mounted on the continuum ll.

                • #74
                  Re: rear mount. You would want to let the speaker into the baffle from behind with a rebate so that you're dealing with 1/4" to 3/8" distance of the woofer behind the baffle surface, and add a roundover or 45 degree chamfer on the woofer hole edge. Also, you would need to use machine screws and nuts to mount.

                  Mr. Bagby used the rear mount on the Continuum because of a complicated woofer shape. DIYSG sold a Continuum enclosure with a more normal front mount woofer with Mr. Bagby's permission.

                  BTW, between the Tritrix and Ochocincos, I would choose the Ochocincos because of better quality drivers, in my mind at least.

                  Comment


                  • eavo44
                    eavo44 commented
                    Editing a comment
                    Been out of town for a bit…Thanks for the feedback…I’ll take a look at the ochocinos.

                • #75
                  Ok…had a little time to think over things. After learning more about impedance and having the S2000’s being recommended…I’m leaning towards them. I have a request in to purchase a single mtm for the center channel so we’ll see if that’s a possibility. Through some unfortunate circumstances…we’re down to a single cat and a dog so the activity on the credenza has calmed down a lot…which has me thinking separate units could be a more straightforward first build. I still like the look of the bar but it’s making the tv feel larger and pulling the mass upwards. If I had more of an expansive wall to work with I’d stick with the bar and run with it. The separates keep the mass lower and will make adjusting the tv on the mount easier along with having speakers that’ll be more flexible for alternate setups. I’ll have time to decide between the 2 as I wait for the parts/kits. I want to build the ochocinco’s as a second build cause I really like the simple woofers being rear mounted. I had ruled them out due to the frame shape but djg reminded me of the rear mount option which looks great! Thanks to everyone for your knowledge and time to help me make a selection for my first build.
                  Attached Files

                  Comment


                  • djg
                    djg commented
                    Editing a comment
                    The S2000 separates built with the DIYSG 1/2" Baltic Birch flat packs are extremely easy to build, even more so if you can get the printed circuit boards for the crossovers. I had that same set two iterations ago of my HT front three, very good sound quality. Sorry about your pets.
                Working...
                X