Announcement

Collapse
No announcement yet.

Thinking similiar to Statement/Khanspires but ...

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

  • #31
    After some research it seems everything from sheetrock mud to shellac has been used to seal, or prep mdf for primer. Made a trip to the local hardware store and returned with a quart of Zinsser BIN, $15. This stuff was pretty easy to work with. Both speakers were up on the saw horses. I'd paint the up side of one speaker, then proceed to the up side of the next speaker, by the time the second speaker was coated, the first speaker was dry enough to rotate to the next side. The stuff dries quick, feels thick, and the fumes weren't too bad. Did a light hand sanding after the first coat, then coated a second time. I would have gotten the orbital after them, but it's raining again, and I have no dust removal system in my small 'shed'. It looks like it'll need a couple more coats to fill the end grain, especially the bases where there are 4 stacked layers of 3/4".

    Has anyone had any problems with body filler or auto body paint/primer when using BIN?

    davidroberts, I had already left for the hardware store before reading your post, or I'd likely came home with shellac. ... about the glue/water mix, I always worry about water and mdf. I know it's been proven many times here, but I still worry, plus some said it was difficult to sand.

    Now, how do I get rid of the seems? body filler?

    ani_101, Looks like you're from Minnesota. Hopefully, one of these days, I'll be able to join jhollander, and his crew on a pilgrimage to a meet nearer you.

    Guys, I appreciate the replies.

    There's another 4 channel chip amp (tk2050), power supply, minidsp, and binding posts on the way.

    Click image for larger version

Name:	photo (7).JPG
Views:	350
Size:	384.7 KB
ID:	1312008
    Last edited by Kornbread; 12-29-2016, 01:18 AM.
    http://techtalk.parts-express.com/fo...khanspires-but
    http://techtalk.parts-express.com/fo...pico-neo-build
    http://techtalk.parts-express.com/fo...ensation-build

    Comment


    • #32
      No worries, there are plenty of raw MDF speakers with glue runs down the side, mine included... So if you can get them to a meet, it is always good

      Comment


      • #33
        The Zinsser Bin is actually just shellac that is pigmented.You can use body filler to hide the seams. I have had better results with glazing putty.

        Comment


        • #34
          Originally posted by davidroberts View Post
          The Zinsser Bin is actually just shellac that is pigmented.
          +1 in the Bin shellac based, water based not good imo
          John H

          Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

          Comment


          • #35
            The neighbor helped schlep one tower upstairs.

            How should I take measurements?

            Normally, I take the speaker to the far side of the patio, and measure from 1 meter on tweeter axis. These are too big to move and I don't know if 1 meter is enough time to allow for all the drivers to integrate. Would it be best to place the mic next to each driver and measure? What about the port that's located on the bottom/center of the cabinet, how would I measure it? Should measurements be taken at the normal listening position?

            Using REW and a PE usb mic.

            http://techtalk.parts-express.com/fo...khanspires-but
            http://techtalk.parts-express.com/fo...pico-neo-build
            http://techtalk.parts-express.com/fo...ensation-build

            Comment


            • #36
              1 meter is good. You just really need to see the baffle effect. It's best to be as far away from other walls and furniture, so out in the middle of the room is my prefered location. You should not need the port for x-o work. You will need the near field and far field. Far field should be gated before the first reflection. Near field is not gated. Take some time to read up on Jeff B's measurement white paper if you haven't done that recently.
              John H

              Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

              Comment


              • #37
                After a couple hours with the minidsp. Taken @ 1 meter, minidsp, all crossovers lr24. Didn't take much hammering. I'm guessing the low end is an effect of mic position and room?

                jhollander, just now seen the post, guess it's time to do some reading. Is this the paper you were referring to? https://app.box.com/s/fefis558wna1d6pd07r3

                Click image for larger version

Name:	rew PE towers LR24 no2.JPG
Views:	336
Size:	83.6 KB
ID:	1312411


                What can I do with the impulse?

                Click image for larger version

Name:	PE tower minidsp lr24 no2 impulse.JPG
Views:	351
Size:	74.5 KB
ID:	1312412

                And this seems high, but my testing levels were fairly low. comments.....

                Click image for larger version

Name:	PE tower minidsp lr24 no2 distortion.JPG
Views:	378
Size:	89.5 KB
ID:	1312413

                Last edited by Kornbread; 12-30-2016, 08:47 PM.
                http://techtalk.parts-express.com/fo...khanspires-but
                http://techtalk.parts-express.com/fo...pico-neo-build
                http://techtalk.parts-express.com/fo...ensation-build

                Comment


                • #38
                  Haven't had much time lately, but finally got around to stuffing the mid enclosure with denim, added a layer to the front panel of the bottom woofer, which was bare, and to the top panel of the top woofer. From what I could find, denim and mineral wool have nearly the same absorption properties and prices are also comparable. http://www.soundproofingtips.com/sou...ng-insulation/ Went with denim.

                  It will take some time before I understand Bagby's paper on how to take accurate measurements, but I 'think' the midrange sounds a bit muffled, but the measurements are nearly identical. Red is w/denim.

                  Click image for larger version

Name:	PE tower minidsp lr24 no2 w denim red vs wout.JPG
Views:	344
Size:	85.7 KB
ID:	1313565

                  The upper midrange/lower treble sounds hot, but my probably inaccurate measurements show it's fine (REW freq. sweep, [email protected], on tweeter). Could this broad area of energy in the upper mid/lower treble be contributing to that?

                  Click image for larger version

Name:	PE tower lr24 wdenim decay.JPG
Views:	369
Size:	117.3 KB
ID:	1313566


                  What's all this hash mean, if anything? It didn't change after adding the denim insulation.

                  Click image for larger version

Name:	PE tower waterfall lr24 no denim.JPG
Views:	360
Size:	205.2 KB
ID:	1313567
                  http://techtalk.parts-express.com/fo...khanspires-but
                  http://techtalk.parts-express.com/fo...pico-neo-build
                  http://techtalk.parts-express.com/fo...ensation-build

                  Comment


                  • #39
                    i looked real quick and didn't see , what tweet did you go with ?
                    Paper Towers
                    RS180P/28F surrounds
                    Boombox

                    Comment


                    • #40
                      Originally posted by filmslayer View Post
                      i looked real quick and didn't see , what tweet did you go with ?
                      xt25tg30-04, had a new pair laying around.

                      Distortion decreased.

                      Before,

                      Click image for larger version

Name:	PE tower lr24 no insulation distortion.JPG
Views:	326
Size:	105.1 KB
ID:	1313575

                      and after.

                      Click image for larger version

Name:	PE tower lr24 wdenim distortion.JPG
Views:	338
Size:	101.9 KB
ID:	1313576
                      http://techtalk.parts-express.com/fo...khanspires-but
                      http://techtalk.parts-express.com/fo...pico-neo-build
                      http://techtalk.parts-express.com/fo...ensation-build

                      Comment


                      • #41
                        I don't know what app you are using to measure, but try to change the vertical scale for the distortion measurements.
                        You want to focus on -40 to -60 dB down from your main frequency response line.
                        I think your distortion is OK, but it's a little hard to read.

                        And if you measure at too low of SPL, you will pick up room noise that messes with things.
                        Shoot for 80-85 dB on axis at 1 meter level. That's quite loud, but it works better than a low level.


                        I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                        "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                        High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                        SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                        My Voxel min sub Yet-another-Voxel-build

                        Tangband W6-sub

                        Comment


                        • #42
                          If you are listening to the speakers near a wall, try increasing the mid, and tweeter level about 3 dB.

                          Comment


                          • #43
                            I find that measuring HD higher at 90-95dB at a meter is better than lower. This offsets the noise floor substantially, but not all drivers can do that level in applied design.

                            Later,
                            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


                            • #44
                              Originally posted by donradick View Post
                              I don't know what app you are using to measure, but try to change the vertical scale for the distortion measurements.
                              You want to focus on -40 to -60 dB down from your main frequency response line.
                              I think your distortion is OK, but it's a little hard to read.

                              And if you measure at too low of SPL, you will pick up room noise that messes with things.
                              Shoot for 80-85 dB on axis at 1 meter level. That's quite loud, but it works better than a low level.
                              i agree ... all my work with the RS family shows the paper cones to be in the -50 to -55 db 3rd HD . the aluminum versions just slightly better at -60 .
                              Paper Towers
                              RS180P/28F surrounds
                              Boombox

                              Comment


                              • #45
                                Your impulse response definitely doesn't look good. I'm guessing this is related to measurement gating. Bad measurements makes everything difficult.

                                I'd be interested in seeing the individual drivers frequency response before/after crossover.

                                Did you unibox the Paper drivers box sizes? I never have, so don't know if the paper need bigger boxes. Your boxes look so darn similar to mine, I don't know if you built differently from the original to accommodate the paper versions.

                                It be interesting to see off axis response and a overall power response to better understand the treble hot issue. Toeing in or out or room may alter your opinion.
                                - Ryan

                                CJD Ochocinco ND140/BC25SC06 MTM & TM
                                CJD Khanspires - A Dayton RS28/RS150/RS225 WMTMW
                                CJD Khancenter - A Dayton RS28/RS150/RS180 WTMW Center
                                CJD In-Khan-Neatos - A Dayton RS180/RS150/RS28 In/On Wall MTW

                                Comment

                                Working...
                                X