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  • #16
    I feel that the PC83-8 requires further investigation.
    I'm wondering if the backside of the test baffle is too restrictive, even with the chamfer.
    I may have to create a new insert out of 0.25" just to test if free-er flow reduces any of the HD seen here.

    Comment


    • #17
      I'm using mine in the OSFA BT-box in a 1/2" ply baffle with no relief, save for the required inset for the frame-lip. It seems like it doesn't have any issues.
      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


      • #18
        PC105-8 Results:

        Frequency Response
        Click image for larger version

Name:	PC105-8 Combined FR.jpg
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ID:	1442183


        Harmonic Distortion

        12" @ 96 dB fundamental
        Click image for larger version

Name:	PC105-8 12 inch HD @ 96 dB fund.jpg
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ID:	1442184


        Harmonic Distortion
        24" @ 96 dB fundamental
        Click image for larger version

Name:	PC105-8 24 inch HD @ 96 dB fund.jpg
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ID:	1442185

        Comment


        • #19
          LY401F Results:

          Frequency Response
          Click image for larger version

Name:	LY401F Combined FR.jpg
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ID:	1442190



          Harmonic Distortion
          12" @ 96 dB fundamental
          Click image for larger version

Name:	LY401F 12 inch HD @ 96 dB fund.jpg
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Size:	100.4 KB
ID:	1442191


          Harmonic Distortion
          24" @ 96 dB fundamental
          Click image for larger version

Name:	LY401F 24 inch HD @ 96 dB fund.jpg
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Size:	105.6 KB
ID:	1442192

          Comment


          • #20
            Originally posted by Wolf View Post
            I'm using mine in the OSFA BT-box in a 1/2" ply baffle with no relief, save for the required inset for the frame-lip. It seems like it doesn't have any issues.
            Later,
            Wolf
            Yeah, I think I was just hoping for better.
            I may still revisit this.

            On the other side of things, I'm pleasantly surprised that the PC105-8 appears to be beating out the LY401F in HD. It can't match the LY401F's sensitivity or thermal management, but looks really good nonetheless.

            Comment


            • #21
              It's a little tough to read, but on HD3 the PC105-8 really seems to win out.
              The LY302F is close if it weren't for the peak at 650 Hz that my measurements bear out, except for the low end where the increased cone area of the PC105-8 takes the cake.

              Click image for larger version

Name:	HD3 Comparison.png
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ID:	1442202
              Attached Files

              Comment


              • #22
                This is a little easier to read since it is clearly a two driver race between the LY302F and the PC105-8.
                Above about 1 kHz, the LY302F looks better in both HD3 & HD5.
                Given that I've been focused on how low I could cross either, I'm leaning towards the PC105-8 which suggests 250 Hz isn't too low.

                Click image for larger version

Name:	HD3 Comparison PC105-8 vs LY302F.png
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ID:	1442206


                Click image for larger version

Name:	HD5 Comparison PC105-8 vs LY302F.png
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ID:	1442207

                Comment


                • #23
                  I ran the 105-4 in a dual-chamber aperiodic sealed alignment, and they really sounded good like that. About a liter a piece with pegboard sandwiching 1" foam across the center. 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


                  • #24
                    Do either of you happen to have an accoustic offset measurement for the PC105?
                    My first 2way build

                    Comment


                    • #25
                      Originally posted by LOUT View Post
                      Do either of you happen to have an accoustic offset measurement for the PC105?
                      It is a relative measurement, as in "offset from what other driver?"
                      Don't listen to me - I have not sold any $150,000 speakers.

                      Comment


                      • #26
                        Originally posted by johnnyrichards View Post
                        It is a relative measurement, as in "offset from what other driver?"
                        I'm guessing that means it can't magically be measured as a woofer's "offset" from the baffle, assuming the baffle as zero? That kind of makes sense I suppose because the measurement must need a second sound source to act as the assumed "zero" or offset point.
                        Do tweeters commonly have their own offset to worry about or is it usually safe to assume a tweeter as zero even if you're changing to a different tweeter while keeping the same woofer and baffle somehow?
                        My first 2way build

                        Comment


                        • #27
                          No, there is no safe assumption as such. If you assume the baffle is zero, than each different point source will exhibit an offset. What you are looking for is offset between two or more point sources. Estimating this distance is fuzzy math at best. If you are running a single point source, than there is no offset. Think of it in terms of a triangle - woofer, tweeter, listening position. So even changing listening position will impact the relationship - which is easily seen in modeling software.

                          You need a microphone and a rigorous test methodology if you want to determine offsets.
                          Don't listen to me - I have not sold any $150,000 speakers.

                          Comment


                          • #28
                            DA215-8 Results:

                            Frequency Response
                            Click image for larger version

Name:	DA215 Combined FR.jpg
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ID:	1443935


                            Harmonic Distortion

                            4" @ 2.83 Vrms
                            Click image for larger version

Name:	DA215 4 inch HD @ 2.83V.jpg
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ID:	1443936


                            Harmonic Distortion
                            4" @ 96 dB fundamental
                            Click image for larger version

Name:	DA215 4 inch HD @ 96 dB fund.jpg
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ID:	1443937


                            Harmonic Distortion
                            12" @ 96 dB fundamental
                            Click image for larger version

Name:	DA215 12 inch HD @ 96 dB fund.jpg
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ID:	1443938


                            Harmonic Distortion
                            24" @ 96 dB fundamental
                            Click image for larger version

Name:	DA215 24 inch HD @ 96 dB fund.jpg
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ID:	1443939

                            Comment


                            • #29
                              The DA215-8 really stressed my test baffle and there was definitely a panel resonance that shows up in the bass HD sweeps. You could hear it at the beginning of the sweep. The power and cone area of the DA215-8 really exposed this.

                              Click image for larger version

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                              The test baffle was never intended to be perfectly rigid; only provide a semi-useful FR curve.
                              You can see in this underside shot how I built the frame using 2x4s and laid the foam board on top of it.

                              Click image for larger version

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                              Consequently, I wouldn't put too much stock into the bass HD sweeps and it also helps explain why that area looked high in the other driver's HD tests.
                              The real test will be once the drivers are loaded into a real enclosure.

                              Comment


                              • #30
                                FR59EXE Results:

                                Frequency Response
                                2.83 Vrms @ 12" (no bass track)
                                Click image for larger version

Name:	FR59EXE 12 inch FR no bass.jpg
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ID:	1446161

                                Frequency Response
                                250 uF cap and higher resolution
                                Click image for larger version

Name:	FR59EXE 12 inch FR with 250 uF cap.jpg
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ID:	1446163

                                Harmonic Distortion
                                12" @ 90 dB fundamental with 250 uF cap
                                Click image for larger version

Name:	FR59EXE 12 inch HD @ 90 dB fund with 250 uF cap.jpg
Views:	528
Size:	104.8 KB
ID:	1446162

                                Comment

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