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  • Measuring Raal 140-15D

    Ho-Ho-Ho
    http://www.diy-ny.com/

  • #2
    Re: Measuring Raal 140-15D

    No, but really, I finally have a pair in my possession for a week or two.
    There was also a 70-10 OEM which I will describe but because it's OEM and the owner asked me not to, I will not post the data on OEM.
    First impressions are. Drivers are build like tanks. Huge transformers. Very heavy. Face plate is thin but sturdy and I am guessing, surface mounting should be just fine. The gaskets are made from cork. I guess that's fine too.
    We did a quick set of measurements of both drivers. Because it was exactly that, a "quick" set, I will re-measure sometime next week.
    First impressions are.
    140-15 has one of the best horizontal off axis performance I've seen AND one of the worst vertical off axis performance I've seen. Use of a foam pads negates the vertical issues but even with pads it's very bad. Horizontal dispersion is not affected by use of foam pads.
    Without foam pads, on axis response is nowhere near as flat as Raal suggests. With the pads, it levels out considerably, however top octave is rolled off. Starting from about 13k it drops by 5db. Not great in my book but again, I will re-do everything to be sure.
    Impedance is almost ruler flat.
    Distortion character is interesting. Low high order distortions and stable 2nd order throughout the range.
    I would say that usable range, based on non linear is 2500hz and up with high order electrical crossover network.
    CSD is good with small ringing present in the 2k area.

    Smaller OEM version had better on and off axis response. It had worst CSD with pronounced ringing around 2K. Looks like it is also limited to 2500hz with better polar response. Smaller OEM version of 70-10 also sounded less efficient compare to a larger 140-15D.

    The thread is about driver performance not "oh how I love it".
    I will start posting data next week.
    If there are any test you would like me to run (gating, terminal voltage and so on) pleas let me know.
    http://www.diy-ny.com/

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    • #3
      Re: Measuring Raal 140-15D

      Do you mean 70-20? That's the OEM.... 70-10 is the standard that anyone can purchase.

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      • #4
        Re: Measuring Raal 140-15D

        OEM version that looked like 70-10. I guess that would be a 70-20 then.
        http://www.diy-ny.com/

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        • #5
          Re: Measuring Raal 140-15D

          I've decided to look at the performance without foam pads first. Also, started with positioning the microphone about 4" away, centered.
          CSD shows a bit of ringing which is probably rear chamber? Founteks and AC have similar resonances.
          All measurements are done with 30mfd in series.
          Attached Files
          http://www.diy-ny.com/

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          • #6
            Re: Measuring Raal 140-15D

            now the Mic is moved to 23cm away from the driver
            Attached Files
            http://www.diy-ny.com/

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            • #7
              Re: Measuring Raal 140-15D

              now we are at 1m.
              FR and distortions are also done in ARTA. I don't use ARTA often and didn't input microphone correction file. Also, note, ARTA FR has 10db steps not 5db like SE.
              Attached Files
              http://www.diy-ny.com/

              Comment


              • #8
                Re: Measuring Raal 140-15D

                distortions in Sound Easy, taken from about 15cm, 1.6v and 2.83v
                at 1.6v driver was averaging 91-92db of SPL according to my $50 spl meter.

                Next, I'll be looking in to polar. Stay tuned.
                Love the tags! All tho one with aaaaaaaaa is getting old.
                Attached Files
                http://www.diy-ny.com/

                Comment


                • #9
                  Re: Measuring Raal 140-15D

                  I may be the only person here to request this, but I'll do it anyway...

                  Do you have a way to measure the driver with a higher value cap (or just no cap at all) so you can go lower in response? I seem to remember the RAAL's having a rising response and it's hard for me to discern if the rising response here is influenced by the use of a cap.
                  I did the math, and it looks like the crossover point is 650hz.
                  A low output test at 1m would suffice. The FR shouldn't change significantly unless you're comparing very low output to very high output and even still it won't be enough for most of us to care. ;)

                  Edit: nevermind about se hd. ;)
                  Have you tried extending your bandpass on the HD sweep? You may get different results by exciting the driver at a lower tone than 1khz. I've seen it happen in stranger situations.


                  Thanks!
                  When you stop caring about being right, you might actually learn something.

                  My test data site:
                  http://medleysmusings.com/

                  Comment


                  • #10
                    Re: Measuring Raal 140-15D

                    Originally posted by ErinH View Post
                    I may be the only person here to request this, but I'll do it anyway...

                    Do you have a way to measure the driver with a higher value cap (or just no cap at all) so you can go lower in response? I seem to remember the RAAL's having a rising response and it's hard for me to discern if the rising response here is influenced by the use of a cap.
                    I did the math, and it looks like the crossover point is 650hz.
                    A low output test at 1m would suffice. The FR shouldn't change significantly unless you're comparing very low output to very high output and even still it won't be enough for most of us to care. ;)

                    Edit: nevermind about se hd. ;)
                    Have you tried extending your bandpass on the HD sweep? You may get different results by exciting the driver at a lower tone than 1khz. I've seen it happen in stranger situations.


                    Thanks!
                    No problem. I may be conservative with voltage because it's not my driver but sure.
                    I don't think rising response is affected by the capacitor. The testing started without foam pads which are designed to shelve the response. Let's see.
                    Crossover with 30mfd (actually 33) is visible from impedance. I can also run analog impedance sweep starting from whatever I choose.
                    http://www.diy-ny.com/

                    Comment


                    • #11
                      Re: Measuring Raal 140-15D

                      Thanks.
                      When you stop caring about being right, you might actually learn something.

                      My test data site:
                      http://medleysmusings.com/

                      Comment


                      • #12
                        Re: Measuring Raal 140-15D

                        actually, I think doing an analog impedance sweep from 300hz up would be a great idea. Ribbon has to have a "string" resonance down low.
                        http://www.diy-ny.com/

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                        • #13
                          Re: Measuring Raal 140-15D

                          Originally posted by r-carpenter View Post
                          actually, I think doing an analog impedance sweep from 300hz up would be a great idea. Ribbon has to have a "string" resonance down low.
                          You won't get any results that matter, since the transformer dominates at the low frequencies. Basically, it acts as a HP filter.

                          I actually drove the 70-10D directly from the woofer XO one time, at significant power levels. Didn't bother it one little bit and once connected properly, performed exactly like before.

                          Built like a tank? Yes indeed.
                          R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio

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                          • #14
                            Re: Measuring Raal 140-15D

                            Originally posted by r-carpenter View Post
                            No problem. I may be conservative with voltage because it's not my driver but sure.
                            I don't think rising response is affected by the capacitor. The testing started without foam pads which are designed to shelve the response. Let's see.
                            Crossover with 30mfd (actually 33) is visible from impedance. I can also run analog impedance sweep starting from whatever I choose.
                            If you're using SE and put the reference probe after the cap you'll get the response of the tweeter all by itself.

                            Ron
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                            The good thing about science is that it's true whether or not you believe in it. - Neil deGrasse Tyson
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                            • #15
                              Re: Measuring Raal 140-15D

                              Well, if the neoX 2.0 performs like this, my planned usage will be golden. I think it might actually perform better.
                              I am trolling you.

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