Announcement

Collapse
No announcement yet.

Update and some questions

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

  • #16
    So what do you like of those you've tested??

    Comment


    • #17
      What do I like...hmm....well a common like is that they all work well with horn loading (waveguide, whatever, lol), with the rudimentary experimentation I've done (except for the Beyma which already comes with it's horn/waveguide). This was critical since I am mating one of them, eventually, to a 10" midbass from either Italy or Spain, so good extension below 2kHz is crucial. Obviously the larger ones tend to work better when taken down lower in frequency, and the smaller ones do better on the top-end, which is to be expected. The Aurum Cantus AST30130 does exceptionally well down low in terms of raw dB output, with usable response below 1kHz if one accepts the slightly higher levels of distortion that accompanies the larger membrane excursions from said usage:





      Even the shape of the response curve changes when high drive levels cause the membrane to really flex it's muscles.

      Comment


      • #18
        The measurement distance can change the response due to diffraction.

        Comment


        • #19
          Me neither. Just waiting for a break in the weather. And getting a DOA ext soundcard replaced. Curious as to how those measured with respect to off axis response, distortion and bandwidth. I'm certainly not going to drive the 25120'2 down to claimed Xover of 1.7 KHz Especially with the bandwidth of the Quenze.

          Where did you get the 31130 anyway? PE no longer carries them and finding suppliers for some drivers can be challenging. The Quenze I had to purchase from Denmark, last time I looked for Beyma, there were no US distributors but everyone over on diy audio seems to think those ribbons are the cats meow. BTW that is a really impressive and interesting flattening of the FR vs drive level. Hope you were wearing ear protection.

          Comment


          • #20
            The other thing I think is very curious as some commenters said the AMT were bullet proof is that on the AC website it says the diaphragms are field replaceable. Not sure what it would take:unfiltered full on low freq thump?

            Comment


            • #21
              Yea I was wearing earplugs and earmuffs simultaneously.

              There's a few US dealers for Beyma, but not all of them advertise as such. US Speaker is one of the ones that does have a website. I got the AST 30130's used on diyaudio. Got a pretty good deal on them, but even then, Aurum Cantus will sell you a pair of 30130's directly for $750 shipped. There's still much testing to be done, as this is just one of the projects on my back-burners. I won't be attempting dipole operation, so I still need to test them in some kind of enclosure.

              As to the robustness of AMT's I can attest that they can take quite a beating, but nothing is 100% bulletproof. Diaphragms are indeed field replaceable, as they are in the Beyma's and others as well. On my testing I run the "bass removed" track which leaves out the sub-300Hz frequency sweep, and I use EQ to pull down that same range even more. That reminds me, I need to order some replacement diaphragms for my Beyma's as well as the 30130's.

              Have you tested your 25120's for FR and/or distortion to see how well they meet up to expectations?
              Last edited by guitar maestro; 01-15-2019, 10:40 AM.

              Comment


              • #22
                In a word no--until I get the ext soundcard replaced I'm limited to FR. Hope to cut the holes tomorrow and do some indoor msmts Thursday. They will be a plain PE box, however. and the effect of baffle diffraction just an approximation based on modeling. But I'll definitely share some listening impressions this w/e.

                Comment


                • #23
                  In the good news and bad news dept: between an attack of sciatica (which is butt hurt for a man second only to passing a kidney stone, and the cold weather, taken me a while to get this far. Good news: Quenze-C is a remarkable driver and able to soak up at least 170 Watts w/o distress. So-so news the AC tweets aren't measuring well. A pic is worth a thousand words:

                  Comment


                  • #24

                    Comment


                    • #25
                      What's the input voltage and distance is the microphone? Are you doing a full frequency sweep?

                      Comment


                      • #26
                        Input voltage I'd have to calculate, but the output of both drivers was 92 dB at one meter, the tweeter was down 9dB to equalize the sensitivity. Log frequency sweeps from 100 to 20K for the woofer, tweeter sweep was truncated to avoid stressing the AMT. Results obviously disappointing on that end.

                        Comment


                        • #27
                          So just to check the accuracy of my measurements, I ran the woofer as before but measured the Russian tweeters Roman was able to source. The other msmt displayed is the other AMT, which sadly I damaged by driving it with a full freq sweep. No excuses except I was tired and the speakers upside down. Unfortunately, PE is unable to get a replacement diaphragm and Aurum Cantus isn't responding to my e-mails. I guess I learn Chinese or e-mail every other dealer in the world. In the meantime I'm buying the G1 ribbons, which hopefully will have less variability. I'll post when I get those in a box.

                          Comment


                          • #28
                            Originally posted by JRS View Post
                            So just to check the accuracy of my measurements, I ran the woofer as before but measured the Russian tweeters Roman was able to source. The other msmt displayed is the other AMT, which sadly I damaged by driving it with a full freq sweep. No excuses except I was tired and the speakers upside down. Unfortunately, PE is unable to get a replacement diaphragm and Aurum Cantus isn't responding to my e-mails. I guess I learn Chinese or e-mail every other dealer in the world. In the meantime I'm buying the G1 ribbons, which hopefully will have less variability. I'll post when I get those in a box.
                            Give them some time, and they will respond. It took them a few days to respond to me. I was planning on ordering some extra diaphragms for my 30130's in a couple months.

                            Comment


                            • #29
                              Thanks. It's been a week, and in the meantime I have sent out feelers to a few dealers in Europe. Provided I get one, I'll likely put her up for sale on E-bay as the undamaged one is headed back to PE. Ribbons should be here soon, in the meantime I have an amp project I'll be posting soon. Basically gutting an old Marantz 5 x 160 amp at replacing the amp modules with ICE power 2x250 + 2x100W for the woofer and mid bass. After rethinking things, the ribbons are a better fit and maybe some day I'll get some 30130's and cross them over to the Audio Elegance woofers, and get rid of the mid bass units altogether, Now that would for sure provide rock concert volumes capable of destroying what little hearing I have. I used to have a system like that--forget what brand the 60 inch tall composite planars XOed to a a pair per side of 8" Scan Speak woofers. Also cut a big hole in the floor and had a couple of long throw 18" woofers in an infinite baffle config. Now that was some some fine base--articulate and capable of flexing my the windows in my home. Only problem was it also flexed the floor--don't build houses like they used to. ;-D

                              Comment


                              • #30
                                That sucks, I would have been willing to buy the pair of 25120's from you.

                                Comment

                                Working...
                                X