Announcement

Collapse
No announcement yet.

Curb Find - Original "The Advent Loudspeaker"

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

  • #16
    That's a nice surprise, finding good veneer under the contact paper. Ya gotta wonder what went on in the mind of the person who put that crap on there. I think I'd make a new baffle that fits flush with the sides, fastened on to the original baffle, even if I were going to use the same holes. That could look really sharp with the de-gooped and refinished veneer. Nice find!

    Comment


    • #17
      Originally posted by Chris Roemer View Post
      I WAS using older sub parms: Qts=0.41, Vas=4.1; but even w/the latest ones: Qts=0.40, Vas=3.2 . . . I see the same F3 as the orig.
      Orig. ADVENT: Qes 0.51, Qms 4.8, (Qts 0.46), Re 5.1, Le 1.6, Sd 341cm^2, Xmax 6.0mm, Pe 60w (orig. Qtc "in box" close to 1.0).
      The older specs had a Qtc near 0.8, whereas the newer ones yield more like 0.7, still I think it would have the flavor of the original.
      Now I get it. If the tweeters are good, near original sound, hmmm ... But the reviews indicate the DCS305 will not cross high enough to meet the original tweeter. I gather you were referring to the an FR taking over down low. Then I'd have to close up the square tweeter opening, no big deal.

      Comment


      • #18
        Nice find! As Chris pointed out, they sound and measure the best with the grills on. I made OmniMic measurements on my pair, both with and without the grilles. And it makes quite a difference. I will be glad to go find my comparison graphs and post them if you like.

        Another possibility would be to find an original (1974 or so) set of masonite woofers on ebay, re-foam them, and then attempt a classic restoration. This is what I tried to do. In any event, good luck with your project. If you are interested, here is a link to my restoration thread:

        http://www.midwestaudioclub.com/diy/...storation-1974

        EDIT 12/2/17: I added a graph comparing grill verses no grill to my thread listed above
        Last edited by 4thtry; 12-02-2017, 02:28 PM. Reason: Posted new graph to linked thread
        Plumber's Delight: http://techtalk.parts-express.com/fo...notech-winners
        Linehopper: http://techtalk.parts-express.com/sh...Esoteric-build
        Plan-Tanic: http://techtalk.parts-express.com/sh...ght=Plan-Tanic

        Comment


        • #19
          Originally posted by 4thtry View Post
          Nice find! As Chris pointed out, they sound and measure the best with the grills on. I made OmniMic measurements on my pair, both with and without the grilles. And it makes quite a difference. I will be glad to go find my comparison graphs and post them if you like.

          Another possibility would be to find an original (1974 or so) set of masonite woofers on ebay, re-foam them, and then attempt a classic restoration. This is what I tried to do. In any event, good luck with your project. If you are interested, here is a link to my restoration thread:

          http://www.midwestaudioclub.com/diy/...storation-1974
          Thanks. I'm not sure yet whether I want to restore or rebuild with modern drivers and XO. If I rebuild, I'll remove most of the original baffle and glue in a new one flush with the front edges to avoid the diffraction cause by the recess. But the corners will still be square.

          I have all the contact paper and adhesive off (except the bottoms). And my cabs seem to be in slightly better condition that those shown in your rebuild. Except the baffles. The contact paper removed any finish on them so some light sanding and a paint job if I keep the original baffle.

          Comment


          • #20
            Well I've cleaned up the cabinets. They show very little distress. On the left, the top rear corner is the biggest ding. And that top looks like it had an amp on it. Also on the left, in the right lighting, you can see "indent" lines, not quite scratches as they appear in the photos. And there are small "water circles" that looks like they're from amp feet.

            Advent Cabinets.jpg

            While these deserve a place in speaker history, they're not worth a ton of money. Near mint condition sets with the original Masonite drivers (refoamed) can be had for under $200.

            There is a new mfg'ed woofer that purports to be the exact replacement for $120 each. But after modeling its T/S parameters in in the Advent enclosure using WinISD its F3 is 60 Hz. That's a big difference from the original's mid 40s F3.

            So I've scoured the net modeling woofers and came upon this: The MCM 55-5725 8 ohm 12" woofer. At 12" it will drop right in to the original cutout. In the Advent enclosure its F3 is 47 Hz. For the WinPCD model, below, I used the 1st order LP inductor specs from Pete Basil's site (thanks Pete).

            You can't really look at much above a few hundred Hz. I couldn't find any FR graph for the Advent tweeter so I just used any tweeter data I had on hand (WinPCD won't display graphs until you enter a tweeter). My only concern is the woofer response above 2K. I could try some caps across the woofer to make it a 2nd order LP and tame that a bit.

            WinPCD Model.png


            At 8 Ohms it might not keep up with the tweeter but I could always pad that. And total cost for both woofers including shipping from Newark (MCMs new outlet) is under $50. I could always make a grill.


            What do you gents think?

            Comment


            • #21
              I thought (you thought) you had wood/or veneered cabs, but those are just what ADVE\T called their "utility" cabs (MDF, or more likely PB, w/a vinyl covering). Those are what mine are as well.

              Comment


              • #22
                Where are you located Mike? I have a pair which need a refoam, but have other ideas for the cabinets. I suppose I could immobilise with medium foam blocks(or shim), I just don't like shipping drivers not in their most resilient condition. They're pretty tough when intact.
                As to the baffle finish, on mine there is none. Henry was not a speaker porn guy, had to be dragged into style related expense. By the time Advent made the Legacy/Prodigy era speakers they were in modern mode, with fully finished cabinets. Speakers like ours varied through the years.
                The grill is an integral part of the speaker, as wth so many of this era. Troels Gravesen tested an old Spendor three way which apparently lacked its grill. He tested the funky shaped Celestion tweeter and showed how important the flush surface is(he used mat board or something).
                If you want a new woofer, try the Peerless used in the Tarkus. If you go all new, send me those tweeters, I love fried eggs!
                Speaking of the Tarkus, these are close enough in baffle width that it would require little or no tweaking to the crossover, it's usually good as long as the cross is above the step.

                p.s. I have the grills also, though one has been abused by a cat(I presume). I had a friend who would make veneered 'baffle plates' instead, as he thought he might hear the cloth.
                Last edited by davidB; 12-06-2017, 02:50 PM. Reason: getting forgetful

                Comment


                • #23
                  Originally posted by davidB View Post
                  Where are you located Mike? I have a pair which need a refoam, but have other ideas for the cabinets. I suppose I could immobilise with medium foam blocks(or shim), I just don't like shipping drivers not in their most resilient condition. They're pretty tough when intact.
                  As to the baffle finish, on mine there is none. Henry was not a speaker porn guy, had to be dragged into style related expense. By the time Advent made the Legacy/Prodigy era speakers they were in modern mode, with fully finished cabinets. Speakers like ours varied through the years.
                  The grill is an integral part of the speaker, as wth so many of this era. Troels Gravesen tested an old Spendor three way which apparently lacked its grill. He tested the funky shaped Celestion tweeter and showed how important the flush surface is(he used mat board or something).
                  If you want a new woofer, try the Peerless used in the Tarkus. If you go all new, send me those tweeters, I love fried eggs!
                  Speaking of the Tarkus, these are close enough in baffle width that it would require little or no tweaking to the crossover, it's usually good as long as the cross is above the step.

                  p.s. I have the grills also, though one has been abused by a cat(I presume). I had a friend who would make veneered 'baffle plates' instead, as he thought he might hear the cloth.
                  I had read last night that they were offered unfinished in the early runs. I don't have the original woofers. They were replaced with Realistic (radio Shack) woofers with foam surrounds that also rotted out. They went in the garbage right off.

                  I do not plan on acquiring the original woofers in need of refoam (never did a refoam). If the tweeters & HP XO test good (hopefully testing tonight), I'm going to try entirely new woofers - MCM 55-5725 12" 8 Ohm. Down low they model the best in the sealed cab. Read my previous post # 20.

                  EDIT: Tweeters and HP XO test good (at least to my ears).
                  Last edited by Millstonemike; 12-06-2017, 06:10 PM.

                  Comment

                  Working...
                  X