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  • #16
    Originally posted by Chris Roemer View Post
    If you want sound quality (today), a 10" 2-way isn't the way to go.
    Also, those cabs LOOK like about 1.5cu.ft. (internally).
    No (modern) 10"ers will get you bass in a (normal) box that small (vented, or eSPECIALly closed).
    It's even small for a lot of 8"ers - which you'll want to vent to get down in the 30-40Hz range.
    Wolf's got an 8" 2-way (using a 3" "mid-tweeter" - NOT a modern "dome") that might work in 1.5cf. That's what would sound best in there (new baffle, of course).

    If the woofer's are OK (and you've got good bass), and if your tweeter's okay (w/just an old bad cap) - all you might need to do is bybass the old XO (and baffle-back cap) and make up a new one (I'd just follow the "Increase" portion of the schematic). All you'd need would be 2 caps and a resistor.
    Got to disagree, I built a 10" 2-way with this driver.
    https://www.parts-express.com/dayton...4-ohm--295-569

    Comment


    • #17
      The original Acoustic Research and later KLH woofers listed as twelves were actually tens as far as the cone diameter was concerned, with oversized surrounds that were part of their acoustic suspension design.
      www.billfitzmaurice.com
      www.billfitzmaurice.info/forum

      Comment


      • #18
        Originally posted by Chris Roemer View Post
        Also, those cabs LOOK like about 1.5cu.ft. (internally).
        No (modern) 10"ers will get you bass in a (normal) box that small (vented, or eSPECIALly closed).
        It's even small for a lot of 8"ers - which you'll want to vent to get down in the 30-40Hz range.
        Completely wrong information.
        Craig

        The lowest possible F3 box alignment is not always the best alignment.

        Designing and building speaker projects are like playing with adult Lego Blocks for me.

        Comment


        • #19
          So Craig's corollary is that it'll be easy for you to find a 10" woofer that'll hit 40Hz in a 1.3 (-1.5?) cu.ft. closed box (like your old KLH one) . . .

          If you look here:
          https://www.parts-express.com/resour...election-guide

          you can sort on the column headers by size (10"), or closed box volume (1.3-1.5cf), or closed box F3 (40Hz?) and look around to find just what you need, or not.

          Comment


          • #20
            If you want to tackle replacing the woofers, you might want to check out the Human Speakers PRO 031 Woofer. The drivers are among the few modern examples (of which I am aware) that model pretty well in classic acoustic suspension designs. According to the vendor's modeling, the 10" PRO 031 should hit an F3 of 38hz with a system Q of 0.7 in 1.3 cu ft. I do not have any personal experience with these drivers, but Human Speakers have popped up in several recent threads on acoustic suspension vs. sealed options. Note that a pair would take up your entire budget, so probably not the best option from that angle...

            I am assuming a robust inexpensive tweeter to cross below 1.6 khz would be the bigger challenge.

            Squib

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            • #21
              Originally posted by Chris Roemer View Post
              So Craig's corollary is that it'll be easy for you to find a 10" woofer that'll hit 40Hz in a 1.3 (-1.5?) cu.ft. closed box (like your old KLH one) . . .

              If you look here:
              https://www.parts-express.com/resour...election-guide

              you can sort on the column headers by size (10"), or closed box volume (1.3-1.5cf), or closed box F3 (40Hz?) and look around to find just what you need, or not.
              Who still uses that outdated and questionable data?

              OK here are a couple of examples:

              A Dayton RS270P-4A (p/n 295-569) in 1.5 cubic foot BR tuned to 30 Hz will have an F3/F6/F10 of 33/28/24 Hz.

              A Peerless 830668 (p/n 264-1110) in 1.5 cubic foot sealed and lightly stuffed will have an F3/F6/F10 of 45/36/29 Hz. It will have much deeper bass than simply focusing on its F3 would suggest.
              Craig

              The lowest possible F3 box alignment is not always the best alignment.

              Designing and building speaker projects are like playing with adult Lego Blocks for me.

              Comment


              • #22
                Wait.
                Stop.
                Back up

                You first need to understand what you have here

                The KLH Six went through many iterations.
                The earliest had the cone of a ten in the frame of a twelve to give clearance to the large(for the time) concave roll surround, and to hold a more massive magnet.
                This frame was integrated into the baffle to make a more sound structure, as at AR, Kloss had seen woofers ripped loose in shipping.

                The grill is often integrated into the box with solid hardwood moulding.

                The crossover is fairly complex for the day, and fully potted in various adhesives, eventually epoxy at some point.
                There are usually three connections, you can run the woofer by itself (through a small value coil), or bridge two terminals to use the crossover and tweeter.

                You can get schematics at classicspeakerpages in the library, repair logs on their forum.

                As a first step, hook them up to run full range(bridge the connections, set at brightest position), and leave them overnight with a low level playing through them.
                This may reform the capacitors,( the setting using the fewest of them) and let you know if the tweeters are working.

                That's a start. We'll figure how much and how to get into the boxes later. Some detail pictures of the boxes, like the front/side edges, the connector plates(w/ser#s) would help also.

                These are actually worth fixing, if the woofers are good. The crossovers can be a pain, I have sometimes left the original in place, putting a duplicate without switches on a new, larger plate that gives me access to the insides, allowing tweeter replacement.

                I should also ask. where are you? Maybe we can get you together with someone who has seen these oldest versions before.

                Comment


                • #23
                  Just sell them as is. Apparently they're very desirable.

                  Comment


                  • #24
                    Well, you ARE porting the 270P - but the 830668 SLS "Sub" looks like it DOES have a low enough Le and a flat enough response that someone COULD use it up to 2k, if beaming wasn't an issue. Good find.

                    Comment


                    • #25
                      Originally posted by squib View Post
                      If you want to tackle replacing the woofers, you might want to check out the Human Speakers PRO 031 Woofer. The drivers are among the few modern examples (of which I am aware) that model pretty well in classic acoustic suspension designs.
                      That does come reasonably close to the original AR woofer, which had a 19Hz Fs. The sensitivity is overstated, it's actually 85dB, but that's what one would expect with an 18Hz Fs. Xmax is only 6mm, so in an HT setting it would still need a sub, though it would be adequate for most music applications.
                      www.billfitzmaurice.com
                      www.billfitzmaurice.info/forum

                      Comment


                      • #26
                        I have one KLH Model 6, and it has its own charm. Have you considered cutting out the rear baffle instead? IDK if the early version has the tweeter rear mounted or front, so that may not work. Another option is to add a mid/tweeter assembly on top of the existing cabinet. This has some info on cutting out the baffle on some old cabinets: http://www.troelsgravesen.dk/JBL-L26-3way.htm

                        Not technically a woofer, and really not meant for a two way, but a pair of RSS265HF's will work in a small sealed box: https://www.parts-express.com/dayton...8-ohm--295-442

                        Comment


                        • #27
                          Originally posted by djg View Post
                          Just sell them as is. Apparently they're very desirable.
                          That's an odd suggestion. I bought them as is for $20. Why would i want to sell them if i'm willing to go through the trouble of making them work, lol.

                          Comment


                          • #28
                            I have nothing to contribute to this thread, but I'm just amazed at the use of a woofer frame glued/epoxied to the actual baffle with no way to remove or work on it. I understand why it was done from the explanations cited here, but it just seems amazing to me.

                            This is one of those super-loose suspended woofers that work well in sealed boxes?

                            I guess that's one way to control the quality of the woofers!

                            interesting!

                            TomZ
                            *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
                            *Part 2 *Gluing multiple curved laminations of HDF *Cello's Speaker Project Page

                            *Building the "Micro-B 2.1 Plate Amplifier -- Part 1 * Part 2 * Part 3 * Part 4 * * Part 5 'Review' * -- Assembly Instructions PDF

                            Comment


                            • #29
                              Originally posted by davidB View Post
                              Wait.
                              Stop.
                              Back up

                              You first need to understand what you have here

                              The KLH Six went through many iterations.
                              The earliest had the cone of a ten in the frame of a twelve to give clearance to the large(for the time) concave roll surround, and to hold a more massive magnet.
                              This frame was integrated into the baffle to make a more sound structure, as at AR, Kloss had seen woofers ripped loose in shipping.

                              The grill is often integrated into the box with solid hardwood moulding.

                              The crossover is fairly complex for the day, and fully potted in various adhesives, eventually epoxy at some point.
                              There are usually three connections, you can run the woofer by itself (through a small value coil), or bridge two terminals to use the crossover and tweeter.

                              You can get schematics at classicspeakerpages in the library, repair logs on their forum.

                              As a first step, hook them up to run full range(bridge the connections, set at brightest position), and leave them overnight with a low level playing through them.
                              This may reform the capacitors,( the setting using the fewest of them) and let you know if the tweeters are working.

                              That's a start. We'll figure how much and how to get into the boxes later. Some detail pictures of the boxes, like the front/side edges, the connector plates(w/ser#s) would help also.

                              These are actually worth fixing, if the woofers are good. The crossovers can be a pain, I have sometimes left the original in place, putting a duplicate without switches on a new, larger plate that gives me access to the insides, allowing tweeter replacement.

                              I should also ask. where are you? Maybe we can get you together with someone who has seen these oldest versions before.
                              I was aware of the info in the first part of your post. You understand the dilemma. Thank you for the alternate suggestion of hooking them up and letting them play. I was not aware that you could "reform" the capacitors. I agree they are probably worth fixing but from what i've read you have to cut open the back of the cabinet to repair these older versions. I'd rather maintain the look and use newer components, but if but if i can keep them original, that is ideal.

                              I am in Westerville Ohio. Attached some pictures. They're in quite good shape for ~60 year old speakers.
                              Attached Files

                              Comment


                              • #30
                                Originally posted by tomzarbo View Post
                                I have nothing to contribute to this thread, but I'm just amazed at the use of a woofer frame glued/epoxied to the actual baffle with no way to remove or work on it. I understand why it was done from the explanations cited here, but it just seems amazing to me.

                                This is one of those super-loose suspended woofers that work well in sealed boxes?

                                I guess that's one way to control the quality of the woofers!

                                interesting!

                                TomZ
                                Super loose suspension and a heavy cone, by the standards of the time. The air in the box was a major part of the restoring force, and the heavy cone helped get a low f3.
                                Francis

                                Comment

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