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Replacement suggestions for old speaker cabinet (10" and 3")

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  • Replacement suggestions for old speaker cabinet (10" and 3")

    First-time poster so apologies in advance... I have my grandpa's old Fischer 95 stereo/record combo and had the receiver serviced. Now I'm looking at replacing the speakers which when I removed were essentially falling apart.

    The cabinets that the speakers are in look great and while I'd like to continue using with the existing receiver (after servicing the right channel has a hum--hoping that's the speaker) I'd be open to using a 3rd-party amp. Each cabinet is about 1.3 cubic ft and has a 3" midrange(?) and then a 10" woofer with what look like some low/high-pass filters.

    How does the following sound for a replacement:

    Dayton Audio DW3-1053SC 3" Full Range Driver
    Dayton Audio DC250-8 10" Classic Woofer

    One concern that the RMS on the woofer is so much higher than the 3" driver. I'm also curious what would the recommended crossover frequency be.

    Thanks!
    Last edited by pjackson; 04-21-2020, 12:10 PM.

  • #2
    The small driver in those things was a tweeter not a fullrange, don't be misled by its appearance. Pretty much any modern driver you select will have a higher power handling than what is being replaced, but don't plan on putting a lot more power into these, the cabs will not be built for it. The passive crossover splits frequencies and energy between drivers and there just isn't as much energy at higher frequencies so it's common that the low freq driver has 3-4 times higher power handling than the high freq driver.
    Paul O

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    • #3
      Welcome to the forum! And your new speaker building addiction..


      It’s cool you want to keep your old classics running. You are on the right track. While the original was a 2-way with a 10” woofer and big tweeter, this is not ideal. Your idea is actually more optimum than the original design!

      PaulO made some solid points. No need to worry about the power handling being lower up high. Also your cabinets are pretty thin as mentioned. Some wooden dowels glued across the inside tying the opposite panels will go a long way.

      The full range / woofer configuration like you chose is common, often referred to as a FAST speaker. The DC 10” looks like the 1.3ft3 sealed will work nicely.

      The full range driver you chose is probably just fine but it is difficult to model with no published frequency graph. Might I suggest this: https://www.parts-express.com/dayton...river--295-156 or this https://www.parts-express.com/peerle...ofer--264-1062. The TC9 is highly regarded but out of stock. The Dayton pc83 looks nice too though.

      What you will need to do is make a separate small internal enclosure for the full range driver. I would just use a 4” pvc tube between the front and rear panel. This will use up some space for the woofer but won’t be the end of the world.

      Someone here can assist you with a crossover (I will if I get time). This will cross low, around 300-500 hz likely.

      I think you will be surprised and happy with your result. One thing about a full range driver is the off axis treble drops quicker. You may find yourself bumping the treble a touch on the receiver (I’m afraid your hum is there and not the speaker btw).

      Comment


      • #4
        Thanks to both of you for the info. Surprised it's a tweeter when I'd think there'd be a frequency gap between the 10" woofer and tweeter. Also good to know that cabinet needs some reinforcement.

        Question about the crossover. The DC250 has a FR of 25-2,500Hz and the PC83's is 80-20,000 so I get setting the cross low like you suggested BUT the assembled crossovers start around 2,500Hz (https://www.parts-express.com/dayton...00-hz--260-142). I assume I'm not understanding this correctly...

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        • #5
          Originally posted by pjackson View Post
          Thanks to both of you for the info. Surprised it's a tweeter when I'd think there'd be a frequency gap between the 10" woofer and tweeter. Also good to know that cabinet needs some reinforcement.

          Question about the crossover. The DC250 has a FR of 25-2,500Hz and the PC83's is 80-20,000 so I get setting the cross low like you suggested BUT the assembled crossovers start around 2,500Hz (https://www.parts-express.com/dayton...00-hz--260-142). I assume I'm not understanding this correctly...
          I doubt an off-the-shelf crossover will work very well. Sometimes they work out, often they don't.
          Francis

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          • #6
            You don’t want an off the shelf crossover. You need a custom design. I’ll try to do one for you tonight.

            what are your baffle dimensions, and how far is the center of each driver from the bottom and left edges of the baffle.

            also, will these be on the floor, on stands, in a true bookshelf, against the wall, out into the room, or otherwise?

            Please get me this data soon and I’ll work on it.

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            • #7
              Also how deep is the cabinet internally?

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              • #8
                Assuming measuring the baffle from the outside:
                W: 12 & 1/8"
                H: 22 & 1/2"

                Woofer from bottom and left:
                Bottom: 3 & 7/16"
                Left: 5 & 7/8"

                Tweeter from bottom and left:
                Bottom: 15 & 11/16"
                Left: 5 & 7/8"

                These will sit on the floor an inch or two from the wall. Thank you!

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                • #9
                  Originally posted by dynamo View Post
                  Also how deep is the cabinet internally?
                  9 & 7/8th with a little bit covered by 3/4" trim around that the back MDF sits against.

                  Comment


                  • #10
                    Here is a schematic. If you would like help with parts selection I can do that tomorrow. Biggest thing is R1 should be 20 watts. I needed a more efficient full range so I went with the FatialPro 3FE25. It is a very nice driver. Here is the link https://www.parts-express.com/faital...-ohm--294-1104.

                    The 3FE25 just needs a sealed 4" id PVC pipe the depth of the cabinet with some polyfil in it (play around with the amount).

                    The crossover point is a little higher to make everything work out. The top end has a significant rise to it that will level out at a position above and or to the sides of the speakers. This is intentional as they will be sitting on the floor. Because of the intended position there is little to no baffle step compensation, so if they were put on stands away from the wall the bass will need boosting. None the less this is only a sim so you may need to dial them to taste with the tone controls anyway. Edit - see Post 23

                    Click image for larger version  Name:	Schematic.jpg Views:	0 Size:	46.6 KB ID:	1438172
                    Last edited by dynamo; 04-22-2020, 03:15 PM.

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                    • #11
                      Click image for larger version

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                      Here is the on axis. Again the rise is intentional given the 3" driver and floor position. Ignore the dip, it was that or a bump. The dip will likely be inaudible where bumps can be annoying.

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                      • #12
                        Click image for larger version

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                        Here is showing how the top end levels off above or to the sides of the speaker.


                        Let me know how they turn out!

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                        • #13
                          The CENTER of your woofer must be more like 6-1/2" up from the bottom (rather than 3-1/2")?

                          I'd use Dayton's "Classic" 10" in that box w/a 3" PrecisionPort that's 10" long (it really prefers a larger box though).
                          Should do 40Hz.

                          Typically you'd like your tweeters about the same level (above the floor) that your ears will be when listening. Using a 3" (mid) for highs will have even less dispersion (than a tweeter) and so the highs will be even more muffled unless you tilt the cabs back (to aim the highs at your head). You'll probably need these towed in as well.

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                          • #14
                            Originally posted by Chris Roemer View Post
                            The CENTER of your woofer must be more like 6-1/2" up from the bottom (rather than 3-1/2")?

                            I'd use Dayton's "Classic" 10" in that box w/a 3" PrecisionPort that's 10" long (it really prefers a larger box though).
                            Should do 40Hz.

                            Typically you'd like your tweeters about the same level (above the floor) that your ears will be when listening. Using a 3" (mid) for highs will have even less dispersion (than a tweeter) and so the highs will be even more muffled unless you tilt the cabs back (to aim the highs at your head). You'll probably need these towed in as well.
                            Chris is right, I measured incorrectly.

                            The woofer is 7 & 3/8" from the bottom and the tweeter is 17 & 5/8" from the bottom. Apologies, dynamo. That's what I get for only double-checking measurements and not orientation..

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                            • #15
                              I figured that out about the driver height when looking at your measurements and adjusted.

                              I was going to suggest you may want to make cradles or feet to raise the front of the speakers a touch to aim them up. I’d still leave the on axis treble response rising, a treble control can dial it down if need be.

                              Chris is absolutely right about the off axis treble response with a 3” driver being far worse than say a 1” dome, but I think it will work out nicely as they even out due to the rising top end.

                              Youll notice the top half octave drops off but I don’t think it will be an issue reality as many humans can’t hear that high anyway.

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