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  • Advice for replacement mids & tweeters

    Hello

    I want to fix up my father's ancient Fisher speakers (he's too cheap to buy monitor 60s or JBL f17s).

    The speakers are Fisher stv-340. Specs are as follow: approximately 1.05ft3, port is 1.75x5 inches long, crossover frequencies are 1.5khz and 6khz.

    I was thinking of using these for replacement mids and tweeters-
    Tweeters: Dayton DC28F-8
    https://www.parts-express.com/dayton...eeter--275-070

    Mids: Visaton M10
    https://www.parts-express.com/visato...8-ohm--292-594

    The enclosure does not have a sealed section for midrange drivers. Baffle cutout for tweeter is 3 inches, mid is 4 inches. I want to keep cost for each replacement driver at $15 or less.

    Do these sound like they'll work decently with specs I've provided? I don't know the speakers rated sensitivity unfortunately. If one can trust the little freq response graph on the speaker, sens seems to average 90-92db across the usable spectrum. They are rated at 50 watts, doesn't say max or rms, but they've been driven with 100 and the woofers handle it well.

    Thanks
    Aaron

  • #2
    Ahh, Fisher. My first set of speakers was a 10" 3-way set of Fisher back in about 1974. Replacing the blown tweeters on those was the hook that got me started with speaker building.

    The drivers you've chosen will probably work just fine, but to get any kind of decent sound from the result you'd need to get a few measurements of the woofer and mid. The DC28 is a pretty well known component but I am unaware of what that Visaton will do.

    Are you planning on just dropping them into the existing crossover?
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    • #3
      Yeah, plan on using existing xover. I should've looked to see if it's a 1st or 2nd order while I had the mid out. He's a cheapskate and the speakers were only $100 25+ years ago. So I can't see sinking anymore than maybe $60 into them. But he loves them.

      Gonna get him a Dayton sub-1000 too probably without him knowing (has crappy passive 5.25 or 6.5 band pass now). He just doesn't know it yet. Don't want to spend more than about $200 total since it's his money.

      Likes his old fishers, likes a more "warm/vintage" sound obviously. Hence choosing a soft dome tweet. The Visaton seems to have decent matching specs and physical measurements, but wanted input from others with more experience replacing drivers. I can build a nice sub, but no experience building a whole speaker (or altering one). I'd hate to alter the cabs (other than new grill cloth).

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      • #4
        The "cross over" in these is a single cap for mid and tweet, I believe. Nothing more
        https://www.facebook.com/Mosaic-Audi...7373763888294/

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        • #5
          Originally posted by isaeagle4031 View Post
          The "cross over" in these is a single cap for mid and tweet, I believe. Nothing more
          I had a feeling it was nothing more than a 1st order xover. Both of those drivers appear to have a nice frequency range, so I'm thinking they should be good replacements, unless I'm missing something? Maybe down the road I can upgrade the xover's.

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          • #6
            Visaton DOES have F/Z curves on their site.
            JUST considering the mid and tweet:
            W/tweeter reversed relative to mid, FR runs from about 500Hz (78dB), to a 93dB peak at 700Hz (+5dB from 88dB Nom.) to a(n) out-of-phase low of 83dB near 4.5k (-5dB), crossing to the Silky around 6.5kHz.
            So . . . (using just a 3uF cap on the Silky, and a 13uF cap on the M10) it (THEY) cover from 500Hz on up at about 88dB +/-5dB.

            BUT . . .

            W/the Silky wired "in-phase", it looks horrendous. With a 77dB (oop) low @ 1.5kHz, and a peak of 97dB just over 5kHz. That's more like 87dB +/-10dB.

            Of course, I don't have (and haven't generated) min-phase files or used any X,Y, Z offsets, so the "proper" phase is yet to be determined. The M10 shows a bad peak at 700 and 5kHz. Visaton recommends a 2nd order HP filter. You'd prob'ly want some kind of "notch" (on an LP filter) necessitating a band-pass on that mid.

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            • #7
              Originally posted by Chris Roemer View Post
              Visaton DOES have F/Z curves on their site.
              JUST considering the mid and tweet:
              W/tweeter reversed relative to mid, FR runs from about 500Hz (78dB), to a 93dB peak at 700Hz (+5dB from 88dB Nom.) to a(n) out-of-phase low of 83dB near 4.5k (-5dB), crossing to the Silky around 6.5kHz.
              So . . . (using just a 3uF cap on the Silky, and a 13uF cap on the M10) it (THEY) cover from 500Hz on up at about 88dB +/-5dB.

              BUT . . .

              W/the Silky wired "in-phase", it looks horrendous. With a 77dB (oop) low @ 1.5kHz, and a peak of 97dB just over 5kHz. That's more like 87dB +/-10dB.

              Of course, I don't have (and haven't generated) min-phase files or used any X,Y, Z offsets, so the "proper" phase is yet to be determined. The M10 shows a bad peak at 700 and 5kHz. Visaton recommends a 2nd order HP filter. You'd prob'ly want some kind of "notch" (on an LP filter) necessitating a band-pass on that mid.
              I followed that up to the "BUT..." part. Obviously I won't need these to handle 100wrms. As long as they fit the budget of $60 total and are suitable replacements, that fit, I'll be happy. I really don't want to sink money into 30yo speakers that only cost $100 when new. But I would like to fix them for my father.

              im open to suggestions to replace these drivers. Hell, if I could afford the $200, I'd spring for Polk 60s or JBL F17s. But with 3 kids and bills, well...most of you know about the WAF.

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              • #8
                $100 twenty five years ago was a lot more than it is today. I had a set of those speakers. Considering that I’m most surely older than your dad, and that his hearing is probably not that great, I disagree with Pete that you need to do any measurements. Just realize that it was probably 1st order so you need a wider frequency range. Pete’s half way decent and your father’s half way decent are not the same. He will be delighted with new drivers.

                35 years ago I built a set of Goldsound 3-ways(still use the 12 inch DVC woofers in a current system with their 2nd surround replacement), for about $200.

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                • #9
                  Originally posted by malboro2 View Post
                  $100 twenty five years ago was a lot more than it is today. I had a set of those speakers. Considering that I’m most surely older than your dad, and that his hearing is probably not that great, I disagree with Pete that you need to do any measurements. Just realize that it was probably 1st order so you need a wider frequency range. Pete’s half way decent and your father’s half way decent are not the same. He will be delighted with new drivers.

                  35 years ago I built a set of Goldsound 3-ways(still use the 12 inch DVC woofers in a current system with their 2nd surround replacement), for about $200.
                  I dunno, dads up there at 74. His hearing definitely isn't the greatest, so I'm guessing those will be decent replacements. Both extend at least one octave +/- of the crossover points, so they should suffice. I wish I could find a sensitivity rating on the speakers. Either way, I doubt that woofer is 89/90db sens, so I'm assuming I should be good on the replacement sensitivity.

                  Since i I can only afford about $200, this will leave me money to get him a sub-1000 or sub-1200 to replace the crappy 6.5in bandpass "HTIB" passive sub he has now.

                  I wont be ordering replacements for a day or two yet, so I'm still open to other advice on the replacement drivers. Thanks guys!

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                  • #10
                    I've decided on the Daytons for the tweeters after looking at the response curves/graphs. However, I'm also considering the Eminence Alpha 4-8 also for mids. https://www.parts-express.com/eminen...-ohm--290-4012

                    Unfortunately, there is no response graph for the Visaton M10. The M10 has a 1db higher sensitivity, and Fs of 700hz vs the 123hz of the Eminence. Leads me to believe the Visaton would be better for these xover points (again 1.5k & 6k) as a replacement. Also, would having a sealed back mid be that big of a benefit with the M10? I assume so since the Eminence is recommend for an acoustic suspension enclosure with an f3 of about 140hz, not exactly midrange territory.

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                    • #11
                      Originally posted by zagnutty View Post
                      I've decided on the Daytons for the tweeters after looking at the response curves/graphs. However, I'm also considering the Eminence Alpha 4-8 also for mids. https://www.parts-express.com/eminen...-ohm--290-4012

                      Unfortunately, there is no response graph for the Visaton M10. The M10 has a 1db higher sensitivity, and Fs of 700hz vs the 123hz of the Eminence. Leads me to believe the Visaton would be better for these xover points (again 1.5k & 6k) as a replacement. Also, would having a sealed back mid be that big of a benefit with the M10? I assume so since the Eminence is recommend for an acoustic suspension enclosure with an f3 of about 140hz, not exactly midrange territory.
                      You need a sealed back in your application, unless you intend to construct an enclosure for the mid range. The specs for that Eminence driver are presuming it's the only driver in the box. In your application they'll get beaten up by the pressure from the woofer.

                      I'd suggest going with Chris's recommendation and you're initial driver choices:
                      3uF cap to the tweeter, wired reverse
                      13uF cap to the mid

                      That will be plenty good within your budget constraints.
                      Electronics engineer, woofer enthusiast, and musician.
                      Wogg Music

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                      • #12
                        These might fit, and they're in your budget:

                        https://www.parts-express.com/grs-5s...range--292-432

                        https://www.parts-express.com/goldwo...8-ohm--280-115

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                        • #13
                          Visaton DOES have F/Z curves on their site.
                          (I repeat.) Visaton DOES have F/Z curves on their site.

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                          • #14
                            Originally posted by chrisn View Post

                            I used the Goldwood 4 ohm (regular duty with the screen). Down low the FR and Impedance graphs are very similar. The peak circa 500 Hz was a pain to tame in Win PCD. Definitely needs a 2nd order HP.

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                            • #15
                              Originally posted by chrisn View Post
                              The GRS falls a little short on freq response. About 2khz short of an octave higher than the crossover point. The Goldwood looks good, and cheap, but I don't think it would fit due to how close the tweeter mounts. If for some reason I don't like the Visaton, I'll take some measurements and see about trying the Goldwood. Thanks!



                              Originally posted by Chris Roemer View Post
                              Visaton DOES have F/Z curves on their site.
                              (I repeat.) Visaton DOES have F/Z curves on their site.
                              Don't know why I didn't think of looking at their site. DOH! I'll take a peak, thanks!

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