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Scan-Speek 4" for 49 cents?

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  • killa
    replied
    Re: Scan-Speek 4" for 49 cents?

    hmm. I have a couple er18rnx that have been sitting around for a while. If I could find a way to accurately cut the slits I would try it.

    Leave a comment:


  • dlr
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by jbruner View Post
    A wood glue coated cone and an uncut caulk striped cone are dry for when I get back in a day or two. I already tried the surround/cone edge damping that Johnny suggested, and the effect was small. That is something I have been doing for years. I'll have to find another sample for that one.
    Try this as a test. These are small bits of a non-drying putty of some kind.

    Click image for larger version

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    This is a KEF (Celestion) F15 driver in a 2-way. I tried a lot of variations, but never slit the cone. I didn't want to risk destroying it, though I was very interested in the SS technique. I tried it and a couple of variations of added damping material. The result was actually fairly good, but the arrangement above was the best result in what I tested.

    Click image for larger version

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    The best single improvement was with the application of the damping at the inner edge of the surround, in the case it is "The Wet Look" purchased from PE. Took several applications (same thing when I modded other drivers). This is the same thing that a lot manufacturers do, SS included. They had (still have?) a small bottle now that is something like $5. Well worth it for experimenting and I suspect far better for damping than silicon caulk or similar. The full set of tests (SPL, no distortion) are described at the link.

    KEF driver tests

    dlr
    Last edited by dlr; 05-04-2014, 09:59 AM. Reason: Added measurements of before/after treatment

    Leave a comment:


  • caleb
    replied
    Re: Scan-Speek 4" for 49 cents?

    I would think that wood glue would damp more than stiffen. Are not the slits designed to do the absorption of the breakup resonances? Then why damp the cone further? I would think you would want to stiffen the cone so that the slits do all the absorption. Just typing my thoughts

    Leave a comment:


  • jbruner
    replied
    Re: Scan-Speek 4" for 49 cents?

    A wood glue coated cone and an uncut caulk striped cone are dry for when I get back in a day or two. I already tried the surround/cone edge damping that Johnny suggested, and the effect was small. That is something I have been doing for years. I'll have to find another sample for that one.

    Leave a comment:


  • J Fallows
    replied
    Re: Scan-Speek 4" for 49 cents?

    Hey, nice work with the dustcapectomy.
    A real surgeon, yeah that's it, a speaker surgeon.
    Great work and a great thread.

    Leave a comment:


  • killa
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by fatmarley View Post
    But don't you need something flexible to help damp the cone? I think something like contact adhesive, puncture repair glue or a thin bead of silicone would be best.
    3M weatherstipping adhesive

    Leave a comment:


  • johnnyrichards
    replied
    Re: Scan-Speek 4" for 49 cents?

    Mr. Bruner - is there any damping around the edge of the cone? If not, I would look into running a thin bead of rubber cement around the edge where the surround meets the cone.

    Leave a comment:


  • craigk
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by Sidi View Post
    I am a jerk.

    There's nothing wrong with this board.

    Fact is, the result was underwhelming.

    Nothing wrong with experimenting, never said he shouldn't continue.

    panties, knots, etc.
    at least we have that cleared up,

    Leave a comment:


  • thekorvers
    replied
    Re: Scan-Speek 4" for 49 cents?

    How is the cone destroyed if its still making music with less breakup and improved response in the pass band?
    I don't know. It just goes against my grain. I would feel very reluctant to do this, especially with more costly drivers.

    Would I try this with a cheap driver just for curiosity's sake? Maybe. Would I do this with amore expensive driver? Probably not as the outcome is a guess. It could just as easily go the other way and result in a driver that is unusable. I think I would just look for a driver that meets my needs. I prefer predictability. YMMV, but by all means, do your thing and slice away!:applause:
    Last edited by thekorvers; 05-02-2014, 07:24 PM.

    Leave a comment:


  • caleb
    replied
    Re: Scan-Speek 4" for 49 cents?

    Maybe you could start with a fresh one and and make the cone stiffer. I don't know what would be best for that without adding to much mass. I was thinking lacquer if there is nothing better available. It could take over a week to fully cure but maybe quicker if baked in the Georgia sun. Then you could measure it before giving it the slits. I wonder if the the added stiffness would cancel out some of the the improvements made by the slits or would it be even better all around?

    Perhaps you could briefly describe the function of the slits and why this works so well. Or did you just figure if it's good for Scan-Speak let's give it a go?

    Leave a comment:


  • Sidi
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by craigk View Post
    this comment is underwhelming. what does this statement contribute, except to make you look like a jerk. this is exactly what is wrong with this board. a few years ago you would never have seen a reply like this.

    I am a jerk.

    There's nothing wrong with this board.

    Fact is, the result was underwhelming.

    Nothing wrong with experimenting, never said he shouldn't continue.

    panties, knots, etc.

    Leave a comment:


  • mzisserson
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by Sidi View Post
    underwhelmed.
    Originally posted by craigk View Post
    this comment is underwhelming. what does this statement contribute, except to make you look like a jerk. this is exactly what is wrong with this board. a few years ago you would never have seen a reply like this.
    Yeah, exactly.... I find it very interesting, specially in the distortion. This is the Chutzpah that DIY is about. In fact, I am inclined to to this on the Sony Buyouts I have which I have been planning a MTMWW built for for a very long time. Play and see what happens. There is NOTHING wrong with learning like this.
    Originally posted by Paul Carmody View Post
    You just cranked up the witty dial several notches.
    Originally posted by johnnyrichards View Post
    A friend left four of those things sitting here, maybe I will frankenstein them somehow. Cool experiment, and an awesome way to showcase how distortion is not always motor related.
    Exactly..... I like Paul's comment too.... Defiantly cranked the whitty dial. Keep it up!

    Leave a comment:


  • NyxOne
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by jbruner View Post
    Alternate thread title: I'm a cutter now!

    I've been trying out driver modifications on some old NSBs.


    Sample2

    I baselined 4 drivers and they were pretty much identical.

    Here is the response of sample 1 before and after Revelator style cut and glue job.


    Blue is modded, brown is baseline. I added a small piece of duct seal to the slit dust cap to smooth the top octave on this one. Sample 1-



    The net result is very impressive. The primary break-up is reduced by 11dB, distortions of all orders are lowered, and subjective sound quality is much improved.

    In other words, there is no downside, unless you like the sound of paper cone break-up.
    Very interessting! I wonder what it could do for a an SB15 or SB17!

    Chuck

    Leave a comment:


  • Paul Carmody
    replied
    Re: Scan-Speek 4" for 49 cents?

    Originally posted by jbruner View Post
    .

    So we need to fill the gap. I will replace the dust cap with a dusty cap.
    You just cranked up the witty dial several notches.

    Leave a comment:


  • johnnyrichards
    replied
    Re: Scan-Speek 4" for 49 cents?

    A friend left four of those things sitting here, maybe I will frankenstein them somehow. Cool experiment, and an awesome way to showcase how distortion is not always motor related.

    Leave a comment:

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