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Thread: Rehabbing PR300's - Seeking Technical Advice

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    Senior Member DerekTheGreat's Avatar
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    Question Rehabbing PR300's - Seeking Technical Advice

    Hey everyone

    If you happened to glance at my previous thread where I mentioned potentially buying a set of PR300's and getting gaskets, well, I got 'em!

    Now that they're here, I've realized I need some guidance from you pros. Here are my concerns:

    1) What do you guys use to remove the old surround residue from both the speaker basket and the woofer cone itself?
    2) The spider seems pretty floppy on these, is this normal or are they worn out? Would soaking them in acetone and then drying them do anything? They either want to sit at the bottom of their travel or fully extended out- not in the middle. So refoaming seems like it will be fun too.
    3) The spider one one is detaching, should I use the same glue provided in the surround kit to reattach?
    4) What to use to clean the cone face? There are some spots on them, kind of looks like someone may have ralphed on the one, like indirect spatter. Pretty gross looking but I didn't want to smell to verify. The smell already emanating from these is "musty basement with a heap of cigarette." Looks like it might come out but I don't want to damage the cone or mark it. The rest of my L150A's are pretty minty, I just went this route because my PR300's were reconed with a deep purple woofer and I'd like to get back to factory appearance. Also looking for a pair of original LE5-12's, pretty sure mine were reconed as well.

    Thank you for reading.

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    Bo did a little how to on a speaker surround, might get you started

    http://www.audioheritage.org/vbullet...d-Step-by-step

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    Senior Member RMC's Avatar
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    Q # 1

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    Senior Member DerekTheGreat's Avatar
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    IPA, ok, I've got that on hand.

    Thanks for the link, Jeff. I remember coming across that thread back in the day. He doesn't discuss removal of the crud much, other than to scrape it. Guess that's what the IPA is for.

    Any of you guys have any input about my other concerns, like with that spider or how to clean the cones up? Is the spider toast or will it not make an audible difference?

    Also, I think it's worth mentioning that these PR300's came equipped with 6 fiber discs on each, with the factory glue dab on 'em. Guessing that's how many should be on there as the ones I pulled from my L150A's only had 4 discs per PR300. Funny how I spent lots of time listening and experimenting only to finalize on a mass which was very close to JBL's target- my 57g vs their 60g.

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    You can buy a replacement 128H spider, no idea how it stacks up against the PR300 spider but at least it'll have some life - might have to adjust the weights to get it to play nice with the woofer

    https://www.simplyspeakers.com/spide...3-fs-6700.html

    Going down that rabbit hole, you might just grab the aftermarket 128H recone kit - it has spiders and a gray cone.

    https://www.simplyspeakers.com/jbl-r...K-JBL128h.html

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    Senior Member DerekTheGreat's Avatar
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    Thanks Jeff.

    I think I'll buy two of the spiders and see where that takes me. This might end up being a wash- I have reconed & functional PR300's currently, I just wanted to get back to the factory appearance of the black cone. That's why I bought the set of PR300's from eBay but it's looking like that might be money wasted.

    Going to try and save those cones. Any advice on how to clean them without damaging them?

  7. #7
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    Not a clue. I think I remember reading something about Kenrick using a black dye to freshen up old cones, not sure if anybody figured out what it was or how it was applied.

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