Heads up for Monitor 11 owners

F1nut
F1nut Posts: 50,557
edited July 2013 in Vintage Speakers
I was doing some upgrades to a set of Monitor 11's the other day and discovered something that may be of interest to the owners of said speakers. Inside the cabinet, under one of the mid-drivers is a 3" thick sheet of Sonex Classic polyurethane foam. It is glued to the cabinet side and to the brace in the middle. In one of the cabinets I was working on, the Sonex material had fallen down. As I pulled it out of the cabinet, it crumbled in my hand. A quick check of the material in the other cabinet showed the same results indicating that this stuff has reached the end of its life span. Therefore, you will want to check your speakers for this issue.

The solution seemed easy enough, buy and install some new Sonex. But NO! I could not find anyone willing to sell a single sheet of Sonex Classic, you have to buy it by the case at about $250.00 per. Eff that! After looking and looking I was able to find one company that had some Sonex melamine foam in 2 1/2" thick sheets that was willing to sell me a few sheets at a much more reasonable cost, still not cheap though. I may find a use for the extra sheets, but maybe not, so if you need some drop me a line.
Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


President of Club Polk

Post edited by F1nut on

Comments

  • intangible
    intangible Posts: 262
    edited February 2011
    I didn't know there was a Monitor 11. Do you have pictures of yours handy for me to admire?
  • mdaudioguy
    mdaudioguy Posts: 5,165
    edited February 2011
    I guess I should open mine up, huh? What upgrades were you doing when you ran into this?
  • F1nut
    F1nut Posts: 50,557
    edited February 2011
    intangible wrote: »
    I didn't know there was a Monitor 11. Do you have pictures of yours handy for me to admire?

    Not mine, but they look exactly the same.

    http://www.polksda.com/ebay/Monitor11_5835330716.pdf
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • F1nut
    F1nut Posts: 50,557
    edited February 2011
    mdaudioguy wrote: »
    I guess I should open mine up, huh? What upgrades were you doing when you ran into this?

    Installing rings (a real **** too) and plotting crossover upgrades.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • mdaudioguy
    mdaudioguy Posts: 5,165
    edited February 2011
    Hmm, not really ready for any upgrades just yet, but I'm curious about the condition of this polyurethane foam... I'm guessing you haven't found a substitute?
  • F1nut
    F1nut Posts: 50,557
    edited February 2011
    Ed, yes I did and noted it in my OP.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • mdaudioguy
    mdaudioguy Posts: 5,165
    edited February 2011
    Yeah, I know. I'm just not familiar with the stuff and noted that you said it was also not cheap. What purpose does this serve? and why only behind one driver?
  • F1nut
    F1nut Posts: 50,557
    edited February 2011
    It's a damping material, normally found in anechoic chambers. It's under (not behind) the one driver only to cut down on the sound waves from that driver reaching the PR. This would help reduce the amount of bass generated.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • 1ShotBill
    1ShotBill Posts: 30
    edited July 2013
    F1nut wrote: »
    I may find a use for the extra sheets, but maybe not, so if you need some drop me a line.

    I just ran into the same issue with our Monitor 11 actually and would be interested in some of your foam is you still have it. Please let me know. Our cabinets have one Sonex piece intact and the other fell off. What did you use to reattach the new foam?

    Also, where was the white baffling located in your cabinets? Mine were scrunched up at the very bottom beneath the PR. I'd have expected that material to be up behind the mid drivers.
  • F1nut
    F1nut Posts: 50,557
    edited July 2013
    As I stated in the other thread, I found a use for the extra foam, sorry.

    I don't remember what the glue was. I definitely did not use epxoy or silicone, could have been white glue or Liquid Nails.

    Yes, the white batting should be up around the mid-drivers. I seem to recall stapling it to the cabinet walls.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk