Building a pair of Polk Monitor 10's

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Comments

  • deucekazoodeucekazoo Posts: 146
    Toolfan66 wrote: »
    With that said, please don't use plywood!! B)

    Toolfan, I just need to know, why so against plywood?
    Not the basic hardware store stuff, we are talking Baltic birch here.
    I made a lot of speakers out of Baltic birch, great to work with. The only thing I would use MDF for is table tops and subs. Don't care for the stuff.
    Polk S10, S8, S4
    Polk RT8
    Polk Monitor 7s
    Working on getting SDAs
  • willwillywillwilly Posts: 185
    edited March 2016
    So I'm starting to do preliminary design work on the cabinet. Polk specifications have the exterior dimensions as 28"x16"x11.5" I'm using a 3/4" wall thickness and 1" back and front. I may need to stretch the 11.5" depth to 12.5" since I'm pretty sure Monitor 10's were 3/4" wall thickness all the way around.

    If one of your has a 10 cabinet you can measure interior dimension exactly, I will duplicate volume. I'm not sure if I will have to compensate for the volume lost on filling the corners?

    Your thoughts?
    ly8qqfahq7lk.jpg
    Post edited by willwilly on
    Will I am
  • willwillywillwilly Posts: 185
    edited March 2016
    Here is the complete unit. I'm showing the back side of the front. I plan on rounding the inside ports.

    Again I don't have the exact locations of the PR, driver and Woofers. If someone can measure theirs I can make changes.

    The front and back are MDF 1" construction. Both the front and back exterior will be laminated with matt black poly textured sheets. Walls are 3/4" walnut laminated.

    I'm not sure if I need to consider having the corners between the front face and sides rounded. Still contemplating.

    Any help you can give on actual measurements would be great be great.

    gagxbzyg0db4.jpg
    Will I am
  • voltzvoltz Posts: 5,361
    I built a pair of Full range crossover less speakers using a kit from Madisounds that uses Baltic birch plywood and I think they sound pretty good for what they are...
    vy8wm97gmpqb.jpg

    poc65ix4ig11.jpg
    rfrukkg3vuw9.jpg
    2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge

    HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD
  • voltzvoltz Posts: 5,361
    edited March 2016
    So have fun with it!
    and BTW
    here is a pair of Stirling Broadcast LS35a that uses 9mm birch plywood :)
    http://store.acousticsounds.com/d/88073/Stirling_Broadcast-LS35a_V2_Speakers-Speakers
    2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge

    HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD
  • willwillywillwilly Posts: 185
    edited March 2016
    Thanks for sharing. I have seen many of these kits and they look like an interesting project.

    The more research I do, the more I discover MDF will produce the best results for the cost. I have seen very pricey solid wood speakers but I'm sure the manufactorer takes that consideration.
    I was originally going to make the cabinets from solid wood but that could have been a disaster
    To put it simply, as someone did for me, wood can be made into an instrument like a note on the marimba. You can't do that with MDF. You can with baltic plywood, it won't sound pretty but it will resonate.
    I'm building a clone vintage Monitor and I'm even now concerned with using MDF rather than the original particleboard. I'm hoping there will be an improvement or at least little difference.

    Post edited by willwilly on
    Will I am
  • westmassguywestmassguy Posts: 6,572
    Polk used regular particleboard, about as low density as you can get. It has a habit of crumbling.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
    Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
    Interconnect: Furez 10/2 with SpeakONs
    ICs: Custom Furez by Douglas Connections
    Den:
    Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
    Carver CT-3 Pre, Carver C-500

    dhsspeakerservice.com/
    Exclusive Distributor of Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • willwillywillwilly Posts: 185
    edited March 2016
    I.e. manufactured wood products,
    Post edited by willwilly on
    Will I am
  • westmassguywestmassguy Posts: 6,572
    Masonite is high density, the stuff Polk used is the exact opposite
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
    Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
    Interconnect: Furez 10/2 with SpeakONs
    ICs: Custom Furez by Douglas Connections
    Den:
    Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
    Carver CT-3 Pre, Carver C-500

    dhsspeakerservice.com/
    Exclusive Distributor of Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • willwillywillwilly Posts: 185
    edited March 2016
    Keep in mind, partial board is more dense than wood, (more mass per volume) but not rigid, poor strength, and as you stated, degradates especially in water. Partial board is the least dense of the manufactured wood products according to Wikipedia which makes since.
    Post edited by willwilly on
    Will I am
  • willwillywillwilly Posts: 185
    I like the analogy, if you can make an instrument out of it, you probably don't want to make a speaker out of it.
    Will I am
  • willwillywillwilly Posts: 185
    edited March 2016
    Not going to give it up are you. I will concur, the M10 design has its issues, but I like its strengths as crude as some may think.
    This was suggested by another forum. The rational is a driver moves air. Rounding the inside promotes that movement, especially since I'm increasing the thickness of the front panel. I can't see how it would hurt.
    Will I am
  • willwillywillwilly Posts: 185
    Na, slightly weaker. From an engineering point of view, and I am an engineer, the material removed offers little structural support to the mounting of the driver. It can hurt the space between the drivers but drawing that takes more than a few minutes so I didn't show that. I don't plan on routing out the material between the drivers, just hand rounding,.
    So if that is what you meant, good catch.
    Will I am
  • willwillywillwilly Posts: 185
    I'm more concerned about to total lack of cross sectional area horizontally through the drivers but since the front panel is affixed to the casing, maybe a corner block in that area wouldn't hurt.
    Will I am
  • willwillywillwilly Posts: 185
    Non issue, possibly for these drivers in a sealed cabinet system. It was suggested for "ported" (the proper term escapes now) system where the amplitude of the driver or woofer is much greater. (Once I start using the proper terms, I'll start remember them)
    Will I am
  • willwillywillwilly Posts: 185
    Kind of like a three angle grind on a valve if you know what I mean. (Got to throw in an engine reference)
    Will I am
  • willwillywillwilly Posts: 185
    Remember, I'm using 1" MDF, not 3/4" particle board.
    Will I am
  • willwillywillwilly Posts: 185
    rmpolk wrote: »
    If it helps I took some measurements of my 10a's
    Thank you so very much!
    That is great help!

    I plan on plotting it 1 to 1 and confirming with the actual components.

    Thanks again.
    Will I am
  • F1nutF1nut Posts: 43,980
    DSkip wrote: »
    I like the rounding of the corners, just not the holes for the driver mount. This is a non-issue and can only be detrimental as you are essentially making the mounting area weaker by having less bulk where it needs it most.

    Agreed.

    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

  • willwillywillwilly Posts: 185
    rmpolk wrote: »
    I think he's referring to rounding the cabinet's inside edges to smooth out the air flow as I read that in the link he provided earlier that included box design [ btw Thanks for that it was a good read] Just curious on this topic -would it be at all detrimental to use a thin veneer on the front face to provide a all wood look?


    Yes! That's what I mean.

    I'm not a fan of that look but it would be interesting with a contrasting wood color. Walnut cabinet and chamfer with a maple face? (with figure)



    Will I am
  • willwillywillwilly Posts: 185
    Question. If I rearrange the components like a 7 starting at the top working down, driver, tweeter, driver, PS, narrow the width to M7's width, keep the depth, but adjust the height of the case to match volume of a M10, wouldn't the design resonance stay the same.

    Of course many bad things could happen but what do you know will happen?
    Will I am
  • willwillywillwilly Posts: 185
    Like my super seven picture posted previously...
    Will I am
  • Toolfan66Toolfan66 Posts: 14,404
    The ideas are looking good, let's see some wood getting cut..
  • westmassguywestmassguy Posts: 6,572
    willwilly wrote: »
    Like my super seven picture posted previously...
    I actually like that idea. You could do an MTM arrangement, and either reverse the phase of the Tweeter, or offset it 45 degrees from the centerline of the two woofers to mitigate lobing. the offset version should be made in mirror images.
    These all fall under the category of Franken-Polks of course.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
    Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
    Interconnect: Furez 10/2 with SpeakONs
    ICs: Custom Furez by Douglas Connections
    Den:
    Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
    Carver CT-3 Pre, Carver C-500

    dhsspeakerservice.com/
    Exclusive Distributor of Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • willwillywillwilly Posts: 185
    Toolfan66 wrote: »
    The ideas are looking good, let's see some wood getting cut..

    This weekend! I'm so looking forward to it! Still looking for 1" MDF locally, the right veneer and contact cement, and waiting for my RD0-194 tweeters.

    Will I am
  • willwillywillwilly Posts: 185
    willwilly wrote: »
    Like my super seven picture posted previously...
    I actually like that idea. You could do an MTM arrangement, and either reverse the phase of the Tweeter, or offset it 45 degrees from the centerline of the two woofers to mitigate lobing. the offset version should be made in mirror images.
    These all fall under the category of Franken-Polks of course.

    How would that effect the PR's performance with drivers not equal distance or is that not an issue?
    Will I am
  • Toolfan66Toolfan66 Posts: 14,404
    willwilly wrote: »
    Toolfan66 wrote: »
    The ideas are looking good, let's see some wood getting cut..

    This weekend! I'm so looking forward to it! Still looking for 1" MDF locally, the right veneer and contact cement, and waiting for my RD0-194 tweeters.

    Your drivers shipped out today..

  • westmassguywestmassguy Posts: 6,572
    willwilly wrote: »
    willwilly wrote: »
    Like my super seven picture posted previously...
    I actually like that idea. You could do an MTM arrangement, and either reverse the phase of the Tweeter, or offset it 45 degrees from the centerline of the two woofers to mitigate lobing. the offset version should be made in mirror images.
    These all fall under the category of Franken-Polks of course.

    How would that effect the PR's performance with drivers not equal distance or is that not an issue?
    It's called fluid coupling, air being the fluid. No difference as long as the internal volume is the same.

    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
    Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
    Interconnect: Furez 10/2 with SpeakONs
    ICs: Custom Furez by Douglas Connections
    Den:
    Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
    Carver CT-3 Pre, Carver C-500

    dhsspeakerservice.com/
    Exclusive Distributor of Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • willwillywillwilly Posts: 185
    edited March 2016
    The expensive parts arrived today.04hpmahx76kb.jpg
    Will I am
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