My Center Channel Project

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Comments

  • NightfallNightfall Posts: 7,529
    edited April 2014
    Aesthetics
    I see, so it obviously doesn't matter then. I have almost the same center channel, two Monitor 5's on their sides shoved together with the tweeters facing each other on the inside. I always wondered if I was causing any issues by having them (tweeters) facing the wrong direction.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.
  • westmassguywestmassguy Posts: 6,064
    edited April 2014
    The Polk Tweeters, actually almost any soft dome tweeter, have a 120-140 degree radiation pattern. It can be mounted in any position. What affects it dispersion, is the location and spacing of the woofers. The MTM/ D'Appolito arrangement causes lobing, which Face pointed out. At some point I'll be modifying the plastic trim on the 198, and raising it up as high as possible to mitigate the lobing. I sounds awesome now, but I'll take the advice. I originally tried two 5js then two 4.6s end to end. With the tweeters next to each other, I found it too bright on axis. That's why my design is essentially two 5jr+s with a single tweeter in a single enclosure.
    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"
  • westmassguywestmassguy Posts: 6,064
    I decided to update this thread, since I've made one, hopefully last change. Based on comments made by Face, others who forgot what I know, and my own research into lobing effects in MTM driver alignments. I raised the tweeter up as far as possible within the restraints of my the cabinet, and my original design. The RDO-198-1 Tweeter's plastic trim had to be carefully cut to be able to fit in it's new location. The plastic trim was removed from the Tweeter. I measured and marked the new size, and clamped my belt sander upside down on my bench. I then slowly ground off the plastic to the marks I had made. The corners were rounded, and finish sanded with 320 then 400 grit paper. New mounting holes were drilled and countersunk.
    On the cabinet, I removed a section of veneer, filled the old hole with Bondo for wood, sanded it flat, sealed the raw surface with brush-on lacquer, and installed a precut section of veneer. The new hole was drilled out, new mounting holes and hurricane nuts installed, and a new gasket was cut and the tweeter installed.
    My initial impression, is more detail in the crossover region. Voice and vocals seem clearer. The overall sound is still superb, but clearer in a very important frequency range. All that remains is a little walnut filler, light sanding, stain, and finish.
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    As an aside, I had picked up a CS350-LS, just to compare, and see if it really does match the vintage models. I upgraded the rather simple crossover with a Sonicap, and tested it with my system. It's certainly a very fine center, very smooth, with plenty of punch. It did blend well with my 2As, and surrounds to a point, but in the end, it could not compete with my own custom built unit.
    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"
  • pitdogg2pitdogg2 Posts: 10,227
    I agree Dave the CS350 is a solid center but it will never dig as deep as the beast you made.
    I missed the update to yours fine job Mr. Craftsman fine job.
  • westmassguywestmassguy Posts: 6,064
    pitdogg2 wrote: »
    I agree Dave the CS350 is a solid center but it will never dig as deep as the beast you made.
    I missed the update to yours fine job Mr. Craftsman fine job.

    Thank you sir. I added the two 12 " midfi Sony subs I had, to the center out. They flank my 2As. I cross them over at 50Hz, and keep the gain down. You'd be surprised how much bass the center has when you run it full range.
    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"
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