SDA-CRS/CRS+ Something Different

Ever since I acquired my CRS+s, I've been amazed at what these little boxes can do. I had
done an initial, cost constrained re-cap on the crossovers, and all the usual upgrades we do. After acquiring my 2As, and doing all the upgrades on them as well, it occurred to me that one upgrade was not really possible with the CRSs, Damping. From the factory, all they came with, was a wad of Dacron on the side where the crossover is located, and that's it. Nearly all the other SDAs, Monitors, and RTAs had rolls of Dacron behind the woofers, extending all the way to the top of the cabinets in most cases. As part of the cabinet upgrades, we remove the Dacron, and install strips of BH5, No Rez, or Sonic Barrier on the rear wall, and re-install and re-position the Dacron. You can't do that with the CRSs. The best you can do is cut and fit small pieces on BH5 et al. and stuff the Dacron back in one side. Not the ideal solution. I had been tossing around a few scenarios for adding additional damping material to mimic what we do with all the other vintage Polks.

My 1st thought was cutting and fitting BH5 on the back wall, adding a doughnut shaped piece of BH5 to the back of the Passive Radiator, then stretching and tacking a double layer of Bonded Dacron directly behind the woofers. The problem with that is the possibility of over damping the enclosure and the fact that we never install Dacron anywhere near the Passive Radiator. My second idea was to create some type of baffle that would mount behind each woofer. I could attach BH5 to the fronts, which would face the back of the woofers, and it would give me a gap where Dacron Batting could be inserted. The baffles would have to be large enough to actually do something, i.e. catch some of the mid frequency back waves from the woofers, but also be small enough not to block, interfere or constrain the larger sound and pressure waves. The intent after all, is to clean up the midrange handled by the woofers, without sucking the life out of the music.

In the interim, my friend Darryl @voltz had acquired a pair of CRS+s, and asked if I would do his crossovers for him. I agreed, and tossed the idea of experimenting with the damping, being a trooper, he said sure. I had planned on rebuilding my crossovers at the same time. We had agreed to do Sonicaps, Mills Resistors, TL Modification, and replace both Lo-Pass inductors with Jantzens. I'd also be supplying Erse Inductors for the Sub Bass Drive, Cardas Binding Posts, and reworking the Interconnect with SpeakONs on his. Darryl supplied me with the same Flat Oval Cable he would be using for the speakers. An 800VA Dreadnaught would also be constructed.

The Crossovers were straight forward. The spool inductors were eliminated; new mounting plates were made, and secured with stainless hex head cap screws and nylon standoffs. The new Jantzen, and Erse Inductors were unwound to the exact values needed. All components were attached with 3M VHB tape, and Nylon Wire ties. SpeakON connectors and Cardas posts were installed on the Binding Post Cups. Darryl wanted the deluxe Dreadnaught, with Copper Shielding, Dynamat, and cast SpeakONs.

For Damping, I decided to go with the baffles. I cut 7" X 7" pieces of 3/16" Masonite. These were glued and bolted to 5" X 5" steel angles. The Masonite was sealed with lacquer, and BH5 applied to the face. I purchased some 1" Bonded Dacron, and cut two 19" X 19" sections, and folded them in half.
Do to circumstances; I was unable to complete my own Crossovers, so I decided to install Darryl’s Crossovers, one set of dampeners and the Dacron in my cabinets for a test run. This would allow me to hear the difference between the stock, and new damping treatment.

I installed the crossovers, and the new Damping Baffles in the left speaker about 5" back from the woofer openings (I believe Darryl eventually placed them 6" back). The Bonded Dacron was installed in the left cabinet, and the stock Dacron in the right. I connected the new Dreadnaught, and fired everything up. I let them breath for a while before playing some familiar tracks. The Stereo Image was dead center, a good sign. I immediately noticed a smoother sound quality from the left speaker. The right speaker sounded as if it were shouting during certain passages. Keep in mind, my woofers were original, and my RDO-198-1 Tweeters had already been broken in. Obviously all the new components needed a good deal of burn-in, but overall, I was very pleased with the improvements. Top to bottom, the left sounded very well balanced, while the right speaker sounded off, more forward in comparison. When compared to my 2As, the left speaker was very similar, while the right, not so much. Although my concern for over-damping the enclosure was well founded, I believe they sound just about right. You can experiment with the alternatives to BH5. No Rez, and Sonic Barrier, may well react differently. I know Sonic Barrier has 5 different thicknesses available, so you can play with the amount of damping. My goal was to duplicate as closely as possible, the additional damping we install in other upgraded vintage Polk cabinets. I believe that goal was met.

There is one caveat; severe space constraints. If you're using the original Spool Inductors as mounts for the Crossovers, Tony's @gimpod boards, or custom Air Core Inductors, the baffles may not fit without some creative rearranging.

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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-350, 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 PM-600

dhsspeakerservice.com/
Now Carrying Gimpod's Custom SDA Circuit Boards

"And keep her under 70, would you, huh? Betty likes a slow ride"
«1

Comments

  • voltzvoltz Posts: 4,681
    1st off I have to say Thank You Dave!! B)

    I didn't want to skimp on anything for this chance to upgrade this Vintage Polks, and I had Dave use Sonicaps all around and make me a Deluxe Dreadnaught as I did not want to have any regrets later.

    But the Damping Boards really took it to a new level and after doing one speaker only and listening between the two I found the Damping boards to give a cleaner sound tighter sound especially with the Mids and I highly recommend anyone with CRS's to give them a try as if you dont like them there easy to remove but you won't ;)

    Did a lot of comparison with my Monitor 10's & Polk 703's and the wilder sound field SDA effect just makes the other speakers fall short and seem plain sounding, but with my 10's I found I was even missing some sound ambient sounds from certain songs like Steely Dan "Black cow" and others that the cross talk on the 10's eliminates but I could hear with my CRS +'s as ambient sound was more isolated off to the left where I could pay attention to it. That is the SDA effect for ya which Dave can explain better the me.

    Fist rate job again from Dave and you should see my smile every time I listen to my NEW Special Edition CRS+'s!! He really knock this one out of the park! Kudos Brother!
    Darryl
    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: 4,681
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    7e2b36wykf0h.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
  • westmassguywestmassguy Posts: 5,797
    Thank you Brother.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • MrBuhlMrBuhl Posts: 1,944
    damned creative - and pretty cool stuff - congrats guys!
    VA HT HK AVR20II, Sony S9000ES CD/DVD/SACD, Polk Audio RC80i / Polk Audio CSi3, 60" Panasonic Plasma, Nordost / Signal Cable A2 / Wireworld / Pangea / Magic Power
    VA 2 Channel , McCormack DNA 0.5 (SMc Gold) Amp, MFA based Cocci Tube Preamp, Polk SDA2BTL (fully modded), A/L 1000VA Dreadnought, Canare 4s11 SDA cable, Sony S9000ES CD/DVD/SACD, Music Hall mmf 5.1 Turntable, Vincent Pho-700 Phono Pre, MIT S3 IC's / MIT Shotgun S3 Speaker Cables / Pangea & Signal Cable MP power
    Noggin Schiit Valhalla, Pangea, Phillips Fidelio X1, Polk UF8000
    LA Toobs Dodd Audio 50wpc Dual Mono Amp, Eastern Electric MiniMax Preamp, Polk LSIM705, Marantz DV8300 SACD, VPI Nomad Turntable w/Ortofon 2M Bronze, MIT AVt3 Speaker & RCA Cables, Pangea & Signal Cable MP power

    Dodd Mid Level Preamp ("on the bench" w/Charlie)
    Polk SDA1c modded
    Soundcraftsmen PCR800
    Yamaha YP-D6
    Bottlehead Foreplay (modded)
    Signal Cable Silver Resolution IC's
    Audible Illusions L1 Preamp
    McCormack DNA-1 Power Drive Amp
    Eastern Electric Minimax CDP
  • voltzvoltz Posts: 4,681
    BTW I bought "The Who's" vinyl box set so I been listening to them last couple of hours on the CRS's & the LP "Who's Next" was Stunning and I had to play it twice in a row :p
    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
  • vmaxervmaxer Posts: 4,006
    Very nice.
    Pio Elete Pro 520
    Panamax 5400-EX
    Sunfire TGP 5
    Micro Seiki DD-40 - Lyra-Dorian and Denon DL-160
    PS Audio GCPH phono pre
    Sunfire CG 200 X 5
    Sunfire CG Sig 405 X 5
    OPPO BDP-83 SE
    SDA SRS 1.2TL Sonicaps and Mills
    Ctr CS1000p
    Sur - FX1000 x 4
    SUB - SVS PB2-Plus

    Workkout room:
    Sony Bravia XBR- 32-Inch 1080p
    Onkyo TX-DS898
    GFA 555
    Yamaha DVD-S1800BL/SACD
    Ft - SDA 1C

    Not being used:
    RTi 38's -4
    RT55i's - 2
    RT25i's -2, using other 2 in shop
    LSI 15's
    CSi40
    PSW 404
  • ptrooperptrooper Posts: 203
    edited October 2015
    Love it , :) Great idea........I would love to own a set of crs+
  • westmassguywestmassguy Posts: 5,797
    Thanks guys.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • leftwinger57leftwinger57 Posts: 2,822
    Dave, pretty amazing work and doing kind of an experiment w/ a customers speaker who of course gave permission. Far be it for me to say anything but when I did my 2Bs w/ the BH-5 w/ the spaced 3" strips from the top of the cabinet to the bottoms of the mid woofers the sound was so dramatically changed I was not sure I liked the change. That I had to get used to and I did and left it in. That stuff does work as advertised. to much and you'll have a real lined monkey coffin. Can't wait for you know what....
    2chl- Adcom 555- NAD 1020a pre/amp- JVC-QL-A200 tt- Denon 1940 ci cdp- Samson - 9 outlet-Adcom GFS-6 -Rectilinear Low Boys - DCM TF 350s- OHM L- , '87 SDA 2Bs - Dynamat Ext.- BH-5- X-Overs VR-3, RDO-194 tweeters, Larry's Rings, gaskets, Stained Walnut tops

    H/T- Toshiba au40" flat- Yamaha RX- V665 avr- YSD-11 Dock- I-Pod- Klipsch #400HD Speaker set-

    Bdrm- Nikko 6065 receiver- JBL -G-200s--Pioneer 305 headphones--Sony CE375-5 disc
  • westmassguywestmassguy Posts: 5,797
    Thanks Lew. BH5 was originally designed to dampen cabinet resonances. We use it to absorb/reduce midrange reflections, which would normally bounce around, and make their way back out through the cone, causing a loss of detail. The other damping materials I listed will have different absorption qualities. I've used Sonic Barrier quite a bit, and the thickest is comparable to BH5. If less damping is required, then one of the thinner versions could be used.
    I'm working on your "you know what" today.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • voltzvoltz Posts: 4,681
    The Bass is so good I have not hooked up my sub yet! especially with Peter Gabriel's "Sledgehammer" or Don Henley's "Dirty Laundry".
    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
  • westmassguywestmassguy Posts: 5,797
    voltz wrote: »
    The Bass is so good I have not hooked up my sub yet! especially with Peter Gabriel's "Sledgehammer" or Don Henley's "Dirty Laundry".
    Only going to get better

    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • corticocortico Posts: 316
    Very nice westmassguy always read with attention your threads. Love mine, I Installed the RDOs, disconected the dimensional tweeters, new armacell tape/nuts around drivers, but haven't recapped it yet. I have to finish recapping an integrated amp I got to my monitor 5 and then I'll get my hands on it...
  • westmassguywestmassguy Posts: 5,797
    cortico wrote: »
    Very nice westmassguy always read with attention your threads. Love mine, I Installed the RDOs, disconected the dimensional tweeters, new armacell tape/nuts around drivers, but haven't recapped it yet. I have to finish recapping an integrated amp I got to my monitor 5 and then I'll get my hands on it...

    Thanks. Your CRSs would benefit as well.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • drumminmandrumminman Posts: 3,346
    Very nice Dave. The CRS+ are tough to work with due to the lack of space. When I did mine I put I mounted the Xovers on the floor of the cabinet to orient the inductors away from the magnetic fields of the MW magnets. I then put BH5 on the back wall and reinstalled the original poly foam. Your idea is interesting and If I decide to go back in mine I may try it.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • westmassguywestmassguy Posts: 5,797
    drumminman wrote: »
    Very nice Dave. The CRS+ are tough to work with due to the lack of space. When I did mine I put I mounted the Xovers on the floor of the cabinet to orient the inductors away from the magnetic fields of the MW magnets. I then put BH5 on the back wall and reinstalled the original poly foam. Your idea is interesting and If I decide to go back in mine I may try it.

    Thanks drumminman. If you decide to revisit them, the top of the cabinet may be the only other location for the crossovers. It should be even farther away from the woofer magnets as well.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • Killer. Any chance you will rebuild my crossovers for me? I have CRS ans 2.3's.
    Pm me.
  • txcoastal1txcoastal1 Posts: 8,466
    Dave is a great cat

    dhsspeakerservice.com/

    Now Carrying Gimpod's Custom SDA Circuit Boards
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures, Simaudio 780D DAC
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Modwright LS100, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers
  • With the reduced room of the smaller cabintes I have always wondered what the downside might be to mounting the crossover outside the cabinet somewhere. Could they be placed on the back of the cabinets? Would there be any benefit?
  • westmassguywestmassguy Posts: 5,797
    With the reduced room of the smaller cabintes I have always wondered what the downside might be to mounting the crossover outside the cabinet somewhere. Could they be placed on the back of the cabinets? Would there be any benefit?

    Not that I can see. They were designed with the displacement of the various parts taken into consideration.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • Thanks for the reply Dave. I was not clear in what I was trying to ask, sorry. I was thinking more of the magnetic fields you and drumminman mentioned above. Is there a guideline on what minimum distances should be observed? What is the effect that might be heard if they are placed to close?
  • westmassguywestmassguy Posts: 5,797
    No clue what a safe distance is. I have to believe Polk mounted it in the upper corner to be clear of any magnetic fields. Inductors have their own magnetic field which is created by the signal passing through them. Any external magnetic field, or magnetic/ferrous metal will disrupt the Inductors field, and could cause distortion, and most certainly change the crossover frequency.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • akajimmyakajimmy Posts: 50
    Those look like good mods. Can't wait to try them in my CRS.
  • westmassguywestmassguy Posts: 5,797
    You'll be a happy camper.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • xschopxschop Posts: 656
    The 3rd CRS build thread I've read thru today. Very ingenuitive solution to damping without interfering with the passive. About what total volumn was removed by those two barriers? Thanks WMG.
  • westmassguywestmassguy Posts: 5,797
    xschop wrote: »
    The 3rd CRS build thread I've read thru today. Very ingenuitive solution to damping without interfering with the passive. About what total volumn was removed by those two barriers? Thanks WMG.

    Virtually nothing. The BH5 is 1.375" thick, but only displaces .25" of incompressible air. The Masonite is 3/8" thick. Each Baffle is 7" X 7".
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • xschopxschop Posts: 656
    Ok I see, the open-cell structure of foam. I've got a question you may be able to answer before I start my project.
  • xschopxschop Posts: 656
    WMG, sorry to bother you again, but what is the distance from the BH5 to the rear of the MW magnets approximately? I'm having my new boxes built next week and want to calculate the new depth with this mod permanently incorporated as internal bracing. Thanks, Rob.
  • westmassguywestmassguy Posts: 5,797
    xschop wrote: »
    WMG, sorry to bother you again, but what is the distance from the BH5 to the rear of the MW magnets approximately? I'm having my new boxes built next week and want to calculate the new depth with this mod permanently incorporated as internal bracing. Thanks, Rob.

    Not sure really. The steel angles were 6" as I recall. On mine, I placed the angle right against the back of the front baffle. I believe Darryl set his back a bit further.
    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-350, 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 PM-600

    dhsspeakerservice.com/
    Now Carrying Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • xschopxschop Posts: 656
    WMG, can the Erse inductor be mounted right next to the board like in your 1st pic? Or will it interfere with the tweeter inductor coil?

    Ill be making a cover and installing board to back of Power Port platform....

    gwio23ivmbda.jpg
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