Inductor DCR Insanity For SDA's

2»

Comments

  • machone
    machone Posts: 1,471
    I measured 106.7 ma output on my "low resistance measurement circuit".

    I measured the inductors in my 1A's and used ohms law to calculate the following:

    Tweeter = 0.68 ohms
    SDA Tweeter = N/A (Removed)
    Stereo Mid = 3.31 ohms
    SDA Mid = 3.31 ohms
    Stock Bass Woofer = 1.45 ohms

    Replacement Solen for Bass circuit = 0.91 ohms (rated by Solen @ 0.91 ohms)

    I have already replaced the bass inductors with the Solens with great results.
    I deliberately revoiced the woofer circuit for more deep bass. I tried three different inductors to get it right.

    I looked at Solen and Jantzen and cannot find inductors that match the tweeter and mid circuits and I don't want to mess with the voicing.

    Experts: Any suggestions?




    Mojo Audio Illuminati v3>>Quantum Byte w/LMS>>Rpi/PiCoreplayer>> Starlight 7 USB >> Mojo Audio Mystique v2 SE>>ModWright SWL 9.0 SE Signature>>Hafler DH-500 Amp+ (Musical Concepts Fully Modded)>>
    SRS 2.3TL (Fully Modded)...Velodyne Optimum 8 subwoofer
    1KVA Dreadnought

    Marantz SA 8005
    Pioneer PLX-1000 Turntable - Shure SC35C/N35X - V15III/VN35HE
    Yamaha TX-540 Tuner...Sony BDP-S570
    Sony PS4

    Separate subpanel with four dedicated 20 amp circuits.
    1. Amplification 2. Analog 3. Digital 4. Video

    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • gimpod
    gimpod Posts: 1,793
    edited December 2015
    Comcast dumped all personal web pages for some reason. Here's the chart again

    Inductor-DCR.jpg



    COULD THE POWERS THAT BE PLEASE MOVE THIS IMAGE LINK TO THE FIRST POST IN THIS THREAD REPLACING THE ORIGINAL LINK "http://home.comcast.net/~gimpod/Polk/Inductor-DCR.jpg" WITH THIS ONE. also it might be a good idea to make this a sticky. Just a thought.
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
  • westmassguy
    westmassguy Posts: 6,850
    Agreed
    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

    dhsspeakerservice.com/
  • I'm not sure what you're asking for.
  • txcoastal1
    txcoastal1 Posts: 13,124
    I'm not sure what you're asking for.

    In the opening of the thread, there was an inductor jpg link that is no longer working.

    I think Tony would like the image in his last post moved to the opening post of this thread....I think this is what he wants?????
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, 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, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • Nightfall
    Nightfall Posts: 10,042
    He wants the stock inductor value chart edited into the original post of this thread.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • gimpod
    gimpod Posts: 1,793
    edited December 2015
    I'm not sure what you're asking for.

    Ken about 5 paragraphs into the first post in this thread there is a line that says "Inductor-DCR.jpg" that use to be a link to the chart above "http://home.comcast.net/~gimpod/Polk/Inductor-DCR.jpg" this link is dead now that comcast has dumped all the private web pages. So I need some one to change the old link "http://home.comcast.net/~gimpod/Polk/Inductor-DCR.jpg" to http://www.gimpod.com/Polk/Inductor-DCR.jpg

    Thanks.
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
  • Is that the way you want it?
  • gimpod
    gimpod Posts: 1,793
    No, It was an inline image above the paragraph you have the link in now.
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
  • Nightfall
    Nightfall Posts: 10,042
    Just put the [IM G] [/IM G] tags around the link in the first post, without the spaces between the M's and G's.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • gimpod
    gimpod Posts: 1,793
    Yo da MAN! Ken Perfect.

    You want fix / rebuild my Teac X-10R? ($$$$$ ouch :smile: )

    Thank You.
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
  • Schurkey
    Schurkey Posts: 2,100
    edited March 2016
    Inductor-DCR.jpg

    I've been researching inductors for my SDA SRS 2 pin/blade speakers. Took me a long time to find the inductor chart above. It's not linked-to on Gimpod's circuit-board site (that I can find.) I'd seen it years ago, so I knew that it existed.

    I have questions about inductor DC resistance: All the Jantzen inductors that I'd need for my speakers are lower in resistance than the Polk inductors listed in the chart. All "my" inductors seem to be 22 gauge except the monster SDA inductors, and I already have iron-core ERSE inductors for that.

    Jantzen P/N 000-0973 = 0.130mH +/-3% 0.31Ω wire 0.63mm=22AWG OD-25 / 8mm
    Not a perfect match for the OEM Polk due to slightly less DC resistance. (0.31 ohms vs. 0.37 ohms. Is 0.06 ohms critical?)

    You list the (000-)1489 Jantzen as a replacement for the 0.40mH Polk inductor, but the Jantzen is similarly lower in DC resistance: 0.640 ohms vs. 0.687, or 0.047 ohms less.

    Jantzen P/N 000-0974 = 1.25mH +/-3% 1,21Ω wire 0,63mm=22AWG OD-32 / 15mm
    Continuing the trend of the Jantzen being slightly less DC resistance than the OEM Polk, 1.210ohm vs. 1.329 = 0.119 ohms less.

    Jantzen P/N 000-1119 = 2.5mH +/-3% 1,840Ω wire 0,63mm=22AWG OD-38 / 15mm
    As expected, lower DC resistance 1.840 ohms vs. 1.953 = 0.113 ohms less.

    1. Can I expect that the Jantzen inductors achieve lower DCR for the same wire gauge based on less wire used (and more-precise winding)? Are they using finer-grade wire?

    2. Can I expect that the Jantzen inductors' lower DCR is not a problem? The slight difference from OEM won't affect speaker voicing, or cause other concern? I'm thinking that the resistance of the drivers will so completely overwhelm the ~0.1 ohm resistance of the inductors that the inductor difference is immaterial--but I've been wrong before. My drivers have more difference in resistance among them than a tenth of an ohm--some driver sets are more like 1-ohm from highest to lowest.
  • westmassguy
    westmassguy Posts: 6,850
    @Schurkey , + or - 5% is fine for the inductors. When I replace inductors, I try to keep the Inductance value < 1%, and DCR < 5%. When moving existing Inductors from the old boards to Tony's boards, I measure them, and also adjust them to be <1% between the left and right channels. I've seen some pretty wide variances from what the schematic says is supposed to be there, and what is actually there. Some Inductors exceed 10% tolerance.
    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

    dhsspeakerservice.com/
  • machone
    machone Posts: 1,471
    Not good to hear about the unbalance :(
    Mojo Audio Illuminati v3>>Quantum Byte w/LMS>>Rpi/PiCoreplayer>> Starlight 7 USB >> Mojo Audio Mystique v2 SE>>ModWright SWL 9.0 SE Signature>>Hafler DH-500 Amp+ (Musical Concepts Fully Modded)>>
    SRS 2.3TL (Fully Modded)...Velodyne Optimum 8 subwoofer
    1KVA Dreadnought

    Marantz SA 8005
    Pioneer PLX-1000 Turntable - Shure SC35C/N35X - V15III/VN35HE
    Yamaha TX-540 Tuner...Sony BDP-S570
    Sony PS4

    Separate subpanel with four dedicated 20 amp circuits.
    1. Amplification 2. Analog 3. Digital 4. Video

    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • Schurkey
    Schurkey Posts: 2,100
    + or - 5% is fine for the inductors. When I replace inductors, I try to keep the Inductance value < 1%, and DCR < 5%.
    All four of the Jantzens I listed are more than 5% lower DCR than the OEM inductors, comparing the specs in Jantzen's .pdf catalog, and the DC resistance chart provided in this thread and on Gimpod's site.

    I have an LCR meter, but I'm guessing it's not sensitive enough to truly match the inductors with. I'll give it a shot and see what happens, though.

    I am going to order the Jantzens anyway, unless I hear (fairly soon) that this is an outright mistake. I'm in no mood to transfer inductors from the old boards to the new Gimpod boards. If I knew of a better match...I'd consider it.

    wwwparts-express.com e-mail:


    Thank you for contacting Parts Express. We notified the manufacturer of your specific needs and received the following information from them. We can special order the items you requested. The cost would be as noted below, plus shipping and handling based on the weight of the item. There is a $25.00 minimum order requirement for special orders. It would take 7-9 weeks to receive. When submitting a special order to the manufacturer, the order would be non-cancelable/non-refundable. In the event you would like for us to order for you, please notify me and I will submit an order for you. If I can be of further service please let me know. All of these with the quantities you requested would meet the minimum.

    Jantzen Audio model number 000-0973 0.13mH, 22 gauge $2.73 each
    Jantzen Audio model number 000-0974 1.25mH, 22 gauge $4.52 each
    Jantzen Audio model number 000-1119 2.50mH, 22 gauge $5.75 each
    Jantzen Audio model number 000-1489 0.40mH, 22 gauge $3.30 each
    Mills resistors in the 2.7-ohm value, 12 watts, cannot special order as they have a 100 piece minimum



    I anticipate placing the order in a couple of days...unless someone talks me out of it.
  • westmassguy
    westmassguy Posts: 6,850
    edited April 2016
    Schurkey, I wouldn't obsess on it too much. All the old Inductors were hand wound. Inductance and resistance varied widely. Some were wound very uniformly, while others looked like a three year old did them. Did Polk buy oxygen free copper back thn? Was the coating the same? Did they buy from the same vendor or manufacturer for all their coils? Who knows. All that information is long gone. If it were me, I'd place the order, measure them when you get them, try and get the inductance within 1% between the left and right crossovers, and be done with it.

    Just for shites and giggles, measure the old inductors once the new crossovers are finished. I think you'll be amused by what you find.
    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

    dhsspeakerservice.com/