Holy Crap those are expensive!
Comments
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wait more than an hour after they are completed :cheesygrin:
ha ha ha ha ha ha!!!!!! -
ha ha ha ha ha ha!!!!!!
Speaking of hours, lol, whats the "burn in" time on these things? -
audiocr381ve wrote: »I'm so excited about this! You'll have to walk me through how to unwind the thing. I don't have any measurement tools so I'm going to have to rely on my ears for this.
I strongly discourage doing this by ear.drumminman wrote: »IIRC DK (or someone) measured impedance with the new Solen air core 16 mH 10 awg inductors as around 3.1-3.4 ohms. Having an amp stable to at least 2 ohms would give that extra margin of safety.
The 1.2TL's DC resistance (not impedance) went down to 3.8 and 3.9 ohms. The impedance varied with frequency and was:
1. Less than 4 ohms below 35 Hz.
2. Between 4 and 10.5 ohms from 35-90 Hz.
3. Between 4.5 and 9 ohms from 90-4 kHz.
4. Less than 4 ohms above 4 kHz.
DCR measurements are discussed in post #57 and impedance plots are shown in post #65 of this thread:
Improvements-To-Modified-SDA-SRS-1.2TL-CrossoverProud and loyal citizen of the Digital Domain and Solid State Country! -
DarqueKnight wrote: »I strongly discourage doing this by ear.
The 1.2TL's DC resistance (not impedance) went down to 3.8 and 3.9 ohms. The impedance varied with frequency and was:
1. Less than 4 ohms below 35 Hz.
2. Between 4 and 10.5 ohms from 35-90 Hz.
3. Between 4.5 and 9 ohms from 90-4 kHz.
4. Less than 4 ohms above 4 kHz.
DCR measurements are discussed in post #57 and impedance plots are shown in post #65 of this thread:
Improvements-To-Modified-SDA-SRS-1.2TL-Crossover
Should I just unwind the 17mh ones that I got until I reach stock impedance? -
Great thread guys! :cool:TOOLFORLIFEFAN wrote: »I would think so, if you can raise the output by just using a steel bolt to mount it I would think soldering a piece in would be fine. But what do I know I'm still a novice in this fantastic hobby.. :-)
IMHO, I would recommend crimping versus soldering in order to avoid damaging the fine coat of varnish. The crimping would also serve as insulation thus not needing to re-vanish the copper. When I fix(ed) coils, I always noticed the termination to use crimping versus solder termination. Oh, not to mention that crimping also allows you to go back easily!DARE TO SOAR:
Your attitude, almost always determine your altitude in life
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audiocr381ve wrote: »Should I just unwind the 17mh ones that I got until I reach stock impedance?
That would work, but how will you know you have reached stock impedance if you don't have measurement tools?Proud and loyal citizen of the Digital Domain and Solid State Country! -
DarqueKnight wrote: »That would work, but how will you know you have reached stock impedance if you don't have measurement tools?
OldmanSRS says 4-5 turns got him there I think. -
audiocr381ve wrote: »oldmansrs says 4-5 turns got him there i think.
Ok..Proud and loyal citizen of the Digital Domain and Solid State Country! -
DarqueKnight wrote: »Ok..
Thanks for the input DK! -
DarqueKnight wrote: »Ok..
LOL!!! Scary ain't it??? Stories like this you best look in a set of SDA's before you buy!!! -
TOOLFORLIFEFAN wrote: »LOL!!! Scary ain't it??? Stories like this you best look in a set of SDA's before you buy!!!
Hey, I've made it this far with great success
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audiocr381ve wrote: »OldmanSRS says 4-5 turns got him there I think.
But I believe he did it by ear rather than LCR so DK's point is quite valid.
This is premature as I just sent the email an hour ago, but I believe Erse is going to quote me on a pair of custom wound 16mH 14 gauge Super Q's. I already asked them if they would quote me a better price for a volume order so no one else needs to email. If possible and there is interest, I will post information about a group buy in this thread if/when Erse quotes me.VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
Conrad Johnson PV-5 w/mods
TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
Tuners w/mods Kenwood KT5020 / Fisher KM60
MF x-DAC V8, HAInfo NG27
Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
NAD SS rigs w/mods
GIK panels -
audiocr381ve wrote: »Hey, I've made it this far with great success
I am just ribbing you!! -
TOOLFORLIFEFAN wrote: »I am just ribbing you!!
:cheesygrin: -
I think you should re-read my results. I said after finding the midbass lacking and cold with the 17 mH coil, I removed wire 4 to 5 turns at a time and listened to the change. I also measured the output of the XO at one of the SDA drivers to understand quantitatively what was going on. For my taste, the coil needed 16 turns removed which provided a up to 4 dB more bass below 100 Hz and about 1 db less bass above 150 Hz.
I doubt the coil ended up at the stock 16.8 mH.'65 427 Shelby Cobra
'72 Triumph TR-6
__________________
'88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
'86 Polk SDA CRS+
'84 Polk Monitor 10A (Peerless tweeters)
'05 HSU VTF-3 Sub (Original OEM)
'20 HSU VTF-3 Sub (three more, 100% cloned)
'93 Carver TFM-35
'88 Carver M-1.0t
'88 Adcom GFT-555
'88 Adcom GFP-555
'88 Adcom GFA-555 (upgraded/restored)
'88 Adcom GFA-555 (a second one upgraded/restored)
'05 Onkyo DV-555 media
'89 Fosgate 360 Digital Space Matrix
'89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
'91 Kenwood Basic M1D Amp
'89 Pioneer Laser Disc media
'89 Sony SuperBeta HiFi media
One PGA2310 based custom built remote volume control
Four Polk T-15's
Four Polk TSi-200's
Four Polk TSi-100's
Two Polk CS-10's -
inspiredsports wrote: »But I believe he did it by ear rather than LCR so DK's point is quite valid.
This is premature as I just sent the email an hour ago, but I believe Erse is going to quote me on a pair of custom wound 16mH 14 gauge Super Q's. I already asked them if they would quote me a better price for a volume order so no one else needs to email. If possible and there is interest, I will post information about a group buy in this thread if/when Erse quotes me.
I hope you are happy with the sound. I think it's plausible to consider that with the reduced DCR in the SDA circuit, the different electrical characteristics of the laminate core VS air core inductor, and the improved damping from the amp, the stock inductance value might not be the best choice in all cases. A little tuning went a long way for me.
Your mileage may vary.'65 427 Shelby Cobra
'72 Triumph TR-6
__________________
'88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
'86 Polk SDA CRS+
'84 Polk Monitor 10A (Peerless tweeters)
'05 HSU VTF-3 Sub (Original OEM)
'20 HSU VTF-3 Sub (three more, 100% cloned)
'93 Carver TFM-35
'88 Carver M-1.0t
'88 Adcom GFT-555
'88 Adcom GFP-555
'88 Adcom GFA-555 (upgraded/restored)
'88 Adcom GFA-555 (a second one upgraded/restored)
'05 Onkyo DV-555 media
'89 Fosgate 360 Digital Space Matrix
'89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
'91 Kenwood Basic M1D Amp
'89 Pioneer Laser Disc media
'89 Sony SuperBeta HiFi media
One PGA2310 based custom built remote volume control
Four Polk T-15's
Four Polk TSi-200's
Four Polk TSi-100's
Two Polk CS-10's -
I hope you are happy with the sound. I think it's plausible to consider that with the reduced DCR in the SDA circuit, the different electrical characteristics of the laminate core VS air core inductor, and the improved damping from the amp, the stock inductance value might not be the best choice in all cases. A little tuning went a long way for me.
Your mileage may vary.
I guess I need to consider this carefully, but I really feel getting "factory" 16mH inductors is important.
I understand what you are saying, and it is valid that you have tuned the speakers to your specifc ears and your specific speaker location. I personally tend to take a number of FR measurements from nearfield, 1 meter/1 amp plus stereo and mono measurements from the "sweet spot". Maybe tuning to my ears at my listening position would be better, but I'm not there yet.
I did learn that Erse can't do a run of custom 16mH 14 gauge for even a few dozen; too small to set up for and make a profit.
Their tech suggested I solder 2 8mH 14 gauge in Series. Is there a downside to having a solder joint in the middle of 2 ??VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
Conrad Johnson PV-5 w/mods
TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
Tuners w/mods Kenwood KT5020 / Fisher KM60
MF x-DAC V8, HAInfo NG27
Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
NAD SS rigs w/mods
GIK panels -
I think I would just go for the Solens then.
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TOOLFORLIFEFAN wrote: »I think I would just go for the Solens then.
gotta wait for the 20% off sale...at the price of them; that makes a nice savings -
Yep I want another set but I will be waiting for the sale this time around..
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wow...i am going to have to put a bookmark and watch for sales. I want to do the inductor mod sometime and didn't realize how expensive they were getting. I checked parts express and the jantzen 12 ga 1.8mH foil inductors in my 15TL's are now like $97 each.
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inspiredsports wrote: »I guess I need to consider this carefully, but I really feel getting "factory" 16mH inductors is important.
Their tech suggested I solder 2 8mH 14 gauge in Series. Is there a downside to having a solder joint in the middle of 2 ??
If you are going for stock then choose air core and to be specific air core with 2.7 Ohm DCR or whatever yours measure.
In the real world, I see no issue with connecting 2 coils in series as long as their magnetic fields don't interact. Laminated coils contain the field very well. A few inches of seperation should prevent magnetic xtalk.'65 427 Shelby Cobra
'72 Triumph TR-6
__________________
'88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
'86 Polk SDA CRS+
'84 Polk Monitor 10A (Peerless tweeters)
'05 HSU VTF-3 Sub (Original OEM)
'20 HSU VTF-3 Sub (three more, 100% cloned)
'93 Carver TFM-35
'88 Carver M-1.0t
'88 Adcom GFT-555
'88 Adcom GFP-555
'88 Adcom GFA-555 (upgraded/restored)
'88 Adcom GFA-555 (a second one upgraded/restored)
'05 Onkyo DV-555 media
'89 Fosgate 360 Digital Space Matrix
'89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
'91 Kenwood Basic M1D Amp
'89 Pioneer Laser Disc media
'89 Sony SuperBeta HiFi media
One PGA2310 based custom built remote volume control
Four Polk T-15's
Four Polk TSi-200's
Four Polk TSi-100's
Two Polk CS-10's -
If you are going for stock then choose air core and to be specific air core with 2.7 Ohm DCR or whatever yours measure.
In the real world, I see no issue with connecting 2 coils in series as long as their magnetic fields don't interact. Laminated coils contain the field very well. A few inches of seperation should prevent magnetic xtalk.
I'm not concerned about the DCR, but I want to be as spot-on 16 mH as possible.
I just purchased 4 each of the 8 mH/14 gauge directly from erseaudio.com for $128 delivered based upon the following message Erse emailed me:
"Greg, Many of our OEM speaker manufacturers connect our inductors in series to get higher values. Keep the coils at right angles from each other and as far away as possible to prevent magnetic coupling. The performance would actually be better since only half the magnetic flux will be in core. The only difference would be a very slight total increase in DCR when comparing the use of two inductors versus one. If you absolutely need a custom 16 mH/14 gauge, we would need an order for a minimum of 50 pcs. Thanks, Jim Smolik, ERSE Audio."
I'm excited to see how these work out (the DCR will be .225 X 2 = .45 for two 8 mH/14 gauge in series).VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
Conrad Johnson PV-5 w/mods
TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
Tuners w/mods Kenwood KT5020 / Fisher KM60
MF x-DAC V8, HAInfo NG27
Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
NAD SS rigs w/mods
GIK panels -
inspiredsports wrote: »I'm not concerned about the DCR, but I want to be as spot-on 16 mH as possible.
I just purchased 4 each of the 8 mH/14 gauge directly from erseaudio.com for $128 delivered based upon the following message Erse emailed me:
"Greg, Many of our OEM speaker manufacturers connect our inductors in series to get higher values. Keep the coils at right angles from each other and as far away as possible to prevent magnetic coupling. The performance would actually be better since only half the magnetic flux will be in core. The only difference would be a very slight total increase in DCR when comparing the use of two inductors versus one. If you absolutely need a custom 16 mH/14 gauge, we would need an order for a minimum of 50 pcs. Thanks, Jim Smolik, ERSE Audio."
I'm excited to see how these work out (the DCR will be .225 X 2 = .45 for two 8 mH/14 gauge in series).
Hmmm, this is super interesting. Can't wait to read about your results. -
inspiredsports wrote: »I'm not concerned about the DCR, but I want to be as spot-on 16 mH as possible.
Recall that lowering DCR was the main reason why Matthew Polk recommended this modification.
It is very difficult to be "spot-on" with reactive components like capacitors and inductors because the value of the component will vary with frequency. With inductors, the inductance value measured will vary with signal level and frequency.Proud and loyal citizen of the Digital Domain and Solid State Country! -
DarqueKnight wrote: »Recall that lowering DCR was the main reason why Matthew Polk recommended this modification.
It is very difficult to be "spot-on" with reactive components like capacitors and inductors because the value of the component will vary with frequency. With inductors, the inductance value measured will vary with signal level and frequency.
Sorry, I should have clarified that I meant I am not concerned with DCR values within the context of 15, 16 or 17mH Erse Super Q's which are RIDICULOUSLY LOW.
My two 8mH 14 gauge in series will add an incredibly low .45Ω to the circuit, a huge magnitude decrease compared to the stock 1987 16mH 18 gauge air cores Polk used. (Plus Erse claims a huge 20A storage capacity before saturation)
My Super Q's arrived today and I will do all further postings in my own 2008 2B update thread at . . .
http://www.polkaudio.com/forums/showthread.php?74945-SDA-2B-Crossover-Parts-List&highlight=crossover+parts+listVTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
Conrad Johnson PV-5 w/mods
TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
Tuners w/mods Kenwood KT5020 / Fisher KM60
MF x-DAC V8, HAInfo NG27
Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
NAD SS rigs w/mods
GIK panels -
inspiredsports wrote: »Sorry, I should have clarified that I meant I am not concerned with DCR values within the context of 15, 16 or 17mH Erse Super Q's which are RIDICULOUSLY LOW.
My two 8mH 14 gauge in series will add an incredibly low .45Ω to the circuit, a huge magnitude decrease compared to the stock 1987 16mH 18 gauge air cores Polk used.
I am looking forward to your findings!! -
My 17mh 16awg Erse Super Q's arrived today. I'm installing them now.
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almost 13 hours and no update!
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almost 13 hours and no update!
Nah.........he's selling them now!!!:twisted:
J/K
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
