Sda srs poly switch
gregmoyers
Posts: 140
Which one is the poly switch?
Also I have a ton of other questions about rebuilding/ enhancing these crosovers. Any help is much appreciated.
Also I have a ton of other questions about rebuilding/ enhancing these crosovers. Any help is much appreciated.
Best Answers
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Have used the c coil in hundreds of builds, no issues ever. Great sda inductor- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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The poly switch was used in both 1.2 & 1.2tl
Answers
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The little blue guy on the lower left.
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Thanks. That was my “guess”.
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You're welcome!
The recommendation that seems to reflect the majority is that it is not conducive to good treble response and should not remain in the circuit. However, it does have a small amount of insertion resistance and a good substitute would be a high quality low resistance resistor, usually 0.5 Ohms is selected. -
^ What Selenium said.
I'll add this, after removing my poly switch I added resistors to test the difference and sound with each value. What I found is I like the sound of my Polk with just bypassing the poly with no resistor. But, I do like a little more treble than what my SDA SRS provided with a resistor in place, that's a personal preference.
I suggest you try all the above to find what you like coming out of your Polk's.
DO NOT bypass/shunt the poly if you don't have the proper amplification, bad stuff can happen.
AVR's & Stereo Receivers are not good with this type of mod... -
Thanks
Im using a Threshold S500 for power. Plenty for any speakers. -
👍 You're good.gregmoyers wrote: »Thanks
Im using a Threshold S500 for power. Plenty for any speakers. -
I am trying to decide on a low DCR 16mH inductor. The only one I can find is the Jantzen C Coil but the .16ohm DCR is kinda scary. What does that do to the overall impedance of the speaker? I have. Threshold S500 I am using and it should be ok. I was looking for the Super Q that DHS recommended but can’t find. Any thoughts? Thanks.
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I ordered Mills resistor to put .5 ohms in place. I did not like the overkill treble with the poly sw. shoted.
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I see this one but it is 2.66 Ohms
https://www.parts-express.com/Jantzen-0873-16mH-18-AWG-Air-Core-Inductor-255-298?quantity=1George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
I ordered the C coil.
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You'd have been better off to post ALL your issues with these speakers in ONE thread. It'd be a lot easier to follow the complete story.
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Looking for the best place to mount the C coils. I know…away from metal. Theres a lot of metal in there. Any suggestions? It’s the original blade blade SRS with all the bracing not 1.2. I hope I posted this in the right place😬
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Thanks everyone. I wound up eliminating the polyswitch. I checked the dcr of both polyswitches and it was 3.2 on one and 3.1 on the other. I have 4 each 1 ohm Mills I may try when I rebuild the crossover’s but for now they are out and it sounds great.
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A one ohm resistor will kill the treble. Never use more than a .5 ohm.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 -
A one ohm resistor will kill the treble. Never use more than a .5 ohm.
He can parallel 2 of the 1ohm
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 -
Of course I bout4 to parallel them for the recommended.5 ohm BUT for me .5 is too much. I heard they were only use on the 4ohm systems like mine then eliminated them on the later srs that were 8 ohms. True?
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False!!!!
Why buy 4 to parallel, makes zero sense.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 -
Bought 4 to parallel 2 in each crossover. Mills .5 ohm were not available at the time. I’m not going to use em. Anyhow….do the 1.2 or the 1.2 tl still have the polyswitch? Just curious . I heard at some point they were eliminated. Set me straight. I get a lot of wrong info. I even had Polk send me SL 2500 tweeters to replace my SL2000’s.🤔
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They were only eliminated on the SDA SRS 3.1TL model. Every other model had them, although different models had different values of the polyswitch. The most common had a pre-trip resistance of .5 ohms. Some were .7 ohms. Looking up the specs for yours it appears yours had a pre-trip value of only .07 ohms, so the .5 ohm would be too much. Therefore, the removal of your polyswitches would not be audible to many. I've played around with incremental values between .1 up to .5 ohms and can clearly hear a difference between .22 and .27 for example.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 -
4 in parallel would increase power handling of the resistor and decrease heat build up.
This isn't really an issue for the Polks but I have done this for many builds for clients with high volume tendencies.
If you do this it would remove any protection the resistor would provide- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit. -
Sweet thanks all.
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For now they are out and in the trash. Good info F1. When I rebuild the crossover’s I will revisit resistors or no resistors. I like the way it all sounds now very much so. But 36 year old caps? I think fresh crossover components are over due.
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Going by the "090" wouldn't the pre-trip resistance be around 0.25 Ohms (0.31max/0.20min) ?
https://www.tme.eu/Document/3224e893b8d3a8cb339f75bf0e3d390f/Littelfuse_PTC_Radial_Leaded_RXEF.pdfGeorge / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Ya I saw just over 3ohms . Regardless I’ve since decided I don’t need them. They were for protection correct? I don’t need protection. Were they put in originally to tune the hi frequency? I don’t think so. So Im not interested in replacing it with a resistor to attenuate the highs which sound perfect to me. But then again I don’t hammer the volume like I used to. Ok , every now and then but I have the power to do it clean. If I still had the SL2000’s I would put resistor’s in. If I had certain amps I have had in the past I would probably tune it down some. Personal preference and very cool for us all to be able to go in and do it to our specific tastes.
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^ I do hammer the volume, when the wife’s outta the house.
Was pounding some talking heads stop making sense at 100db while outside doing yard work. The poly’s are by-passed but, I have lots of clean power at hand. I prefer the extra highs with my blade/blade SDA’s. To me, the SDA’s are a tad on the warmer side sounding speaker compared to my kappa 9’s and I like the added clarity of the bypassed poly’s… personal preference.
Not sure the poly switches were designed, into the crossover of the SDA’s, for sound quality vs their protective abilities to limit tweeter damage. Designers had to account for all types of amplification when building these.
Experimentation is your friend. What you like is different than what I like.
If the SL2000’s sounded as good as the 194’s I would have kept them in my speakers, they are extremely over the top built drivers. Just from holding the two in my hand I would bet a beer the 2000’s could handle the wattage I have available more than the 194’s.
Just can’t stand those ice picks in my ears 😂
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Cool. A blade blade brother. Seems like its all about the 1.2 and TL’s sometimes. What power do you have? Always curious to see what people power these with. Did you do a low dcr sda inductor?
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gregmoyers wrote: »Were they put in originally to tune the hi frequency? I don’t think so.
The poly switch was put in for protection but since the resistance of it was likely factored in when the crossover was designed, then I guess you could say it was also used in tuning the high frequency.
Post edited by joebass3 on -
Absolutely, the resistance of the polyswitch was factored in.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
