removing polyswitch

neighbor
neighbor Posts: 15
edited March 2011 in Vintage Speakers
hello all,can someone please tell me if i can remove the poltswitchs for my sda srs,and if so how do i go about doing it,any help will be greatly appreciated.thank you all.
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    Can you solder? If you can we can proceed. If you can't we can try to find someone near you, or I can do it for a small fee. You may wish to upgrade them while you are at it.
    I hope this helps.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Disc Jockey
    Disc Jockey Posts: 1,013
    edited February 2011
    if you do remove the polyswitch, you should replace it with a .5 ohm resistor to keep the resistance of the tweeter circuit intact.
    "The secret of happiness is freedom. The secret of freedom is courage." Thucydides
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    Disc Jockey wrote: »
    if you do remove the polyswitch, you should replace it with a .5 ohm resistor to keep the resistance of the tweeter circuit intact.

    No. A new Poly Switch is lower than that in resistance. Also why would you want to add a resistor directly in-line to tone down the treble an almost unmeasurable amount? Resistors in series with the driver also affect the SQ. A 4ohm driver with a 4ohm resistor drops the loudness 3db. So increasing the resistance by .5r would would only measure a difference of less than half a db. The Polk's that have fuses or no protection at all don't have a resistor in place of the Poly switch. There is a reason why:wink:
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Disc Jockey
    Disc Jockey Posts: 1,013
    edited February 2011
    Umm, he wasn't talking about replacing the poly with a new one. If he wants to preserve the sq, he will have to replace the resistance of the polyswitch with the equivalent resistance, which is about .5 ohm. It's not a lot but it is noticeable. Some may like it, some may not, but it will be different.

    I would guess that the Polks that don't have any were designed that way from the beginning. :wink:
    "The secret of happiness is freedom. The secret of freedom is courage." Thucydides
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    Polk started with fuses that have no resistance. Then they added Poly switches. The replacement is an RXE-135. The resistance is less than .2 ohms when new so really we are talking about less than .2db. I never install the extra resistors, and I won't. I have done about 100+ XO's for Polkies. Look at the diagrams for the speakers. I guaranty you will never see a .5r resistor in series with any of their vintage speakers.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Joe08867
    Joe08867 Posts: 3,919
    edited February 2011
    ben62670 wrote: »
    Polk started with fuses that have no resistance. Then they added Poly switches. The replacement is an RXE-135. The resistance is less than .2 ohms when new so really we are talking about less than .2db. I never install the extra resistors, and I won't. I have done about 100+ XO's for Polkies. Look at the diagrams for the speakers. I guaranty you will never see a .5r resistor in series with any of their vintage speakers.

    Agree 100%. The resistor is just added garbage in the signal path.
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  • geppy1
    geppy1 Posts: 3,075
    edited February 2011
    Here is a questin that ties into this. On early RTA 12cs (and Bs) they used a .75 Amp fuse. On the late 12Cs they went with a polyswitch and a 2ohm resisitor where the fuse holder was. Are these setups equal????
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    No they modded the XO's.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • geppy1
    geppy1 Posts: 3,075
    edited February 2011
    How?? as far as I can tell they look exactly the same and have all the same values just different manufactures. The only difference I can see is the the polyswitch with a 2ohm sand resistor v a fuse and holder. eith
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    Do they use different tweeters? Different MW's? A fuse has no resistance and adding a resistor and a polyswitch would drop the DB level on the tweeters by roughly 1.5db. Maybe the originals sounded a little bright?
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • geppy1
    geppy1 Posts: 3,075
    edited February 2011
    OK that is what I wanted to know.
    You are saying the fuse and holder have almost no resistance.

    The polyswitch (.5ohms) and resistor (2ohms) would be around 2.5 ohms

    Bottomline is they are not equal Right ??

    So When everything else stayed the same (drivers and the rest of the crossovers) but when they went from the SL1000 to the SL2000 they went from fuse and holder to 2 ohm resistor and polyswitch.
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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    The SL2000 must be more efficient than the SL1000. That is why the padded down the tweeter.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Schurkey
    Schurkey Posts: 2,101
    edited February 2011
    A fuse has almost no resistance when measured with the tiny current of an ohmmeter.

    What happens in terms of voltage drop when the fuse is carrying close to it's rated amperage? My bet is that it's restricting current flow just as if it had more resistance...but I've been wrong before.
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  • F1nut
    F1nut Posts: 50,543
    edited February 2011
    ben62670 wrote: »
    Polk started with fuses that have no resistance. Then they added Poly switches. The replacement is an RXE-135. The resistance is less than .2 ohms when new so really we are talking about less than .2db. I never install the extra resistors, and I won't. I have done about 100+ XO's for Polkies. Look at the diagrams for the speakers. I guaranty you will never see a .5r resistor in series with any of their vintage speakers.

    Polk not only used the RXE135, they also used a RDE050A, RDE070A and RDE090A in different models over the years. One should note that on earlier schematics when there was a change from a fuse to a poly that the series resistor was decreased by .5 ohm. It is also noted on the 3.1TL schematic that when the poly was deleted the resistor went from 1.0 ohm to 1.3 ohm. Therefore, it follows that Polk seriously considered a value as small as 0.3 ohms to be important.

    Polk has also commented that removing the poly will add a tad bit more detail. That is because of the decrease in resistance. Some may like that while others will not. However, when one doesn't account for the change in resistance when removing the poly, you are actually altering the intended sonic signature that Polk designed into the speaker.

    I and a number of other folks have found that after removing the poly's the top was a little too hot for our liking. Adding a .5 ohm resistor to account for the removal of the poly brings the top back to a more pleasant level.

    Seeing as how you don't actually listen to all the speakers you mod, I think it's brazen of you to say, "I never install the extra resistors, and I won't." I mean if you are going to do it, you should do it right.
    Joe08867 wrote:
    Agree 100%. The resistor is just added garbage in the signal path.

    No, it's not. Please see my comments above.
    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

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  • ben62670
    ben62670 Posts: 15,969
    edited February 2011
    The replacement is the RXE-135 whether or not a 50, 70, or 90 was stock.
    The current polyswitches that are provided by Polk to replace the RDE parts are Raychem part number RXE135.
    The current replacement polyswitch, the RXE135, has a resistance range of 0.12 to 0.19 ohm, with a post trip resistance 0.30 ohm.

    I should have said if someone asks for it I will, but I won't on my own. If Polk's replacement is an average of 0.15r and a post trip of 0.30r The increase of the tweeter spl is nearly unmeasurable. 1db change is supposed to be the least amount of change that the human ear can detect. Also if the Poly was tripped many times the increase of resistance is higher than the spec level. If the Poly had been tripped many times you would be more likely to hear the change of using a jumper because the the piece was out of spec.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • F1nut
    F1nut Posts: 50,543
    edited February 2011
    The RXE135 is not the replacement for the other poly types. That may be the only one Polk stocks right now, but it is different. For example, the current replacement for the RDE090A is the RXEF090, which is rated at .47 ohm. The RXE135 is rated at .3 ohm, so I am a little high by using a .5 ohm resistor in its place, but after trying a number of different resistors, that is what I liked the best. So it seems have a number of other Polkies.

    I guess some of us have super bat hearing, including the guys at Polk as noted by the value choice of resistor in the 3.1TL. I know one Polkie that tried the .5 ohm and ended up preferring a .22 ohm instead. I myself could hear the difference between a .62 ohm and a .5 ohm.

    My point here is that using a resistor in place of the poly does matter.
    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

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  • Toolfan66
    Toolfan66 Posts: 17,237
    edited March 2011
    Now that it's easy to get to anything on my crossovers, I will try a .5 ohm resistor in place of my wire...
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2011
    You could put a switch on the front to cut the tweeter. Remember .5r is less than half a DB, and the original was the RXE-135 which was .30r after being tripped. Do you have an SPL meter? I would love to see what the levels would be jumped and with a resistor. The Rat Shack one can be used with REW and the correction file.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Toolfan66
    Toolfan66 Posts: 17,237
    edited March 2011
    I will put it to the test Ben, I am going to order a few things from Sonicraft anyway,and it's a cheap test...
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2011
    That's cool Larry. Do you have a Rat Shack SPL meter? I would like to get a few measurements if you do. REW is fairly easy to operate.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Conradicles
    Conradicles Posts: 6,081
    edited March 2011
    I heard a very pleasant upgrade when I added the .5 ohm resistor in place of my wire. Not as noticeable as when I removed the polyswitch. Removing the polyswitch was night and day, adding the resistor sweetened the deal.
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2011
    I wonder if the sound is changed by the resistor. Face has noticed different SQ with different brands of resistors of the same value. Hopefully he will chime in.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Conradicles
    Conradicles Posts: 6,081
    edited March 2011
    I used Mills and you could be correct Ben.
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  • allstock
    allstock Posts: 136
    edited March 2011
    I tried a .55 in mine in place of the poly, but it was too much. A .22 might have been better. It all depends on set up/room etc. If it's too hot without the poly adding SOME resistance will help. I changed ic's to some that are a little "laid back" on the top and I find it's good. (for now:wink:)
    Two Channel-SDA SRS 1.2tl's,modded, Cambridge Audio 851w amps(2),Cambridge 851e pre, VPI Scout 1.1 tt, Moon audio phono pre,oppo bd105.
    HT-Denon avr3808ci,Carver a-753x,Panasonic ae4000 projector,120" screen,ps3,wii console w/full rockband,Panamax conditioner,dbx120 subharmonic synthesizer,jvc dvd-a player, Polk RTi12 mains,Polk CSiA6 centre, Energy ES-18xl sub,two custom 10" powered subs, Def Tech bp2x surrounds(4),Paradigm monitors-rear(2)
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2011
    Did you try it with just a jumper in place of the Polyswitch. Also keep in mind everyones house is different. Lots of reflective surfaces might benifit from the resistor, but if your room is "soft" you might be better off without it.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • Joe08867
    Joe08867 Posts: 3,919
    edited March 2011
    ben62670 wrote: »
    Did you try it with just a jumper in place of the Polyswitch. Also keep in mind everyones house is different. Lots of reflective surfaces might benifit from the resistor, but if your room is "soft" you might be better off without it.

    A soft room might be the reason I liked the extra bit of highs I get with a jumper instead of the polyswitches or resistor. I have not tried my speakers with a resistor but may give it a whirl to see if there is a benefit or loss in my situtation. The room I use would most definitely be considered soft. The room is a carpeted 20x30 room with minimal reflective surfaces. I use bass traps in the upper corners and have wall absorption to block reflections on the outer and rear walls.
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  • Face
    Face Posts: 14,340
    edited March 2011
    ben62670 wrote: »
    I wonder if the sound is changed by the resistor. Face has noticed different SQ with different brands of resistors of the same value. Hopefully he will chime in.
    Yes, Mills adds a small amount of warmth compared to Mundorf and Duelund.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • elayatola
    elayatola Posts: 1
    Hello, please your advice.

    To replace the polyswitch by a resistor on a RTA-11t, either 0.5 or 0.22 ohms (or what ever you choose), what would be the recomended power in watts for that resistor replacing the polyswitch?



    Thanks in advanced.
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  • pitdogg2
    pitdogg2 Posts: 25,440
    10 or 12 watts I'd advise. The polyswitch had .5ohm of resistance so I'd keep that if you do not want a hotter tweeter.
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