Richard Savary Posted December 28, 2020 Share Posted December 28, 2020 Hello, I'm looking to replace a damaged 5,25" woofer on one of my RP-250F towers. Based on schematics and part listing found on Klipsch website, part number for the woofer is 1061255. Same part number applies for the Center Channel RP-250C and the surrounds RP-250S/RP-502S. Specs varies from 35hz-25Khz @ 96db for the RP-250F towers, 60hz-25Khz @ 96db for the RP-250C Center, 58hz-25Khz @ 95db for the RP-250S surrounds. However, for what appears to be the same 5,25" woofer on different model of the range (i.e. RP-150M bookshelfs and RP-450C center channel), there is another part number : 1060722 ? Specs are 48hz-25Khz @ 93db for the RP-150M and 58hz-25Khz @ 97db for the RP-450C. For what I know, i don't believe these specs would matter since it's all about the internal crossover. So is there any difference between the two woofer ? Part #1061255 seems to be out of stock, as the other one is available. Thanks ! Richard Quote Link to comment Share on other sites More sharing options...
OO1 Posted December 28, 2020 Share Posted December 28, 2020 the difference is that your woofer is 8 Ohms , the second is 4 Ohms - The RP 250F Woofer ---klipsch part number 1061255 is 8ohms , The RP 450C Woofer --klipsch part number 1060722 is 4ohms -- Quote Link to comment Share on other sites More sharing options...
Richard Savary Posted December 28, 2020 Author Share Posted December 28, 2020 Thanks ! I did find the same 4 omhs/8 ohms on a "generic" repair/part website. Hence my post. However, all specs from Klipsch website for the speakers mentionned above states : " NOMINAL IMPEDANCE 8 Ohms Compatible " Which makes me believe that it's only a compatible thing alligned to an amp (vintage ?) that is only set for 8 omhs speakers. So the main question remains. Quote Link to comment Share on other sites More sharing options...
boom3 Posted December 29, 2020 Share Posted December 29, 2020 This nominal value means that owners should not worry too much about the speaker drawing too much current from the amp. Some years back, people often paralleled two speakers on each amp output. Two 8 ohm speakers in parallel shows the amp a 4 ohm load, which most modern amps are OK with. Two 4 ohms paralleled on one output shows the amp a mere 2 ohms, which will make amps overheat and possibly blow output transistors. That was then, and now 5.1 channel amps are common, so I have not heard of anyone paralleling speakers on an amp recently. Still possible with vintage amps and receivers that have "Speaker A/B/A+ B" selectors. No amp is "set" for any impedance, the manufacturer is just suggesting that speakers around 8 ohms will present an acceptable load. In practice, solid state amps are happy with speakers whose "nominal impedance" is between 4-16 ohms. 2 Quote Link to comment Share on other sites More sharing options...
OO1 Posted December 29, 2020 Share Posted December 29, 2020 On 12/28/2020 at 6:19 PM, Richard Savary said: Thanks So the main question remains. if the parts were the same , klipsch would only use 1 part number ---in this instance , 1 part is 8ohms , the other is 4 ohms - the 4 ohms woofer draws 2 times more power from the amplifier so yes , both parts are very different -and the 4 ohms woofer will run hotter than the 8 ohms - 1 Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Chief bonehead Posted December 29, 2020 Klipsch Employees Share Posted December 29, 2020 Dcr of the woofer matters and therefore so does nominal impedance 1 Quote Link to comment Share on other sites More sharing options...
Richard Savary Posted January 6, 2021 Author Share Posted January 6, 2021 Sounds more realistic with the explanations. Tks !😉 Quote Link to comment Share on other sites More sharing options...
geoff. Posted January 6, 2021 Share Posted January 6, 2021 @Richard Savary, In a conventionally designed crossover, as you would find in your speakers needing a replacement driver, the crossover point will change if you use a woofer(driver) with a different impedance. That in addition to a difference in volume from the stock vs. non-stock driver in that application. Good luck with your search for a replacement (have you tried the bay?). Quote Link to comment Share on other sites More sharing options...
boom3 Posted January 7, 2021 Share Posted January 7, 2021 To be clear, I was speaking of entire speaker systems, not individual parts. Quote Link to comment Share on other sites More sharing options...
MusicSteve Posted January 23, 2021 Share Posted January 23, 2021 (edited) On 12/28/2020 at 4:38 PM, RandyH000 said: the difference is that your woofer is 8 Ohms , the second is 4 Ohms - The RP 250F Woofer ---klipsch part number 1061255 is 8ohms , The RP 450C Woofer --klipsch part number 1060722 is 4ohms -- Also The Rp-250 and RP-5000 the woofer are wired in parallel (8 ohms /2 = 4 ohms total) The Rp-450, Rp-504 - Uses two woofers that are wired in series and the other ones are to (2 inside woofers and 2 outside woofers) so 4 ohms +4 Ohms=8 Ohms per set, so 8 Ohms in parallel w 8 ohms = 4 Ohms total So the woofer are not the same and can not be be switched between speakers even if they are 5 1/4" woofers Note - this example is dc resistance and is not the same as impedance Also the speaker that have one woofer the RP-500m and RP-150 also use the 4 ohm woofer The theory is that w a smaller box you need more energy /less ohm to get the woofer to move so they are the same as the RP-450 and Rp-504. Edited January 23, 2021 by MusicSteve Quote Link to comment Share on other sites More sharing options...
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