Does Part number differences really matters

[Richard Savary]

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

 

 

 

  

[OO1]

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 --

 

 

 

[Richard Savary]

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. 

 

 

 

[boom3]

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.

[OO1]

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 -

 

[Chief bonehead]

Dcr of the woofer matters and therefore so does nominal impedance

[Richard Savary]

Sounds more realistic with the explanations.

 

Tks !😉

[geoff.]

@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?).

 

 

 

 

 

 

 

[boom3]

To be clear, I was speaking of entire speaker systems, not individual parts.

[MusicSteve]

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