LSi-15 partial meltdown??
Comments
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Higher wattage rating is a hazard for other components. I would prefer having an innexpensive and easily replacable ceramic resistor than replacing smaller and potentially more expensive electronic parts surrounding the resistor.....
I disagree with that.
Higher wattage ratings on resistors simply means it can dissipate more heat and handle more current than lower rated compnents, thus preventing premature failure of the resistor. If the resistor fails due to overheating (or with a underrated resistor), the resistor can fail and in addition to just causing an open a failure can also potentially cause a short-THAT is a hazard for other components, and then some. A resistor is not a sacrifice component like a fuse-at least not in this application.
Ratings are also chosen based on the cost and size of the parts. The Lsi9 uses both 5W and 10W resistors. Note the size difference:...but values are decide by engineers for a reason as they affect each other. ...Was there any mod recommendated by Polk in reference the increased in wattage? Going from 5 watts to 12 watts is rather a drasting change IMHO???
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HT:Onkyo 805, Emotiva XPA-5, Mitsu 52" 1080p DLP / polkaudio RTi12, CSIa6, FXi3, uPro4K
2-chnl : Pio DV-46AV (SACD), Dodd ELP, Emotiva XPA-1s, XPA-2, Odyssey Khartago, LSi9, SDA-SRS 2 :cool:, SB Duet, MSB & Monarchy DACs, Yamaha PX3 TT, SAE Tuner...
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ROTFLMAOSolidSqual wrote: »
I'm sure we can then agree to disagreeI disagree with that.
Higher wattage ratings on resistors simply means it can dissipate more heat and handle more current than lower rated compnents, thus preventing premature failure of the resistor. If the resistor fails due to overheating (or with a underrated resistor), the resistor can fail and in addition to just causing an open a failure can also potentially cause a short-THAT is a hazard for other components, and then some. A resistor is not a sacrifice component like a fuse-at least not in this application.
Ratings are also chosen based on the cost and size of the parts. The Lsi9 uses both 5W and 10W resistors. Note the size difference:
On a more serious note. Resistor rarely short that I know of if ever. As pointed out by McLoki there isn't too many parts that can be fried on those Xo (however, my concern is what would be the cost of a replacement Xo versus the cheap ceramic resitor). Now I also pointed out that I would prefer replacing the cheap resistor than potentially replacing drivers (more likely the tweeter in this specific case) if the resitor is rated so high that while not failing potentially allows for damage of the driver(s).
As pointed out, moding the resistor to a higher value has often been done on many occasions on this board without any issues so who knows, maybe the resistor was miss-rated originally, or maybe Polk knows better and wants to make sure the driver(s) are protected if the speakers are abused? I any case, Polk is looking to it. Kim, I hope you will report the engineers findings and recommendations in that matter.
Cheers!
TKDARE TO SOAR:
Your attitude, almost always determine your altitude in life -
TK, the Vifa ring radiator is a pretty robust tweeter and in Polk's application, it isn't put under a lot of strain. As long as people don't abuse them(ahem), a 10watt resistor should be fine."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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That is what I figured since CP has been moding that way for a while and there is no report of damage due to this mod. As you say, pushing further than the limit can be the problem thus IMHO the reason why Polk would use lower wattage resistor. However, I hope Kim will report the engineers finding and recommendations on this matter. Who knows, maybe the original resistor was too low wattage in the first place? May such thread will lead Polk to upgrade new products with higher wattage resistor? The new Lsi line is actually going through redesign, maybe this is some to consider....TK, the Vifa ring radiator is a pretty robust tweeter and in Polk's application, it isn't put under a lot of strain. As long as people don't abuse them(ahem), a 10watt resistor should be fine.DARE TO SOAR:
Your attitude, almost always determine your altitude in life -
Been a while, but thought an update was in order...
Kim @ Polk CS came through with the new crossovers, and the speakers are working better than they ever have. As we already know, Polk is a first class outfit and I thank Kim and everyone else for their help and support.
According to him, the crossovers were damaged severely, but he would not disclose cause of failure. I still suspect I just ran them to hard at way above their rated capacity, but I guess the world will never know.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
TK, the Vifa ring radiator is a pretty robust tweeter and in Polk's application, it isn't put under a lot of strain. As long as people don't abuse them(ahem), a 10watt resistor should be fine.
I checked the specs on the 'factory' Vifa XT25TG30-04 and they are listed as 400w short term and 950 long term power rating. IDK what differences in the Polk versions, but that sounds pretty robust to me.
https://www.madisound.com/store/manuals/vifa/xt25tg30-04e.pdf
Glad CP/ Kim took care of you -
Who knows, maybe the original resistor was too low wattage in the first place?
Nope.CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint. -
Thanks for the details and link.I checked the specs on the 'factory' Vifa XT25TG30-04 and they are listed as 400w short term and 950 long term power rating. IDK what differences in the Polk versions, but that sounds pretty robust to me.
https://www.madisound.com/store/manuals/vifa/xt25tg30-04e.pdf
Glad CP/ Kim took care of you
Thank you for the answer, this however gets me to wonder what is the fuss for moding with higher value. Mind you higher value is not negative as it provides for superior protection of such component especially knowing that the driver can take the abuse.Nope.DARE TO SOAR:
Your attitude, almost always determine your altitude in life
