LSi 15 crossover burned

vmaxer

See attached photo of the LSi 15 crossover that burned...What causes this??

McLoki

I would guess to much power - but not sure. (or maybe your amp shorted and was putting out a DC current...)

It looks like the resistor got hot. A pretty inexpensive fix. Order a 12watt mills and go on with your day.... Any other components that got melted?

ben62670

McLoki wrote: »

I would guess to much power - but not sure. (or maybe your amp shorted and was putting out a DC current...)

It looks like the resistor got hot. A pretty inexpensive fix. Order a 12watt mills and go on with your day.... Any other components that got melted?

Plus 1. Come over and I will do the mod for free.

vmaxer

What mod?? Are you talking modifying or repairing as it was?? I just got the speakers today and played a couple of hours...Thinking it should be a warranty item??

Face

What are you driving them with?

F1nut

Sizzle lean with Jimmy Dean!

What are you driving them with?

Good question. And how high was the volume control?

vmaxer

I have them hooked up to a Sunfire Signature 405X5. I really didn't have the volume that high. As I said I had just got them and only played them a couple of hours. The tweeter on that speaker was weak from the start, I actually unplugged the bottom wires to see if the tweeter was playing before it burned up??

All I have read about the LSi 15's says the more power the better. I have accessories coming to actually bi-amp them with 405 watts to the top and another 405 to the bottom?? I know they won't take that much (at 4 ohms this amp is pushing 810 watts). I had this amp hooked up to RT55i's and played them a lot louder without any problems. If it matters I am using a Sunfire TGP 5 pre...

This is going to sound stupid....how do you know the limit on the volume?? Do they make an in-line meter so you can see how much power you are feeding them?? My problems in the past were not enough power and frying tweeters on the RT55i's??:eek:

vmaxer

I updated my sigature so you can see what I am using now...

george daniel

I'm wondering if the resistor was on it's way out when you got them,,and you just helped it along, you should be able to replace it with a mills 12 watter and be good to go,barring any other bad components in the crossover,,having heard a pair with the upgraded crossovers(Ben's work),,if you are in the neighborhood,, take him up on his offer.Good luck,,let us know how it turns out.

vmaxer

Okay..I don't know much about this, I can replace it but I don't know where to get the part you mention??

vmaxer

Should I do this on both seakers?? When I look the part up it is available in several ohm ratings?? What part number do I need??

ben62670

Partsexpress.com
I would replace both.

vmaxer

There are many Mills 12 watt, which one do I need??

george daniel

Replace them with the same rating(ohms),,ex; 2 ohm 5 watt----replace with 2 ohm 12 watt.

Look at the specs on the original resistors on the crossover.

McLoki

There are 3 - 2ohm resistors going to the Tweeter and 2 5.25 mid-basses. There is also (I think) 1 - 3.5 ohm resistor going to the 8" bass driver.

I am going to guess that you smoked the resistor going to the tweeter (you will want to verify that though) what speaker is not working?

I think the resistor in the tweeter circuit is a weak link in the LSi's. I have seen one and heard of 3 others, lSiC resistors that have desoldered themselves from the circuit board in the tweeter circuit of the LSiC. Based on that, i would just replace the 2 ohm reistor in the tweeter circuit of both speakers.

On a side note - If you just purchased the speakers from an authorized reseller, I would call Polk customer service and ask if it is covered under warrantee before you make any purchases. Either way - it shouldn't be a hard fix.

Michael

vmaxer

I purcased them as refurbished direct from Polk Audio. I sent Ken Swauger a message and will talk to him a little later. It is the tweeter that stopped working.

:DI want everyone to know that I sincerely appreciate the answers!!:D

This forum is great!!:D

It sounds like I need to modify the crossovers at some point in time either way??

nooshinjohn

if you got them from POlk Direct, they will probably send you a replacement without to much hassle. You may want to test the tweeters as well. Polk service rocks!

[Deleted User]

Hello,
Sorry I wasn't here yesterday, dental surgery. Hopefully you were able to contact one of the other folks here?
Regards, Ken

BlueFox

vmaxer wrote: »

I have them hooked up to a Sunfire Signature 405X5. I really didn't have the volume that high.

It is certainly a good thing you were not using an AVR. Otherwise, everything would have burnt up; speakers, crossovers, cabinet, etc. I can only thank my lucky stars my 4 LSi15s and LSiC did not burn up for the three years I used an AVR before I got my Sunfire TGA5400. Oh, wait....Sunfire. Oh!! No!!!!! :rolleyes:

ben62670

Kenneth Swauger wrote: »

Hello,
Sorry I wasn't here yesterday, dental surgery. Hopefully you were able to contact one of the other folks here?
Regards, Ken

Well I hope all is well with you. Tooth aches can suck real bad.
Take care Ken
Ben

vmaxer

BlueFox wrote: »

It is certainly a good thing you were not using an AVR. Otherwise, everything would have burnt up; speakers, crossovers, cabinet, etc. I can only thank my lucky stars my 4 LSi15s and LSiC did not burn up for the three years I used an AVR before I got my Sunfire TGA5400. Oh, wait....Sunfire. Oh!! No!!!!! :rolleyes:

I'm not sure of how to take this?? Care to provide a bit more insight??

vmaxer

ben62670 wrote: »

Plus 1. Come over and I will do the mod for free.

Ben,

What mods do you do/suggest??

[Deleted User]

Hello,
Thanks, Ben. I'm much better today. I had a molar that had broken off and left the roots still in place. Yesterday the roots were removed, some bone grafts done and an implant post installed. It took about 3 hours to do, but the oral surgeon is very skilled.
A dull ache and some tenderness is all I feel.
Ken

McLoki

vmaxer wrote: »

Ben,

What mods do you do/suggest??

If you are going to mod - this is a proven place to start....

Michael

BTW - Ken, Glad you are feeling better.....

vmaxer

Does anyone here know if there is such a thing as a "wattmeter" that you can check and see how much power you are sending to your speakers?? I know some amps have them?? I sure would like to know where my limits are...

I don't think that is what caused this failure as I wasn't playing them that loud..

F1nut

how do you know the limit on the volume

The meters you refer to are not an accrurate measure of power, they more or less just look cool.

You can tell when your amp is clipping by the sound coming from your speakers. When the treble starts sounding harsh and the sound gets compressed, it's clipping.

A general rule of thumb is to keep the volume knob below 12 noon.

quadzilla

F1nut wrote: »

The meters you refer to are not an accrurate measure of power, they more or less just look cool.

You can tell when your amp is clipping by the sound coming from your speakers. When the treble starts sounding harsh and the sound gets compressed, it's clipping.

A general rule of thumb is to keep the volume knob below 12 noon.

Hmnmmm... what if you only have an LCD display that measures in db? I've had mine up to reference level (0) and it still sounded fine. It didn't start sounding harsh until I hit about +15.

vmaxer

Isn't clipping from not enough power?? I think I have the opposite problem.. The Sunfire Signature is rated at 810 watts at 4 ohms. Ken Swager also said it can be caused by too much power. As I understand the tweeters usually get fried first from clipping. I use to have that issue until I upgraded to the amps I have now.....

My pre doesn't have a marked knob, it turns a long way also, so the 12 o'clock don't work either.

I have a pair of crossovers coming from Polk and will be back up.

vmaxer

okay, I went and taped e a marker on the volume knob, it takes just over 6 full turns to go from 0 to 100...so I can't use the 12 o'clock rule...

Face

12 o'clock = halfway = 3 full turns

vmaxer

Face wrote: »

12 o'clock = halfway = 3 full turns

This is true, or since my display goes from 0 to 100 I could use 50 as the mark. I put a SACD in and played it there with the one speaker and get around 78 db on the SPL meter. If that is all I can get from this system I should go back to my Onkyo receiver and RT55i's.:( They would go well above that???

The reading was taken aout 10 feet from the speaker.