replacement driver for LSi-C center speaker

timhj

I have a LSi-C speaker with a blown 5 1/4" midrange/driver. I have been trying to get a clear answer from Polk tech support as to if the same sized driver from one of the other speakers in that series (LSi-7 ,9, 15,25) would be compatible to swap out. They will simply say that they "don't recommend it", but I can 't get an answer as to why. The agent with whom I spoke was able to confirm that at least the models 7, 9 and C have the same model number of driver (was MW 5534, later RD 5534-1) I can find both of these model numbers for sale on E-bay, advertised as pulled from a LSi7 or 9. I need to know if there is any reason they would not be compatible. On a related note, Polk's tech support has gone off a cliff in the past decade. It has taken me several phone calls to get the limited information I now have. I appreciate any insight anyone can share.

VR3

All the same drivers across the board to my knowledge

sgmsmg

Are you sure the driver is bad. If I remember correctly it is common to suspect a bad driver on the LSi-C but one of the drivers is for lower frequencies so it sounds like it is not working. It does not output the same as the other driver. If you search on here you will find many instances of people suspecting a bad driver but that is how it normally functions. I know when I had the LSi-C I thought is was faulty as well.

VR3

First gen lsic used a large single inductor for the bass driver that is known to melt, fwiw

timhj

sgmsmg: According to the Polk phone rep (for whatever that may be worth), I should hear the same thing coming out of both cones. I have heard elsewhere what you are describing. Tonight, I will swap the two, turn off all other speakers and see if I get the same result. I will also be able to see the part number and manufacture date. I will let you know what happens.
VR3: Do you know when they changed the design away from the single inductor? If I have the older design, can you describe what I should look for to see if it is damaged?
Thanks, both of you, for your help.

pitdogg2

Take pictures of the XO board and backs of the speakers and post them, it will help.

timhj

pitdogg2: What is an XO board?

pitdogg2

crossover board, it will show the components

VR3

I believe when they went to a painted finish versus vinyl the crossover was also updated

F1nut

I should hear the same thing coming out of both cones.

That is incorrect.

VR3

F1nut wrote: »

I should hear the same thing coming out of both cones.

That is incorrect.

Exactly, one woofer does almost all bass frequencies

timhj

Gents/ladies: In an effort to eliminate as many variables as possible, I decided to use a Bluray as a source material, whereas I first found this problem when watching Breaking Bad on Netflix. I'm glad I though to try this. I watched "Heat", using two scenes: the gang blowing the door off of the armored car and the climactic bank shoot-out. In both cases, I could see the left woofer moving, and to the extent I could hear such frequencies, I could hear it when I covered the right woofer and the tweeter with a pillow. I also varied the low cut-off frequency via the receiver, varying from 40HZ all the way to 200HZ, and sure enough, the left woofer performed differently as I varied it. I also watched the restaurant scene, which is all dialog and some background noise and it sounds fine. The bottom line is that I think the problem was crappy streaming audio. Upon concluding this, I didn't take the unit apart.
sgmsmg: With all this said, it would seem that you are correct, that the two woofers handle different frequency ranges. This contradicts what the tech phone support said, but I am learning to not be surprised by that. Out of morbid curiosity alone, I will call tomorrow to pose the same question and see if I get a different answer. Thanks everyone, for your help.

F1nut

Understand that Polk CS isn't what it used to be. Most of it is outsourced and those folks are not the most knowledgeable. You received the correct answers here and discovered for yourself the info provided here was correct. There's no point in tying up the CS phone line tomorrow.

timhj

I have a couple final questions regarding he LSi series, for anyone who can take them. I also have LSI25s, LSi9s and LSi7s. I am guessing from the different specified frequency ranges and crossover frequencies between the model 9 and 7, that the model 9 is configured much like the LSiC, in that the two 5 1/4" drivers handle different frequency ranges, rather than both putting out the same. Secondly, I wonder if the LSi25, due to having a separate 10" woofer, has its two 5 1/4' drivers both putting out the same frequencies, unlike in the LSiC. Can anyone speak to these two? Thanks again.

VR3

as far as I can remember ALL of the LSi MTM speakers have the cascaded array (one driver is oriented to bass)