Ohms question about Polk drivers

B

Batesmotel

New Member
I need to know the Ohm's of a Polk Audio MW 7100 driver from a LS 90 tower. The LS 90 has four identical drivers, two in series on one set of leads and two in parallel on another set of leads. The speaker is 8 Ohm's. The butyl rubber is falling apart so I want to rebuild them.

Does anyone have info on the drivers? I want to replace them but I don't know it they are 4 or 8 Ohm.

Thanks.
 
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How are the sets of leads connected? Parallel?

Why don't you just measure the DC resistance of the drivers with a multimeter? The DCR will be slightly lower than the impedance, for instance, 6-7 ohms for an 8 ohm driver.
 
You don't really need to know what the ohms are on that driver. Call Polk Customer Service direct at 866-764-1801. If you are a member at the Polk forum and let CS know, you will receive a discount.

btw....pretty sure it an 8 ohm driver.
 
nick12345 said:
How are the sets of leads connected? Parallel?
Click to expand...

One set (top) parallel, one set (bottom) series. That is what is throwing me.
Club Polk doesn't have the info I want.
Polk won't tell me. They want to sell me new Polk drivers. $75 X 8 = $600. Bit high for speakers I spent $20 on.
I want to rebuild them with another brand.
I will measure them and hope to get a definitive answer.

Thanks for the help.
 
Can you post a few pics of your drivers? Don't think I have ever seen the rubber surrounds "falling apart" on Polk drivers. And yes they are 8 ohm drivers. There is a set of LS90's on eBay right now btw.... You may be able to replace the surrounds, not sure though.

Also you may try Madisound or Parts Express for a suitable replacement driver. I'd be a little weary that the cabinet and XO are not gonna be designed for the replacement drivers you choose though.
 
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Hi Batesmotel. Replacing the original polk drivers with something new can certainly be done. i haven't seen the butyl surrounds deteriorate either but remember when i was selling their car stuff that they had a bad run with faulty glue they they came apart. if this is the case, superglue was the fix. if not, parts express has generic surrounds and might have something compatible. i would guess that not having the original type of surround would be a minimal mismatch.
to replace them, see if one of each type is in good shape and can be tested. you will want to know as much as you can to ensure that you choose suitable replacements. partsexpress (i know, i sound like a salesman) has a pc-based speaker tester for about $100 which would give you the values you will need to look for matches.
 
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