Polk Audio zero resistance

R

Remo10

Audiophyte
I have LCR Polk Audio TL1 speakers that all read zero Ohms but still function correctly...any thoughts?
 
lovinthehd

lovinthehd

Audioholic Jedi
What are you trying to measure particularly and with what?
 
R

Remo10

Audiophyte
Shouldn't the speaker read 8 Ohms when tested with a multimeter?
 
Verdinut

Verdinut

Audioholic Ninja
Shouldn't the speaker read 8 Ohms when tested with a multimeter?
Not precisely. The DC resistance of a driver normally is less than its nominal impedance. Usually, it measures between 65 and 85% of its real impedance.
 
Last edited:
R

Remo10

Audiophyte
I get that...but these read zero ohms at the speaker terminals...
 
lovinthehd

lovinthehd

Audioholic Jedi
Why are you trying to measure it in the first place?
 
R

Remo10

Audiophyte
Because the Denon amp that they were attached to stopped working, and I thought they might be the culprit.
 
Kvn_Walker

Kvn_Walker

Audioholic General
Because the Denon amp that they were attached to stopped working, and I thought they might be the culprit.
I hate to ask this dumb question but are you sure you’re checking for resistance with your meter and not voltage?

If a disconnected speaker is reading 0 ohms at the terminals, then there is a dead short somewhere. Your first post says they still function correctly. I don’t see how both of those statements can be true.
 
Verdinut

Verdinut

Audioholic Ninja
You probably blew your amplifier with shorted speaker terminals. Shorted AVR speaker outputs are really deadly.

That situation does not happen with many pro audio amplifiers but most audiophile amplifiers are more fragile as they don't have the appropriate protection circuits.
 
TLS Guy

TLS Guy

Audioholic Slumlord
I have LCR Polk Audio TL1 speakers that all read zero Ohms but still function correctly...any thoughts?
First of all, are you measuring the speakers at the terminals completed disconnected from everything else including the wiring?

What meter are you using, and what scale setting are you using?

If you are getting a very low DC resistance, the speakers will not be playing normally.

If the speakers have been over driven, then some of the insulation of the VC wire can be fried, shorting VC turns. These speakers can produce sound, and draw very excessive current from the amplifier and destroy it. I have seen this happen.

Lastly because there will always be one or more caps in series with the tweeter, when you measure the impedance of the speakers at it terminals, you are reading the DC resistance of the woofer only, and getting no information about the tweeter.

If your meter is accurate, as measured by testing a resistor of known value, then you should remove the woofers and test them at their terminals. If you then get a very low DC resistance measurement, then those speakers are destroyed.
 
R

Remo10

Audiophyte
I hate to ask this dumb question but are you sure you’re checking for resistance with your meter and not voltage?

If a disconnected speaker is reading 0 ohms at the terminals, then there is a dead short somewhere. Your first post says they still function correctly. I don’t see how both of those statements can be true.
I should have said, reads fully open...no resistance.
 
TLS Guy

TLS Guy

Audioholic Slumlord
I should have said, reads fully open...no resistance.
Well that was a time waster. Those speakers are miserable small ones. It is common in low end speakers like that, for a cap to be placed ahead of the woofers. That helps prevent customers from blowing them up. It means however that a multimeter is useless for checking the speakers. The reason is that a capacitor will not pass DC.

So that explains why the meter shows open circuit and yet the speakers work.
 
R

Remo10

Audiophyte
Me neither...so the speakers didn't cause the amp failure..that's what I was looking for, thank you!
 
slipperybidness

slipperybidness

Audioholic Warlord
I should have said, reads fully open...no resistance.
Fully open = infinite resistance (NOT zero resistance as you had mistakenly stated previously and caused confusion)
 
TLS Guy

TLS Guy

Audioholic Slumlord
Me neither...so the speakers didn't cause the amp failure..that's what I was looking for, thank you!
So in effect the speakers are driven from a first order high pass filter. This mitigates over excursion of the bass driver and damage from excessive power. This is the crudest form of woofer protection.
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top