Natban

I'm running Infinity Reference speakers and they claim they are a 2ohm design as opposed the usual 4ohm design of most car audio speakers.

Is this BS? When I measure the speakers resistence with an ohm meter they do read 2ohms however I've never measured a typical 4ohm speaker. I wonder if the amp sees a 2ohm load when the speaker is powered or does it see an increased impedance of 4ohms due to inductance, heat build up, etc.

What I want to know is when choosing a 4-channel amp should I be looking at the rms power rating at 2ohms or 4ohms.

The speakers are 5 1/4" components and 2-way coax 6x9's.

fresh1

iTrader: (2)

I have some speakers rated at 4 ohms that read 2.6, and others that read 3.8. I wired 4 of them together to a 4 ohm final configuration and they read 3.5. I'm not helping, just thought I'd share.

d4rin

It's probably something Infinity implemented to make buyers think they are better. 4ohm rating is your best bet with those.

RomanticMoments

It has everything to do with heat in the voice coil. It will start around the 2 Ohm mark cold, and as the speaker's coil heats up, the resistance will follow suit. However, at "warm" temps, the speaker will register around 4 Ohms, making it safe for factory systems. Look at the 4 Ohm ratings on amps. JBL did the same thing

Natban

OK thanks RM. I see that JBL and Infinity are both owned by (or whatever) A Harman International Company. I'll stick with the 4ohm rating of the amps.

I figured this was marketing BS anyways but come time to match amps there's a sig. cost difference between 80Wx4 @ 4ohms and 80Wx4 @ 2ohms.

Thanks again guys.

Blu

iTrader: (7)

Keep in mind that the impedance rating listed is a nominal rating - actual impedance will vary by frequency.

You should be fine with most amplifiers.

trunk_munkey

Well resistance has little to do with impedance. To test this claim you need an impedance meter. Its a little devise that emits a frequency and calculates the impedance accordingly.Aat the FS of the driver it should read very close to 2 ohms. The reason is... with some unregulated amplifiers the lower the impedance the more output from the amp and any bridgeable amp will run at 2 ohm stereo (which essentially is 4 ohm mono). So in some cases those speakers will be louder.

Blu

iTrader: (7)

At FS the impedance of a driver is at it's highest... did you mean when the speaker is at rest and simply connected to an Ohm meter?

Dukk

Bingo. Charles is smrt!

Nice looking gear in the avatar too!

Natban

WTF is FS?