Effect of running 4 Ohms into 8 Ohm speaker?

No harm to any speaker running them in any configuration, as long as the speaker is driven in it's ratings. You can't run 200w to a 20w speaker at max volume.

So back to your first question 2 8ohm speakers in parallel is 4ohm to amp no problem. If you desire 4 speakers with 1 amp then 4 8ohm speakers in parallel is 2ohm to a 4ohm amp not good. I suggest you run 2 speakers in series with the other 2 speakers run the same way, then place these speakers ends in parallel for 8ohms as both sets are 16ohm. Or you could run these off another amp, this way you could run them the first way, as the amp would see 4ohms.

Simplistically, if the least amount of resistance your speakers present to the amplifier is 8 ohms, 8ohms is what your amp will see.

Even if your amp was rated for 1 ohm loads, it would still "see" just 8 ohms from an 8 ohm speaker.

Amps don't "put out" ohms, they "react" to the loads that speakers put on them.

Where you run into problems is the OPPOSITE situation, 4 ohm speakers will cause the average 8 ohm amplifier to run too hot or fry by putting nearly double the current draw on it than what it was designed to comfortably supply.

Hmmm......original thread date, 2006.

By the way, what is "a 4 ohms setup"?

It's pro gear.....see my sig in red.

hsbgmkt wrote: »

I've always used 4 ohms setup, 4 ohms have professional grade electronics. 8 ohms is geared more towards consumers,

If you want Professional Sounding Audio, save your money and buy 4 ohms rated amp and speakers. With 4 ohms you'll get more power bec of less resistance, and bigger fuller detailed sound.

OUCH!!!!!!!

Welcome to Club Polk hsbgmkt!

I took you quite a few years to respond to TomTesch (I was not even a member of CP when this thread was opened:eek:). Where were you all that time, were you in a coma or some of the sort?

Hey forum, i have a question actually a few questions. i warn you they are loaded questions so please bear with me. I am new to this so your expertise will help me out a lot and is needed.

the topic: impedance, resistance, ohms (i think they are all the same thing)

Gear tested: sony 5600 es avr (8 or 4 ohm capable), Monitor 2 line. 70's on the front, cs2 center, 40s on the rear and surround rears. Cables: 10awg. Maximum cable run, ~25ft.

Configuration and procedures: all speakers bi wired. runs begin at the binding post at the amp. Banana plug has 2 runs mounted in each plug.
I tested at the mount on the banana plug since this is where the 2 cables terminate.

Meter: fluke II multimeter, pretty basic.

results: all channels report 4~4.3 ohms, except center channel 4.3~4.5, (no bi wire option) but when i was tinkering inside the cabinet i noticed they are wired parallel.

questions:

1. On polk website nominal impedance is 8 ohms for the whole line of monitors. Buuut, i have meter results at 4 ohm. what should i trust? is "nominal" used for safety and the layman who just hooks up the speakers and listens? or even with a meter showing 4 ohms is it still supposed to be run at 8ohms?

2. dangers, through research i keep reading of dangers of mix matched ohms on the receivers. IE 4 ohms driven at 8 ohms, or vice versa.
I learned that running low ohm loads at higher ohms results in heat and lost power in the amp. is this true? i have been running these speaker at 8 ohms for about a month plus and haven't noticed abnormal heat, i thought the receiver was a touch warm but i couldn't cook a steak on it. I am also never running my system at peak levels or super high levels i always stay at low to moderately loud. perhaps that saved some heat.

2.1 I have read several dangers of running AVRs in 4 ohm, that is lowers the sound floor, makes the amp clip sooner, thus causing damage to your equipment because of too much demand. My AVR has a volume range of -92 to +23db, (or so it says on the display) the loudest i have ever played my system during its 8 ohm run is at -10db. what happens when you clip an amp? it fries? quits? is it the "protect mode" i hear about? How can i find my sound ceiling with out causing damage to my gear? For any of you out there with the sony AVRs in your expert advice is my normal listening range at 4 ohms ok? -57 to -10db.

2.2 :eek: ohms, watts, current?
i get lost when reading about these. one place gives formulas, and some places talk about 8 ohms being safe for 4 ohm speakers because they take less current? other info sites that even if you amp can go to 4 ohms it changes the current draw and you can fry everything if the amp cant handle the current? Its all a big mess to me, if any one can clear up current, watts and i think i got ohms, but, hey, i can always learn more. please help, the over all big question is am i going to fry my gear, by running 4 ohms?

3:biggrin: Benefits? I have read several times that for optimal sound and efficiency everything should be matched. IE, my meter shows my speakers at 4 ohm load, thus i have put my AVR into 4 ohm load. What can i reap as benefits, perhaps louder volume at lower db levels (on the display)? I cant test right now as it is 230am and wife is sleeping. any other benefits you guys can enlighten me to would be welcomed!

i know its a lot to ask but, all your help is greatly appreciated so perhaps one day i can add intelligently to the discussions on the forum.

i also have to say this, i love the longevity of this thread, started in 2006, then a year break and then bam 2011. seeing that it was posted on so recently is why i decided to add to it.

thank you all for your help
ESR.:biggrin:

Impedance varies with frequency so a "nominal" rating is an average of all impedances at all frequencies.

Nominal = average.

Your readings are just at the driver without any signal present. As the signal moves through the components (drivers, x-over components, etc) as a complete circuit from input to output the impedance will vary greatly. It may be as low as 3-4 ohms at very low frequencies and as high as 100 ohms or more at very high frequencies.

H9

Esreuter wrote: »

topic: impedance, resistance, ohms (i think they are all the same thing)

Resistance is a DC measurement that indicates the pure resistance whereas impedance is an AC measurement that also includes the effects of any reactive components(inductance,capacitance)in the circuit.

Meter: fluke II multimeter, pretty basic.

results: all channels report 4~4.3 ohms, except center channel 4.3~4.5, (no bi wire option) but when i was tinkering inside the cabinet i noticed they are wired parallel.

You are merely measuring the DC resistance of the woofer(s) voicecoil and any inductors that are in series with it.

Be interested to know how this plays out.

Thank you all,

I only wish i had the gear to do such a test to see impedance. From your guidance i have found information about impedance fluxing with frequency, and learned a deal about how the manufacturer creates the guidelines for nominal impedance. i wont post it you guys already know this stuff. Again i thank you for the right path to find the correct info.

i got steered wrong at another forum where a person metered their tsi400 at the binding posts on the back of the cabinet. he metered the top at 7.6ohm with out the jumpers, then put the jumpers on and metered 4ohm. this is where i got the bright idea to do the same to mine, just to see. i read the posts there and no one mentioned the facts of impedance you guys did.