RTi12's Run at 4 or 8 ohms?

MMcguire

Just upgraded my speakers to Polk RTi Series and wanted to get some advice on how to best connect them to my 100w x 5 & 8ohms Yamaha reciever. In additon to the default 8 ohms all around setting, I can set the reciever for 4 ohms on the fronts which puts 6 ohms on the remaining channels. It would seem this would be the better setting since it would drive the fronts better...and if you actually measure the RTi12's impedance it is 4 ohms.

Granted the better option is to buy a amp, but in the mean time... which would bet the better setting?
__________________
Polk RTi12 (fronts)
Polk CSi5 (center)
Polk FXi5 (rear)
Polk PSW505 (Sub)
Yamaha HTR 5280 Receiver
Toshiba 61" soon to be upgraded to a 60" Sony XBR2
HP MCE PC w/Creative X-FI and DTS601

ohskigod

I dont know dude, that might be playing with fire. I would go with whaever the speaker is rated at, which I believe is 8 ohms.

just my .02

aaharvel

NEVER set an a/v receiver to 4ohms. Even if you have 4ohm speakers.

Holydoc

MMcguire wrote:

and if you actually measure the RTi12's impedance it is 4 ohms.

It kills me that people keep saying this but the manufactorer, the one that makes this speaker, rates it at 8ohms. It is like someone at AVSForums started this rumor and now everyone takes it as truth.

unc2701

Yeah, someone probably hooked up an ohmmeter to it and that's what they got... which is really measuring the DC impedence of the crossover&drivers.

Anyhow, aaharvel is right- that switch is there for UL purposes and restricts the amount of current that'll go throught the receiver. leave it at 8 and if you're worried, make sure that there's 5-8 inches of clearance around the amp so it has plenty of room to breathe.

Altmanfan

aaharvel wrote:

NEVER set an a/v receiver to 4ohms. Even if you have 4ohm speakers.

So........if my AVR is only powering my backs, which are 8ohms, and is otherwise working as a pre to my Outlaw amp, which is powering the 4-ohm LSi series, the AVR setup should be set to 8ohms? Or 4ohms?

aaharvel

Altmanfan wrote:

So........if my AVR is only powering my backs, which are 8ohms, and is otherwise working as a pre to my Outlaw amp, which is powering the 4-ohm LSi series, the AVR setup should be set to 8ohms? Or 4ohms?

Already been answered. Welcome to the forums.

Plus, it's possible that the rti12's are 4ohm speakers. Afterall, the lsi7 are 6ohm, yet Polk says they're 4ohm. Anyway, almost every speaker dips from 8,6 or 6 to 4 throughout the wavelength. Take the average, and you have your correct measurement.

BIZILL

Altmanfan wrote:

So........if my AVR is only powering my backs, which are 8ohms, and is otherwise working as a pre to my Outlaw amp, which is powering the 4-ohm LSi series, the AVR setup should be set to 8ohms? Or 4ohms?

yup, you quoted your own answer.:rolleyes:

aaharvel

BIZILL wrote:

yup, you quoted your own answer.:rolleyes:

oh give 'em a break Bizill. At least he kept it under 6lines.

BIZILL

disneyjoe7

aaharvel wrote:

NEVER set an a/v receiver to 4ohms. Even if you have 4ohm speakers.

OK why?

aaharvel

disneyjoe7 wrote:

OK why?

see UNC's post.

gregure

Impedance ratings by manufactuer's are supposed to be NOMINAL impedance. Every speaker dips and spikes in Ohm resistance due to certain frequencies requiring more or less current to produce. What's most important is the nominal level.
Still, the lower the resistance, the better amp you need, regardless of nominal. Take my Vienna's for example. The nominal impedance is 4 Ohms, however their lowest measured resistance is around 2.8. Believe me, my B&K gets HOT when driving these babies. If I had a lesser receiver, it would probably shut down.

disneyjoe7

aaharvel wrote:

see UNC's post.

Thanks sorry I missed this last week.

reeltrouble1

State Farm--What your house burned down?

PCM--Well, yea, I mean it was an ohm thing here see my post on my new computer, the old one burned up in the fire, can you send the check right away?

State Farm--Gee, your in good hands there but this ain't Allstate, we are the Good Neighbor people, please see your policy neglingency paragrah, section 6.

WAAAAAAAAAA..................j/k

RT1

disneyjoe7

Funny but to bad it maybe true.....

unc2701

Most AVR's these days have a thermal override, too, so the ohm switch is sorta redundant.