6 ohm / 8 ohm

[kuei]

Hello all.
I just recently picked up a pair of 6ohm infinity composition prelude speakers. It was a great price. The rest of my speakers are 8 ohm infinity overture 1's, 2's and 3's.
My receiver is a Yamaha rx-z9. The yamaha has a 6 ohm/8ohm speaker setting. Is it possible to run at 6 ohms without running into problems with the 8 ohm speakers, or can the 6 ohm speakers be easily modified?

[GMichael]

Your receiver should have no trouble with most 6 ohm speakers. Do you have a graph of those speakers impodence swings?

[kuei]

A graph? I would not know where to find one.
By running the 6ohm speakers with the 8 ohm speakers would it be best to set the receiver on 6 ohms?

[GMichael]

Your receiver should have no trouble with most 6 ohm speakers. Do you have a graph of those speakers impodence swings?

From this site: http://www.stereophile.com/floorloudspeakers/295/index7.html
I found, "The graphs showing the ultra-low resonances and distortion characteristics of these C.M.M.D. drivers are truly astonishing. In addition, the impedance curve of the system is said to be 4 ohms, ±1 ohm across the full audio bandwidth—itself an impressive engineering feat, and super-critical when driving the tower section with tubes, or any amplifier with a high output impedance."

Nice speakers by the way.
Looks like your receiver should have no trouble with them.

[kuei]

Much thanks

[GMichael]

My bad. Those were not the same as the ones you have. These look more like the right models: http://www.soundstage.com/systems/systems200001.htm

If so, your receiver will have even less than no trouble.

Edit: Oh, and these are nice too.

[kexodusc]

Yep, GM is right - your receiver is plenty powerful and those speakers could easily be called 8 ohm speakers by some other companies. Your receiver has protection circuitry in it that will guard against anything serious happening...if anything starts to sound bad as you crank the volume loud (and I mean very, very loud), simply turn it back down.

[GMichael]

Yep, GM is right - your receiver is plenty powerful and those speakers could easily be called 8 ohm speakers by some other companies. Your receiver has protection circuitry in it that will guard against anything serious happening...if anything starts to sound bad as you crank the volume loud (and I mean very, very loud), simply turn it back down.

Dude,

You are so gonna hit 7k soon! What time is the party?

[Smokey]

By running the 6ohm speakers with the 8 ohm speakers would it be best to set the receiver on 6 ohms?

I would set the receivers impedance switch at 8 ohms. At 6 ohm setting, receiver tend to limit current to speakers via reduced output voltage as to protect itself against lower impedance speaker loads. So performance is compromise in favor of protection. on lower impedance settings.

As GMichael and Kex said, you should be alright with different load speakers as long as plaster on the wall is not shaking :D

[RoadRunner6]

The pros say it much better than I can:


Audioholics comments on this switch:

......." What Doesn't Matter?

Impedance Selector Switches
This so called feature, used by some manufacturers, is designed to prevent overheating of the receiver or damage to its output transistors because of excessive current flow. The manufacturer accomplishes this in one of 2 ways: 1) Stepping down rail voltage supplied to the power amp or 2) feeding half the signal strength to a voltage divider of power resistors. Both of these methods severely limit dynamics and current capability of the power amp. This results in an audible decrease in bass capability and dynamics transient sound because the 4 ohm setting effectively increases the receiver's output impedance. Unfortunately many manufacturers put these features on their products to ease customer concerns with driving low impedance loads and for safety reasons when getting UL approvals. Note: In order to meet UL requirements, a receiver cannot be rated down to 4 ohms without having this switch onboard. Receivers without this switch are usually rated down to 6 ohms. In most cases, well designed receivers can easily handle 4 ohm loads safely and efficiently. It is highly recommend to keep the impedance switch set to 8 ohms regardless of your speakers impedance and make sure your receiver has plenty of ventilation."........

RR6

[kuei]

thank you all for the info