Connecting 6 ohm speakers to 8 ohm rated receiver?

[quadropenta]

Putting together an audio system for a PC in my office. I was given a pair of PSB Alpha A/V speakers rated at 6 ohms. Old but with good reviews (much like myself :^) Every receiver I have requires speakers rated at a minimum of 8 ohms though. Is it OK to use them? I don't want to damage my electronics. Thanks for your suggestions.

http://www.audioreview.com/cat/speakers/floorstanding-speakers/psb-speakers/alpha-a-v/prd_124144_1594crx.aspx

 

[TheWarrior]

No need to be worried! For warranty purposes, almost all receivers are rated for 8 ohms. It's the speakers that dip below 4 ohms that can cause heat build up and damage. Enjoy!

 

[quadropenta]

Thanks for the quick reply TheWarrior, I'll use them. Just out of curiosity, I've never seen 6 ohm speakers before. Why would they be designed to be 6?

 

[TheWarrior]

You're welcome! Good timing... I just logged on!

It's just a sum of the drivers used, not that a speaker is designed in such a way.

Impedance is the measure of opposition a circuit provides when voltage is applied. It is similar to resistance, but in an AC circuit, impedance includes both magnitude AND phase. Which also means it is constantly variable, so the number printed on the back is typically the lowest impedance the speaker provides.

So when dealing with LOWER impedance speakers, such as 4 ohms, there is little opposition to the voltage, so the speaker will willingly take whatever an amplifier will give it. And with lower end receiver amps, this can be a very bad thing. A warm receiver is normal, a HOT receiver needs to be shut down immediately!

 

[YammyFan72]

You shouldn't have anything to worry about putting together a small office system using 6 ohm bookshelf speakers assuming they won't be driven too hard (it is an office after all).

It's the 4 ohm speakers powered by an 8 ohm receiver in a large, main audio set up that might cause some problems.

 

[-Jim-]

Gents,

While I see no issue here for this application, Speaker Engineers have the ability to design speakers to a targeted nominal resistance. (It's not like they plug these components together at random.) I don't remember what interview I saw, but Andrew Jones recently talked about why his units were 6 Ohms - that included the Elac Debut series and his efforts at Pioneer. His most recent Unifi units are 4 ohms; but he says most receiver /amplifiers will have no issue driving them.

 

[TheWarrior]

Gents,

While I see no issue here for this application, Speaker Engineers have the ability to design speakers to a targeted nominal resistance. (It's not like they plug these components together at random.) I don't remember what interview I saw, but Andrew Jones recently talked about why his units were 6 Ohms - that included the Elac Debut series and his efforts at Pioneer. His most recent Unifi units are 4 ohms; but he says most receiver /amplifiers will have no issue driving them.

Absolutely! It's a matter of economics:

If you are designing a budget/entry level series of speakers, you can safely assume that the user will not have a high end receiver/amp capable of safely powering low impedance speakers.

The Unifi series is hardly entry level. So I think Andrew was making a broad generalization in assuming that the end user would not be running Unifi's with a $299.99 receiver!

 

[Dan Madden]

There will be no problems at all using those speakers (Those Alpha's are nice speakers by the way!) I had 4 ohm speakers at one point and my Yamaha receiver had no problem driving them.