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Posted By: gulf979cb Center channel VP-150 impedance - 03/31/10 11:14 PM
Hi all...
Just a quick question that i'm sure someone has an answer for.
I currently have the awesome Axiom M22v2 speakers powered by a newer Pioneer receiver at 8-ohms.
I am interested in buying a Center VP-150v2 but i noticed that it is rated at 6-ohms?? Is this correct and if yes what if any damage can i do running different rated speakers by this receiver.
I have the capability of running the speakers at either 6 or 8 ohms from the receiver. All speakers i currently have are 8-ohm speakers. Can i run the VP-150 at 8 ohms?

oh-toil and trouble... what to do...what to do??
Posted By: RickF Re: Center channel VP-150 impedance - 03/31/10 11:17 PM
Yep, it's rated @ 6 ohms and no you won't have any problems.

I'm running 8 and 6 ohm speakers through my AVR, and have been doing so for quite a long time without any problems whatsoever ... as long as you have the AVR setting to 8 ohm you'll be fine.
Posted By: gulf979cb Re: Center channel VP-150 impedance - 03/31/10 11:21 PM
Will i notice a performance difference running this speaker at 8 ohms instead of the rated 6?
Are there limitations to running it at a higher impedance then recommended?
The receiver will have no harm done to it by running this 6 ohm speaker and the other 8 0hms together?
Posted By: RickF Re: Center channel VP-150 impedance - 03/31/10 11:25 PM
Nope.

I run an 8ohm VP100 and a 6ohm VP150 wired in parallel and have not had any issues at all. You'll be perfectly fine.
Posted By: gulf979cb Re: Center channel VP-150 impedance - 03/31/10 11:35 PM
What is your receiver set to?? 6 or 8 ohms?
I just searched the manual for my Receiver which is a
Pioneer VSX-1018AH-K and it says it recommends using 8 ohm speakers and if you want to run 6 ohm you have to set the receiver to 6 ohms.

I trust your advice RickF...no offense -- but i would love to hear from more people before i place my order.

The VP-150 is a very efficient speaker and if i run it at a 8 ohms instead of 6 will this affect the characteristics of this speaker?
Posted By: Wid Re: Center channel VP-150 impedance - 03/31/10 11:44 PM

Rick is correct, leave it set to 8 ohm.
Posted By: gulf979cb Re: Center channel VP-150 impedance - 03/31/10 11:57 PM
I am reading various things on different forums about setting the receiver to 6 ohms and driving all speakers with that..including the 8 ohms i already have?? thoughts on that? perhaps an Axiom engineer can chime in and give me an official answer as to what to do.
I don't want to cause harm to my wonderful Axiom speakers i already have ....or my receiver for that matter.

why is this particular speaker rated at 6 ohms? Is it due to the number of drivers in each one??
Posted By: Wid Re: Center channel VP-150 impedance - 04/01/10 12:03 AM

You will not harm speaker nor receiver. The very worst thing that can happen is the receiver will shut down, but it shouldn't.

From an article at Audioholics.:

"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."
Posted By: gulf979cb Re: Center channel VP-150 impedance - 04/01/10 12:08 AM
See....it's the word "shouldn't" that causes me great distress.

I don't have an unlimited amount of money to just try things out and see what happens. "IF" i have a problem then what do i do?? Other then perhaps sell my stuff to some of you fine people??

Unless i get an "official" answer from an Axiom tech rep...i might have to shop somewhere else for an 8 ohm rated quality center speaker. Not a threat at all...just very worried....
Posted By: Wid Re: Center channel VP-150 impedance - 04/01/10 12:14 AM

If you are worried about your receiver and the VP 150 you should take a look at the M22s impedance curve. It dips down to 3 ohm in the 4KHZ range. I'm telling ya you will be fine running the 150 with that Pioneer.
Posted By: RickF Re: Center channel VP-150 impedance - 04/01/10 12:52 AM
 Originally Posted By: gulf979cb

Unless i get an "official" answer from an Axiom tech rep...

Well slap me on the ass and call me Francis, I thought you posted the question on the forum. Sorry.
Posted By: Wid Re: Center channel VP-150 impedance - 04/01/10 01:06 AM


Will a kick in the ass due.............Francis \:D \:D
Posted By: Adrian Re: Center channel VP-150 impedance - 04/01/10 01:24 AM
Greg, a simple phone call to Axiom will alleviate your concerns, but what Rick and Francis have told you is correct.
Posted By: JohnK Re: Center channel VP-150 impedance - 04/01/10 01:33 AM
Greg, welcome. If you have an understanding of the technology involved you won't be concerned. First, you can't choose what impedance to run speakers at; this is determined by the internal construction of the speakers and can't be changed by the receiver. For example, your(and my)M22s vary between about 3 and 20 ohms at various frequencies and the M80s vary between about 4 and 14 ohms. Manufacturers generally put an average impedance rating on their speakers and the M22s are no more 3 ohm speakers than the M80s are 4 ohm. The so-called impedance setting on receivers is somewhat misleadingly labeled, as what it does in actuality is to reduce the voltage output to help prevent overheating during UL(Underwriters Laboratories)safety tests. The reduction in voltage capability results in a reduction in current and power(following Ohm's Law)and tests have shown that the use of the lower so-called "impedance" setting cuts maximum power capability roughly in half. The setting should never be changed, regardless of what impedance rating was given to the speaker, and should be left at the default of 8 ohms if the maximum capability of the amplifier is to be realized.

So, there's no reason to be concerned with the impedance rating of the VP150s, and whatever you decide about speakers, don't consider changing the receiver "impedance" setting.
Posted By: nickbuol Re: Center channel VP-150 impedance - 04/01/10 01:34 AM
I have a Pioneer receiver and I am running my 8 Ohm M60's in the front, with a 6 Ohm VP150, and 6 Ohm QS8's for the surrounds. No problems what-so-ever.
Posted By: gulf979cb Re: Center channel VP-150 impedance - 04/01/10 01:59 AM
Well alrighty then..... i guess with all the butt kickin..it finally got through..... no hard feelings guys...

Sounds like everyone is on-board with no harm to anything.
just plug and play and enjoy the awesome sound.

looks like i will be placing my order tomorrow..

Thanks for all your help and the good old fashioned butt kickin...
Have a good night all!!!!
Posted By: ClubNeon Re: Center channel VP-150 impedance - 04/01/10 05:12 AM
Check my sig. I have the VP150 on the 1018. It's fine.
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