Hi, im new to audio and video and i recently get the onkyo 609 (amercan version) and is rated at 6 ohms, but i like the M80 and i would like know how is the performance, i have read here and there about impedance and some ones say no problem conecting that configuration and others just dont recomend conecting 4 ohms speakers whit amps rated at 6 or 8 ohms, so now i am more confused... i can buy the M60 but i like more the M80 thinking in the future stay whit them and just complete the 5.1 or 7.1 setup.

I am planning move to a bigger house and i would like modify the living room whit big doors to comunicate whit the patio for whatch sports whit friends and beer of course and few little partyes.

that is why im asking who have that onkyo and M80.

how will perform the M80s whit an 2 ohms power resistor in serie? will be the performance equal to M60? or stay better than M60? this arrangement is just curiosity.

thanks in advance for your help.

Ther are lots on the forum that are running Onkyo and m80s and have had no problems, however if you are planning on running the M80s outdoors (loudly) or even indoors really loud, you may find the amp will over heat and shut off, moving to some external amplification would help with this situation.

I don play music very loud realy adn the little parties and sports are just few at year so i will go whit m80s then.

Thank you Jason

I dont think the 609 can't do an external amp.

J2, welcome. The fact that the 609, as well as most other receivers doesn't carry an official 4 ohm rating shouldn't be a matter of concern. To have such a rating under FTC(Federal Trade Commission)amplifier power regulations, they'd have to drive a 4 ohm laboratory test load at full power for at least 5 continuous minutes. This sort of thing doesn't take place in the real world of home listening and typical receivers such as your 609 can do fine with the M80s unless they're played at extremely loud levels for a long period. The M80s are slightly above average in sensitivity(therefore require less power)and average about 6 ohms in impedance over their frequency range.

Hi jesbarmo2,

As others have pointed out on this thread, if you have your Onkyo trying to fill a large room with doors open to a patio, you're likely to run it beyond its capabilities and it could overheat and shut down.

By the way, there is no point in using a resistor in series with a pair of M80s. You'll just waste amplifier power heating up the resistor.

The M60s are an easy 8-ohm load so those would be a good choice. For the big room, M80s would be a better choice, but I'd consider a larger AV receiver from perhaps Denon, with pre-outs for the option of adding a couple of outboard power amplifiers. (Denon receivers have no history of shutting down driving the 4-ohm M80 towers.)

Whichever receiver you use, always run it with the impedance setting at 8 ohms so you don't limit the receiver's output.

Regards,
Alan

I recently purchased the Onkyo TX-NR5009 as an upgrade to use with a new Sony VPLHW30ESB 3D projector. I also wanted to swap out my front speakers (Infinity Studio Monitor 155's) for a pair of the M80 Axioms. Defintely nothing wrong with the Infinity's, but the Axiom's had a smaller profile and I wanted to be able to use as much of the available projection space I had available to me as possible (the Sony VPLHW30ESB is simply an awesome machine!)and the SM 155's cut into that. So, I was thinking about trying the M80's. I contacted Axiom, but they didn't know if I could use them in my system which was basically an 8 ohm system ... two fronts, center, two surrounds, two back surrounds, two front wides, and one sub.

Page 13 of the Onkyo manual states that if any of the connected speakers is 4 ohms or more, but less than 6 ohms, the minimum speaker impedance has to be set to 4 ohms. But on the bottom of page 14 of the manual, it states that you cannot set speaker impedance individually. So, my question basically was this: Is this a bad idea ... to use a pair of 4 ohm speakers in what is essentially an 8 ohm system? (Page 13 of the manual also mentioned that using speakers with a lower impedance might cause the built-in protection circuit to be activated if the amplifer is used at high volume levels for a long period of time ... but, were they referring to all speakers in the system having a lower impedance, or would that happen if one were to use just two lower impedance speakers as I would like to do?)

Anyway, I contacted Onkyo. I didn't get a response, so I contacted them again. This is their reply: Hope it helps.

"You can't use both 4 and 8 ohm speakers onto this unit- doing so will cause damage to the speaker channels. You can use both 4 and up to 6 ohms- no higher and not affect the receiver as much as using 4 and 8 ohm speakers."

Don't change the setting. It will just limit power and could cause clipping and overheating.

Otherwise, if you leave it on 8 ohm and mix the speakers, it'll be just fine. Whoever emailed you from Onkyo is full of it.

Well, since it came directly from Onkyo, why wouldn't they know what they're talking about? If you don't mind ... what are your qualifications? Are you familiar with the Onkyo TX-NR5009?

The Onkyo receivers only give you a choice of 4 or 6 ohms, Ken is right leave it in the 6 ohm setting and you should be good to go with the M80s.

There are others here that run the higher end Onkyo's with the M80s with no ill effects.

Onkyo HAS to give you that advice to cover their own ass IF something were to go wrong.

Well, I've run a mix of M80s (4 ohms), QS8s/4s (ie 6 and 8 ohms) and a VP100 (8 ohms) on a midrange Harman/Kardon for 10 years or so without it melting.

Also, I've read LOT of these questions and answers. If'n you don't want advice from random people, don't ask...

So ... something could go wrong? Would make sense not to do it then, wouldn't it? It's not an inexpensive piece of equipment to replace.

You say there are people here who used the M80's mixed with 8 ohm speakers ... with the high end Onkyo?

Actually, I wasn't asking for advice ... I was giving it ... to the original poster. Also, an Onkyo is not a Harmon Kardon.

Something can always go wrong no matter the brand. The receiver, any receiver, has no clue what ohm the speakers are. It is the resistance to the load of the receiver, the lower the ohm rating the less resistance.

If I were to spend that kind of money on a unit and it couldn't run a 4 ohm load I'd return it for a refund.

I understand that something can go wrong. No one's making a receiver today and calling it the Titanic after all. However, if the manual ... and a representative from the company ... suggests not doing it, it would make since not to, don't you think? Or, is it "Damn the ice, we're unsinkable! Full speed ahead!"

And, the Onkyo definitely can run a 4 ohm load ... just not mixed with 8 ohms.

Hi NikonShooter,

Please take the time to read this article. It will answer all your questions in great detail!

http://www.audioholics.com/education/amplifier-technology/impedance-selector-switch-1

Cheers!

People do it all the time. Most of the receivers can handle it. If not, they'll just shut down temporarily. Usually no harm done. I'm not running a 4 ohm load, but I am running 2 sets of 8 ohm for L and R and C channels in parallel with a Pioneer Elite model.

If the receivers couldn't run the 4 and 8 ohm loads at the same time, then they couldn't run the M80s and QS8 surrounds at the same time.

Thanks for the link, BlueJays1. Interesting article. Even more interesting comments there. And, an interesting See Also: article ... the first one. The articles are definitely not addressing the situation I described though.

Nikon, I understand you're not inclined to listen to what you perceive as non-experts on the internet, but understand that impedance curves are just that--curves. So at any given time, two speakers on different channels, even if they have the same nominal impedance of say 8 ohms may well be presenting a different impedance to the amplifiers in the receiver. Note "amplifiers" plural.

I would wager that very few people have 4 ohm speakers on all 5/7/9/11 channels. And I have never once heard of a receiver or speakers being damaged by mixing impedance. Many people whose knowledge on the subject I respect (including Axiom employees) have said categorically that there is no problem. If you're not comfortable with what you're hearing from Onkyo, return it. Or buy M80s for all channels. Or M60s instead of M80s.

I ran 8 and 6 ohm speakers with an Onkyo 707 until I got the VP160.

Nikon, I haven't heard of anyone having issues with 8 ohm QS8's and M80's up front(as I have). I'm running M80's, VP150 and QS8's which are rated at 4 ohm, 6 ohm, and 8 ohm respectively, through a mid level Denon. I know there's a few guys here with Onkyos and similar setups, and fancier. I haven't heard of any issues reg mixing ohms, but hopefully those owners can chime in at some point.

NikonShooter,

Those articles have all the relevant information for this discussion.

Impedance is not constant on a loudspeaker. It varies with frequency. So when you start to hook up two different models of speakers (even if they are the same brand) you will be mixing impedances at pretty much all frequencies. The rated impedance of a speaker by a manufacturer if its 4, 6 or 8 ohms means pretty much nothing.

To get an understanding how well a particular receiver will play with a speaker you would need to know the impedance and corresponding phase angle at each frequency. Speaker efficiency is another key factor, listening distance and SPL all matter too.

Well, I contacted Axiom and they couldn't help me. That was the very first thing I did. So, if they've said it here on this forum, I'd appreciate it if you'd direct me to just exactly where that is. Second, I don't think it would be very practical to use M80's for all channels now, do you? Surely you're not serious. I've got a big AV room ... but not that big. (I'd say there might be some audio problems associated with turning an M80 on it's side to use as a center channel speaker, too. ) That's one of the reasons I wanted to swap out the Infinity's in the first place. Third, just because you have never once heard of a receiver or speakers being damaged by mixing impedance, doesn't mean it hasn't happened. Indeed, for most folks maybe discretion has been the better part of valor. Fourth, it is incorrect for you to assume that I'm not inclined to listen to what you perceive as non-experts on the internet. As I already mentioned to you, I wasn't looking for advice. I was simply stating what I had found out from Onkyo (not Axiom) as I was trying to decide on the M80's. And that was posted here on this forum to perhaps help the original poster in some way.

That being said, show me someone who has been doing what I describe, with the Onkyo TX-N5009 ... doing it for some time with no problems whatsoever ... and Axiom just might sell another pair of M80's.

Well, it really doesn't you know. And,I'm well aware that impedence is variable over the course of the audio material being presented.

When it comes to receivers, it is high current(low impedance) demands that can potentially put AVR's into protection mode. So if anything adding multiple speakers rated the same at 4 ohms could be potentially problematic over one set of speakers rated at 4 ohm and one rated at 8 ohm.

If you want to limit the power capability of your Onkyo and play it paranoidsafe, please go ahead and set the switch as Onkyo recommended.

It's actually the opposite. The most likely scenario that could cause shutdown and overheating issues would be to hook up all 4 ohm speakers to that Onkyo. Even then it would be still dependent on how efficient the speakers are, the SPL at the listening distance, the source material being used and how long high SPL's are sustained.

He was giving advice not wanting it from what I gather.

Just FYI, I have heard a setup with 5 M80s, 2 QS8s and an EP600. It was rather staggering. Dude was powering it with 5 Parasound amps, as I recall.

That said, he was having shutdown issues originally (with Outlaw amps) because of how loud it was (>115dB) and the fact he was running 5 4 ohm speakers, not because he mixed 4 and 6 ohm.

Shooter, welcome. The response you got from the Onkyo rep is total nonsense. He apparently was trying to interpret what the manual suggested, but he had no understanding of the technology involved. If there was a problem with using speakers with different impedance ratings simultaneously(there isn't)using 4 ohm with 8 ohm would be less of a problem than using 4 ohm with 6 ohm. The point is that the overall net impedance, taking all the speakers into account, determines the amount of current used at a given volume level.

There are no problems with lesser units than your 5009, and you certainly should experience none. In any case, keep the impedance setting at the default higher number, since setting the lower one simply restricts the amount of voltage available from the receiver's power supply section. This results in limiting current and power available(following Ohm's Law)and reduces the chance of overheating, but at the expense of limiting maximum performance capability(tests show that the lower setting cuts maximum power output roughly in half).

I know someone personally who is running M80's, vp150, and qs8's on an Onkyo 1009 and as far as I know has never had a problem. If your that worried get an XPA 5.

Grunt on the forum runs the 3007 with heights as I recall and he has 3 M80s across the front with QS8s for surround, rear and height channels, this would be as close as possible to the 5009 I have heard of on the forum.