Axiom Home Page Forums General Discussion Technical Questions What happens when you mix ohm loads in a 5.1 setup

I admittedly know next to nothing about home audio. Is it wiser to choose a setup of fronts + center + surrounds that all share an equal ohm load, like 8 ohms, or is it okay to mix ohm loads, like 4 ohms for your fronts and 8 for everything else? Do funky things happen when you adjust the volume dial?

First, don't worry so much about the impedance rating of loudspeakers.

And second, the setup routines in surround processors allow you to "trim" the individual volume levels for each channel. In fact, most modern receivers do this for you automatically with the use of an included microphone. Once the channel trims are set, the main volume will adjust all the speakers equally, keeping them at the same level.

You can mix the ohms, whenever I was running M80s, VP150 and QS8s for my system, that was a mixture of 4 (M80s),6(VP150) and 8 ohms(QS8s) ... as long as you have an AVR or amp(s) that is rated for 4 ohms you should be fine.

Hi Artisan,

Matching 8 ohm or 4 ohm specifications is meaningless. In fact it is impossible. Loudspeaker impedance is not constant and varies with frequency. For example if you look at the impedance graph of the M80 it ranges from 9ohm to almost 10ohm between 1k - 1.5k and dips as low as 3.2 ohms at 20 hz. 8ohm or 4ohm stated in manufacturers specifications is more or less an average.

http://www.axiomaudio.com/gallery_disp.html?image=M80-imp.gif&title=M80

The only thing you have to be careful with in regards to impedance is impedance minimums (below 4 ohms) and those occurring in the lower frequencies as that is what causes receivers or amps to go into current limiting/overheating.

Most of that information goes over my head with my current level of understanding. The takeaway message there that I'm picking up is that it doesn't matter and I shouldn't worry about it. Is that an accurate distillation?

What receiver do you have?

Nothing! Ha!

I'm looking at my first set of speakers for a 2.0 or 2.1 stereo setup for music first, with a desire to eventually upgrade that to a 5.1 home theatre. Music is my primary directive. I'm looking at a receiver in the ~$500 range. The one that stood out to me is the Onkyo TX-SR608.

Onkyo TX-SR608

That receiver should be just fine with any combo of Axiom speakers. Be sure to leave the ohm setting switch to 8 ohms and you should be good to go.

What speakers are you planning to get?

I don't know, yet. I'm being pulled every which way, but I keep returning to a starting point of a pair of M60s in 2.0 and eventually working my way up to an Epic 60 + 350 or 500, but I haven't ruled out M22s or M80s, either. Might even end up with M3s. No idea at this point. Gut instinct tells me M60s.

For the speakers you are looking at no it doesn't matter. On the other hand if you tried to run 5 M80's off that AVR then yes the low impedance posed by each of them would be a problem and you would need an amp with a beefy power supply.

Arti, yes that's an accurate distillation. Any receivers of the quality that we would seriously consider(certainly including the Onkyo which you're considering)can drive any of the Axioms to beyond safe(to your hearing)listening levels. Rated speaker impedance(which in actual practice fluctuates widely at different frequencies)shouldn't be a matter of significant concern.

Arti, to help nail down the 'sound/speaker' you are looking for I am wondering if you like a good midrange/better detailed sound or something more laid back?

Jake, I'm looking for a full-range sound with a smooth, linear response from the lowest to the highest frequency my ears can hear. At the same time, I want detail. Specifically, I want instrument separation. I want to be able to pick out every instrument without all the instruments getting muddled together.

I wouldn't say I'm looking for "midrange", per se. Rather, I'm looking for everything. I found my way to Axiom because while I want high-quality audio, I don't want to pay a hundred-thousand dollars to get it.

If a speaker exists that plays back +/- 0 db from 0 hz to infinity hz, that's what I want. Not sure I can afford it, though.

The Revel Salon 2 has a listening window of 26Hz to 20kHz ±1.0dB at a price of $20,000/pair.

If you go with the normal ±3 the Salon2s go from 23 Hz to 45 kHz.

Some people dream about striking it rich and buying super cars. If I found a couple million the first thing I'd do is buy a complete set of Ultima2s.


...and then get a Ferrari 408.

This 408? Or did you mean something else, 'cause damn, that thing is ooglay.

The M80s offer the best detail, the M60s and M22's would be next on my list and a re very close to the M80. You could start with the m22's and see if you like the 'Axiom sound' this way if you don't like them it is cheaper to ship them back, if you do like them you can return them for the M60 or 80's. (Axiom pays shipping when 'upgrading' to a more expensive speaker)

I wasn't sure of the model, as I had just heard about the car. My Google Fu failed me. It should be the Ferrari FF.
http://pictures.topspeed.com/IMG/crop/201101/ferrari-ff-awd-sport_1600x0w.jpg

Not the prettiest, but I'd drive it in winter.

At least that's prettier...

Looks like it has hip dysplasia.

Makes me think of the BMW Z3 coupe.

That Ferrari looks like a stretched Mazda 3, to me.

Hi Artisan,

Here's a link to a precise explanation of impedance curves, which appeared in the last Axiom AudioFile newsletter (Jan. 2011). Scroll down to the Question of the Month:

http://beta.axiomaudio.com/archives/January2011.html

Regards,

Alan

I'll second that. Is that car from this century? The Ferrari designers fell asleep on that one.

Look at the 80s' supercars, they are all boxes. Except for Porsche, they look the same then as they do now.

962CR?