Axiom Home Page Forums General Discussion Technical Questions 4 ohm towers Hooked to 6 ohm amp

Another explanation.

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."

And another reason.

Because we say so

As I said, if you think your amp can handle it, go for it. Want to roll the dice and take a chance at blowing your amp or speakers, go for that too.

If you want to do things the "right" way, get an amp rated for 4 ohm load.

By the way, I can detect clipping with my Denon 3806 when I play it loud. It's severe (to the point that I am damaging my speakers) when playing things like William Tell's 1812 Overture.

It's one of the reasons I want a separate amp for the M80s.

What's driving your M80's wid?

I have a Rotel RB 1080 with 330 watts @ 4 ohm. I think it can handle the M80s .

How big is your room?

Note: In order to meet UL requirements, a receiver cannot be rated down to 4 ohms without having this switch onboard.

I don't know of any Denon's that have this switch, but they have certainly proven to drive 4 ohm loads without a problem. Because a receiver does not have this switch it should not be implied that it cannot drive a 4ohm load. Sure there are some receivers that have problems with 4ohm loads and Axiom has been pretty specific about which ones, personally I'll stay away from the ones that have the switch.

Man you must play it really loud

I know, it was kinda a rhetorical question (Nice amp!) But that is kind of the focus of my point. A couple of the posters here that say it's okay have beefier amps driving the M80's. Nothing wrong with that, I want to do the same...

My room is 2600 ft3, but that has no impact on the amp clipping.

And, yes, I do like to play it loud sometimes.

I kind of figured so, I like posting the power rating. I have been a big advocate of large beefy amps ever since I joined here but I have pretty much been in the minority. It's always been my motto to buy as much power as you can comfortably afford.