What happens when I combine 4ohm speakers with an 8 ohm amp?

[Madcowz]

I hear this degrades sound a bit... does this hold truth?

 

[gerbz]

If your amp specifies 8 ohm loads, It may overload, overheat, and if lucky, shut itself down if you play it too loud for too long into 4 ohm speakers. Any degradation of sound quality is just the amp slowly sizzling itself.

You could put a 4 ohm resistor(non-inducting) in series with each speaker to bring it to 8 ohm and insure a longer life for your amp.

 

[A2KLAU]

Basically when the sound starts to go wrong, its time to turn the volume down or the thing could blow, unless if it has one of those safty cut off things built in.

Good Luck,

Albert. (SKY)

 

[BA]

Don't do it! I've got a dead amp sitting at home right now...

Adding a 4 ohm resister in series will work, but it'll halve the power the speaker's putting out. You'll just be dumping half your amp's power into heat.

 

[BigLance]

OHMs refers to Impedance, the lower the impedance the more of a direct short you have, so 4 OHMs puts a harder load on the amp. It will usually make the amp put out more power than it does at 8 OHMs which sounds like a good thing but its not, it can damage the amp permantly and will also put out more disortion...

If you wire the subs/speakers in series it will bump the load to 8OHMs, however that would become MONO and unless your running just subwoofers Mono sucks...

 

[lotust]

dont do it beavis J/K but really you will heat that amp up

if you have an 4 ohm amp you can drive 8 ohm speakers not the other way around though.

 

[dee]

Have been using a pair of B&W 4ohm speakers with an 8ohm technics amp for the past 4 years - use it probably 4hrs/day during that time. Sound is absolutely fine given the level (low end) of the system & have never had any probs. The amp does though have a breaker circuit which cuts the speakers if they're driven too hard, so I'd advise you to watch the vol levels.

If you look through the hifi mags you'll see speakers rated 4-16ohms & so long as you careful not to push volumes if power ratings are not perfectly matched you should be fine (low ohm speakers could damage amp & high amp speakers driven too hard may blow).

Bare in mind though, that if the amp has very low power output it may not be able to drive the speakers too well.

 

[Workin']

Many amps are perfectly capable of driving nominal 4-ohm loads with no problems or degradation. In fact, the load a speaker presents to the amplifier is not so simple as 8 ohms or 4 ohms. The impedance of a speaker is reactive, and it varies with the frequency of the input signal. So an "8 ohm" speaker may in fact really present a load ranging from under 3 ohms to over 20 ohms, depending on frequency.

So, unless the manufacturer of your amp specifically forbids using 4-ohm speakers, you should be fine and suffer no ill effects.

 

[klod]

Fire and brimstone coming down from the skies! Rivers and seas boiling! Forty years of
darkness, earthquakes, volcanos, the dead rising from the grave! Human sacrifice, dogs and cats living together... mass hysteria!

-or-

When you connect a speaker with a high impedance rating to an amplifier, the speaker "pulls" current from the amp. When you connect a speaker with a low impedance rating, it will pull more current. Connecting a 4-ohm speaker to a given amplifier will draw twice the current from that amp as connecting an 8-ohm speaker to the same amplifier would. Amplifiers that cannot handle this doubling of current demand from speakers have speaker impedance switches with a setting for 4-ohm speakers and another one for 8-ohms. This switch is nothing more than a current limiter (in the 4-ohm setting) that prevents the amplifier from frying itself when trying to provide current to a 4-ohm speaker above its capability. Naturally this also limits the output power of the amplifier (as well as dynamics, etc.). This risk of overtaxing an amplifier with too high a current demand from the speaker only becomes significant at high listening levels. At moderate levels, the amplifier will be operating at much below its maximum capability anyway, so a doubling of the current demand would not be likely to push it past its limit. Technically speaking, of course...

 

[TravisBickle]

LOL
liked the bit about dogs and cats living together

 

[Auric]

Smells like Bill Murray.