Paging stereo bods

I wouldn't worry, or at least try it without first.

Yeah, it's efficiency not impedance that determines the oomph/ouch ratio. All the 6ohms means is that if you try to drive them near full blast with an amp that can only cope with 8 ohm speakers, you risk frying the amp or possibly the speaker coils.

If they are efficient speakers and you have a decent head unit, try it driving them direct.

If you need/want an amp, then anything rated to drive speakers of 6 ohms

*or lower* will be fine. A 4 ohm amp will be quite safe driving them.

For the technically minded (setting myself up for a fall here, but what the hell...) what happens is that to get a certain power from the speakers the amp pushes a certain current through the speaker coil. A current through an impedance means a voltage is developed across it. At the extremes, one of two things happens:

- the voltage raises so high the amplifier can't take it and breaks down internally.

- the amp runs out of more volts to give it and clips. This puts a DC waveform across the speaker coil (effectively a short circuit with DC driving it) and melts it fairly rapidly.

As you can imagine, neither of these are good things.

With 6 ohm speakers and a 4 ohm amp, the developed voltage can never get as high as the maximum design voltage, so you're safe from both of these problems.

(Sits back and waits to be shot down...)

Me too. IIRC, most head units are rated for 4 ohm speakers, so won't be harmed by driving 6 ohms, so I'd try it and see if it goes loud enough for you - then install an amp if it doesn't!

Even if the headunit is rated for 8 ohm speakers, unless you drive it essentially flat out then you aren't going to damage it.

Normally the amps operate in a voltage gain mode - in other words they set the voltage, and the current follows according to the impedance. At the extreme, the current drawn becomes too high and the output transistors overheat and die.

It's not that you get a DC term exactly, but you do get essentially a square wave, and the RMS power of a square wave is twice that of a sine wave of the same amplitude, so the speakers have to dissipate twice as much as the rated RMS power[1] of the amp and, as you say, tend to melt.

If your speakers are rated at a maximum continuous power handling of more than twice the rated RMS output of your amp, then they are safe.

[1] el-cheapo amps tend to have thier RMS power measured when they are clipping, because it gives a power figure of twice the real power. It would sound awful if you used it that way, but it is technically true, I suppose. Best bet is to look for amps which quote the rms power at

Hehe. Er. gadda-gadda-gadda?