Power Hungry Speakers

[NOHDjunkie]

Won't a 4 ohm load on a 16 ohm amp KILL the amp even with a 12 ohm resistor in series?

I have been looking for the thread titled "Why 4 ohm loads stress your amplifier" but cannot seem to find it.

The amp in question is rated for 16 ohms only when bridged mono.

 

[whoaru99]

The amp in question is rated for 16 ohms only when bridged mono.

But, just by nature of that, it implies that 8 ohms stereo is the minimum impedance.

16 ohms bridged = 8 ohms per channel stereo
8 ohms bridged = 4 ohms per channel stereo
4 ohms bridged = 2 ohms per channel stereo

 

[NOHDjunkie]

But, just by nature of that, it implies that 8 ohms stereo is the minimum impedance.

16 ohms bridged = 8 ohms per channel stereo
8 ohms bridged = 4 ohms per channel stereo
4 ohms bridged = 2 ohms per channel stereo

Just repeating what the OP said in his original post.

 

[Westy56]

For Magnepans to image correctly, you need to have the dog lie in a straight line between the speakers. I thought this was common knowledge...

I had the speakers pointed towards friends sitting at a table. It was the only way everyone could get a decent listen.

Moving Coco between the speakers did help with imaging. Thanks for the tip.:thmbsp:


Steve

 

[PioneerGuy75]

The resistor becomes part of the load. With the 12 ohm resistor in series with the 4 ohm speaker, it presents a 16 (12 + 4) ohm load to the amplifer.

But, as I understand it, the resistor is fixed resistance. The speaker impedance is not.

Am I correct?

 

[whoaru99]

Yes, that's correct, but the amplifier still sees the sum of the speaker impedance and the resistor's resistance regardless of any variance in the speaker's impedance value.

So, say the speaker drops to 2 ohms, you'd still have 14 ohms load on the amp which is quite likely close enough to 16 ohms. However, it's still a waste to burn up all that power across the resistor. You'd be better off just to use a lower powered amp with the speaker than burn up the excess in a resistor because the resistor also totally screws any damping factor that you'd hope to maintain.