Receiver Selection/Question

[gus_mp]

First off, I'm not great with the lingo so please excuse me if I say something wrong. I'm pretty ignorant with this stuff.

I recently installed one speaker which has a dual coil inside and two seperate speaker connections. Each coil is rated at 100w X 8ohms. The speaker also has a setting u can switch between 8 and 16ohms.

I set the speaker to 16 ohms, plugged the wires into my receiver and turned everything on. All was going well until halfway through a song when the protect feature kicked in on my receiver. I turned the volume down to give less voltage and everything was fine until about 4 min later when the protect feature kicked on and now the receiver won't work. It's an old Sony receiver that is rated 100w per channel at 8ohms.

Where did I go wrong with the connections? (I do have another volume switch built in the wall). What should I look for in a new receiver since I hope to buy one in the very near future?

 

[Seth=L]

It will not operate safely in 16 ohm, you need to bring the impedance to a more managable level for the receiver (it needs to be around 8 ohms).

 

[gus_mp]

I'm probably dumb since I'm missing something here. I do understand now that it should be at 8 ohms, but why would the receiver get shot with more resistance. Would the sound quality just be a lot weaker?

 

[Seth=L]

I'm probably dumb since I'm missing something here. I do understand now that it should be at 8 ohms, but why would the receiver get shot with more resistance. Would the sound quality just be a lot weaker?

The amplifier is like a pump. It is pushing power into the speakers, but the high resistance acts as a bottleneck. It is more strenuous for the amplifier and since it has protective circuitry it shuts off before serious damage is done. Beware that the safe mode is for protection, and that the receiver could still be damaged by intense loads such as the one described.

 

[no. 5]

What does the impedance look like to the receiver? If you have a multi meter you could unplug the leads from the receiver and measure the resistance there. I have a suspicion it's the volume control in the wall that is causing the problem.

There is no way that I can think of that would cause a receiver to go into protection mode when powering speakers of higher impedance than specified.

 

[mtrycrafts]

I'm probably dumb since I'm missing something here. I do understand now that it should be at 8 ohms, but why would the receiver get shot with more resistance. Would the sound quality just be a lot weaker?

As no 5 indicated, ordinarily a 16 ohm speaker would not cause this problem but what you think would happen, less volume. But, you have an in-wall volume control so that is affecting your setup somehow. You may need to do some resistance measurements of the speaker setup through the wall switch at the amp wire pair with it unplugged from the amp and see what the resistances are at different setting, both on the speaker and with the wall volume over its range of settings. I think you will find the answer, too low resistance.

 

[nick1000000]

The amplifier is like a pump. It is pushing power into the speakers, but the high resistance acts as a bottleneck. It is more strenuous for the amplifier and since it has protective circuitry it shuts off before serious damage is done. Beware that the safe mode is for protection, and that the receiver could still be damaged by intense loads such as the one described.

Actually the higher the resistance the better it is for the amp. Since the voltage and current are in sync with each other is a resistor the amp has no problem with the resistor. It just takes more time for the current to travel around making the amp not work as hard to pump current into it. At low resistance the amp has to pump current a lot faster into the speakers.

 

[Seth=L]

Actually the higher the resistance the better it is for the amp. Since the voltage and current are in sync with each other is a resistor the amp has no problem with the resistor. It just takes more time for the current to travel around making the amp not work as hard to pump current into it. At low resistance the amp has to pump current a lot faster into the speakers.

Thank you, I learn something new every day.

 

[mtrycrafts]

Thank you, I learn something new every day.

Well, I don't think the speed of the current depends on resistance

Higher resistances in line with the amp speaker terminal will reduce the current available to the speaker or in the speaker. Do some calculations with Ohm's Law both current and power.