4 Ohm vs. 2 Ohm series/parallel

[Epmes]

I've just installed a Kicker 400.1 amp and have to make some choices.

At 4 ohms, the Kicker amp will put out 150 watts per channel. That "per channel" is what's killing me. At first I split the audio signal and was running four wires from the amp to the dual voice coils, two per channel/coil, so 4 ohms per channel. BUT my speaker, the CompRT 6.75", says it can only handle 150 watts TOTAL power. Not per channel.

If I go with a single channel and wire the 4 ohm Kicker in parallel, this results in a 2 ohm load. With my amp, that's 300 watts and I've killed my speaker.

If I go with a single channel and wire the 4 ohm Kicker in series, this results in an 8 ohm load. With my amp, that's 75 watts and I've killed volume.

So the question is, should I go with a 2 ohm Kicker speaker in series? This would be a 4 ohm load, hitting 150 watts and the recommended power for my speaker.

I happen to have a 2 ohm Kicker on hand, but didn't want to do this if my assumptions are wrong. Please check me on these? Thank you all!!

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[thepear]

It doesn’t matter if the channel maximum output is 300W RMS output and the speaker is only 150W RMS. You will be using Ohm’s law when setting the gain to ensure you are not overpowering the subwoofer. Plus it helps take load off the amp not running it at max output.

You will need a multi meter set to AC voltage reading. Check this link out too.
https://www.bcae1.com/ohmslaw.htm

Edit- Also to clarify, you will be using the subwoofer’s values when calculating ohms law, do not use the Amps information.

 

[timhood]

I've just installed a Kicker 400.1 amp and have to make some choices.

At 4 ohms, the Kicker amp will put out 150 watts per channel. That "per channel" is what's killing me. At first I split the audio signal and was running four wires from the amp to the dual voice coils, two per channel/coil, so 4 ohms per channel. BUT my speaker, the CompRT 6.75", says it can only handle 150 watts TOTAL power. Not per channel.

If I go with a single channel and wire the 4 ohm Kicker in parallel, this results in a 2 ohm load. With my amp, that's 300 watts and I've killed my speaker.

If I go with a single channel and wire the 4 ohm Kicker in series, this results in an 8 ohm load. With my amp, that's 75 watts and I've killed volume.

So the question is, should I go with a 2 ohm Kicker speaker in series? This would be a 4 ohm load, hitting 150 watts and the recommended power for my speaker.

I happen to have a 2 ohm Kicker on hand, but didn't want to do this if my assumptions are wrong. Please check me on these? Thank you all!!

I looked up the specs on your sub. It's got dual 2-ohm voice coils. Run a wire from the positive connection of the first channel on the amp to positive connection on the first terminal. Bridge negative on the first terminal to positive on the second terminal. Run a wire from the negative connection of the second channel on the amp to negative on the second terminal. I've assumed your amp is a two-channel amp.

 

[Epmes]

It doesn’t matter if the channel maximum output is 300W RMS output and the speaker is only 150W RMS. You will be using Ohm’s law when setting the gain to ensure you are not overpowering the subwoofer. Plus it helps take load off the amp not running it at max output.

You will need a multi meter set to AC voltage reading. Check this link out too.
https://www.bcae1.com/ohmslaw.htm

Edit- Also to clarify, you will be using the subwoofer’s values when calculating ohms law, do not use the Amps information.

Update: Kicker said that gain is just an input, and doesn't effect the power of the output. The manual literally reads "The input gain control is not a volume control. It matches the output level of the source unit to the input sensitivity of the amplifier. Maximum power out of the amplifier is possible with the gain in the lowest position."

Kicker suggested wiring the 2 ohm speaker in series, and then adjusting the gain using a multimeter. Apparently 24.5 volts using their test tone is what I want.

I'll give this a go tonight, after work.

 

[Epmes]

Results: I’m quite happy. I used the 2 ohm Kicker sub, wired in series to present 4 ohms of resistance to the amp. Dialed in the gain, then cranked the bass.

It’s not “rattle the windows” loud, but it sounds GOOD. With the Polk Audio upgrades I did for the other six speakers, it’s really good.

My biggest problem was that the 2 door panel didn’t fit back over the amp; it’s a little too big. It’s a matter of less than an inch, though, so I may just take a heat gun to it. I did get the panel back in place but a couple of the snaps don’t quite fit. Pulling it all out and re-rigging the amp is the right answer, but I’m ready to be done.

 

[CalvinT]

You're overthinking this.

The difference between 150 watts and 75 watts is 3dB. That's barely audible.

https://www.e2s.com/references-and-...se of 3,determined by several complex factors.



Also according to Kicker your speaker can handle 150 watts RMS, 300 watts peak. You never listen at that level. Never. Usually your amp will be putting out 15 watts or less for normal listening levels. Your speaker won't burn out the instant your amp puts out 150 watts.

https://www.antarestech.com/community/a-beginners-guide-to-dynamic-range-in-audio-production

Stereo salesmen either don't know this, or ignore it. They'll tell you there's a difference between 75 watts and 100 watts. A meter can measure the difference, your ears can't hear the difference. But you'll be spending more money for something you can't hear. If you do an A-B test you will hear the differnce between 75 watts and 150 watts, barely.

Our bodies have a logarithmic response to sound, light, pain, even percieved distance.

edit: I just read your last post. Seems you discovered what I just said. Also since your amplifier isn't being pushed as hard, you probably have a little less distortion.

 

[Area51BS]

You're overthinking this.

The difference between 150 watts and 75 watts is 3dB. That's barely audible.

https://www.e2s.com/references-and-guidelines/db-decibel-ratings#:~:text=Although an increase of 3,determined by several complex factors.



Also according to Kicker your speaker can handle 150 watts RMS, 300 watts peak. You never listen at that level. Never. Usually your amp will be putting out 15 watts or less for normal listening levels. Your speaker won't burn out the instant your amp puts out 150 watts.

https://www.antarestech.com/community/a-beginners-guide-to-dynamic-range-in-audio-production

Stereo salesmen either don't know this, or ignore it. They'll tell you there's a difference between 75 watts and 100 watts. A meter can measure the difference, your ears can't hear the difference. But you'll be spending more money for something you can't hear. If you do an A-B test you will hear the differnce between 75 watts and 150 watts, barely.

Our bodies have a logarithmic response to sound, light, pain, even percieved distance.

edit: I just read your last post. Seems you discovered what I just said. Also since your amplifier isn't being pushed as hard, you probably have a little less distortion.

This is very good advice. Only thing I will add is a speaker will be happier being overpowered to a point with clean un distorted power vs being run on a low power amp constantly running in a distortion state. Lots of bad things are happening at this point. More so with mid/high frequency speakers. But same none the less.

 

[CalvinT]

This is very good advice. Only thing I will add is a speaker will be happier being overpowered to a point with clean un distorted power vs being run on a low power amp constantly running in a distortion state. Lots of bad things are happening at this point. More so with mid/high frequency speakers. But same none the less.

That's true. In the situation you describe the amplifier can start clipping. That generates a lot of high frequency harmonics with enough power to burn out high and maybe mid frequency speaker coils. Any time you hear audible distortion you're risking speaker coils. What's ironic is it's the lower frequencies that are being clipped since they demeand the most power from the amplifier.

 

[Area51BS]

That's true. In the situation you describe the amplifier can start clipping. That generates a lot of high frequency harmonics with enough power to burn out high and maybe mid frequency speaker coils. Any time you hear audible distortion you're risking speaker coils. What's ironic is it's the lower frequencies that are being clipped since they demeand the most power from the amplifier.

Another reason full active is better than passive crossovers. You relieve amplifiers from reproducing frequencies not intended for the drivers they are hooked up to. Less damaging to those higher frequency drivers.

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