Is there anything wrong with running 4 ohm components up front with 2 ohm coaxials in the rear to an amplifier that is both 4 ohm and 2 ohm stable?

 

It's not a problem. This being said, have you considered not installing the rears? Music is recorded in stereo, meaning 2 channels that culminate in a 3-dimensional image.

 

By design the 2 ohm speakers will be louder. So, just adjust the gains according to what ever is level to you.

 

...huh?

 

Compared to the 4 ohm speakers!?

 

Short answer - No

Longer answer:

It's a numbers game played by the car audio industry.

2.83V @ 8 Ohms = 1w
2.83V @ 4 Ohms = 2w
2.83V @ 2 Ohms = 4w

As can be seen above, nothing changes other than the power needed to drive the speaker to a given level of amplitude. The car audio industry uses this property to sell folks on amplifiers making more power as the speakers' impedance drops. However, and this is a HUGE however, no amplifier is a perfect voltage source. As such - with lower impedance speakers - we have a system that doesn't actually play as loud at the same level of distortion, a system that hits its limits quicker, and a system that needlessly sucks current from the car's electrics.

On a personal level, I have a lot of problems with the car audio industry, mainly, because it constantly tries to deceive the consumer and because it offers shamelessly horrible gear to boot. If you really want to learn about audio, look to ANY other audio discipline. It doesn't matter what it is. Sure, High-End tends to be more technically sophisticated, as opposed to HT and Pro, but the basics remain the same. Audio is a science, but the numbers are the least of it. We, as humans, are equipped with the best audio detection device ever devised. Our ears. Use them.

 

So the 4 ohm speaker and 2 ohm speaker will sound the same when an power amplifierwith equal gain is applied?

 

What FJF is trying to tell you is that there are a whole mess of variables that will affect how loud the speakers will be. You can't just say a 2ohm driver will play louder than a 4ohm driver. It's much more compacted than that. Might you get more volume out of a 2ohm driver? Maybe, may be not. If so its probably at the cost of sound quality and a siphoning of your electrical system.

 

^^^ Much better explanation than the one I edited out. Thanks!

 

I too get frustrated with the car audio industry and those that often fall for the gimmics. I think the OP had a legit and sincere question and I am in the holiday spirit so my explanation was Letter to Santa worthy if you follow me?

 

Just to be clear, I'm the OP and the volume question did not come from me.

But thanks everyone for the feedback and happy holidays.

 

They will not sound the same, because when the amplifier senses 2 ohms, it will result in higher current draw and more power output. Therefore, your coaxials will get driven more WRMS than the ones at the front.

 

Then there's the second part to this. At 2 Ohms a speaker needs twice the power to reach the same amplitude. As no amplifier is a perfect voltage source, the sound level may actually be lower (all thing being equal). That's what I tried explaining above. An amplifier's input sensitivity is typically higher at 2 Ohms giving the illusion of sounding louder. Once we figure in gain, as well as the distortion component, everything falls back into place.

 

You will get typically double the power from the amplifier when you change the load from 4 ohms to 2 ohms. Most amplifiers make full power at 2ohms. Always match the amp to the speakers accordingly.

 

It doesn't seem like you understood anything that was said.