witHonor

Right now I have a very cost efficient amplifier, a Crunch PZi 250.2 that says it can run 250x2 @ 4Ohms and 500x2 @ 2Ohms, powering two eD 7Kv.2's D4 subwoofers. The amplifier doesn't have a switch or button that makes it run at 2 or 4 Ohms, so my assumption, and I hate to assume, is that if I wire these subwoofers in parallel they will create a 2 Ohm impedance and therefore the amp will, at max settings, run 500watts RMS to each speaker automatically. Is this correct?

That is my exact situation right now, but in general, an amplifier will create an output within its capabilities based on the speakers acceptance and how it is wired?

Now, if I wired the subwoofers in series, that would create an 8 Ohm impedance and the amplifier isn't capable of that, so it wouldn't sound great? Will an amplifier put out different Ohms to each channel? I had both subwoofers running in series to begin with because I didn't completely understand the diagrams I saw. I changed one to be parallel and left the other in series and it didn't seem to make much difference, both still sound the same.

These subwoofers sounded better when everything else was stock. Now, because the 7Kv.2's were making the stock stuff sound inadequate, I have an Alpine 9885 head unit, JL Audio VR650 CSi components in the doors, the eD 7Kv.2's in the sail panels, and JL Audio VR650 CXi coaxials in the back. These are powered by the Crunch PZi 250.2 to the 7Kv.2's and a Crunch PZi 100.4 to the others. Should I just give up on the eD's and get a "real" subwoofer? I'd hate to do that because they sounded great before. Are the other parts of my system now overpowering the 7Kv.2's? My thought is that I should just move the VR650 coaxials to the sail panels and add a JL 10W6v2 powered by the 250.2, for now, that can put out 500watts RMS @ 2 Ohms, and take the 7Kv.2's out completely. According to the specifications of the amplifer, it could power two W6's...Is that correct?

Thank you for taking the time to read my post. If you can answer one or all of my questions, I'd certainly appreciate it.

WhiteBird00

iTrader: (4)

You have to understand amps don't "put out" ohms. Think of a direct currrent circuit consisting of a battery and a light. The filament in the light bulb introduces a certain amount of resistance into the circuit that the current flows through. If you add a second light the resistance doubles, the current flow is cut in half, but both lights still illuminate. The battery doesn't "care" whether there is one or two lights connected. On the other hand, if you remove the lights and just run a wire across the battery, the lack of sufficient resistance (short circuit) will cause too much current flow and either melt the wire or damage the battery.

Audio is more like alternating current so the "resistance" is called impedance but it's still measured in ohms. The speakers you connect to the amp provide the impedance or load for the amp to push current through. Amps are rated for their impedance handling because reducing the load increases the current flow causing more heat generation. An amp is designed to flow a certain maximum amount of current so if you use speakers with too little impedance the amp could heat up and suffer damage.

The amp doesn't have to do anything to adjust for different speaker impedance - it's just the nature of electricity. If you replace a 4-ohm load with a 2-ohm load, the current flow (and hence the power output) will just increase without any adjustment on the amp.

So, to answer your specific questions...yes, you should wire the subs in parallel to produce a 2-ohm load because you'll get maximum power that way. The amp will output to that load automatically with no settings or adjustments necessary. The amp is perfectly capable of outputting to an 8-ohm load but the power would be reduced accordingly so there would be no benefit. And yes, an amp will put out different power to different loads on separate channels. Again, it's not the amp "doing" anything, it's just the mathematics of electricity.

The eD subs are only 6.5" so they aren't capable of moving the air volume that larger subs can. They are great for replacing the factory 6.5" subs but when you start doing more system upgrades you will probably appreciate a bigger sub. Whether or not you put full range speakers in the sail panels is a matter of personal taste.

witHonor

Clarified, thanks Whitebird00.

Your response made things much clearer for me, I appreciate it.

The 7Kv.2's were awesome when I simply swapped out the sail panel speakers. So for anyone reading this and not wanting to do a lot to make a great improvement on bass, they are an excellent choice. Once I changed everything else though, they were just good.

I just finished my install and put the interior back together. As it stands now I have:

Alpine 9885 head unit
Crunch PZi 100.4 powering...
JL Audio VR650CSi components in the doors and...
JL Audio VR650CXi coaxials in the sail panels/backseat
Crunch PZi 250.2 powering...
Boston Acoustic G51044 subwoofer in the trunk

I chose this subwoofer based on the recommendation of the guy at the stereo shop I've been going to. It's more than a JL W6 and almost, if not, a W7. From the short amount of time I pushed it, at 2am, I am very happy. Right now it's in a sealed box where the t-tops go. I'm either going to make my own enclosure or get a subthump stealth box. In the future when these amplifiers die or I have an extra $850 I will get something better, but for now they are doing a great job.

Thanks again Whitebird for the education, and thanks to those who have asked questions and answered them before mine. Time to move on to the next projects. I have some NGK spark plugs to go in, an Eibach Pro-Kit to install, and a Spec Stage 3 clutch with a Fidanza aluminum flywheel to replace the "slowly showing signs of dying" LS6 stuff.