Well, California tax sucked but with the promo code, they were cheaper than the other options I was looking at. I forgot to add the free sound deadening kit and when I called, they gladly added it and said my order would be shipped first thing tomorrow. That sonicelectronix.com has some pretty good prices on other stuff too. The plan for now is to see how the Nvx speakers sound with just the Kenwood unit and if I like them but need more power, I may order 2 more speakers and a 4 channel amp. I really just needed to fix 1 blown speaker but since they are sold in pairs, whatever. Now that I got bit by the "upgrade bug," I talking about 2 more speakers, an amp and maybe even a better compact sub. I swear, this is just as bad as computers, music gear and all my other hobbies!

 
Thanks for all the help guys and I will let you know what I think when I get them installed!

nateman_doo
I have been out of the game for some years, but I can tell you find the amp with the largest RMS power, lowest THD, and don't worry about the wattage of the speaker.  I have pushed 4K through a single tweeter for a short while.  My point is a speaker will handle tremendous power, as long as its clean power.  I saw someone mentioned clipping.  That is basically when your speaker output (as seen on an Oscilloscope) looks like square waves, instead of clean sine waves.

Not always the case with a subwoofer (that I know of). I did exactly what you mention above, where I had a 600RMS amp powering a 350RMS subwoofer - at 2ohms. The subwoofer kept clipping, and I had to set it to 4ohms to get the RMS closer to the subwoofer's output. The issue then went away. It could be the subwoofer, yes, but the issue also went away when I took 2 more subwoofers, and drove them with the other subwoofer to get the RMS rating closer to what the amp was pumping out, 600RMS. Not really sure at this point, but my issue with driving the 350RMS sub at 2ohms went away once I hit the switch to drive the sub at 4ohms, which then brought the amp to 400 watts.

stalinx20

nateman_doo
I have been out of the game for some years, but I can tell you find the amp with the largest RMS power, lowest THD, and don't worry about the wattage of the speaker.  I have pushed 4K through a single tweeter for a short while.  My point is a speaker will handle tremendous power, as long as its clean power.  I saw someone mentioned clipping.  That is basically when your speaker output (as seen on an Oscilloscope) looks like square waves, instead of clean sine waves.

Not always the case with a subwoofer (that I know of). I did exactly what you mention above, where I had a 600RMS amp powering a 350RMS subwoofer - at 2ohms. The subwoofer kept clipping, and I had to set it to 4ohms to get the RMS closer to the subwoofer's output. The issue then went away. It could be the subwoofer, yes, but the issue also went away when I took 2 more subwoofers, and drove them with the other subwoofer to get the RMS rating closer to what the amp was pumping out, 600RMS. Not really sure at this point, but my issue with driving the 350RMS sub at 2ohms went away once I hit the switch to drive the sub at 4ohms, which then brought the amp to 400 watts.

The reason for this is that speakers are rated for certain amounts of power based on the spiders/suspension built into it. Clipping doesn't only have to do with "dirty power" (AKA trying to push your amp more than it's rated for), it's also caused when a speaker bottoms out. If you take a sub rated for 350W RMS and pump 600W into it, it might perform fine at a higher frequency (when cone movement is less), but when you start going lower (below 40Hz), that's when the sub has to move further to output the specific frequency. The maximum deviation from its resting position is called Xmax. Try to go past this, you'll get clipping due to the cone literally smacking against the bottom of its suspension OR you get a blowout from the cone trying to push OUTWARD and rip itself off of the frame.
 
If you want a visual representation, check this video out at 2:00 and onward (for difference in cone movement for frequencies): https://www.youtube.com/watch?v=pTlFzMX879c
 
Another example of proof for this is bass competitions. Lower frequency = more cone movement = more air being pushed. When you see "hairtrick" videos, they're not done using a high frequency. Say at 50Hz the cone moves 10mm in either direction. Let's say 25Hz moves 20mm in either direction. That's going to push at LEAST double the amount of air, resulting in a flexing windshield, hairtricks, etc.
 
 
IF you are going to use an amplifier rated for more Watts RMS than your speakers, use a DMM and match the gain with the output of your speakers. You can make a 600W amp push only 300W.
 
Adjusting the gain adjusts the Voltage delivered to the speakers/subs. To find the amount of volts needed, you'd do: sqrt(Wattage of speakers * Load Resistance) = Voltage.
 
If you have a sub rated for 300W at 4 Ohms, you would to sqrt(300 * 4) = Voltage = 34.64V. If you push more than that, you're going to run into issues. 
 
Your headunit may be rated for 50W but is that RMS or peak, and at what impedance? Most times they advertise the peak values and you'll have problems. If it's rated for 50W at 2Ohms and you use 4Ohm speakers, you're only going to see an end result of 25W to each.

its always best practice to match your amp and speaker rms power ratings as closely as possible, you will not achieve the speakers full range if you over or under power it.
you can also cause damage to the speaker running them below and over there rms rating 
 
I have just completed a full install in my Vw Multivan of focal speakers and sub powered by 1 alpine pdr75 75w rms as the speakers are 75w rms its extremely load if wanted but always powerful

fusionssl
its always best practice to match your amp and speaker rms power ratings as closely as possible, you will not achieve the speakers full range if you over or under power it.

 

fusionssl
you can also cause damage to the speaker running them below and over there rms rating 

Over RMS rating, yes. Under, no. In that case, any time you lower the volume you'd risk damaging it. The RMS rating is a "max" kind of like an RPM. Your car has a max RPM of say 9000. You can do anything under it just fine (the lower the RPM though, obviously the less performance - in the audio case it'd be decibels/loudness) but if you go over,
 

SethH

fusionssl
its always best practice to match your amp and speaker rms power ratings as closely as possible, you will not achieve the speakers full range if you over or under power it.

 

fusionssl
you can also cause damage to the speaker running them below and over there rms rating 

Over RMS rating, yes. Under, no. In that case, any time you lower the volume you'd risk damaging it. The RMS rating is a "max" kind of like an RPM. Your car has a max RPM of say 9000. You can do anything under it just fine (the lower the RPM though, obviously the less performance - in the audio case it'd be decibels/loudness) but if you go over,
 

Nope. RMS is just pointer, it depends on many things like mostly enclosure.

Mkkari
Nope. RMS is just pointer, it depends on many things like mostly enclosure.

If you run a speaker/sub out of its rated RMS range, you void warranty. If you run an amp below its rated Impedance, you void warranty.

Of course you can go higher than what it's rated for. If you have a huge sealed box, you can't do nearly as much power as one that's a lot smaller, etc.

If you have a ported box, then it really comes down to box tuning along with enclosure size.

Then you can get into 4th order, 6th order, bandpass, etc. and things get wonky. If you're not an expert or don't have a lot of experience, stick to rated RMS. And if you're doing any 3 listed above, at that point you probably have AGM batteries, a bigger alternator, big 3 upgrade, etc. anyways and know what you're doing.

SethHIf you run a speaker/sub out of its rated RMS range, you void warranty. If you run an amp below its rated Impedance, you void warranty.

Of course you can go higher than what it's rated for. If you have a huge sealed box, you can't do nearly as much power as one that's a lot smaller, etc.

If you have a ported box, then it really comes down to box tuning along with enclosure size.

Then you can get into 4th order, 6th order, bandpass, etc. and things get wonky. If you're not an expert or don't have a lot of experience, stick to rated RMS. And if you're doing any 3 listed above, at that point you probably have AGM batteries, a bigger alternator, big 3 upgrade, etc. anyways and know what you're doing.

Now we're talking about. We got little bit different warranties while misusage still voids warranty. That goes only to cases that there was no run-in done or adjustments were really bad. Damage contains to spiders, and coils. Spiders ripped and coil is starting to burst.
 
We got little bit carried away, sorry for this. Remember to have nice clean power on everything and voltages up 

how would a manufacturer know if you over, or underpowered their speaker?  you break it its still broke.  If its under the warranty, they will likely still honor it.  - unless you poke a hole in the surround with your cordless drill... come on, we all have done it ;) 

fusionssl
its always best practice to match your amp and speaker rms power ratings as closely as possible, you will not achieve the speakers full range if you over or under power it.
you can also cause damage to the speaker running them below and over there rms rating 
 
I have just completed a full install in my Vw Multivan of focal speakers and sub powered by 1 alpine pdr75 75w rms as the speakers are 75w rms its extremely load if wanted but always powerful

This is exactly what my issue was, and i'm fully well aware of the circumstances that can happen if one was to power a sub well over the subwoofers nominal power; by me powering a subwoofer well over the sub's nominal power, it would clip, as Seth included, it was because i was pushing the sub below 50hz, which i was, with a 600rms amp when the sub is 350rms rating; The subwoofer is not cheap in any way. However, as soon as i switched over to 4ohms, issues solved, bringing the amp to 400rms, even when i pushed the sub and amplifier at below 50hz. The subwoofer i have has a switch to go from either 2 or 4 ohms.