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I own a 1997 Hyundai Accent hatchback. My front speakers are 4", rear 5.25", which limits my amp/power options. I currently own:
1) An Infinity Reference 475a amp. At 4ohms it is 75w x 4 or 180w x 2.
2) A Kenwood KFC-W3011 sub. It is a single-coil, 4ohms, and rated 400w RMS.
3) Four G-series pioneer speakers rated 25w RMS, 120w max.
I don't NEED to use the Infinity amp. In fact, I am considering possibly buying one of these two amps:
--- Alpine MRP-F250... $150 -- The reason why I might buy this is because it is 40watts per channel, which assures me I probably won't kill my speakers. Also, I really like the features (i.e. the crossover knob well marked) and Alpine is a very trusted brand.
--- Rockford Fosgate P400-4... $180 -- Crutchfield is selling these refurbished. It seems like such a great deal that I am compelled to buy it even if I don't use it. However, if money weren't an issue I wouldn't be here, would I? My only concern is that most RFs have a true RMS power output of about 120-150% of their advertised power (one guy who reviewed this one said the birth sheet said 75w RMS x 4!!) and that it would be more power than I needed, like the Infinity amp I already own. Which raises another question...
Should I upgrade my speakers? I have ruled out components, and it seems like the only good quality 4" coaxial speakers that can handle >40w RMS are these... http://www.crutchfield.com/S-HIpntMSPEE2/p_500SPS400/Alpine-SPS-400.html
Also, I don't NEED to use my sub. I was considering taking advantage of this deal and get two p1s415 subs. They are rated at 200w RMS, so this would open up the option for using my Infinity 475a to power them.
The last issue: subwoofer(s) amp. I was considering these:
--- For the KENWOOD sub... $130 - Kicker 08ZX350.2 (refurbished from HifiSoundConnection)
--- For the KENWOOD sub... $190 - Rockford Fosgate P300-2 (like I said, this amp will really push out 350-400watts RMS)
--- For the KENWOOD sub... $170 - Infinity Reference 1600a (would match the 475a, if I used it. on the downside, it is a class D amp and I've heard that AB amps sound better even at low frequencies)
--- if i got the RF subs... $140 - Rockford Fosgate P300-1 (refurbished from Crutchfield)
--- if i got the RF subs... $110 - could buy another Infinity 475a and bridge it (on clearance at Best Buy)
So that makes 15 different combinations. And each one of those combinations makes some sort of financial/technical sense. I'm this close to saying "screw it," maxing out my credit card, and buying every single product that I mentioned. Help!?
Power these sensitive 2-ohm Infinity 4" with your headunit, highpassed by some method at 300 hz, maybe use bass blockers, use foam baffles.
Get a 40 +/- watts rms x 2 amp for these or a 3 way capable amp for sub also.
This is a dandy 3-way capable, very adaptable amp. You can bridge 2 channels to output 2x50 watts RMS @ 4 ohms and 150 watts x1 RMS @ 4 ohms.
You can highpass the coaxials at 150 hz. and lowpass the sub at same freq. Awesome.
Better yet, just power those 4 Pioneers with the headunit, but highpass them so they sound better. Get a bigger mono amp for the sub. MTX has an awesome 500 watts RMS X 1 @ 4 ohms. You can set the lowpass all the way up to 200 hz to blend in with the small speakers better.
Glad to help. Let us know.
Thanks for your response! A few questions:
1) How would I go about using my headunit to power the 4" speakers? I'm assuming they'd get twice as much power, correct?
2) Would 150 watts to the sub give me enough bass in my music? I am not looking for "competition" bass by any means, just enough to fill up the sound. But I have been told that if I'm amping up the speakers, I will probably want 200+ watts to the sub. Is this true or should 150 be plenty?
3) What do you think of these...http://www.crutchfield.com/p_500SPS400/Alpine-SPS-400.html
Your headunit probably only outputs around 14 watts RMS per channel. The 4" Infinity speakers will handle it well at 2 ohms. They might recieve 20 watts RMS if you are lucky. The thing is, they need to be restricted to 600 hz and above. This will make them alot cleaner and even more efficient. 4" speakers are more like a large tweeter or small midrange. You will need bass blockers. Foam baffles will also help, as will new speaker wire.
Your headunit might be able to highpass the 5.25" at 150 hz. If not, use bass blockers for those also. Your front speakers might seem louder, but will help with a nice soundstage.
Power that sub with a mono amp to it's potential, but try to get an amp that has a lowpass filter that goes up to 150 hz, so all speakers will be overlapped as far as frequency reproduction.
Okay so my HU puts out 22w x 4 at 4-ohms.
There might be a change in plans. My Hyundai has a shot header pipe (in between manifold and catalytic converter) and my local shop said that since the part is obsolete, it would cost around $250, that is if they can even find one. So I might be putting my Legacy station wagon back on the road. That thing uses for 6.5" speakers.
As far as the sub amp goes, would you recommend the Rockford Fosgate P300-2? From what I've heard, I can expect the true RMS rating of the P300-2 to be somewhere between 350-400watts. It has a lowpass filter that goes all the way up to 500Hz. That might be unnecessary, but does the fact that my sub has a frequency response up to 800Hz make a difference?
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