what amp power do I really need?

Systems

I just bought 6 3/34 components for the door rated at 100 watts & 6 3/4 polk coaxels in the deck lid I need an amp 4 channel I guess. I was told a 75 x 4 can I get away with less and have great sound because I waNT to save money for my sub and amp?

Systems

Originally posted by terry
I just bought 6 3/34 components for the door rated at 100 watts & 6 3/4 polk coaxels in the deck lid I need an amp 4 channel I guess. I was told a 75 x 4 can I get away with less and have great sound because I waNT to save money for my sub and amp?

Dont Skimp on your amp.. You might like it in the beginning.. but go ahead and work that overtime and get the 75x4 amp. Believe me.. Amps isnt one thing you want to skimp on.. lots of online site with great prices.

Jstas

You don't really need anything more than a 50Wx4 amp.

In full range speakers, the point of an amp is not to play loudly all the time. The point of an amp is to give solid power reinforcement. Most of the head units out there may say soem astronomical number like 40w x 4 or 44w x4 for power out but thier rms rating are usually less than half that. Consequently, they run out of steam and peter off druing musical peaks. A 50w x 4 ampilifier won't do that. Also, an amplifier does not have teh tape deck or CD player noise or the inherent ground loop from the radio antenna affecting it.

So, for an amp for a full range speaker, you will be fine with a 50W x 4 if that is what your budget can handle. Just do your self a favor and get a wiring kit that is bigger than what you need. It will cost a little more but it's certainly no where near the same cost difference between a 200 watt amp and a 300 watt amp. That way, in the future, you can easily upgrade to a more powerful amplifier.

Also, while more power is a good thing, getting an amplifier too powerful for your selected speakers is not a good thing. Full range speakers are much more delicate than subwoofers and tweeters are more so than any other. A 75W x 4 amplifier could be too much for your speakers to handle. Many coaxial speakers won't take much more than 50 watts unless you get really high end stuff. The same goes with seperates. So don't go with the idea that you need the most powerful amp in the world. If you have a budget, stick to it and don't shop outside your price range. Select your components well and you'll be happy with what you get.

PoweredByDodge

Jstas has a point regarding both economical use of money as well as proper power for speakers.

However, I think there has to be a proportion obvserved as well.

If you're going to run something in the range of one 500 watt sub, or two 200 watt subs, then 50 x 4 amp power is probably just fine, if not ideal.

However, you spoke of "subs"-plural- and wanting to save more money to put towards those, and so I'm guessing you may be going for something in the ballpark of two 500 watters or something even stronger.

In which case you may need to "push the limits" of your coaxials so as to balance the highs and lows to a tasteful listening quality.

Assuming an efficiency on the component sets of 90 db's and maybe 93 on the coax (as this is about par for the polk EX III comp/coax), you're probably going to want to look at something in the range of 75 - 100 x 4 rms for the amp... dont settle for a THD of over 0.1%, as believe me, you'll hear it in highs. I had a dirty mtx amp 0.3% for liek 3 weeks and i just about shot myself in the head for ever buying it.

the real "fail safe" here is that if it turns out you've got a hair too much power, you can always dial down the gain so as that that 75 or 100 x 4 is actually only doing like 50 or so x 4. better to have more and not use it than less and kick yourself later.

I'm tryin to think of some bare bones low end 75 x 4's that you could get on the cheap... *cheap being like 200 bucks retail / 125 - 150 ebay for a new in box item, used or such would be obviously less*...

well there are two that came up on sounddomain that i'd look at...
1- Lightning Bolt 400.4 - 75 x 4 @ 14.4 volts / 0.05% thd / s to n ratio of great than 90 / hp and lp xovers. -- 179 bucks.
2- pioneer gmx-574 - 50 x 4 @ 14.4 volts but only 0.008% thd, which makes me belive the amp is under rated... if its 50 x 4 at 0.008, its probably like 65 x 4 at 0.01 and maybe if u're lucky over 70 at 0.1%... dont take those numbers are gospel.... s to n ratio of greater than 100. - 189 bucks.

crutchfield has what might be your best bet for now...
US Acoustics 4085 - @ 12.9 volts its rated 85 x 4 with 0.01% thd ... s to n ratio of 101 and built in xovers. -- 179 bucks.

that's probably youre best shot right now to maintain cheap but still pretty decent quality equipment/power. I'm tryin to think who makes the US Acoustics amps -- i think its the same overseas plant that builds Memphis's stuff. damned if i'm sure of it though.