Which amp for highs?

[rta60460 10+ year member]

I am having a hard time deciding on a good priced amp (under $300)with clean power and at least 100w rms x4 @ 4ohm @ 12v...right now it's between the infinity kapp four Infinity - Car Audio or the precision power pc640.4 PrecisionPower - Products - Amplifiers - Power Class - PC-640.4 I can get either of the two for $250 each brand new....any other suggestions or what would you pick out of the two I have chosen...thanks. Scratch these two choices, I've realised they are garbage.....I have two other choices below

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[zako 10+ year member]

A Russian car audio web site compared a bunch of 5-channel amplifiers head to head, PPI, Audison, Alpine MRX, etc, and PPI PC series 5-channel amplifier was their top pick from the bunch. They took measurements for wattage, THD, SNR, channel separation, etc. The article is here: http://www.avtozvuk.com/az/2011/10/050-ppi.htm (use google translate or whatever)

I assume the 4-channel version of PPI PC line is also very good. Kappa on the other hand seems problematic. I have seen negative reviews claiming that it sends nasty pops on turn on and off. Among these two, PPI would be my pick.

Another interesting amplifier is MB Quart REF4.80. I just picked up one for $100+shipping. The same web site gave it a very high rating, the top spot in its group, beating Boston GTA for example. Even though it's rated 4x80watts, they measured 4x110 watts RMS into 4 ohms. Good value IMO. It's kind of small to power a sub without forced cooling, but it seems like a nice amp for the highs.

 

[mclerico83 5,000+ posts]

JBL GTO1004 GRAND TOURING 4-CH FULL-RANGE AMPLIFIER | eBay

amazing amp

ZRS-C9 CADENCE 4 CH 1000 W AMP SPEAKER & SUB AMPLIFIER | eBay

also an amazing amp, look at the low thd 24db crossovers

 

[Bettr n' Revrse 5,000+ posts]

I have a PDX amp the will fit your needs...

 

[BnGRacing 10+ year member]

I can get either of the two for $250 each brand new....any other suggestions or what would you pick out of the two I have chosen...thanks

The Infinity amp has a S/N of 85dB AT ONE WATT!!! Not exactly clean now is it? Unfortunately, I doubt the PPI thing will be even better. Usually vendors try to hide or fluff up their numbers to make them look better or they just hide them. Seems you've found two amps; one fluffs the number up and the other hides it.

Just curious; why do you need "at least 100w rms x4 @ 4ohm @ 12v"? If it's b/c you have speakers that have "100w" printed on its sticker or b/c you think that's just a good number - forget it. You will never hear a difference between 50w & 100w if you use the crossovers on the amp. Never. And anyone that says they can are either lying or they're hearing something else at play that isn't wattage.

On that last bit; a good quality 50w amp will sound louder than cheapie 100w+ amps. Why? They're better able to drive reactive loads, have cleaner on-board processing (like crossovers), and are usually rated a different way than cheap amps. Most of the better amps rate their amps with all channels driven and at some obscenely low distortion figure. Cheap amps will rate everything at 1% THD and usually with only 1 channel driven. BIG DIFFERENCE.

But the best amps under $300 will almost always be used. If you're thinking of PPI, you can find a host of old Art Series amps for well under than price.

 

[rta60460 10+ year member]

taking everything said into consideration, looks like my amp choices ******....I'm now thinking either the older U.S made ppi pcx480 PrecisionPower PCX480 4 Channel Car Amplifier-640 Watts-Cooling Fan (PPI PCX480) or the arc audio FD4150 WoofersEtc.com - FD 4150 - ARC Audio 4 Channel 640 Watt Amplifier .....any thoughts of these two amps or which is better? thanks

 

[RAM_Designs 5,000+ posts]

Get the Phoenix Gold Xenon X200.4 for sale in the classifieds. Dude is local to me and has a ton of feedback on diyma. You won't find anything cleaner or more powerful for under $300.

 

---------- Post added at 07:17 AM ---------- Previous post was at 07:16 AM ----------

 

comes with a couple of goodies too: Phoenix Gold Xenon X200.4 w/ LPL-44 knob & RMD digital display - DIYMA.com - Scientific Car Audio - Truth in Sound Quality

 

[rta60460 10+ year member]

I've never really known pheonix gold to be that good.. I've been out of car stereo stuff for like 10 years though and now feel like putting together a good every day driver system..right now i have a pioneer unit, 2 12 pioneer champion pro subs, crossfire bmf 1700 mono amp....still need to buy my mids n highs but thinking focal for those

 

[audiobaun 5,000+ posts]

:imo:Out of your 2 choices My preferance would be the PPI over the Infinity amplifier, as it has less TDH, and a better DB rating

 

[rta60460 10+ year member]

:imo:Out of your 2 choices My preferance would be the PPI over the Infinity amplifier, as it has less TDH, and a better DB rating

I'm past those first two choices, I've decided they were bad choices..i have two different choices now listed above..thanks

 

[audiobaun 5,000+ posts]

The PPI is a better made SQ amp in my opinion:yumyum:

 

[RAM_Designs 5,000+ posts]

I've never really known pheonix gold to be that good.. I've been out of car stereo stuff for like 10 years though and now feel like putting together a good every day driver system..right now i have a pioneer unit, 2 12 pioneer champion pro subs, crossfire bmf 1700 mono amp....still need to buy my mids n highs but thinking focal for those

Well 10 years ago they were quite good. Their older stuff from the 90's hold their value really well, and the Ti amps from the early 2000's do as well. The Xenon line was their top of the line amps in the mid 2000's. I had a X200.4 myself...loads of power.

 

[zako 10+ year member]

The Infinity amp has a S/N of 85dB AT ONE WATT!!! Not exactly clean now is it? Unfortunately, I doubt the PPI thing will be even better. Usually vendors try to hide or fluff up their numbers to make them look better or they just hide them. Seems you've found two amps; one fluffs the number up and the other hides it.

The Russian language article that I linked actually provided measurements for the Precision Power PC740.5 amplifier:

Sub channel

output (14.4V): 226/311 (4ohm/2ohm)

SNR: 106dB

sensitivity: 0.46-11V

frequency response: 23/147 (+0/-1dB)

speaker channels:

Output: 76/120 (4ohm/2ohm)

input sensitivity: 0.2-9V

SNR: 97.5dB

channel separation: 68dB (left right), 62dB (front rear)

frequency response: 25-25100Hz

There were quite a bit of other measurements and graphs which I don't understand. However, this was their top pick in that group of amplifiers. It was closely followed by Alpine MRX and Audison SR5. I assume the 4-channel PPI has very similar performance.

Just curious; why do you need "at least 100w rms x4 @ 4ohm @ 12v"? If it's b/c you have speakers that have "100w" printed on its sticker or b/c you think that's just a good number - forget it. You will never hear a difference between 50w & 100w if you use the crossovers on the amp. Never. And anyone that says they can are either lying or they're hearing something else at play that isn't wattage.

I was one of the people who thought that if the sticker says 110watt RMS then it will not sound good with "only" 60watts RMS.. I was wrong. Example, when driving it with only 60watt amp channel, I was able to hear my Alpine SPR-17S bottom out when some alternative rock music with some deep bass notes in it if crossover was not used. Even if crossover is used, I could heard the Alpine speaker bottom out playing test tones and some nasty SPL bass stuff. So Alpine's claim that this is a 110watt RMS speaker is complete BS unless you like using 150Hz crossover frequency. On the other hand, no matter how much nasty stuff I have thrown at my Hybrid Imagine woofer (rated for like 70watt RMS) with the same amplifier channel bridged (!) I could not hear it bottom out. I stopped these "tests" because I was afraid of damaging the speaker. The bottom line is that most speakers sing really well on just 50-70watts of power no matter what the sticker says. The sticker claim is probably based on thermal power handling limit, however most speakers will reach their mechanical excursion limit before reaching the thermal power handling limit.