Looking for an amp that would give me at least 90x4 at 4 ohm, but can't really find anything out there. Just need the name and model number so I can shop around.

 

JL 300/4

 

There is a Crunch P4125 amp, 125x4 at 4ohm for only 80 bucks on ebay!!! should I buy it?

 

Crunch? Probably 125 total watts with both pairs of channels bridged into a 4 ohm loads.

One amp with that power is the Arc Audio 4150, another is a Diamond Audio D7 - I can't rememer the model number. Kicker may have one. I don't think any of RF's really have that much power to 4 channels at 4 ohms.

 

JMAX, I won the ebay auction for Crunch P4175. Dont hate me 'cause I really got a good deal on it. Some peeps said there were issues with overheating, but this baby will power my Kappas (90rms at 4ohm, 270w max) I think I'll be alright. Now I am looking for inexpensive amp with like 300 rms at 4 ohm per channel for one 12" Kicker Comp VR DVC...

Specs:
P4175 Power Rating:
-- 4 Ohm Load: 175w x 4
-- 2 Ohm Load: 350w x 4
-- Mono Bridged into 4 Ohm: 700w x 2

P4175 Specifications:
-- Frequency Response, -3db: 20Hz - 30kHz
-- Damping Factor: >150
-- S/N Ratio (A-weighted): >95db
-- THD & N: 0.05%
-- Channel Separation: >70db
-- Variable Input Level Control: 0.2V - 4V
-- Input Impedance, RCA Jack: 47 Kohm
-- Input Impedance, high level in: 22 Ohm
-- Power and Diagnostic LEDs
-- Short, Thermal and Overload Protection
-- MOSFET Power Supply
-- MOSFET Audio Output Device
-- HP/LP/Flat Crossover Selector Switch
-- Variable High Pass Filter: 60Hz - 1.2kHz
-- Variable Low Pass Filter: 40Hz - 450Hz
-- Variable Treble Boost: 0-18 db
-- Variable Bass Boost: 0-18db
-- Dimensions(WxHxL): 10 x 1.86 x 14.75

 

Dude, I don't hate you or anybody. But I should point out that Crunch claims that amp is three and a half times more powerful than my Alpine. But it uses the same size chassis.

 

I was kidding, thought I may get critiqued for going with that brand. You know, there are other amps then Alpine, and their stuff may not be the best. Oh, well...

 

I have a Soundstream amp that is 125x4 and is 24x12.25x4. The thing is freakin huge. Not sure how Crunch rates their amps but I find the specs. hard to believe.

 

cmon guys, I am reading this and none of you actually ever had a Crunch amp, all you do is flame it because it is a cheapo. Well, I had my Volfenhag 100-dollar amp for over a year and it served me very well.

 

Has anybody had any experience with Mobile Authority? I can't find any reviews on it and their prices are pretty competitive.
Jae

 

Honestly all amps sound the same. $25 from radio shack or $2000 from Zapco. And installed properly the cheapo amps will last a long time. It's when there are "user" errors that the more expensive amps reliability becomes a factor. But I still appreciate honesty in specs. I have used a lot of amps other than Alpine. I just mentioned that one because I do have a 4-channel with very similar dimensions to the crunch you just got. But Alpine only claims it puts out 50X4 at 4 ohms.

 

there's an amp on crutchfield with 7% THD. would you still recommend that amp?
Jae

 

All amps sound the same. 7%, there is probably a typo there.

 

I like the Soundstream 600-4 myself. Classic stylings and beefy output of 4x75 at 4ohm and 4x150 at 2. Quality construction and all that jazz.

 

i have a rockford 550X, but i'm not using it the way i think you would use it. i got the front channels hooked up to my components, and the rear channels bridged for my sub. its 65 x 4 @ 4 ohms, 137.5 x 4 @ 2 ohms and 275 x 2 @ 2 ohms. costs a little less than $300, but i think you can find something a little cheaper ( or better ) for your needs, just throwing a suggestion at ya.

 

Zapco AG360

 

According to certain folks, if an amp is not a brand name and is relatively small in size, then it is probably overrated. Have you actually performed any tests to verify the output??

I would draw a parallel in Maxima vs. BMW 325. Nissan also lasts 200K mi, has all the options, but at the same is faster and costs up to a 10 grand less. There are instances (with Alpine) where you are paying for brand name.

 

Yes, a bench test was performed on the amp prior to shipping from the factory. You have to use some common sense when evaluating equipment. If the majority of amps in a power range have similar sized cabinets and heatsinks, it is logical that they are all near the minimum size possible for the power range. We already know that they all use similar techniques to amplify the power. Now if another amp comes along and claims to put out 3 times as much power from the same size "black box", using the same logic it's easy to guess who's full of you know what. I never said that Alpine is competitively priced. I also never said that just because two amps sound exactly alike and have the same power that they are both worth the same amount. Telling the truth about output power is worth a 2-3 fold price increase in my book.

 

What is a bench test? I dont see one rely on the common sense unless he is an engineer that designs/fixes these amps. What you are talking about comparing the sizes and simply following the logic of techniques to amplify the power may not be enough to stand up and say that this manufacturer is overrating his products. Lets give a benefit of a doubt: all of us know that the businesses are punished for deceiving its customers. What company would knowlingly advertise something about their product that is not true?

 

You mean like Marlboro's get you laid? Is that the type of advertiseing you want? It got you to buy the amp, and no one who bought it is complaining yet. So why should they worry about deceptive advertising? If you are really confident of it's power and trusting of it's reliability send it in for a test. There may be a local electronics repair shop that can do the test for you. Or maybe a physics professor in your high school with time to kill.

 

The amp may very well output what it claims. However, there is more to an amp than just that. The quality of the sound and the durability of the product is directly related to the quality of the internal devices. The larger the output transistors the more heat they can dissipate and the longer the amp will live. This is just one example of getting what you pay for. The amp may work very well for a few years. But I seriously doubt that it will be kicking around ten years from now like an old Phoenix Gold MS series amp. Now those things were works of art.

 

No, I am talking about the type of advertising that directly affects the buyers' decisions, product specs. Like when Nissan claims Maxima puts out 255hp, and Acura claims its RSX will put out 200hp.

Or maybe a physics professor in your high school with time to kill. [/QUOTE]

btw I am a college grad and not "your high school kid" so better respect that

 

btw I am a college grad and not "your high school kid" so better respect that[/B][/QUOTE]

You obviously did not understand the intent of the post. Most high school physics professors have the knowledge required to bench test the amp. They might even feel it is an interesting topic and not a waste of their valuable time. A college professor will also have the ability and almost definitely the tools, or at least will have access to the tools. But, this may be to medial a task for a college prof to waste his or her time. Also, if I bumped into a high school prof while out they would know my name. A college prof with 200 or more students in each class might not even recognize my face.

I guess you are referring to flywheel horsepower? Or inferring that the amp could output that much power if connected to a huge power supply?

You are funny dude, don't forget it.

 

oh never mind then, cant we all get a long lol. I will let you know how my Kappas going to sound when run through that cheap Crunch amp, claimed 175rms x4 at 4 ohm.

 

Old Rockford 500a4

 

alright, not to hate, but if you get a REAL GOOD amp that puts out that kind of power you'll notice a HUGE difference. my phoenix gold tantrum 600.4 is rated at 75 watts RMS x 4 at 4 ohms. i have kicker resolution RS6C in the front, they are rated at 100 watts RMS 200 peak. and boston Aqoustics NX series 57's in the back rated at 140 watts RMS. i have the amp x-overed at like 120HZ(normal setting) and i can't go above HALF on the gains. that amp puts out some SERIOUS power and a LOW LOW THD to boot. not to rain on yoru parade but your not gonan get an amp that really puts out that much power for that much money. it will prolly do half the watts rms it says it will. 175 watts x 4 RMS at 4 ohms is HUGE.

 

I know it sounds huge...so I'll see if I can have the real output checked at the shop that will do the install...Honestly, I dont need all that much power, so I wont be very upset if those ratings turned out as a BS. 'Cause for $$ I paid for it....everyone would jump on this.

 

exactly, if you get 50watts RMS x 4 that will power those kappas good enough, they are good speakers but there are some powerful speakers out there that dont even take 175 watts RMS. there are subs that can't handle that lol.

 

LOL. BTW, what kind of wiring kit do I need to buy for this amp, and what is a good one out there, where can I get it. Best Buy wants to charge me $100 for a kit, and I saw some on ebay for $30.

 

If you told them it puts out 175 X 4 that's probably about right. What size fuse is supposed to be used? According to crunch? Let's go from there. Because the wire gauge depends on the current the amp will draw.

 

As you can see from my sig I have this years Eclipse 4 channel pushing my components all the way around. Power is 85x4 continuous.

 

im partial to the us amps tube amps. ive got a tu 4360 coming in a few days. gonna have lots of fun with that

eric

 

I'm in the process of installing my kicker 800.4 amp total of 1020w and pushing 100 x 4 @ 4ohm.

All I can say is this better be worth it for all the trouble i'm going through installing this and my kappa components.

 

there are 2x30amp fuses

 

60 amps of current. 4 gauge wire will be plenty for a small system. If you plan to get a sub in the future I would go larger, that's how I am. I try to be prepared for the next step up. 2 gauge will be good for up to about 105 amps. 0 gauge for anything larger.


60 X 12.5 = 750 watts. 750 @ 50% efficiency = 375 watts. 375 / 4 channels = 93.75 watts per channel. That is being very optimistic.

 

I already have a sub run by a separate amp...the one I was trying to sell, 170rms at 2 ohm. The amp for the sub is already hooked up by some thin wires, I assume these will have to go. So, 2 gauge?

 

Add up the fuse rating of all the amps. This is not 100% accurate as the fuse rateing's can be off. But it's normally pretty close.

If you have a spec sheet that indicates the maximum current draw use that number instead of the fuse rating.