"Full Range" D class amps?

[boy&hisdogs]

I'm looking for a 4 channel amp to power my door speakers. They're Alpine 610C's, (6.75", 80w RMS, 4 ohm). I may in the future add a set of 4 inchers for the rear since I kind of miss having rear speakers.

I'm drawn to the Rockford Fosgate R400-4D "full range" amp. On paper it looks good. The price, size and power is right, it's got HP and LP filters built in, speaker level inputs (I'm keeping the stock HU for low-pro/anti-theft reasons), and it matches the R500-x1D that I already have for my sub.

I am concerned about the fact that it's class D though. The research I have done on "AB vs D" usually boils down to two things:

1) If you spend enough money, you won't be able to tell the difference.

2) AB is better, because that's the way my girlfriend's aunt's neighbor says it's always been.

By car audio standards, I can't afford to "spend enough money". I'd like to keep it under $200. While "that's how it's always been" arguments usually have a grain or two of truth backing them up, just a few years is like an eternity in the world of electronics and new stuff comes out every day.

Does anyone here have this specific amp or another "full range" D class powering component speakers? How does it sound compared to other budget-minded setups you've heard? Keep in mind that I'm a college student who drives a pickup. I'd like to keep the price reasonable and footprint minimal.

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[trumpet 5,000+ posts]

Full range Class D is a very mature topology. If any company can do it right it should be Rockford Fosgate. I have installed and used for myself lower budget full range Class D amplifiers. I have been recommending Precision Power i520.4 and Clarion XC1410 for those who really want to keep the price down, and Precision Power P900.4 for the ~$200 range. P900.4 is my pick out of these 3 because of the power output, then i520.4 followed by XC1410. For smaller speakers or those with lower power handling you can keep the gain turned low, possibly to the minimum position(highest volt markings) and still get loud and clear sound. That does also depend on the RCA pre-out voltage on your head unit, among other things. My point is to not be turned away by the 100w+ RMS power ratings on a reputable amplifier.

 

[Jeffdachef 5,000+ posts]

I'm looking for a 4 channel amp to power my door speakers. They're Alpine 610C's, (6.75", 80w RMS, 4 ohm). I may in the future add a set of 4 inchers for the rear since I kind of miss having rear speakers.
I'm drawn to the Rockford Fosgate R400-4D "full range" amp. On paper it looks good. The price, size and power is right, it's got HP and LP filters built in, speaker level inputs (I'm keeping the stock HU for low-pro/anti-theft reasons), and it matches the R500-x1D that I already have for my sub.

I am concerned about the fact that it's class D though. The research I have done on "AB vs D" usually boils down to two things:

1) If you spend enough money, you won't be able to tell the difference.

2) AB is better, because that's the way my girlfriend's aunt's neighbor says it's always been.

By car audio standards, I can't afford to "spend enough money". I'd like to keep it under $200. While "that's how it's always been" arguments usually have a grain or two of truth backing them up, just a few years is like an eternity in the world of electronics and new stuff comes out every day.

Does anyone here have this specific amp or another "full range" D class powering component speakers? How does it sound compared to other budget-minded setups you've heard? Keep in mind that I'm a college student who drives a pickup. I'd like to keep the price reasonable and footprint minimal.

Thats a pretty outdated claim. Many of the mainstream companies today are moving over to class D technology because of the efficiency/less heat aspect of it along with a smaller footprint. Class Ds have a very flat sound not coloring the sound in anyway. In a sense, its pure efficient power. I've compared my ppi ion 520.4 vs an older JL AB 300.4 and to be honest they sounded pretty much the same but the ion was a tad louder at 1/3 the size of the JL.

My test: Precision Power iON 520.4 ~~ thats a clamped test for power

this is a full review from a reputable car mag PASMAG | PERFORMANCE AUTO AND SOUND - Precision Power P900.4 Amplifier

both are under 200 dollars and perform phenomenally and they are TINY

 

[72Impala 10+ year member]

Personally I hate the sound of class D full range. Sounds empty to me. But maybe it's just me...

 

[boy&hisdogs]

Personally I hate the sound of class D full range. Sounds empty to me. But maybe it's just me...

Could that be compensated for (or maybe caused by) other factors? Maybe different EQ settings or tweeter placement or something?

 

[72Impala 10+ year member]

Could that be compensated for (or maybe caused by) other factors? Maybe different EQ settings or tweeter placement or something?

I don't think so. I have done direct swaps and been disappointed even after lots of tuning and TE and what not

 

[gckless 5,000+ posts]

I'm happy with my Zed.

 

[fly_marlin]

I've had the same internal debate about this myself when shopping for an amp. I couldn't get myself to do the class D amp, though I've read many reviews on these, and much like trumpet said, the newer class D full range technology has matured and I doubt you'll be able to tell there difference, especially with a budget friendly setup.

If it's worth anything, I have an ARC class H amp - it's essentially a class AB amp pushed by a class D amp. I'm a very happy with it, the footprint is tiny and I'm getting about 300W per channel from it.

 

[treesive 10+ year member]

I have come to the conclusion that if class D is pure flat unaltered sound reproduction then I don't like the sound that way. I have used only three brands of the full range d's but at least two would be called top notch and I just did not like something about the sound of them. Impala hit it on the head as they just don't seem to have any depth or fullness to them or something. I have known may people I trust to be honest with me say they have loved their class d's on speakers but I personally have never been able to get myself to keep a class D amp for running my mids and highs. I would vote you look at the ks series amps from arc though for a good alternative. Would probably be hard to get one for 200 but I have seen a lot of them go for about 300 on the forums.

 

[72Impala 10+ year member]

I have come to the conclusion that if class D is pure flat unaltered sound reproduction then I don't like the sound that way. I have used only three brands of the full range d's but at least two would be called top notch and I just did not like something about the sound of them. Impala hit it on the head as they just don't seem to have any depth or fullness to them or something. I have known may people I trust to be honest with me say they have loved their class d's on speakers but I personally have never been able to get myself to keep a class D amp for running my mids and highs. I would vote you look at the ks series amps from arc though for a good alternative. Would probably be hard to get one for 200 but I have seen a lot of them go for about 300 on the forums.

^^ this, seems like cold, almost like they midbass does not play all the way through the note or something, hard to explain. Just generally does not sound good to me.

 

[hispls 5,000+ posts]

Surely if a modern and well designed class d sounded any different than comparable a/b we would be able to see the difference with precision measuring equipment? Somebody show me some hard data and I'll consider that claim.

 

[treesive 10+ year member]

Surely if a modern and well designed class d sounded any different than comparable a/b we would be able to see the difference with precision measuring equipment? Somebody show me some hard data and I'll consider that claim.

Well if I had a guess that precision measuring equipment would also state that a record sounds much worse than a present mp3 and that an old tube amp doesn't sound better than a new class d amp. Both to my ears would be inaccurate so there is obviously something that the precision measuring equipment cannot tell me about what is going on in the sound that I find pleasing from that of what is "better sounding" to the machine. It just tells me that the human ear isn't a machine and thus is flawed on what it likes.

 

[Jroo 10+ year member]

I used to think it mattered but dont anymore and I think price point factors into this. I figure if guys like Mark Elridge and Scott Buwalda in his G37 run class D amps and have winning comp cars, it is more than enough for me on any guy on the street. I have loved a lot of the oldie but goodie amps and I do believe some amps have a sonic signature. I think if you compare a 1000 dollar class AB or and old school favorite like the Soundstream Class As, you could hear a difference from a class D. Put your normal 3 or 400 class AB against a 3 or 400 class D, doubt you will hear it and your electrical will thank you.

 

[trumpet 5,000+ posts]

I have tried different AB and D amplifiers and I've heard differences that I would not attribute to differences in power output alone. When someone asks me about this topic I tell them they might hear a difference between amplifiers, but I make no promises. Right now my system has 12 channels with most of the pairs bridged, and between 2 amplifiers the footprint I give up in my trunk is only 23" x 7". I put my trust in installation techniques, clean headroom, speaker selection, location and aiming. I don't place the value of a sonic signature of an amplifier, should it have one, above any of that.

 

[fly_marlin]

I think that's a good way to do it. I think all amps, when designed, want to get as close to being hi-fi as possible. That means they output a signal as close to the original source as possible - minimal loss and minimal noise. I think budget is important here. For me, personally, if I have an established budget and can get a class AB amp for the front stage within my budget, I'd go with that. If you're really tight on money and/or space and a smaller footprint amp is a must, I doubt you will be unhappy with a full range class D amp. For people looking to "color" their sound, the amp is not the way to do it. For that, you get an EQ or a DSP and color away.