dual a/b amp vs mono d amp
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=111997
Printed Date: April 27, 2024 at 5:31 PM
Topic: dual a/b amp vs mono d amp
Posted By: jyojiman
Subject: dual a/b amp vs mono d amp
Date Posted: February 28, 2009 at 2:29 PM
I have two dvc pioneers rated at 400 rms @ ohms each.
I'm not sure if I should get a dual A/B amp which will put out 450 rms @ 2 ohms per sub, or get a mono D amp which will put out 900 rms @ 2 ohms in total so 450 rms per sub as well.
I was leaning towards A/B but someone said the D amp would be better, any input would be great, thanks.
Replies:
Posted By: soundnsecurity
Date Posted: February 28, 2009 at 3:47 PM
the class D amp will be more efficient. but as far as the sound, you wouldn't really notice a difference.
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Posted By: i am an idiot
Date Posted: February 28, 2009 at 4:25 PM
If you are talking about a Dual brand of amplifier, you would really be better off with any class D amp.
Posted By: jyojiman
Date Posted: March 01, 2009 at 12:27 AM
By dual i meant 2 channels
Posted By: No1stunna
Date Posted: March 14, 2009 at 9:12 AM
"the class D amp will be more efficient. but as far as the sound, you wouldn't really notice a difference." I have to dissagree with that, yes a class d is typically more efficient, but at the expense of sound quality. On a sq setup you can tell a night and day difference between A/B and D, the A/B will always sound cleaner and typically crisper and deeper. I'v ran a number of quality class D amps (alpine, mmats, crossfire, and memphis) and I have over the years gone back to all A/B amps, they use a little more power but its worth it for good sq. So it boils down to whether you are concerned with hot amps and bigger current draws associated with class A/B amps. if you're willing to sacrifice SQ, or are running a bandpass or a poorly ported box, or strictly want spl or don't have good airspace around your amp for cooling... go for the class D. if you want quality sound and can provide the power and can mount your amp with sufficient room for cooling then go for the A/B. |
Posted By: haemphyst
Date Posted: March 14, 2009 at 11:54 AM
No1stunna wrote:
I have to dissagree with that, yes a class d is typically more efficient, but at the expense of sound quality. On a sq setup you can tell a night and day difference between A/B and D, the A/B will always sound cleaner and typically crisper and deeper. I'v ran a number of quality class D amps (alpine, mmats, crossfire, and memphis) and I have over the years gone back to all A/B amps, they use a little more power but its worth it for good sq. So it boils down to whether you are concerned with hot amps and bigger current draws associated with class A/B amps.
WHA...?!?!
No1stunna wrote:
if you're willing to sacrifice SQ, or are running a bandpass or a poorly ported box, or strictly want spl or don't have good airspace around your amp for cooling... go for the class D.
Again... WHA...?!?!
No1stunna wrote:
if you want quality sound and can provide the power and can mount your amp with sufficient room for cooling then go for the A/B.
Which is why Spectron amplifiers (Class D, my friend) are some of the most expensive amplifiers on the planet, watt for watt. Which is why Jeff Rowland no longer builds Class AB amps - ALL Class D, now. Which is why B&O ICEPower amplifiers are frequently reviewed as "the world's most perfect amplifier module". Which is why Audi uses Class D amplification in it's MOST high-end (translation: $$$) cars, and they also have been reviewed as "the best sounding car stereo on the planet". Not "OEM", not "aftermarket": ON... THE... PLANET.
Yeah, Class D isn't quite ready for prime-time, I'd say.
You are wrong, I have 2200 watts of PDX in my trunk, and I have had DOZENS of systems in all of my various cars, from Precision Power to Special Edition to Alpine to Nakamichi to Orion to Linear Power, and all of those "old school" by the way, not the new garbage; all of those names arguably the best that there was in their heyday. The PDX amplifiers are some of the most neutral sounding, controlled amplifiers I have ever heard. The ONE amplifier that I would have instead of the PDX would be McIntosh. ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: No1stunna
Date Posted: March 14, 2009 at 2:42 PM
WHA....?!?! WHA...?!?!? wow, sorry to offend you, theres no reason to be an anus about it. If the pdx is anything like the last v12 series its sound output is nothing compared to the old school v12. On the exact same setup I have noticed over and over just by swapping amps that there is more clarity with a class a/b. obviously this is a matter of opinion, but many others agree also. and part of the reason that all new ammp manufacturers are going digital is because its cheaper typically and it offers digital compliance with the rest of the digital world. I'm just a rookie so I'm sure i'm wrong but in sq competetions the vast majority of people run class A/B or better for fullrange and sometimes class d for subs dont they? there are far more expensive amps out there than spectron, and cost isn't a direct correlation of "best". anyway, I did'nt mean to offend anyone with my apparent ignorance I'm just going by personal experience and what I've observed . haemphyst i know your'e very knowledgeable but there is alot of hard evidence that backs up my claims and yes class d is getting better and soon class a/b likely won't even be made available. in any event you can't honestly back up this particular subject with cost, and opinion, and judgement of factory installed amplifiers which are respectively chosen for their superior power draw and mountability.
Posted By: No1stunna
Date Posted: March 15, 2009 at 2:05 AM
sorry if I confused this topic for you jyojiman, and haemphyst can correct me if I'm wrong. Bang and Olufsen's ICEPower Class D system has been used in the Alpine PDX range and some Pioneer's PRS range and Eclipse I believe. "These revised designs have been said to rival good traditional AB amplifiers in terms of quality." Before these higher quality designs existed ( ICEPower) an earlier use of Class D amplifiers and prolific area of application was high-powered, subwoofer amplifiers in cars. Because subwoofers are generally limited to a bandwidth of no higher than 150 Hz, the switching speed for the amplifier does not have to be as high as for a full range amplifier. The drawback with Class D designs being used to power subwoofers is that their output filters (typically inductors that convert the pulse width signal back into an analogue waveform) lower the damping factor of the amplifier. This means that the amplifier cannot prevent the subwoofer's reactive nature from lessening the impact of low bass sounds. *Class D amps are switching or pulse-width modulation (PWM) amplifiers. Because the switches are either fully on or fully off, losses in the output devices are drastically reduced. Efficiencies of 90-95 percent have been reported. The audio signal is used to modulate a PWM carrier signal, which drives the output devices. Since Class D amps are switchers they create switching noise. The last stage is a low pass filter that removes the high frequency PWM carrier frequency. AB amplifiers have the advantage of not creating EMI I have not personally owned a newer class d with the ice technology so I cannot comment on it, apparently they are very good. If you're concerned with the power requirements or if you need a smaller cooler running amp then definately go with a class D. I personally prefer A/B's becauce I, in my humble opinion, think that they provide a little tighter bass. I suggest that you go to a high end audio store and listen to a few amps and decide for yourself. If haemphyst says the amp using ICEpower sound just as good or better than a A/B then I'm sure he's right....But this is a fairly new technology and not all class D's meet that standard.
Posted By: DYohn
Date Posted: March 15, 2009 at 10:45 AM
Damping factor is an extremely overrated and misunderstood amplifier property. Choosing an amp based on published damping factor is very foolish, IMO. New Class D technology is every bit as high fidelity as any class A/B amplifier. Is there a difference? Sure, any two amps can sound different from each other. But just because of its design class does not mean very much these days about an amp's sound quality. ------------- Support the12volt.com
Posted By: soundnsecurity
Date Posted: March 15, 2009 at 12:31 PM
No1stunna wrote:
I'm just a rookie so I'm sure i'm wrong but in sq competetions the vast majority of people run class A/B or better for fullrange and sometimes class d for subs dont they?
if what you are saying is true, then you just proved my point. -------------
Posted By: No1stunna
Date Posted: March 15, 2009 at 1:22 PM
Like I said in my past post, I haven't heard the new class d's using B+O icepower so I cannot comment on that, however I and many other people prefer the sound of A/B as there is a distinguishable difference between classes when comparing all but possibly the newest higher end class d's. If it was such a black and white issue, then every audio forum on the net wouldn't be plagued by this question. summing it up to which class is better is pointless anyway, most evidence of which sounds better is based on user judgement/opinion and everyones ear and taste is different. The low end of either class is a disgrace and comparisons are not cut and dry. Only your ear can ba the judge, so the question is how much do you want to debate about it. I think any class d with the exception of the newest ones lack a little bit but you'll never decide which to buy if you are waiting for a "right " answer. The original post was asking for input on which one is better and there is no right answer, go to a audio shop (not the big box stores) and listen to both classes on the same subs so you can decide for yourself. Or just pick the best one that fits your budget. The best amp will only sound as good as the rest of your setup will allow it to anyway so doon't fret over it too much B/C it's a vicious cycle. DYohn summed it up pretty well, between the newest amps of any reasonable quality you probably won't notice a difference in fidelity in classes. IMO when it comes to the older class d's I don't think it's even debatable that A/Bs sound better....So are you asking about new technology or will you be buying an older amp?
Posted By: haemphyst
Date Posted: March 16, 2009 at 11:33 PM
stunna... First, let me apologize, I could have worded that better. That being said, "anus" is one of my defining characteristics.
One thing I will often do, even at the risk of hurting someone's feelings is "call them" when a generalization is being flung about - I don't like generalizations.  There is FAR too much information available for anybody with internet access to spew those! 
Secondly, I wasn't using expensive brand names to tout the superiority of today's Class D technology, I was using expensive names, because thay got that expensive way BECAUSE OF HOW THEY SOUND. I know there are more expensive names than Spectron, but I did qualify that claim with a "watt-for-watt" clause. If Class D sounds THAT good, so as to drive such names as Bang/Olufsen (their invention, so it stands to reason...) and Spectron and Rowland and Eclipse and Alpine (in their high-end lines, at least) to use ICEPower exclusively, then it must be pretty good (and in my experience, it IS that good).
Also, PROPERLY implemented Class D is not less expensive than Class A/B, it is in fact significantly MORE expensive. Compliance really has nothing to do with it, rather it is simply another step in the technology, much like SATA drives in computing: it's just the next step. Faster, but not (necessarily) less expensive. I'll grant you, it does GET to that point, but initially, it isn't.
Here's a link to the build of my system, almost two years ago... I only include this information so you can see that I am completely SERIOUS about sound quality, and I don't EVER joke about it! It's really just a "point of view starter". :P If you don't want to read the whole thing, here's a quick copy of my review of the Alpine PDX4.150:
haemphyst wrote:
Oh... My... God...
These PDX amps are INCREDIBLE. I haven't put them in the car yet, but I needed to see what I was in for. I pulled one out to my living room, with my 100A power supply, and proceeded to run one of the 4.150s through it's paces.
Bridged mode: What can I say? Powerful, musical, dynamic. I was able to wrinkle my 52 inch ribbons full length, with "Kiss the Girl" from the Little Mermaid soundtrack (don't knock it, it's an AWESOME reference recording) which I have discovered though previous experimenting happens at approximately 280 to 300 watts. My usual amplification for the ribbons is an NAD 216THX, rated at 220 watts per channel into the 4 ohm resistive load presented by the ribbons, and it can't wrinkle 'em. I heard no sense of strain, just music. My ears couldn't take any more, and I heard no clipping or excessive distortion. What distortion I DID hear was probably from my CERTAINLY non-optimal room, and all of it's terrible reflections, and/or my ears complaining.
Stereo mode: Even better. I know... but it WAS! I ran all 4 drivers in the system off that amp in 4 channel mode, using the built-in crossover. The highs were even smoother... The mids were even MORE liquid. MILES ahead of the NADs. The bass... oh, the BASS! I didn't try that (running bass) in bridged mode, but in stereo, it was deep, controlled, accurate bass... FAR better control (even with 1/3 the power) than the Adcom GFA565 powering the woofer section right now. I have never HEARD those systems sound that good, LITERALLY!!! All I could say was "WOW! I mean WOW!" Are the SURE that it's only 150W x 4? The sound was FAR more powerful than I would have imagined, especially from such (relatively) modest power output, and even MORE amazing was the fact that it did all this with my painfully inefficient ribbons!
The crossover and pre-amp section are very clean, and perfectly serviceable... They do an admirable job at their jobs. The crossover has a WIDE range of settings, I want to say it's 30 Hz to 400(?)Hz. PLENTY of range for most systems. Anybody contemplating full-range digital owes it to themselves to get a look at these amplifiers! Alpine and B&O have teamed up in an over-the-top fashion, and hit it out of the park!
Damn, Bob! You gotta dump the JL stuff in your car and get the PDX's going in there! No messin' around here... I'm completely serious man!
So, really... Just please accept my apology? ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: No1stunna
Date Posted: March 17, 2009 at 9:23 AM
Apology accepted, my mistake was assuming the newest class d's were just like the older ones...The newest D I had was an alpine mrd-m605 and before that it was a vr1000d so I cannot speak accurately about the new technology and I did generalize which is unfair to any audio topic like this. Nice setup by the way
Posted By: flogger11
Date Posted: March 23, 2009 at 8:25 AM
Class D is "ok". A/B FOR SURE SOUNDS BETTER. And anybody that doesnt think damping factor doesnt matter hasnt done an A/B comparison of an average or poorly damped amp vs a good one. When I went to my ZPA the first thing I noticed was CONTROL. My sub has a touch more quickness and control vs any other amp I have run. Yes, DAMPING FACTOR MATTERS, especially on a sub. The problem when comparing ratings is most amp manufactors dont list WHAT FREQUENCY their damping factor is rated at. You can have a damping factor of 1000 at 1000hz, yet only have a damping factor of 300 at 100hz. The reason most amp designers rate their damping factor at 1000hz instead of 100hz is an amp has a much easier time staying in control at 1000hz vs 100. Damping factor is the amps ability to control a speaker, how fast can it start/stop its power to a speak. Class D has wiz poor control, thats just the way it is. We havent even touched on the power switching problems inherent in a class d design, another time. The bottom line is Class D is fine if you need outragous power and dont want to make the financial commitment to your charging system, however a properly set up A/B with the same power rating will CHEW UP any Class D. Why do you think A/B costs so much more than a Class D amp of the same power? You get what you pay for, sorry. Class D, yuck.
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Posted By: ragsports
Date Posted: March 23, 2009 at 8:44 AM
Flogger You ARE wrong! Did you not read the rest of the post?
Posted By: flogger11
Date Posted: March 23, 2009 at 9:06 AM
ragsports wrote:
Flogger You ARE wrong! Did you not read the rest of the post?
Nope, Im not wrong, but thats ok, you guys just keep running that class d stuff, it doesnt hurt my feelings. -------------
Posted By: haemphyst
Date Posted: March 23, 2009 at 12:59 PM
Dude... You've been fooled. Seriously. I'm thinking Dr. Bose himself told you it was important. How close am I?
MATHEMATICALLY PROVEN to make little to no difference, EXCEPT in all but the most extreme of cases. I, too, used to be of the belief that it made more difference than it does. ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: flogger11
Date Posted: March 23, 2009 at 1:17 PM
haemphyst wrote:
Dude... You've been fooled. Seriously. I'm thinking Dr. Bose himself told you it was important. How close am I?
MATHEMATICALLY PROVEN to make little to no difference, EXCEPT in all but the most extreme of cases. I, too, used to be of the belief that it made more difference than it does.
You have to agree, all variables being the same, an amp with a higher damping factor is going to have more control over a speaker, therefore making it a better amp. I am not saying it is the "end all" spec, and I agree it can be a subtle difference, but the diff (on a subwoofer at least) IS audible to a trained ear. IMHO of course. LOL! -------------
Posted By: flogger11
Date Posted: March 23, 2009 at 1:20 PM
and haemphyst, who the heck is dr. bose? the guy that invented "no highs no lows they call us bose" speakers? ;) I learned a great deal of my knowledge from a very well educated, experienced gentleman by the name of Steve Davis. Thanks Steve!
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Posted By: audiocableguy
Date Posted: March 23, 2009 at 1:43 PM
"Why do you think A/B costs so much more than a Class D amp of the same power?" Could it be the reduction in heatsink/cooling requirements? Could it be the new surface mount devices with higher tolerances? Could it be Class D requires less components to create the same values?
Class D is the wave of the future like it or not. . . I have heard the Alpine PDX and would have zero problem replacing an A/B amp with it.
Posted By: flogger11
Date Posted: March 23, 2009 at 2:06 PM
audiocableguy wrote:
"Why do you think A/B costs so much more than a Class D amp of the same power?" Could it be the reduction in heatsink/cooling requirements? Could it be the new surface mount devices with higher tolerances? Could it be Class D requires less components to create the same values?
Class D is the wave of the future like it or not. . . I have heard the Alpine PDX and would have zero problem replacing an A/B amp with it.
I have to admit to never hearing a modern class d on comps, but I would bet my PG ZX-450 chews up an alpine 150 watt x 4 PDX. Maybe not as loud, but the PG is certainly a more transparent amp. The reason that class d is the future for mid-fi is the price, cheaper to produce and cheaper to feed power. class d will never replace an a/b design for top of the line, high budget SQ applications. IMHO. -------------
Posted By: DYohn
Date Posted: March 23, 2009 at 2:21 PM
flogger11 wrote:
audiocableguy wrote:
"Why do you think A/B costs so much more than a Class D amp of the same power?" Could it be the reduction in heatsink/cooling requirements? Could it be the new surface mount devices with higher tolerances? Could it be Class D requires less components to create the same values?
Class D is the wave of the future like it or not. . . I have heard the Alpine PDX and would have zero problem replacing an A/B amp with it.
I have to admit to never hearing a modern class d on comps, but I would bet my PG ZX-450 chews up an alpine 150 watt x 4 PDX. Maybe not as loud, but the PG is certainly a more transparent amp. The reason that class d is the future for mid-fi is the price, cheaper to produce and cheaper to feed power. class d will never replace an a/b design for top of the line, high budget SQ applications. IMHO.
You admit you have never heard one so your opinion means about as much as that of a toad. Go listen and compare on similar systems and then you can make an informed statement. Otherwise, you simply come off sounding like a fanboy. ------------- Support the12volt.com
Posted By: flogger11
Date Posted: March 23, 2009 at 2:33 PM
I said i havent heard a modern, as in PDX, class d on a set of comps, just on subs. So my opinion may have a touch more meaning than a toads. As far as the ZX-450 being a cleaner amp than an alpine pdx, now that i would put money on. Class D, yuck.
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Posted By: haemphyst
Date Posted: March 23, 2009 at 5:17 PM
If you've never heard it, then YOUR OPINION IS WORTH A TOAD'S, ya fanboy! (just to make DYohn's comment stick!) You cannot say you don't like something if you've never experienced it. Food, drink, or amplifiers... You cannot comment and be meaningful or even remotely informed!
I have already told you that Class D is more expensive to implement effectively, it is OBVIOUS that you never read any of the thread up to this point... If we were talking in person, I'd tell you straight-up that this was an A-B conversation, so C your way out.
If you happen to live in Cali, I will DRIVE TO YOU to let you hear what properly implemented Class D sounds like. I can promise you, (and I have been listening to and owning TRUE high-end audio for possibly longer than you have been alive) that you would have no problem hearing the fantastic audio quality and attention to detail in the PDX amps.
Huh... A whole 72 watts for your highs, huh? (Oh, I'm sorry... 350, IF you are running 13.8V and 2 ohms... Well, if you are, there goes your precious damping factor...) I run two and a half times that to my 8 ohm midbass drivers... EACH! (Don't talk to me about damping...) 31 bands of true parametric EQ, 48dB crossover slopes, three-ways in the doors, a single 10" TCSounds ISO loaded stuffed TL in the trunk... Oh, wait... THAT'S designed with as high an impedance as possible, as well...! (Again, don't talk to me about damping...) Now, we can go all day one-upmanshipping each other, but I can GUARANTEE you that there are only a few people on this board that have ever taken the time to go to the lengths that I did to make my system sound as good in their car as ANYTHING they have ever heard in the home. You are NOT talking to the John Q. Public Car Stereo Guy, here. My system was quite critically reviewed by an iASCA sound quality judge, who listens to Martin-Logan electrostats in his living room, (I myself have Bohlender Graebner 52" ribbons in my living room) and I was told to RUN, not walk, to the next SQ competition, and "get this thing in those sound-offs".
My system was built from the ground up with imaging, frequency response, headroom and linearity built in. EVEN YOU would not be able to tell that the amps are PDX amplifiers. I have had two driver engineers from Harman International in Northridge listen to my system, as well as five members from this very forum listen to my system. I defend it's capabilities quite aggressively. I will not say that the ZX is an incapable amplifier, they are not, BUT that is technology from a day when Phoenix Gold gave a crap... You WILL NOT be able to put anything PG against decent Class D today, and prefer it - it's crap now. I have heard more than a few people say that it is the best sounding car stereo they have ever heard, and one of those people was a Zapco owner.
My offer still stands. I will drive to you.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: stevdart
Date Posted: March 23, 2009 at 5:42 PM
So, who else was born in '68?  BTW, toads have opinions too. And frogger11 is ent....frogger? heh ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: soundnsecurity
Date Posted: March 23, 2009 at 7:15 PM
stevdart wrote:
So, who else was born in '68?
BTW, toads have opinions too. And frogger11 is ent....frogger? heh
i think it's flogger, as in, someone who beats people with whips. i dont get it either -------------
Posted By: haemphyst
Date Posted: March 24, 2009 at 1:41 AM
stevdart wrote:
So, who else was born in '68?
BTW, toads have opinions too. And frogger11 is ent....frogger? heh
OOh, OOh, I was, I was... ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
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