A/B vs Class D for Subwoofer SQ

[DidUHearThat? 10+ year member]

I think people when comparing AB vs. D speak more about the older amps circa 2000 and older. At those times with the technology the differences are more apparent. With technology catching up or caught up the differences between class AB vs. D are almost indistinguishable by ear. If Richard Clark would have offered that test in 1997-2000, he would have been bankrupt. In 2006, the technology was way better.
Again these scientific tests are for today's amps more or less not the "old school" amps.

RC has been offering the challenge for over 15 years.

 

[cleansoundzz 10+ year member]

The right people did not take the test then.

 

[gunz4me 10+ year member]

Yeah but running a class D @ 4 ohms is where you will get the best sound quality. After experiencing a high amount of bass over many years, then SQ is more important. SQ comes from not stressing a class D as much. I know RF has the T1500-1BD that will give out about 500 watts at 4 ohms. Class D if used properly can have the same SQ but again at higher impedances.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Yeah, but I purchased my 25 to Life Punch 150 for $150 in used but mint condition. I don't think a T1500-1BD would go for that low used/mint //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif Regardless, I thought it was a good deal for something that birthed around 1,000 watts @ 4 ohms when I only needed 600

 

[bass_lover1 10+ year member]

Yeah, but I purchased my 25 to Life Punch 150 for $150 in used but mint condition. I don't think a T1500-1BD would go for that low used/mint //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif Regardless, I thought it was a good deal for something that birthed around 1,000 watts @ 4 ohms when I only needed 600

What was the rated voltage? A lightning strike? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[gunz4me 10+ year member]

What was the rated voltage? A lightning strike? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

Hmm... it has 120 amps of fusing and birthed at 328 watts per channel @ 4 ohms 600 watts RMS is easily attainable on this amp It barely gets warm after beating on it

 

[DidUHearThat? 10+ year member]

The right people did not take the test then.

Mostly proffessional audio engineers, but what do they know?

The test is still open if you want to try.

 

[rc10mike 10+ year member]

Mostly proffessional audio engineers, but what do they know?
The test is still open if you want to try.

Where?

 

[DidUHearThat? 10+ year member]

Where?

Why didn't you follow the link I posted on the top of the last page? I've already answered most of your questions about who was tested, how and what they determined.

Really this is a very dead horse your beating, but knock your self out.

http://tom-morrow-land.com/tests/ampchall/rcrules.htm

http://www.tom-morrow-land.com/tests/ampchall/index.htm

Here is a long thread on another car audio forum where RC posted more comments and again challenged people who claimed they could hear a difference.

http://www.audiogroupforum.com/csforum//showthread.php?t=2759

 

[DBfan187 5,000+ posts]

post in that thread and RC just might show up too. lol

 

[Bassman999 10+ year member]

I though Richard Clarks' test was to compare 2 amps, one low end and one high end, and u tell him which one is which? I didnt think it was to tell the difference between amp classes?

Anyway I love good sound quality. With that being said I am far from a SQ setup. My best sounding system was in my 91 Prelude. I had linear power 2502 iq's running. I had 3 of them i for the front mids and highs, and 1 for each sub. It was the most musical setup I have ever had. My friends still talk about it. I dont know how much the a/b amps impacted that. I think the actual vehicle you use is extremely relevant in SQ. Install, things like tweeter location are very important too. So what am I saying? My one remaining LP amp is still my fav amp, but I run a class d to my sub(s) these days because the current draw of a/b is just too much. I have a pro audio amp crest audio cd2000. It is a full range class d. I think it sounds better than the cc 1800 a/b that it replaced. So I cant choose a side.

 

[rc10mike 10+ year member]

According to that FAQ, It looks as if there were no sub amp tests.

 

[DidUHearThat? 10+ year member]

According to that FAQ, It looks as if there were no sub amp tests.

How does that change the claim that you can hear the difference between class D vs AB amps?

It doesn't.

 

[rc10mike 10+ year member]

How does that change the claim that you can hear the difference between class D vs AB amps?
It doesn't.

Read the title of this thread...

After all, I have a class D mid/high amp..

 

[gunz4me 10+ year member]

I though Richard Clarks' test was to compare 2 amps, one low end and one high end, and u tell him which one is which? I didnt think it was to tell the difference between amp classes?

Actually knowing Richard Clark, he will probably throw some other amps into the mix to see if you can tell the difference! If you bring two amps, you run the risk of guessing correctly, but if he throws in two of his own, now you have a 1 in 4 chance of getting it right every time

Anyway I love good sound quality. With that being said I am far from a SQ setup. My best sounding system was in my 91 Prelude. I had linear power 2502 iq's running. I had 3 of them i for the front mids and highs, and 1 for each sub. It was the most musical setup I have ever had. My friends still talk about it. I dont know how much the a/b amps impacted that. I think the actual vehicle you use is extremely relevant in SQ. Install, things like tweeter location are very important too. So what am I saying? My one remaining LP amp is still my fav amp, but I run a class d to my sub(s) these days because the current draw of a/b is just too much. I have a pro audio amp crest audio cd2000. It is a full range class d. I think it sounds better than the cc 1800 a/b that it replaced. So I cant choose a side.

I hear you on the Linear Power amplifiers because they are my favorites too

As for subs, a couple of months back, I thought I could tell a difference between Class AB and Class D, then I noticed some idiot gain/bass boost settings combined with the use of the head unit's loudness feature and overzealous use of the bass control too. In other words, bonehead setups were to blame not the topology of the amplifier. I will say this though, most Class D amps clip harder and faster than most of the Class AB amplifiers I am used to dealing with, especially with retarded settings...

I even thought I could tell the difference in my Mustang which is the Rockford Fosgate 25 to Life Power 1000 that is Class AB on the front/rear channels and class D on the subwoofer channel. Well, come to find out, the dorks at the Ford dealership messed with ALL my radio settings and amp gain settings when I brought my Mustang in for a factory recall. If there is ever a next time, I am pulling the face to the radio!

 

[DidUHearThat? 10+ year member]

I though Richard Clarks' test was to compare 2 amps, one low end and one high end, and u tell him which one is which? I didnt think it was to tell the difference between amp classes?
Anyway I love good sound quality. With that being said I am far from a SQ setup. My best sounding system was in my 91 Prelude. I had linear power 2502 iq's running. I had 3 of them i for the front mids and highs, and 1 for each sub. It was the most musical setup I have ever had. My friends still talk about it. I dont know how much the a/b amps impacted that. I think the actual vehicle you use is extremely relevant in SQ. Install, things like tweeter location are very important too. So what am I saying? My one remaining LP amp is still my fav amp, but I run a class d to my sub(s) these days because the current draw of a/b is just too much. I have a pro audio amp crest audio cd2000. It is a full range class d. I think it sounds better than the cc 1800 a/b that it replaced. So I cant choose a side.

Is there one sentence that can describe what the test is designed to show? When compared evenly, the sonic differences between amplifiers operated below clipping are below the audible threshold of human hearing

...

How can audio consumers use the results of this test?

When purchasing an amplifier, they can ignore the subjective sound quality claims of marketers. Many amplifier marketers will claim or imply that their amplifiers have some special topology, materials, or magic that makes the sound clearly superior to other amps at all volume levels. Many consumers pay several times more than they otherwise would for that intangible sound quality they think they are getting. This test indicates that the main determinant of sound quality is the amount of power the amplifier can deliver. When played at 150W, an expensive 100W measured amplifier will clip and sound worse than a cheap 200W measured amp.

Does this mean all amps sound the same in a normal install?

No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. The gain setting of an amplifier can make huge differences in how an amplifier sounds, as can details like how crossovers or other filters are set. When played very loud (into clipping), the amplifier with more power will generally sound better than a lower powered amp.

Most people perceive slight differences in amplitude as quality differences rather than loudness. The louder component sounds “faster, more detailed, more full”, not just louder. This perceptual phenomenon is responsible for many people thinking they liked the sound of a component when really they just liked the way it was set up.

I changed amps in my system to another one with the same measured power and I hear a sound quality difference. Does this show that the test results are invalid?

No. Installing a new amplifier involves setting the gains and crossovers, and any slight change you make to those settings is going to affect how things sound.

Do the results indicate I should buy the cheapest amp?

No. You should buy the best amplifier for your purpose. Some of the factors to consider are: reliability, build quality, cooling performance, flexibility, quality of mechanical connections, reputation of manufacturer, special features, size, weight, aesthetics, and cost. Buying the cheapest amplifier will likely get you an unreliable amplifier that is difficult to use and might not have the needed features. The only factor that this test indicates you can ignore is sound quality below clipping.

If you have a choice between a well built reliable low cost amp, and an expensive amplifier that isn't reliable but has a better reputation for sound quality, it can be inferred from this test that you would get more sound for your money by choosing the former.

http://www.tom-morrow-land.com/tests/ampchall/index.htm