Question on class D amps

WWC said:

I have a question about class d amps and the technology that they are today. Whe  they first became popular in the late 90s/early 2000s they were strictly a high efficiency, low frequency, low sound quality amplifier that was suitable for subwoofer amplification only. I see now on sites selling class d amps that are a full frequency amp that is to be used on more than just subwoofer amplification. 

My question is when the class d technology changed from the 'highly efficient, low frequency/low sound quality' subwoofer amp that it was in the late 90s/early 2000s to the full range amp suitable for full frequency speaker amplification that it is now??

Thanks!!

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Its been like that for awhile, they massively improved the way it outputs the signal to the point where its literally no different from class A/B in the higher end class Ds.  Legendary sound quality brands like hertz, zed audio, hybrid audio technologies are also moving to class D.   In a high dollar amp setup, there is no difference in sound quality from class A/B and class D however class D will literally have double to triple the power class A/B does at half to 1/4 the size and keeps ice cold. if you want a cheap little test, get a pioneer gm 8704 to play around with. Pretty cheap price point with a lot of power but decent build quality. Not the best in sound quality compared to the high dollar class Ds but you'll still see how far the technology has gotten even with the budget class D amps.

I've been running class d full range on my mids  (Rockford 1000-4ad) since 2011 and have never looked back....it replaced a old Mb quart QAA 2500 

Jeffdachef said:

Its been like that for awhile, they massively improved the way it outputs the signal to the point where its literally no different from class A/B in the higher end class Ds.  Legendary sound quality brands like hertz, zed audio, hybrid audio technologies are also moving to class D.   In a high dollar amp setup, there is no difference in sound quality from class A/B and class D however class D will literally have double to triple the power class A/B does at half to 1/4 the size and keeps ice cold. if you want a cheap little test, get a pioneer gm 8704 to play around with. Pretty cheap price point with a lot of power but decent build quality. Not the best in sound quality compared to the high dollar class Ds but you'll still see how far the technology has gotten even with the budget class D amps.

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So when you say not the best in sound quality does that mean it doesn't sound good or it just takes more tuning?

Jeremy11 said:

So when you say not the best in sound quality does that mean it doesn't sound good or it just takes more tuning?

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It means one weirdo out of 100 will try to explain how it "lacks warmth" and sounds "digital" or some other BS in a poor attempt to justify the huge, heavy, inefficient tank of an expensive amp they just bought.

And the rest of us will say it sounds great

Jeremy11 said:

So when you say not the best in sound quality does that mean it doesn't sound good or it just takes more tuning?

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Im actually nitpicking as hell when i say not as good. Mainly a little less resolution and more noticeable when clipping. The difference is very small. Everything else matters a million times more than the amp given you have a powerful enough amp with headroom for your application aka 1.5 x 2 rms headroom

Not that this is entirely the factor but you can tell when class AB amps from the early 2000s had S/N of the upper 70s and today have around 100, when the Class D full range meet that 100 or greater in S/N, it shows.

The key is headroom with class d amps otherwise they are un-equalizable nightmares when pushed too hard. They sound very good when used appropriately but there are reasons why Brax, Thesis, Phass and other no compromise brands stay away from class d.

WWC said:

My question is when the class d technology changed from the 'highly efficient, low frequency/low sound quality' subwoofer amp that it was in the late 90s/early 2000s to the full range amp suitable for full frequency speaker amplification that it is now??

Thanks!!

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 Xtant made the first one (at least for car audio) in the early 2000's. This was the only article I found on it, dated 2003.

http://www.superstreetonline.com/how-to/aftermarket-parts/0309-impp-car-amplifier

If it matters on this post here but, I have 2 4ch Kenwood XR401-4 High Definition certified amps in my High Def system. These amps are
class D amps and there certified High Def. That is how far the technology has come. Plenty of power and sound good.
One amp in 4 ch mode power my High Def Pioneer component 6.5 speakers 4 corners and One amp bridged into 2 ch for two
8 inch subs.

stephgirl said:

If it matters on this post here but, I have 2 4ch Kenwood XR401-4 High Definition certified amps in my High Def system. These amps are
class D amps and there certified High Def. That is how far the technology has come. Plenty of power and sound good.
One amp in 4 ch mode power my High Def Pioneer component 6.5 speakers 4 corners and One amp bridged into 2 ch for two
8 inch subs.

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see this is how snake oil works

according to that high-res logo you hold so dear
<Analogue process>

• (1) Microphone response performance: 40 kHz or above during recording
• (2) Amplification performance: 40 kHz or above
• (3) Speaker and headphone performance: 40 kHz or above

and according to kenwoods own specs on your xr401-4

so that means below 20 or above 20khz its over + or minus 1 db, usually a staggering roll off (notice the jas doesnt give strict parameters that qualify)

and techically most amplifiers can output over 40khz (not that we could hear it anyway) so that japan audio society is just a license firm for companies to pay and use that logo to dupe suckers into thinking they are getting something special

there is nothing high def about an analog amplifier unless it has coax or fiber input and does its own d/a

staan said:

see this is how snake oil works

according to that high-res logo you hold so dear

Japan Audio Society | Hi-Res Audio Logo

オーディオの普及に向けた活動や情報提供を行い、「オーディオ・ホームシアター展」等のイベントの開催など、オーディオに関わるイベントを主宰する日本オーディオ協会の公式WEBサイト

www.jas-audio.or.jp

<Analogue process>

• (1) Microphone response performance: 40 kHz or above during recording
• (2) Amplification performance: 40 kHz or above
• (3) Speaker and headphone performance: 40 kHz or above

and according to kenwoods own specs on your xr401-4

Frequency Response	20-20kHz(±1dB)

so that means below 20 or above 20khz its over + or minus 1 db, usually a staggering roll off (notice the jas doesnt give strict parameters that qualify)

and techically most amplifiers can output over 40khz (not that we could hear it anyway) so that japan audio society is just a license firm for companies to pay and use that logo to dupe suckers into thinking they are getting something special

there is nothing high def about an analog amplifier unless it has coax or fiber input and does its own d/a

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say what you want, but the main thing is that it is sounding good for me and that is what matters. I have heard the pros and cons of High Def. High def is higher bit rates also that capture more of the music info that is being produced. And that is also in the 20 to 20,000 hz area too. So it is not just the 40,000hz or so but the higher resolution that exceeds CD sound. There is more to High Def sound then you say

So for you staan if you don't like it or think it is snake oil then it is not for you. Continue using your cassette tape. But for many others and the music industry that is producing more high resolution recording there is a difference. It is good to here both sides of an argument or new technology. But to come out and say it is just snake oil is wrong and deceiving.

But the whole point was to comment on the original post about Class D amp technology and how far it has come. To extend the conversation in a meaningful way. Sorry WWC for Staan for straying away from your original post. Staan you just photo bombed on WWC post and he was a newbie, Should of commented something about your experiances with Class D technology. Staan what is your experiances with Class D and add to WWC post. Your post was posted in the wrong post anyway. Should of posted in the original post about High Def audio. but its ok I will not attack you. I still like you.

What i posted is great for a new person cause it makes them think logically by looking at specs and actual meanings of terms and not trust marketing BS I've also been recording, mixing and mastering high bitrate audio since the earlier 90's so your cassette comments are just stupid.

snake oil.....in a blind test you wouldnt be able to hear the difference between your amps vs another brand....psychoacoustics

.......vs a "reputable brand"