Please explain the differences between the class A/B amps and the D amps?

[45js45 10+ year member]

Please explain the differences between the two?Is there a sound difference?Do the class D amps get hot like the old school amps?

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[Horsemanwill 10+ year member]

ZED AUDIO CORPORATION

readign is fun

 

[Magnus 10+ year member]

Class D is more efficient and used mostly for mono block amps. There are a few full rang class D amps howeva. A/B are less efficient and typically used for full rang amps.

 

[Buck 5,000+ posts]

ZED AUDIO CORPORATION
readign is fun

So is spelling //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Horsemanwill 10+ year member]

spelling is over rated

 

[bubbagumper6 5,000+ posts]

It's the way the electronic circuitry is designed, most likely we could explain the difference and you wouldn't understand...Class D's are more efficient but are generally not as clean as AB which is why they are mostly used for bass (where SQ isn't a concern).

 

[cleansoundzz 10+ year member]

The key to getting the best sound quality out of a class D amp is not running it at 1 ohm. If you can run a class D amp at 2 ohms or 4 ohms, the bass will generally be a lot tighter. The amplifier itself will be much more efficient as well when running at 2 or 4 ohms.

 

[Buck 5,000+ posts]

The key to getting the best sound quality out of a class D amp is not running it at 1 ohm. If you can run a class D amp at 2 ohms or 4 ohms, the bass will generally be a lot tighter. The amplifier itself will be much more efficient as well when running at 2 or 4 ohms.

Try to tell the bassheads that.

 

[cleansoundzz 10+ year member]

You are right. I have heard the differences between running a good class D amp at 1 ohms and 4 ohms and it is very noticeable. Plus the amp runs much cooler at 4 ohms.

 

[helotaxi 5,000+ posts]

Running 1/4 the current makes it run cooler? Who'd have thought...

 

[45js45 10+ year member]

I will likely be putting in a class d for the subs and running it at either 4 or 2 ohm....most likely 2.I am unfamiliar with class d,my question is how much air for cooling do they need?It will be placed in a storage pocket behind the seat.I remember my old RF and PPI amp running very hot.Will the class d run cool enough not to need much air flow?

 

[RAM_Designs 5,000+ posts]

I will likely be putting in a class d for the subs and running it at either 4 or 2 ohm....most likely 2.I am unfamiliar with class d,my question is how much air for cooling do they need?It will be placed in a storage pocket behind the seat.I remember my old RF and PPI amp running very hot.Will the class d run cool enough not to need much air flow?

Class D's can run very cool so long as you're not running them below their rated ohm loads, and you're not pushing it very hard. Maybe put a couple of 12V computer fans back there to keep air moving. I did that for my under-seat amp(Sundown 1500D) and it worked very well. I cut a couple of strips of MDF to lift the amp off the floor 3/4" as well.

 

[RAM_Designs 5,000+ posts]

Running 1/4 the current makes it run cooler? Who'd have thought...

Who said he was pushing the amp to the max in both instances?

 

[gunz4me2 10+ year member]

The advantage to class D is that they are more efficient at lower volume when it comes to current draw versus your typical AB amplifier. Generally, a typical class AB amplifier will draw 50 to 75% of its maximum current draw at lower volume levels whereas a class D will draw less. Class D amplifiers also tend to run cooler, but this isn't always the case (*cough, choke* the new Alpine PDX).

As for which one sounds better on subwoofers... Until someone shows me a double blind test with statistical relevance, I am going to say that a quality class D amplifier compared to a quality class AB amplifier will not make a difference on subwoofers.

Why?

1. Because it is reproducing the area of the sound spectrum where the human ear is least sensitive to changes in frequency.

2. Because it is installed in a freaking car! What is the lowest noise floor to overcome? 60 dB in the most quiet of vehicles and 90+ dB in the noisiest of vehicles? Sure, I believe all these individuals who hear a difference between the different quality amplifier class topologies.//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[bubbagumper6 5,000+ posts]

The advantage to class D is that they are more efficient at lower volume when it comes to current draw versus your typical AB amplifier. Generally, a typical class AB amplifier will draw 50 to 75% of its maximum current draw at lower volume levels whereas a class D will draw less. Class D amplifiers also tend to run cooler, but this isn't always the case (*cough, choke* the new Alpine PDX).
As for which one sounds better on subwoofers... Until someone shows me a double blind test with statistical relevance, I am going to say that a quality class D amplifier compared to a quality class AB amplifier will not make a difference on subwoofers.

Why?

1. Because it is reproducing the area of the sound spectrum where the human ear is least sensitive to changes in frequency.

2. Because it is installed in a freaking car! What is the lowest noise floor to overcome? 60 dB in the most quiet of vehicles and 90+ dB in the noisiest of vehicles? Sure, I believe all these individuals who hear a difference between the different quality amplifier class topologies.//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

I don't think anyone was arguing that there's an audible difference between the two in the subwoofer range...I certainly wasn't