Do Class D Amplifiers Deliver Rated Power?

[Old_School_Brad]

Probably. That's what the Internet is for
..it's probably horses for courses...

On point!

 

[wwenze]

Probably. That's what the Internet is for

I also agree that what people experience in the real world - e.g. wanting to play a sustained bass line at 30Hz to 60Hz for 3 minutes at high power - seems probably tougher than using a sine wave to measure clipping point at 30Hz for 20 seconds into a resistive load. All I can add, is that, having done both the sustained bass line and the sine wave testing ( ) , sine wave testing is a great deal more brutal with much quicker temperature rise than the sustained bass line! However, 3 minutes of sustained load is obviously also tougher than 10 seconds. So it's probably horses for courses...

A signal of 0dBFS continuous regardless of frequency (and mathematically the frequency wouldn't matter) would definitely be more demanding than a signal of 0dBFS for 10% of the time. (Frequency would matter for power supply output impedance i.e. capacitor sizing, but not heat.)

Currently nobody knows what % is acceptable.

I skip the worry and settle with 100%

 

[livinon2wheels]

Here is what I believe to relevant. This applies to movies or music, it really makes no difference. When I am sizing a system for my home, I asked myself, what do I need to reproduce is a rock concert at live levels. Then I pick components that will give me approx 115 db at one meter. Realistically, I dont listen at those levels for even a minute. But this is the headroom built into the system. It needs to be able to do that on peaks. But I base it off RMS power available and speaker sensitivity. Not exact, but close enough for government work. With a system so designed I have never felt it to be inadequate in any way. my average level might be 85 or 90 db I need to be able to reproduce the dynamic range that exists above and below the average level. If I cannot do this I will ultimately start looking for upgrades.

 

[Waxx]

It all depends on the music, and music with a long continues bassline that low is rare. Dub and dubstep are sometimes like that and both genres have their subwoofer killer tracks, that not many subwoofers can handle (mostly because the amp distort). This is such a track (but youtube so filtered). The original digital ep goes down to the low 20's and vinyl to about 30hz.

This track has quiet a few subs on it's killlist (pun intended ). But off course most music is not that demanding for subbass. And most of you won't need this kind of rms power for bass.

 

[Jukka]

I would like people's opinions who have owned and/or tested class D amplifiers.

In general, do they deliver their rated power at all sine wave frequencies from 20Hz to 20KHz, both channels driven, for an indefinitely long continuous period of time without clipping (lots of debate over how much distortion is audible, so I'll be easy on the amps and consider their max power to be what they output just below clipping) and deliver that into typical loudspeaker loads?

By the way, I do not refer to "rms power" because there is no such thing. The definition of RMS does not apply to power. I am asking about continuous long term power both channels driven over the entire range of frequencies generally considered to be audible to most humans.

In short: yes they do, but their definition of "rated" is different from what you write.

In my opinion it would be a lot easier to compare amplifiers if all power ratings were given before clipping.

 

[Waxx]

In short: yes they do, but their definition of "rated" is different from what you write.

In my opinion it would be a lot easier to compare amplifiers if all power ratings were given before clipping.

There surely should be a standard for this, and both RMS and peak ratings should be in it at a certain distortion (a bit like Amir does it) if you ask me. Now power ratings are defined like the manufacturor wants it, and they don't always specify how they define it.

 

[Bjorn]

The Vera Audio P400/1000 achieves these numbers continuously:

Stereo, both channels driven at 8 ohms:
– 400W with maximum 1% THD+N
– 330W with maximum 0.01% THD+N
– 300W with maximum 0.004% THD+N

Stereo, both channels driven at 4 ohms:
– 750W with maximum 1% THD+N
– 620W with maximum 0.01% THD+N
– 550W with maximum 0.004% THD+N

Bridged, driven at 8 ohms:
– 1500W with maximum 1% THD+N
– 1100W with maximum 0.01% THD+N
– 800W with maximum 0.004% THD+N

 

[mhardy6647]

The Vera Audio P400/1000 achieves these numbers continuously:

Stereo, both channels driven at 8 ohms:
– 400W with maximum 1% THD+N
– 330W with maximum 0.01% THD+N
– 300W with maximum 0.004% THD+N

Stereo, both channels driven at 4 ohms:
– 750W with maximum 1% THD+N
– 620W with maximum 0.01% THD+N
– 550W with maximum 0.004% THD+N

Bridged, driven at 8 ohms:
– 1500W with maximum 1% THD+N
– 1100W with maximum 0.01% THD+N
– 800W with maximum 0.004% THD+N

Out of not entirely academic curiosity: Achieves these numbers continuously across what band of frequencies?
If on the order of 20 Hz to 20kHz, this is what I would call a 300 watt per channel amplifier (FWIW, which, admittedly, ain't much).