Class D Technology

I've been living with ICEPower based amps for six months, I don't hear any of the issues being discussed, and my speakers have extension beyond 30kHz. 

 
Some folks hear the issues and others don't. Some folks are really sensitive to phase/point source issues or maybe they focus on the image across the soundstage. If someone told me that the image was off, I would just shrug and keep enjoying my gear/music because it's not something that I notice.    

Speakers shift phase much more (in opposite direction) at higher frequencies.  Imaging should be OK as long as phase in both channels match (no reason not to).  As for the switching noise - I cannot hear 500kHz, but I'm pretty sure some people here will claim they can.

I cannot hear 500kHz

Nobody can hear 500khz, it the filter that has to deal with it and what's left over and the byproducts of it that is the problem.

Read the link and carefully try to absorb it.
http://epc-co.com/epc/GaNTalk/Post/13752

Cheers George

Erik,

     I agree with you that, if I can't detect any issues in the audible range on my current class D amps due to their switching frequency being not high enough, than there is no need for concern and I should just enjoy them and my music.  Actually, this is what I've been doing since I installed the amps, I just tried to intently listen for any issues for a short period when I first heard of this theoretical issue.  

      Once an affordable class d amp with a switching frequency in the 3-5 mega hz range is on the market and there are any objective or even subjective reports that it sounds significantly better than current amps, I'll audition one.   I believe this is a more effective approach than not using class D until the theoretical  performance benefits of a 3-5 mega hz switching frequency becomes a reality, since the numerous benefits of class D amplification will not be utilized and enjoyed between now and then.      
      I would think just 2 of class D's benefits, sound quality and electricity cost savings, would be sufficiently convincing for many to switch right now.  If it's only going to get better, upgrade to class D now and then upgrade again whenever you determine future improvements are worth it.  The cost of world-class amplification has never been less expensive,as long as you're willing to be open minded, a bit more adventurous and let your ears guide you.


Enjoy,
 Tim  
 

Nobody can hear 500khz, it the filter that has to deal with it and what’s left over and the byproducts of it that is the problem.

What is left over is 500kHz. Byproducts are possible (modulation), assuming nonlinearity of motion, if tweeter can move membrane at 500kHz - no chance.

Filter or frequency have very little to do with quality of the sound, IMHO. It is related to quality of the modulator, slew rate of output devices (accuracy of the duty cycle), ringing caused by inductance and capacitance of output devices etc. Actually, increasing switching frequency can make it worse because it will reduce accuracy of the duty cycle - calling for deeper NFB. As I showed before (using 50kHz Lamm amp as an example) phase delay in audio band has nothing to do with extension and, if anything, might be beneficial since most of the speakers accelerate phase (much more) at these frequencies.

Also, increasing switching frequency will reduce amount of residue on the speaker cable but at the same time it will make it radiate much better.