Originally posted by Sydney
View Post
Announcement
Collapse
No announcement yet.
Class D Amp Specs
Collapse
X
-
Re: Class D Amp Specs
-
Re: Class D Amp Specs
Originally posted by Deward Hastings View PostThere is also the argument (probably more correct than not) that the kind of distortion and output level at which it occurs matters as well. It is not uncommon for a Class AB amplifier that measures very low simple harmonic distortion at high power nevertheless sounds terrible at low power where crossover distortion dominates. This is the area where Class A and Class D amplifiers shine . . . while they often measure with slightly higher simple harmonic distortion (which is nevertheless for all practical purposes inaudible at any level) the lack of crossover distortion generally results in a much "cleaner" sound at the low output levels (the "first Watt") more common in home listening.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Sydney View PostTube amps may not have the lowest HD measurements at the extremes of their performance envelope, but this is less objectionable than non-harmonic distortion.
Some speaker distortions may also not be particularly objectionable, such as the nonlinear responses near the excursion extremes of the voice coils. This is also probably more of a soft clipping situation as long as they don't run into a hard stop.
As for an example of non-harmonic distortion, I have seen only a fleeting mention of intermodulation distortion other than to note that it is quite objectionable.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Whitneyville1 View Post... What I really love are the new DTV final amps. Channel 9's "blockhouse" I've been in. 7.8 megawatts effective output at 0% distortion. ...
Audio systems are really asked to make some extreme performance contortions as compared with the RF domain. Zoom camera lenses have a comparable problem: Try to design a really good 20:1 zoom with imperceptable pincushion, barrel, and chromatic aberration throughout its range, and at reasonably fast apperture. There are ~3:1 fast zooms that are nearly perfect, but beyond that, the compromises start showing.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by dpasek View PostIt's the coupling between the engine and the planetary gearing for the Turbo Hydramatic 400 that has been very popular for many years in drag racing because it's almost bullet-proof. Those aren't worth anything to some people but worth their weight in gold to others. Depends on your priorities.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Pallas View PostWhat is this "torque converter" thing?
Certainly nothing that exists on any automobile worth anything!
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by PWR RYD View PostThan what does win races
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by CUtiger View Postclass D topology(B&O ice module) the first thing I noticed was that it sounded better at lower volumes. . . . wonder if this has anything to do with it?
At moderate levels the differences are not nearly as noticable.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Deward Hastings View PostThere is also the argument (probably more correct than not) that the kind of distortion and output level at which it occurs matters as well. It is not uncommon for a Class AB amplifier that measures very low simple harmonic distortion at high power nevertheless sounds terrible at low power where crossover distortion dominates. This is the area where Class A and Class D amplifiers shine . . . while they often measure with slightly higher simple harmonic distortion (which is nevertheless for all practical purposes inaudible at any level) the lack of crossover distortion generally results in a much "cleaner" sound at the low output levels (the "first Watt") more common in home listening.
At moderate levels the differences are not nearly as noticable.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Deward Hastings View PostThere is also the argument (probably more correct than not) that the kind of distortion and output level at which it occurs matters as well...the low output levels (the "first Watt") more common in home listening.
The top portion of the "envelope" is where the brief peaks occur: That area of power output will be of more signifcance: If a wide crest factor or dynamic range is required and the speakers are not sensitive.
Leave a comment:
-
Re: Class D Amp Specs
Originally posted by Sydney View PostOEM Class D amp manufacturer's are often of the opinion that there is too much emphasis on amplifier distortion figures, considering the level of distortion in loudspeakers is much higher.
Leave a comment:
-
Re: Class D Amp Specs
This is an obvious divergence:
Does anyone think an engine producing 8000 hp short term can do so for 24 hours ( the engines are torn down and rebuilt in 75minutes after every run )...
http://www.hotrod.com/techarticles/e...d/viewall.html
By the same token an amplifier test can produce a high short term number for domestic persuation but that operating condition is not long term. Amplifiers have protection ( or should ) for being driven beyond a "performance envelope" .
The better amplifier manufacturers publish a variety of test conditions including extreme ( short term ), or continuous duty or fault tolerance.
Any semiconductor manufacturer knows the relationship between operating temp and device life.
OEM Class D amp manufacturer's are often of the opinion that there is too much emphasis on amplifier distortion figures, considering the level of distortion in loudspeakers is much higher.
They also advocate that the testing methodology for Class D is not the same as Class A & AB.Last edited by Sydney; 05-15-2012, 12:37 PM.
Leave a comment:
-
Re: Class D Amp Specs
Length of the race (time or distance) has nothing to do with it. In every form of racing the goal is to have both superior power and adequate endurance. A part's failure at 3 seconds into a 1/4 mile race can be just as bad as a part's failure 23 hours into a 24 hour race. Having 20% less power than your competitors is just as much of a disadvantage regardless of the type (length) of racing. FIA, or F1, or NASCAR, or NHRA... they are all trying to win the power vs. parts life game.
Leave a comment:
-
Re: Class D Amp Specs
Than what does win races
One favors short term power over parts durability and endurance.
Leave a comment:
Leave a comment: