Bandwidth Limitations Of Class D Amps??

Realize that switching frequency spec of a switching amp would seem to set a clear theoretical limit to what is possible with that design in terms of frequency response. But alone it does not determine sound quality, even as measured. It may determine an absolute limit in theory, but the reality is many factors affect amp performance, switching amp or not. Specs are informative but alone do not tell the whole story. Only our ears can do that and each story will probably be a bit different as a result, especially when it is differences in the fine details of what is heard that is in question.

Most Class D amplifier designs require a filter at the output to remove the high frequency switching noise that is present in the signal. Various designs use different types of filters with varying cutoff frequencies. I doubt that any are designed to remove frequencies under 20KHz, but Class D amps are generally more frequency limited at the high end than conventional output stages can be. Whether this is audible can be a subjective question. Some engineers feel that in order to avoid introducing any phase shift to the audible high frequencies requires an amp to have a flat bandwidth response extending to many multiples beyond the audible frequency limit.

My Gilmore Raptors are -3db at 60khz
Alan

"My Gilmore Raptors are -3db at 60khz"

Arh, are those Class D amps an end to end proprietary design by the maker or do they incorporate another company's Class D amp modules?

ANything more to back up the published specs?

-3db means there will be phase shift problems all the way down to 10khz.
Why some say the upper mids and top end is hard could mean the the filtering is too high and letting the nasty switching noise intrude.
Why some say the upper mids and top end is bland and opaque could mean the filtering is too low and effecting the harmonic content of the upper mids and highs.

This is why you'll see class d manufactures bringing out different versions or mk 1 2 or 3 They change the filtering to the above to either or a combo of both, which I think sounds the worst.
Once technology get more advanced and they invent components whith much higher switching frequencies so they then can use the filter so the effects and phase shifts of them are well out of the audible range then Class D will compete with the good of linear amps, until then it is comprimised, but great for subwoofers.

Cheers George