db Poweramp recommends converting DSD to PCM @ 96khz?

[tboooe]

I've been using JRiver Media Center to convert my DSD files to 176khz, 24bit files. I only chose 176 because I think I read somewhere thats ideal (real scientific huh?). Anyway, I decided to switch to db Poweramp to do the conversion and on its codec page it recommends converting to 96khz because "by default 96KHz is used, this is the best frequency to use for reasons of ultra-sonic noise. DSD has a sample rate of 2.8MHz, known as D64, or 5.6MHz (D128), but only 1 bit, which creates high frequency ultra sonic noise when decoded to 352KHz, or 704KHz. In-fact it is our understanding that SACD players are recommended to have a low-pass filter of 50KHz to filter out this high frequency noise (you cannot hear it, but your cat or dog might, also the tweeters on the speakers might run hot from it). By using a 96KHz file this noise is pretty much filtered. It is possible to decode to any number of frequencies, anything above 96KHz should use a low pass filter (DSP effect), ideally set to 48KHz (which is the same as decoding to 96KHz)."

 

So a couple of questions...

 

1. can I really hurt my speakers by converting to 176khz?

2. what is the ideal sample rate?

[firedog]

1. Doubtful. And what about your DAC? Does it upsample internally and/or apply a filter during processing? If so, then it really doesn't matter. And BTW, everything DBP said about 96k will apply to resampling to 88k also. I believe in any case that the JRiver conversion by default applies a pretty steep filter, so that would also take care of the problem.

 

2. You can get lots of different answers from different people. It is at least partly person and system dependent.

 

For instance, Berkeley Audio says a proper 176k conversion of DSD is actually superior sounding to DSD playback. Lots of users here will vehemently say the opposite, or will even upsample DSD to 2X or 4X DSD for playback. You have to try different resamplings and see what sounds best to you or if you even hear any difference on your system.

[audiventory]

1. can I really hurt my speakers by converting to 176khz?

 

If conversion is not accurate and may be for some speakers, for very very long work time, theoretically - may be.

 

It depend on used hardware/playback software.

 

But practically, I suppose, even not accurate conversion should not damage tweeters due ultrasound.

 

Ultrasound first can lead to additional noise in audible range due non-linear distortions for some audio systems.

 

Possibly use DSD conversion software with ultrasound limiting for «best sounding» sample rate of your DAC.

 

 

 

2. what is the ideal sample rate?

 

 

Properly working DSD to PCM converter provide same quality as for 44.1xN as for 48xN kHz output sample rate ranges.

 

You can use:

1. non-oversampling DAC (that playback incoming sample rate as is)

 

2. DAC with pass by (turn ON/OFF) builtin oversampling

 

3. DAC with always turned on builtin oversampling

 

You can:

 

A. Found «best sounded» (for you) sample rate (mentioned above)

 

It may be not highest sample rate of your DAC.

 

If we can properly measure your system’s features, found such sample rate significantly simpler than on hearing.

But it is impossible for home.

This approach can be used for all cases #1 … #3.

 

B. Or use highest sample rate, also for cases #1 ... #3

 

Lots of users here will vehemently say the opposite, or will even upsample DSD to 2X or 4X DSD for playback. You have to try different resamplings and see what sounds best to you or if you even hear any difference on your system.

 

Here example how impact to noise floor oversampling D64 to D128 DSF oversampling. D64 vs. D128. Real advantage of sound?

 

But I suppose it depend or source record and converter (noise management during DSD resampling).

[ecwl]

When you convert DSD to PCM in JRiver to 176kHz, a low-pass filter is always applied. You can choose 24kHz, 30kHz or 50kHz.

[Skeptic]

The ultrasonic noise in DSD starts around 24kHz, and must be filtered out.

 

 

None of that is audio - it's all noise.

 

If your signal only extends to 24kHz, you could arguably convert that to a 48kHz PCM file without losing anything.

But 88.2kHz would be a better choice if you want to use a gentler filter. Absolutely no reason to go above that.

 

As long as you are filtering out the ultrasonic noise when converting to PCM, there should be no problems from using higher sample rates like 176.4kHz or 352.8kHz - there just isn't much reason to.

[audiventory]

Reason use higher sample rate may be due analog+digital filter system into PCM DAC can work more properly in these sample rates.

 

Analog filter isn't steep.

 

If we use low sample rate, analog filter (and even digital into DAC) may not provide enough supression of artefacts of digital-analog conversion. It depend on DAC, of course.

 

We can use slow accurate software online/offline pre-filtration (before DAC) ultrasound and use higher sample rate.

 

It allow DAC's filter part of future artefacts (DAC output noise) that, possibly, pass by to analog output DAC without pre-filtering.