DSD ultrasonic filter, yes or no

[nonesup]

I currently have activated the ultrasonic filter for DSD, since I read that the high frequency noise of DSD 64, can break the tweter. The fact is that I like the music without the filter, I would like to know your opinion on whether you can deactivate the filter safely, considering that my speakers have beryllium tweter.

 

[audio.bill]

I would suggest checking directly with Rockport or their dealer for the question of whether it's safe to play unfiltered DSD with their speakers. The tweeter diaphragm being beryllium isn't really the determining factor, more an issue of whether its voice coil can handle the level of such high frequency output. I've heard of it being a problem with true ribbon tweeters, but bandwidth of the driving electronics and cables can also be a factor. Better to be safe than sorry, especially with the high level of your system.

 

[YuriKorzunov]

Couple weeks ago I appied new 100 kHz filter in my AuI ConverteR (will available online in February 2017).

For D64 sample rate there too many ultrasound noise. In my case there lost about 2 dB of dynamic range.

Technically possibly move sigma-delta-modulation noise out of playback band more. But it can cause more unstability of the modulator.

For wide band in some apparatus may be caused additional audible noise.
Because the apparatus have non-linear distortions, and intermodulation products of inaudible ultrasound will rised in audible range.
But level of the audible products by ultrasound depend on apparatus, of course.
For some apparatus it is not issue.

For D128 noise picture is better than D64.

For D256 and D512 the picture more better.

For D1024 band 100 kHz have level noise about 32-bit float PCM.


As I understand, DSD initially purposed for playback 0 .. 20 kHz range with noise level better than CD.

Playback non-filtered DSD:
1. Give wider playback band
2. May cause additional noise in audible range
3. Decrease dynamic range

 

[jfrech]

Nonesup,

I have Rockports also but a different DAC. I haven't had any issues...

 

[nonesup]

Thanks to all three.
An inexperienced question, the possible harm will be, proportional to the volume of listening, or is it independent?

 

[jfrech]

Thanks to all three.
An inexperienced question, the possible harm will be, proportional to the volume of listening, or is it independent?

Volume...my guess this is more if something doesn't lock on and you get some nasty digital noise vs listening to music.

 

[wklie]

Lumin players are shipped with this setting disabled by default since 2013, and so far I believe we have no user saying leaving this setting disabled killed their tweeters. We never enable this setting except for testing.

I agree with audio.bill that it's best to check with Rockport if you are concerned about it.

My understanding is that clipping, underpowered amplifier producing distortion, too high volume, DC offset, etc. are the common things that fry tweeters.

 

[Nikhil]

Thanks to all three.
An inexperienced question, the possible harm will be, proportional to the volume of listening, or is it independent?

What software are you using for playback? Sound quality is affected by the quality of the re-sampling filter and the appropriate noise shaping/dither algorithm. Enabling the filter is recommended as there is a fair amount of noise in the ultra high frequency spectrum.

Here is spectrum for a PCM 32/384 file which is comparable to DSD64

And here is the DSD 128 spectrum of the same file:

 

[nonesup]

Well, I use a Lumin A1, with Minimserver on the NAS

 

[Nikhil]

Well, I use a Lumin A1, with Minimserver on the NAS

DSD playback with the A1 is very well regarded as is the Wolfson WM8741 chip it uses.
Not sure what the issue could be but since you can't access the software not much can be done.

I would recommend leaving the filter on until you hear from Lumin/Rockport.