Behringer DCX2496 digital X-over

[oettle]

Using 16/44.1 audio data it’s best to set the digital output of your PC to 24/44.1. So there is no quality loss by a software SRC. Quality loss can be significant. Typical values of software SRCs are between -50 and -180 dB THD.
If you use digital volume control or you are not sure your software does set your digital output to 24 bit. That’s because 16 bit data is equivalent to a dynamic range of about 110 dB. With e.g. a -40dB volume set up the dynamic range is reduced to 70 dB. If your digital output supports 16/44.1 only avoid digital volume control and use an analog volume control between DACs and power amps.

The internal data rate of the DCX is always 24/96. So 24/44.1 kHz data needs to be up sampled by an ASRC. The THD of an AD1896 is about -140dB. To improve this value it is possible to up sample data by e.g. a -170dB software SRC. But you have to replace the digital input (PLL + ASRC) of the DCX by an USB to I2S converter which is synchronous to the DCX clock. If this converter has its own clock which is not synchronous to DCX there is an additional ASRC necessary. So total THD would get worse.

Because nobody is able to hear the difference between -140dB and -170dB this USB mod isn’t a high priority mod. More important are other components of your audio chain like DCX crystal oscillator (-70dB), DACs (-100 dB), analog outputs (? dB), power amps (-60 to -100 dB) and speaker drivers (very good ones -60 to -70dB). Nevertheless THD is added. So it’s a matter of choice where to start with modding.

[oettle]

Originally Posted by qusp

this also seems to disregard ASRC that doesnt change samplerate, only reclocks asynchronously wrt the input time, this can most certainly reduce jitter and it doesnt only have to do with spdif, just shifting the clock domain to the one local to and synchronous to the target dac.

Once again:
A SRC (sample rate CONVERSION) is always a conversion of time domain. Otherwise it is not a conversion at all. A SRC is NEVER LOSSLESS.

A SRC is like converting digital data to analog and back to digital again. But instead of a DAC and ADC there is a DSP with mathematical algorithms.

[oettle]

reCLOCKing is ALWAYS a change of time domain and therefore always needs a SRC.

[IMSTOOPID]

OK DOES ALL THIS Go out the window say when u put franks clock int he dcx and feed a direct 110ohm aes/ebu signal straight to the dcx main board at the transformer ??
would it matter feeding from a src or asrc device?

say a musical fidelity v link.. i got to think the aes connection is far superior to the spdif
at least in term of digital signal reflections.. which can cause jitter at the clock???

[IMSTOOPID]

asnswer V link 192~ it will output native input upsample(software) before you input the to the v link and presto feed the dcx 24/96 native.. much much better

go over to computeraudiophile.. there are some completely loss-less src converters..ie null test from one upscale to back to original and signal completely nulls..I said some.. no free one I have seen is completely lossless. that i have have found yet.. but it's better than letting the dcx upsample.

[linuxworks]

technically, an inverse function does not imply lossless.

if you map a to a-prime and then a-prime back to a, that conversion could be a proper inverse (not sure what the right math term is for that; symmetric? reflexive? I forget.) but a-prime may STILL be a lossy mapping.

[IMSTOOPID]

ok just been following the threads over at computeraudiophile(phool) I wish i could find the thread but in compares a lot of the SRC's and does a lot of testing showing which ones will null and some wont..if it nulls on a different SRC than the one it was upsampled on pretty good bet it's inaudible that's why I say loss-less i e upscale SRC "a" downscale on SRC "b" and you get a null.

but only a few do that no free ones.. the worst sounding ones are the one that lose phase linearity.

[Julf]

Originally Posted by IMSTOOPID

go over to computeraudiophile..

I'd rather not...

[IMSTOOPID]

lmao

YEA WELL WE STILL DON'T HAVE A STRAIGHT ANSWER IF ITS BETTER TO LET THE DCX UPSAMPLED OR FED IT A SOFTWARE UPSAMPELD 24/96 SIGNAL???

stoopid caps button

[oldies]

could a 2496 be used as a sound card of a measurement mic (ECM8000)? I know it has Phantom Power but I don't know how date should be transferred to PC