Behringer DCX2496 digital X-over - Page 38 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st September 2005, 04:26 AM   #371
sfogg is offline sfogg  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MA
"I think that might have something to do with 75 ohm S/pdif and expecting 110 ohm XLR connection."

I tend to doubt that. The difference in impedance isn't going to change just the samples for the high end... it doesn't work like that.

The non-audio data pre-amble bits in a frame of S/PDIF have different meanings between consumer and pro formats. I think one of the bits that is different is the bit for pre-emphasis. Possibly the Behringer is getting confused and applying/not applying pre-emphasis which would screw up the high end of the signal.

Shawn
  Reply With Quote
Old 21st September 2005, 10:12 AM   #372
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
It could be a problem of mistermination because the pulses will not be totally absorbed in the 110R load, causing a reflection to bounce back to the 75R source where it will be totally absorbed. However, the cable is quite short (<1m), so I doubt that a slight mistermination will have very much effect on pulse shape. I think the problem is far more likely to be that S/PDIF is typically only 0.5Vpk-pk unbalanced whereas AES3 is typically 5Vpk-pk balanced, so AES3 enjoys greater immunity from induced noise spikes.

Agreed (consumer) S/PDIF has a bit for invoking 50/15 equalisation, but it's highly unlikely that the (professional) Behringer is designed to act upon it. No, the occassional loss of HF is a symptom of it getting its knickers in a twist, no more, no less.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 21st September 2005, 12:46 PM   #373
diyAudio Member
 
Madmike2's Avatar
 
Join Date: Apr 2005
Location: Toronto
soooooo. what you are saying is that the S/PDIF cable into an XLR adapter will make my behringer DCX2496 accept digital input ?
__________________
Persistence is better then intelligence. Unless persistence kills you.
  Reply With Quote
Old 21st September 2005, 12:54 PM   #374
sfogg is offline sfogg  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MA
"Agreed (consumer) S/PDIF has a bit for invoking 50/15 equalisation, but it's highly unlikely that the (professional) Behringer is designed to act upon it. "

Pro format has pre-emphasis available on it to and has more available settings for pre-emphasis then consumer S/PDIF.

For Pro format S/PDIF transmissions it is configured with pre-amble bits 2,3 and 4 of byte 0.

Bit 2 is emphasis not indicated so it defaults to no emphasis but allows over-riding that setting based on bits 3 and 4.

In the consumer format pre-emphasis is also in Byte 0... however it is encoded in bits 3,4 and 5. Bit 2 (the start of the pre-empasis bits in Pro) is Copy Protect status.

It very well may be the Behringer is just flipping out but I have heard other times converting from Consumer to Pro caused a loss of treble in totally different equipment.

Shawn
  Reply With Quote
Old 21st September 2005, 04:37 PM   #375
diyAudio Member
 
Join Date: Feb 2001
Location: Mars
Quote:
Originally posted by Madmike2
soooooo. what you are saying is that the S/PDIF cable into an XLR adapter will make my behringer DCX2496 accept digital input ?
Don't mess around and buy that stuff I posted
  Reply With Quote
Old 22nd September 2005, 02:10 AM   #376
diyAudio Member
 
Madmike2's Avatar
 
Join Date: Apr 2005
Location: Toronto
Thanks Thy but i am going to buy a used Ultramatch they have at the pro shop for 63 bucks. that will kill two birds with one stone as it has a gain control on it so viola' i now have a pre amp

Only bad part is that it is NOT 192 capable
__________________
Persistence is better then intelligence. Unless persistence kills you.
  Reply With Quote
Old 22nd September 2005, 02:26 AM   #377
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Quote:
Originally posted by Madmike2
Thanks Thy but i am going to buy a used Ultramatch they have at the pro shop for 63 bucks. that will kill two birds with one stone as it has a gain control on it so viola' i now have a pre amp
Um, what you actually have is an expensive means of converting S/PDIF to AES3. The volume control is a means of increasing distortion.

The ideal solution is to convert your source to produce AES3 and to use stepped attenuators at the outputs of the crossover to ensure that the DACs are operated at their optimum level.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 22nd September 2005, 02:33 AM   #378
diyAudio Member
 
Madmike2's Avatar
 
Join Date: Apr 2005
Location: Toronto
hmmmm ... i dont know about expensive. The adapters he is speaking of come out to pretty much the same thing. And how would i introduce distortion to digital feed ?

Right now Winamp is my volume control ANYTHING will be better then that.
__________________
Persistence is better then intelligence. Unless persistence kills you.
  Reply With Quote
Old 22nd September 2005, 10:51 AM   #379
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Quite apart from whether the gain calculations and subsequent dithering are done correctly, if you send a signal to the DACs that has been adjusted to be a produce a quieter analogue signal, then you must have increased the distortion compared to operating the DACs at full resolution. Given that DACs aren't perfect, the optimum place for a volume control is after the DACs.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 23rd September 2005, 10:24 AM   #380
diyAudio Member
 
oehlrich's Avatar
 
Join Date: Feb 2004
Location: Bavaria Germany
Quote:
Originally posted by Madmike2
Only bad part is that it is NOT 192 capable

Madmike2,
look here, (http://freerider.dyndns.org/anlage/B...ut-Stage-E.htm) I built a 192Khz Interface. Works great!

Charly
__________________
For best results keep audio in the digital domain as long as possible
http://freerider.dyndns.org
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 04:22 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2