[lemm]

I am in need of a soundcard capable of Dolby Digital Live (DDL) and have come up with many options such as the older Sound Blaster X-Fi Surround 5.1 Pro and Asus Xonar U1or U3 to the newer Asus Xonar U7 and Sound Blaster Z.
 
Despite comparing specs on these cards there is still one factor that is not easily available that is of most importance: DDL latency. I'm hoping that users here with some experience would be able to advise on which soundcard would be best for this purpose or if there are other better choices for DDL (ie HW rather than SW encoding) that you are aware of?
 
I've tried to break down the issues for easier discussion:
 
1. What kind of latency are people getting from each card? I'm hoping in the region of >50ms would be reasonable.
 
2. I know Asio support is available on the newer U7 (Asio 2.2) and Z (Asio 2.0 without direct monitoring whatever that means). What are the differences in these 2 implementations of Asio and does Asio support even affect DDL encoding or only apply to analog output? If not what's the benefit of Asio?
 
3. Does going for USB over internal make a difference on latency? Which is preferred?
 
Thanks.

 

[PurpleAngel]

Are you trying to send DDL thru S/PDIF optical or S/PDIF coaxial?
 
I'm not sure of what, if any differences for DDL between different sound cards.
The Creative Labs Sound Blaster Titanium (non-HD) and the Asus Xonar DX & D1 sound cards come with DDL (optical) output and can sell for $50-$70.
 
I'm assuming with DDL, your trying to send 6-channels (5.1) of surround sound gaming or movie audio thru DDL?

 

[lemm]

That's exactly what I'm trying achieve, get native 6 channel audio encoded via DDL over optical. Thanks for the extra recommendations. The Titanium looked promising for a second as it had Hardware-accelerated EAX and OpenAL but unfortunately no mention of Hardware-accelerated DDL so I don't think it's worth it for me as I don't really need the other features. Shame it doesn't mention Hardware-accelerated DDL as that would have been ideal to reduce any latency but I'm beginning to think all soundcards only encode to DDL in software unless someone knows otherwise. Nonetheless, I still need to make a choice from all the available options so it would be great to know from head-fi users which one implements DDL best. Again, thanks.

 

[PurpleAngel]

Quote:

That's exactly what I'm trying achieve, get native 6 channel audio encoded via DDL over optical. Thanks for the extra recommendations. The Titanium looked promising for a second as it had Hardware-accelerated EAX and OpenAL but unfortunately no mention of Hardware-accelerated DDL so I don't think it's worth it for me as I don't really need the other features. Shame it doesn't mention Hardware-accelerated DDL as that would have been ideal to reduce any latency but I'm beginning to think all sound cards only encode to DDL in software unless someone knows otherwise. Nonetheless, I still need to make a choice from all the available options so it would be great to know from Head-fi users which one implements DDL best. Again, thanks.

As Dolby is the one who writes the software encoding for DDL and then supplies that same code to everyone,
I would assume it's all done about the same speed no matter who is using that software.
Now a days I would assume if some want to send audio as fast as possible, I would think they would use HDMI, as HDMI does not have to compress or uncompress the audio stream.

 

[lemm]

That's a good point. I have a feeling that different soundcard manufacturers would implement the same process differently or with different priorities and therefore produce different results. But you may well be on to something. If i knew they were all say 50ms latency then I'd probably just go for the most basic soundcard that offers DDL.However, even a small difference from 50ms to around 200ms becomes noticeable which is what I'm trying to avoid through this post.
 
HDMI is another aspect that I was about to mention on this forum, but I still require DDL over optical aswell.