[maximage]

Running a Dual 1.8 G5, 3GB RAM, GeForce 6800, 10.4.2 and teh latest Doom III v 1.3. Thing is that teh new Surround feature doesn't seem to work. Does the inbuilt Optical Out not support the Surround option, does it only work with external cards? If so, pretty slack, I would have thought more people would have the new G5s and iMacs with the optical out than those with external cards. Reason I can tell it doesn't work is that I have the Logitech Z-680 system hooked in which tells me the type of signal it is getting. It stays on Stereo despite clicking on the Sourround option. Anyone else tried it?

[suvsr4terrorists]

Fas as I know, I've never seen a mac with working surround sound in a game. That's a PC only thing.

[a2daj]

WoW and UT2K3 and UTk4 as well as a few other games have had working 5.1 surround for awhile now.

You will not be able to get true surround sound for games out of the digital out on Macs. You have to have a device which supports discrete channels like the M-Audio Revolution cards and Sonica Theaters or the, so far, vaporware Firewave. There may be a few other devices out.

Once you have a card which supports 5.1 for gaming you then have to configure Mac OS X for multichannel support.

For more info on multichannel support, check the IMG HW FAQ (some of the earlier posts need to be updated since Macs have supported 5.1 for awhile now):
http://www.insidemacgames.com/forum/...t&p=198328

http://www.insidemacgames.com/forum/...t&p=220666

[maximage]

So the G5 based machines that have optical sound out and are actually capable of 5.1 sound as exhibited in DVD Player, won't do it in this game even though they claim to now support surround? Rather half arsed in my opinion.

[a2daj]

DVDs have pre-encoded audio. Games have to do it on the fly. Big difference. There's no built-in encoder in Mac OS X. You don't see any PC games with dolby encoders. Any system that does on the fly encoding relies on hardware to do it.

[maximage]

Actually plenty of games have the Dolby logo plastered on them.

[a2daj]

Originally Posted by maximage

Actually plenty of games have the Dolby logo plastered on them.

Doesn't mean actual game play uses on the fly encoding. The pre-rendered cinematics may use dolby surround but the game won't output dolby encoded sound without hardware assistance.

[Leonard]

Ummm... guys, this a beta version of the 5.1 surround sound for Doom and I don't know about other news site, but http://www.macworld.com/news/2005/07/18/doom3/index.php was pretty explicit that only Macs with PCI cards would work. That G5s with optical digital audio out would not work in this release. How I read that is they haven't written the code yet for the G5s for the optical digital out.

I'm not sure I understand what a2daj is saying. The M-audio cards just contain a decoder like my Z-5500s (or Maximage's Z-680s), the game has to provide an encoded signal to the M-audio card more or less the same as it would provide an encoded signal to the digital optical out port.

[a2daj]

M-Audio cards will not support 5.1 from games if you use the digital out, same limitations as the G5's built-in digital out.

However, the M-Audio cards have the analog outputs for the discrete channels. You have to have a card which support discrete multiple channels for the games to output 5.1 audio correctly. If CoreAudio sees your output device supporting multiple channels then Mac games which support 5.1 will be able to output 5.1 via that output device. The M-Audio card is not decoding encoded game audio. When the M-Audio devices are set to Analog outs, they're recognized as a device with either 6 or 8 channels (depending on your device). CoreAudio is sending audio to each channel. When in digital mode, CoreAudio only sees 2 channels.

This is just like Unreal Tournament 2003, 2004, and World of Warcraft. I've been playing games which support 5.1 ever since Apple released their implementation of OpenAL which is built on top of CoreAudio to take advantage of the CA speed and multichannel support. All of them require my M-Audio Revolution 7.1 card to be in Analog out mode for 5.1 to work properly.

I have a set of Z-680s connected to my Revo 7.1 with both the digital and analog connections. when I play DVDs I have to switch to Digital out for both the card and the speakers. With games, I switch both to analog.

Maybe some of you are confusing Dolby Prologic with Dolby Digital. Dolby Prologic isn't true 5.1 sound. If a game uses the Miles Sound library you can get on the fly Dolby Prologic encoding, but it's not the same as encoded Dolby Digital. That would require much more CPU power for a software solution to be used.