Hello,

Very soon I'll be ordering a MacBook for use at University, and I intend to use it as my primary means of audio entertainment (playing FLAC out to my amp + speakers, instead of taking all my CDs and my CD player). Having done some research, I've managed to find that the integrated audio is a part of the Intel chipset, and is in fact one of the new Intel HD Audio devices.

I have been looking into external USB audio devices, but having read about the quality of the HD Audio (i.e. it really isn't that bad compared to affordable USB devices/is much better than AC'97), I may suffice to use the internal audio. One advantage of using USB audio, however, is the ability to route output independently.

This seems beneficial, as I can play music through one stereo output without dings and alerts and whatever else other applications decide to introduce through the standard audio output. Using the HD Audio, there is, apparently, a multi-streaming capability to provide something similar. I was wonder if it is possible to use this to route independent stereo channels to the auxilary output and the internal speakers of the MacBook.

So, to simplify: the auxilary/headphone output is driven by a single application, while all other sound comes through the speakers. I happen to know, from reading about Linux on MacBook (Pro)s, that audio routing (between headphone and speakers) is software controlled. (Under Linux, a patch is required to route the audio to any form of output, and currently plugging headphones into the output does not disable the internal speakers). I also understand that Core Audio supports some rather advanced audio routing capabilities (like merging multiple devices into one for multichannel playback/recording, though I don't know about 'splitting' a device into multiple devices).

I hope someone can help me with my musing.

smiler

I have an Intel iMac using the Intel HD Audio chip (made by SigmaTel) and am very happy with it. It is a big improvement over AC '97 style audio chips. I can play FLAC files using Cog (Mac OS X) or via Winamp with FLAC plug-in (under Boot Camp 1.1) via Windows XP.

The previous version of Boot Camp (beta version 1.0) had a bug where sound came out both the internal speakers AND the external speakers at the same time, which was quite annoying sounding. This only happened in Windows XP (boot Camp) mode, as in Mac OS X mode the sound was either coming from the Mac's internal speakers OR the external ones (if plugged in).

Now with Boot Camp beta 1.1 that just came out a week or so ago, this problem has been fixed. Now I can use Adobe Audition under Windows XP to properly edit my audio files without getting the "double echo" from both the internal and external speakers. I don't know why you'd want to do "multi-streaming", but I am not sure if that is possible.

I recommend you wait a week or two to get your MacBook by the way, as new models are rumors to be appearing any day now, and should feature a Merom chip (Intel Core 2 Duo) 64 bit capable chip, instead of the current Yonah (32 bit) chips. Should be faster CPU speeds too. Enjoy your new Mac!

This is great to hear. I've been using the internal AC'97 on my PC for a few years now, and it's been OK, though I improved output with a software resampler somewhat. It never really seemed necessary to upgrade - it was good enough. Here, I just use the hi-fi for most listening.


Well, I tried to explain lol. I'll try again: my idea is to plug my amplifier into the headphone/aux. output of the MacBook for music. That's straight forward, but while I'm listening to music and working, I don't want to hear system bells, Flash anitmations, film clips, etc. through the amplifier. I thought that, perhaps by using the multi-streaming feature, I could send only the output from one application to the amplifier, while all other sounds use the internal speakers (thus they'd be no echo - they're totally different sounds).

I managed a similar setup with my AC'97 card using the Surround output to record to tape whilst still using the PC. The surround output was used exclusively by one instance of foobar2000, while all other sound used the 'front' stereo output. Obviously, there's no built-in surround sound decoder on the Mac, or output for it, but there are two outputs in effect: the speakers and the headphone socket. The question is really whether they can be addressed independently, whether by Core Audio, or some sort of thrid party add-on/hack.


Now that's very interesting. I held out for WWDC to see if Apple would announce anything, but was disapointed. I'll have a look around the rumour sites to see just how feasible this might be... and to think I almost ordered it last night! Thanks goodnews

I would assume it works like every other Apple notebook - when you plug something in to the headphone jack, the internal speakers are disabled. This is almost 100% likely when using analog audio - when using Toslink, I am not sure if you would be able to use the internal speakers as well. OS X provides its own audio routing preferences and does let you select a separate output for alert sounds.

http://www.macrumors.com/pages/2006/08/20060814180417.shtml

Here's a link to the rumour about Merom laptop CPU's being available this Monday (tomorrow). It may take a week or two for Apple to announce after that, but they are likeley to appear soon. The date I hear is Sept. 5th for a massive Apple refresh across their various lines (Mac Mini, iMac, and MacBook lines):
http://www.macrumors.com/pages/2006/08/20060826164321.shtml