Hi everyone, Thanks for all the brilliant feedback, and especially Michael and Eric for their very detailed thoughts. I've got a lot to think about, but, for my needs, it seems the expense of an 8-channel periphonic system will mostly depend on the quality of speakers (and their mounting). My application is rather low-fi and involves no recording, and my listening space would be a small lab room. So it seems an 8-channel USB/Firewire sound card coupled with decent powered speakers (no separate amp) would be a clean solution, and just as importantly, could fit into my research budget! I think that's also great news for people motivated to put together a budget periphonic system at home.
I'll summarize the most important things I learned off-list for posterity: 1) Perhaps unsurprising to the gurus here -- S/PDIF can pipe Dolby/DTS 5.1 but not their more recent 7.1 formats, and otherwise provides only 2-channel PCM! So this rules out the built-in optical output on Macs and inexpensive PC sound cards… 2) HDMI supports 8-channel LPCM audio, but requires a video signal (apparently, the audio is clocked to the video signal) 3) The above knowledge alone probably rules out a 7.1 home theater receiver for full periphony, but in any case, the .1 LFE channel is line-level rather than amplified in most (all?) systems, so certainly not ideal for using as an 8th channel. Perhaps it's possible to get a 9.2 receiver working, but it's not worth the cost/hassle unless you already have one. Also, you'd need to send HDMI with a dummy video signal since there seems to be no other way to input 8-channel audio to these receivers. 4) DisplayPort/Thunderbolt (as found on newest-generation Macs and some ATI video cards) is supposed to support 8-channel LPCM audio without video, but there aren't any such audio devices available yet! Cheers, Sarang On Jul 31, 2011, at 6:14 PM, Marc Lavallée wrote: > > This other module (less than $30) is limited to 16bit > but seems to work at 48Khz with 8 channels: > http://www.sabrent.com/category/audio/USB-SND8/ > Umashankar have one. > > -- > Marc > > Sat, 30 Jul 2011 01:17:57 -0400, > Hugh Pyle <hp...@cabezal.com> wrote : > >> I have one of these, and it's cheap and works well. The biggest >> issue is the sample rate limitation; with 8 channels you can only >> run at 44.1 kHz. >> >> On Sat, Jul 30, 2011 at 12:07 AM, Ben Bloomberg <b...@mit.edu> wrote: >> >>> Has anyone tried anything from ESI audio? It looks too good to be >>> true. >>> >>> http://www.esi-audio.com/products/gigaporthd/ >>> It seems like they can be had for around $100. >>> >>> ben >>> >>> On Fri, Jul 29, 2011 at 9:41 AM, Dave Malham >>> <dave.mal...@york.ac.uk> wrote: >>> >>>> >>>> >>>> On 29/07/2011 11:30, Michael Chapman wrote: >>>> >>>>> Now I would like to construct a higher-order sound system, >>>>> ideally with >>>>>> consumer-level (and consumer-priced) components. I don't need a >>>>>> big dynamic range, high power, or the best sound fidelity >>>>>> possible, I just need a working prototype. This is the part I >>>>>> have found very little information on in my research� >>>>>> >>>>>> My understanding is that 8 channels is the minimum needed for >>>>>> stable >>> 3-D >>>>>> Ambisonics (rather than planar surround). >>>>>> >>>>> There was a recent reminder, on this list, within the last >>>>> month, that one could use 6 channels (the mid points of the >>>>> faces of a cube). I've never heard anyone say they've done it, >>>>> let alone say it was >>> 'nice'. >>>>> (The engineering would, also, not be fun ... though you are not >>>>> obliged to place speakers mid-wall/ceiling/floor ... you can >>>>> tilt the cube!) So I'd stick to eight unless you are really >>>>> adventurous. >>>>> >>>>> We've used it in the dim and distant past and it's not to be >>> recommended >>>> as it is right at the limits of usability (very unstable image, >>> incredibly >>>> tiny sweet spot and so on). I would compromise on the quality of >>>> the speakers so that I could buy eight, rather than buy only six >>>> better ones (ditto for the audio interface and amps) >>>> >>>> Dave (signing off for now as I'm off on vacation, >>>> hurrah!) >>>> >>>> >>>> -- >>>> These are my own views and may or may not be shared by my >>>> employer /*************************************************************** >>>> **********/ >>>> /* Dave Malham > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
