timbley2

Mike, The room is looking great, and reminds me of a 2C3D room (2 channel 3 dimensional sound), with TubeTraps distributed fairly evenly along the walls. I see you've moved the skyline diffusers off the front wall and on to the overhead. How would you describe their sound when on the front wall vs. the overhead?

My boss loaned me a book: "The New Stereo Soundbook" https://www.amazon.com/New-Stereo-Soundbook-Ron-Streicher/dp/0966516206?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-osx-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=0966516206 In there I came across a chart, which you can see here: https://www.semanticscholar.org/paper/Loudspeakers-and-Rooms-for-Sound-Reproduction-—-A-*-Toole/7b0e3101e1788608d75d024ac926d25a077b85bc/figure/5 Looking at that chart I decided as an experiment to adjust my side and center channels to be 20ms delayed and 9 decibels attenuation. That puts them in the zone of detectability by not enough to shift the image. The result is highly agreeable to my ears. It sounds like normal, good stereo in a good, larger room. Compared to running all channels at full volume and time aligned, this is much more stable. With four channels at full volume, very little head movement will change the sound appreciably. With attenuation and delay, there's much less perceived change when moving around. The book also mentioned that even in anechoic chambers, when extra channels are added with time delay and attenuation, an sense of spaciousness is restored. My room is nowhere near anechoic, but it's pretty well damped at this point with lots of absorption panels and some tube traps turned with their reflectors toward the wall. I'm thinking that for small bedrooms, a highly damped room with extra spaceousness channels is a good way to go. I'm thinking I'm going to keep adding absorption to see if it's even possible to over-deaden the room with this setup.

It gives me an error if I do anything other than 2 channel. I'm using optical out. Perhaps it needs HDMI.

Interesting. I tried JRiver this evening on my macbook but so far haven't got it to send a 5.1 signal to my receiver.

Is anybody besides FOURFRONT using the system? They responded to my e-mail, asking how I found their website.

I'll have to play with PL II some more. In the past I thought it sounded pretty good but preferred 2 channel stereo not upmixed. Agreed that a real multi channel mix sounds best, although a good stereo recording in multichannel stereo is surprisingly close.

Thanks! I stumbled across your patents a while ago as I was pondering the possibilities of upsampling stereo. Seems like a great idea. It's interesting that just using four speakers without any processing still works pretty darn good! Very clean and pure. The only problem is a pretty tight sweet spot if you're near field. Far field seems to work at least as well as 2 channel stereo. With a real up-mix it seems to me the sweet spot would be less important.

Their website doesn't say much. I sent them an e-mail asking for more info. What are your patents?

Reviving this topic. I just discovered multichannel stereo for myself. Works a charm in a small bedroom. Everything is very enjoyable to listen to, and simultaneously produces a very wide sound stage with a super solid center phantom image. It really sounds at time as if there are four distinct channels playing. I use the 30 degree / 60 degree arrangement, trying to be careful that everything is symmetrical , especially that the two left speakers are precisely as possible the same distance from the left ear, and two rights to the right ear, to avoid cancellation errors. The side speakers should be letting more of the highest frequency stuff reach the eardrum than the fronts so it doesn't have to be head-clamp perfect to keep from killing the highs. One thing that's always concerned me about just using two speakers is the head related transfer function coloring everything except sounds that are panned to sound like they're coming directly from one of the speakers. I figured having coincident sounds reaching the ear from different angles at the same time should average things out and eliminate unwanted localization of the speaker. It makes me wonder if it would be even better to get four more speakers, making an array of four speakers on each side. Hmm, where would they fit? How would I power them? How hard will it be to get them all arranged in two perfect arcs? I'll wait on that. etc6849, you say you've stepped away from all this, back to two channel now that you have a comprehensive and effective room treatment system at work. Can you elaborate on what you've done in terms of room treatments? I've just started working for ASC here in Eugene Oregon so I'm really interested in the excellent results you achieved. If I was in SC I'd definitely want to have a listen!