colterphoto1 Posted February 18, 2009 Share Posted February 18, 2009 At the 2008 Pilgrimage there was a demonstration of the electrical mono third channel using digital delay via DX38 unit. Was there any handouts or does anyone have any notes regarding that process? A Forum member has contacted me regarding such a setup and I'm trying to find notes. I have the DFH already on the traditional 3rd mono channel. Quote Link to comment Share on other sites More sharing options...
DoubleJ Posted February 18, 2009 Share Posted February 18, 2009 Here you go Michael!! http://forums.klipsch.com/forums/p/106402/1072330.aspx#1072330 JJ Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 19, 2009 Author Share Posted February 19, 2009 Thanks JJ and Bob R! I'll pass this info along. I've attached it here for easier searching. M 3rdChannelDelay.pdf Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted February 19, 2009 Share Posted February 19, 2009 I don't really swing that way. Quote Link to comment Share on other sites More sharing options...
LarryC Posted February 19, 2009 Share Posted February 19, 2009 How much was the Belle delayed relative to the K-horns? I think I recall something like 6 ms. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted February 19, 2009 Share Posted February 19, 2009 Three speakers....in DSP terms...we call this Pro-Logic...most HT recievers support this ability. Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 19, 2009 Share Posted February 19, 2009 I think I would enjoy 3-channel stereo a lot more with 3 identicalchannels....I found the timbre mismatch between the belle and khornterribly distracting [A] As far as the delay - it should be justenough such that the center channel wavefront arrives at the listeningposition the same time as the LR channels. If you figure roughly 1msperfoot, and a wall about 20ft wide...the center channel would be about10ft away and the LR speakers about 14ft. So that'd be about 4ms frommy crude back of the hand calculation. The spead of sound is closer to0.9ms per foot, so you're looking at more like 3.6ms. I believe the actual delay was closer to 3ms. If you want an easierformula - it should always be about 18% the width of the room in feet when thekhorns are mounted in the corners. (When sitting on-axis of two corner loaded speakers, you will alwaysbe a distance of X from the center channel and 1.414X from the LRmains, where X is half the width of the room. The difference in feet is1.414X - 1X, which comes to .414X. Divide by two to convert for thewidth of the room and you're looking at a difference of 0.207Y feet,where Y is the width of the room. The speed of sound is 1132ft/s, sotake the inverse of that, multiply by 1000 and you're looking at.883ms/ft....multiply that by .207Yft and you get .183Yms....or 18% thewidth of the room measured in feet). There will need to be a slight offset to account for propagationdelays through each speaker, which is rather difficult to do with theKhorn + Belle combo because there's no way to line up all three drivers(without individual time delays for each driver). I think that's one ofthe big reasons that there was so much allowable play with the actualydelay setting....since for different songs, changing the alignmentwould introduce different patterns of comb-filtering (essentiallyacting like a phasey equalizer). Maybe one of these days I'll have the opportunity to hear it with 3totally identical channels...I think that would combine the strongcentral image with a whole new level of clarity (of course, it's onlygoing to have that clarity for a single listening position centeredbetween all 3 speakers). Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 19, 2009 Author Share Posted February 19, 2009 Can that 18% be counted on? Doesn't the math depend on where you're sitting in relation to the front wall? I.E., if you were sitting 1 foot from the front wall, therewould be considerable difference in distance from ear-center andear-main, whereas the further back the listener sits, the less thedistance, hence the less the needed delay to bring all three intoproper time domain. As we've discusssed in other threads, 1/2 the width of the front wall is not commonly the 'best' seating location and not practicable by many furniture placement standards (WAF). I have determined that .7 to .8 x times the front wall width is the most commonly reported 'good soundstage' for Klipschorns. I'll recalculate 'Doc's Delay' based on your formula. Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 20, 2009 Share Posted February 20, 2009 My math was assuming you were on axis with the LR Khorns....giving you a 90degree stereo spread before the center channel is added. When perfectly time-aligned and at the same volume, the center channel will reduce your effective stereo spread to 45degrees. Generally, about 60degrees is considered ideal, which I think requires the center channel be about -6dB relative to the LR mains. Without the center channel, sitting back .8x the front wall width lands you at about a 60deg stereo spread (I think it's 64 degrees to be exact) [8-|] Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 20, 2009 Author Share Posted February 20, 2009 are you restating that this is why the .8 works? If so, great. I'm too tired to recalc the Doc's Delay, care to help? Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 20, 2009 Share Posted February 20, 2009 Yep. What's Doc's Delay? Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 20, 2009 Author Share Posted February 20, 2009 just a cheerful little name for your easy-to-calc third channel delay. Quote Link to comment Share on other sites More sharing options...
DrWho Posted February 20, 2009 Share Posted February 20, 2009 So you want an easy number for when sitting back .8x the front wall width? Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted February 20, 2009 Author Share Posted February 20, 2009 let's call it .75 the range seems to be .7 to .8 it'll likely be somewhat less than the delay at 45 degrees because the change in distance (between main-ear to center-ear) won't be so great. Quote Link to comment Share on other sites More sharing options...
BuyOtherSoundEquipment Posted February 23, 2009 Share Posted February 23, 2009 I think I would enjoy 3-channel stereo a lot more with 3 identical channels....I found the timbre mismatch between the belle and khorn terribly distracting Someone actually was complaining about that during the free-listening session... Jay I think it was. I could not distinguish any timbre difference at all, although it was my first time to hear Khorns... and a Belle. lol I thought the three-channel concept was excellent, and really effectively filled in the gap. Quote Link to comment Share on other sites More sharing options...
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