Deang Posted July 26, 2005 Author Share Posted July 26, 2005 He's running ALK Universal Type A Replacements, EV-350 Tweeters, and a McIntosh. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 Well, it's ABOUT TIME! Granted that it won't fit in a Khorn top like Al's (get his for Khorns) - but remember: I WAS FIRST! na-na-na-na-na-na!! When are you guys EVER going to listen to me?!! DM Quote Link to comment Share on other sites More sharing options...
jim-analog Posted July 26, 2005 Share Posted July 26, 2005 Greetings, As Dean was so kind and correct to note: My system is '86 khorns bought new, ALK's original x over, EV-T350s mounted verticaly in an external top cabinet, a Velodyne UDL-18 sub crossed over at 70Hz, and right now a McIntosh 225 runing full range. I have Al Ks' new transformer attenuators for the tweeters and a pair of Fostex R-100 transformer attenuators for the squakers. I have both the K77M and V drivers and thought the M sounded much better with the T-400 horns. A Manley Labs Massive Passive tube EQ is making some slight corrections; very steep low pass @ 18KHz, about -2dB @ 1K8Hz with a rather broad bandwidth. The attenuators are set to -3dB on the tweeters and -6dB on the mids. I have a set of JBL 2426H mid drivers on order. Front end is digital only (sigh) with a Meridian transport and Theta DAC. CJ tube pre-amplifer. What's realy strange is that before the T-400 horn upgrade with no external attenuators in the system, the T350s were definately too hot, but otherwise things sounded pretty darn good. The new horns threw everything out of whack balance wise. They have a clearer, more defined sound, but seemed to be too hot from about 2KHz up into the treble range. I changed the auto transformer taps in Als cross over to where I felt it was close (-7dB), then added attenuators to bring the highs down. Now I'm trying to get things rebalanced and hear what they really sound like. It became a completely new, unfamilar system after the Thorns were installed. I suspect it will take some time to sort out, but no doubt will be worth the effort. I haven't had a chance to run any frequency repsonse tests since the Thorn upgrade and have been doing it all "by ear". I have plots from right before that, so soon as I get a chance will be able to make comparisons. Regards, Jim ---------------- On 7/26/2005 12:06:00 PM sunnysal wrote: jim, what crossovers are you running on your speakers? can you describe a bit the whole system as it stands now? thanks, tony ---------------- Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 26, 2005 Share Posted July 26, 2005 D-Man Isn't that your P-Audio horn? I don't think that is a tractrix at all. A nice horn, but not a Tractrix flare. Bruce Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 It's overall horn length is 9-1/2" - I don't know of any realistic way to acheive a 400Hz cutoff in that length unless its a tractrix...look at the flare. DM Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted July 26, 2005 Share Posted July 26, 2005 Jim, I think you are going to need to use instruments to find out where your problem might be. The Trachorn will tend to give you the impression of more upper midrange. This is partly becasue some of my tests on the K400 show that it droops a bit there. You may just need to get used to it. You also simply may have a very "lively" listening room. It that case you will need to call in the experts (your wife) to redecorate the room! Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted July 26, 2005 Share Posted July 26, 2005 "It's overall horn length is 9-1/2" - I don't know of any realistic way to acheive a 400Hz cutoff in that length unless its a tractrix.." JBL has bi-radials at that depth with 400hz specced as the low frequency limit. The 2380a for example. Shawn Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 For a better view, but remember this will NOT fit in a Khorn top cabinet and its a 2" throat to boot: DM Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 26, 2005 Share Posted July 26, 2005 D-MAN, You notice how the side walls are flat? It isn't a tractrix flare. Look at Al's website (or any place that shows the tractrix flare) and look at his horn from the top. You can easily discern the difference. Bruce Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 Wait! Tractrix flare rates are SUBSTANTIALLY exponential until very close to the horn mouth, where they flare much more dramatically than an exponential one would, due to the supposition that the waveform is curved (round) rather than flat. DM Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 26, 2005 Share Posted July 26, 2005 Have a look at the attached and you can see what I mean about the flare. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 For reference, from Dinsdale articles from www.volvotreter.de DM Quote Link to comment Share on other sites More sharing options...
jwc Posted July 26, 2005 Share Posted July 26, 2005 I think you guys are agreeing. Looks to me like the "flare" of Marvels schematic is similar to Dman's horn Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 26, 2005 Share Posted July 26, 2005 Same diagram overlayed to scale drawing of the 4525 horn in question. I rest my case! (But you gotta love Marvel who keeps us all honest!) DM Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 27, 2005 Share Posted July 27, 2005 ---------------- On 7/26/2005 7:33:13 PM jwcullison wrote: I think you guys are agreeing. Looks to me like the "flare" of Marvels schematic is similar to Dman's horn ---------------- Only because the last part of the flare widens out so much. BUT, the majority of the side wall is FLAT, which doesn't match a tractrix flare at all. A tractrix flare always has the wave front perpendicular to the side wall (Top and bottom too actually, but we aren't being that perfect). This means the side wall will be chaging all the way to the mouth. To quote someone else, I rest my case. Where's Dennis when you need him? Bruce Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 27, 2005 Share Posted July 27, 2005 It seems extremely clear to me that its a tractrix horn with a constricted throat. here's some info on constricted throats, whether they are good or bad, I don't know - they are used to increase and/or control the horizontal dispersion characteristics of the horn. It is also somewhat related to a throat compression chamber, there is info on that too that I won't post (yet), that effects the upper frequency response corner through the horn. DM Quote Link to comment Share on other sites More sharing options...
sfogg Posted July 27, 2005 Share Posted July 27, 2005 "Same diagram overlayed to scale drawing of the 4525 horn in question." Rotate the diagram a little further and the exponential will fit the horns shape too... without clipping the bottom like the tractrix curve is doing in your diagram. Just going by looks this one: http://www.p-audio.co.uk/products/db_product_6_14_ph-4530.htm# Looks more like a Tractrix then the 4525. But without knowing the expansion rate and such we can't say for sure unless you get the answer from P Audio themselves. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted July 27, 2005 Share Posted July 27, 2005 Guys, The only way to know if a horn is Tractrix or not is to compare the area of many cross sections from the throat to the mouth with the tractrix equation. The curvature of the individual sides can be anything so long as the area expands like the equation dictates. The only time (I think) that the expanding "bubble" will be perpendicular to the sides at all times is with the round "salid-bowel" type horn. My Trachorn uses flat top and bottoms with the sides flaring to get the needed tractrix area expansion. The angle between the top and bottom was computer iterated to make the throat a perfect 1 by 1 inch square. Al K. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted July 28, 2005 Share Posted July 28, 2005 ---------------- On 7/27/2005 3:18:06 PM Al Klappenberger wrote: Guys, The only way to know if a horn is Tractrix or not is to compare the area of many cross sections from the throat to the mouth with the tractrix equation. The curvature of the individual sides can be anything so long as the area expands like the equation dictates. The only time (I think) that the expanding "bubble" will be perpendicular to the sides at all times is with the round "salid-bowel" type horn. My Trachorn uses flat top and bottoms with the sides flaring to get the needed tractrix area expansion. The angle between the top and bottom was computer iterated to make the throat a perfect 1 by 1 inch square. Al K. ---------------- Al, I was noticing the same thing. I seem to remember seeing round Tractrix horns somewhere. Doesn't the designation mean that it follows the equation, regardless of if two sides are flat or not? Not that you would want to do this, but I think that you could have one flat side and three curved sides as long as the configuration could follow the tractrix expansion curve. Chris Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted July 28, 2005 Share Posted July 28, 2005 Chris, You are thinking of the Bruce Edgar "Salid-bowel" horn. Both my Trachorn and the slid bowel horns are Bruce Edgar designs. My horn simply uses two flat sides to simplify the design and construction and makes its mouth have the maximum area that will fit in the Khorn. The Tractrix equation only describes the ratio of area of a cross section to the distance from the mouth. The area can be any length to width ratio, or round and still satisfy the equation. As to what effect that has on the sound beyind simple directivity is beyond me! Al K. Quote Link to comment Share on other sites More sharing options...
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