07-31-2009 Post does not mapped to Knowledge Tree Romy the Cat Boston, MA Posts 10,159 Joined on 05-28-2004 Post #: 101 Post ID: 11243 Reply to: 11240 Some comments for now. fiogf49gjkf0d Dominik, I did not check the geometry of the horn, I am sure you did it correct. At the first approximation it looks like right numbers. Here are a few comments. 1)   Please next time name the images to upload to my gallery more identifiable. The name “dominik.jpg” does not give an idea what it is. The images then get moved to the site global images repository and to general image name because a management problem. 2)   What material the horn will be done from? 3)   You decided to go with Tratrix. The reasons for it are…? 4)   The back chamber is 250mm which is almost 10” deep. Are you sure that you need such a huge back chamber? Does your driver have such a long magnet? 5)   I do not know what the material will be but if it is a wood then the bottom of the horn look a bit flimsy to me with 1.5” walls. 6)   Think right now about the frame for your horn and about the farms for your MF section. They both must be a part of the upperbass horn design. 7)   The 30mm border on the back of the horn’s mouth is something that I do not like. The wave of the MF will be bought from it reflecting back to MF. I would smooth it up That is all for now. The Cat "I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-01-2009 Post mapped to one branch of Knowledge Tree Dominik Poland Posts 48 Joined on 09-14-2008 Post #: 102 Post ID: 11248 Reply to: 11243 Reply:Some comments for now. fiogf49gjkf0d 1) OK 2) mdf 3) a)LeCleach 115 its too big (where to put mf and tweeter... )     b)spherical vs rectangular  "The spherical horns integrate better with high-range and image way better the thier rectangular brothers"     c)and one more  reason but it is hard to write in English for me. 4) Now it is 7,8" 200mm 5) Now it is 4" 6) Thinking right now about that. 7) Corrected

08-01-2009 Post does not mapped to Knowledge Tree Romy the Cat Boston, MA Posts 10,159 Joined on 05-28-2004 Post #: 103 Post ID: 11249 Reply to: 11248 The speed of the profile for upperbass horm fiogf49gjkf0d Come on, Dominik, no one cares about the LeCleach for bass. You might consider slower opening profile: like exponential of hyperbolic. Exponential will give you a bit more horn gain at bottom and hyperbolic will give you even more gain. Hyperbolic would allow you to go even a bit below the mouth rate. If you are not willing to go too high with your upperbass horn then it might be an option to exercise. The disadvantage is that slower opening profile are a bit longer and you need to look yours of you will be able to integrate the horn with MF in your room. Also, the sound. With 100Hz Tractrix it is very difficult to get problem with sound from your upperbass.  With slower profile you need to be VERY accurate, very informed and very sensible what you do as stressing the slower profile too much would throw the horn into sonic mess. Put in this way: with 100Hz Tractrix you get out of the horn all bass that you can take and you very little worry about consequence. With slower profile and particularly  the hyperbolic you need to very tuneful to how locate the beast, how to crossover/EQ it and how much you would allow the horn to use its own full gain. This is the problem with most of the installations with exponential of hyperbolic horns. The Morons always try to get more bass from their upperbass horns but slower profiles requires way more sensible and more surgical views about sound then juts flooding the horn with lower octave as most of fools do. Dominik, I understand that it might implant an ambiguity to you soil and it is not what you need now. I just lay out for you options and it is your decision what to do. If I go for my 40Hz horn then it will be slow profile.  Probably the same would be for 80Hz horn. The 170Hz horn I would go for Tractrix but the 115Hz, if I do it again? I do not know the answer. I know that if I done everything properly then any profile in my room I will be able to make to have right Sound because I know what and how to listen and I know how to react upon the heard.  It might be some benefits with slower profiles as you have some bottom gain reserve that you might use in SOME cases. There are no common rules for it however.    THe Cat "I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-01-2009 Post does not mapped to Knowledge Tree jessie.dazzle Paris, France Posts 456 Joined on 04-23-2006 Post #: 104 Post ID: 11250 Reply to: 11249 Oval upper-bass fiogf49gjkf0d I haven't really thought this through, but if I were doing upper-bass horns again, especially if cut using a numerically controlled router, I might consider making tham oval, which would permit going for a horn with a lower cutoff (larger mouth) while not requiring that you raise the MF horn(s). Though the image below shows an upper-MF horn, the same could be applied to upper-bass (minus of course that big square flange): Photo courtesy of Ulf I should add that going for a lower cutoff on the upper bass horn may not be desirable; depending on your MF solution, the upper-bass horn may be asked to do some lower-MF as well. How do you plan on handling MF (dedicated lower-MF and upper-MF horns, or a single MF horn)? The answer to this question might also influence your selection of profile (tractrix vs a slower flare) for upper-bass. Best of luck with the project, jd* How to short-circuit evolution: Enshrine mediocrity.

08-01-2009 Post does not mapped to Knowledge Tree Dominik Poland Posts 48 Joined on 09-14-2008 Post #: 105 Post ID: 11251 Reply to: 11250 Oval profile fiogf49gjkf0d I go for tractrix because: "I know that if I done everything properly then any profile in my room I will be able to make to have right Sound because I know what and how to listen and I know how to react upon the heard." I dont. Yet... "with 100Hz Tractrix you get out of the horn all bass that you can take and you very little worry about consequence" Its sounds good. Jessie, "lower cutoff (larger mouth) while not requiring that you raise the MF horn(s)." Its sounds very good, but how to calculate oval profile. Above project comes frome tractrix calculator with one Roomy posted. There was "auto cad option". I found "auto cad guy" give to him those numbers and he make all drawings in 10minutes. But he is not a horn person, he know nothing about horns. Ps. Next week I am arranged meeting in Warsaw audio shop with avantgarde acustics horns. I am little bit sceptical, they have trio in 25meter square room... Dominik

08-01-2009 Post does not mapped to Knowledge Tree jessie.dazzle Paris, France Posts 456 Joined on 04-23-2006 Post #: 106 Post ID: 11252 Reply to: 11251 Calculating an oval horn fiogf49gjkf0d Dominik wrote : "...Its sounds very good, but how to calculate oval profile. Above project comes frome tractrix calculator with one Roomy posted. There was "auto cad option". I found "auto cad guy" give to him those numbers and he make all drawings in 10minutes. But he is not a horn person, he know nothing about horns..." I don't know of any calculators that output data for oval horns, but this should not stop you. Think of horn flare as a series of sections; the evolution of the area of these sections relative to each other is what determines the flare. You can deduce the flare for an oval horn by starting with a round horn; to make it oval, you need only keep the relative evolution in area (for each section) the same as that given by the calculations for the round horn, while keeping all transitions gradual. You can calculate the area of any shape, so there is no reason why it can't be done, though it might not be so automatic. Again, going with a lower cutoff for the upper-bass horn may not be desirable (see my previous post). About your rendez-vous with the Avant-Garde horns : Don't be too discouraged if you don't like what you hear. I've heard Avant-Garde Trios once, and was very disappointed, however, the installation was done by someone who did not take the time (or have the knowledge) to get the best from them. The biggest problem was that the bass "horns" (Avant-Garde's horn subwoofers) were not even close to being properly integrated. What bass there was, was not pleasant. Also, the MF and HF horns were being driven by big solid state amps. I had the impression that I was listening with cotton in my ears. jd* How to short-circuit evolution: Enshrine mediocrity.

08-01-2009 Post mapped to one branch of Knowledge Tree Romy the Cat Boston, MA Posts 10,159 Joined on 05-28-2004 Post #: 107 Post ID: 11253 Reply to: 11252 About the elliptical mouth upperbass horns. fiogf49gjkf0d Dominik, Jessie is right - it is irrelevant the precession of your profile if you horn does not go to high into HF. The LF gain of upperbass horn happens in the first half of horn anyhow. I do not insists that I am right but I have a hypothesis that what they “call horn gain” by slow opening profiles happens in fact by lucky creation and amplification by the horn bell the miniature standing waves in the beginning of horns. The slow opening profiles have very slow rate of opening in beginning – the channel is always parallel and I think it creates some minute resonances that become the “extra bass”. This BTW might explain why this extra bass from hyperbolic horn always is very muddy and boomy and need VERY accurate control in order do not be so.. Jessie is partially right that it is not always good idea to get more bass from midbass horn but it is in case if you have more complimentary channels the can hams it. If you have just one upperbass horn and MF channel then you of course would like to get from your horn as much as you can but if go more then 35”-37” upperbass then you might have difficulty to locate it under you MF driver and to keep a nearfield capacity. This brings the oval profile into the picture, or as I call it elliptical mouth horns. I thought about it before and I do not see a lot of difference. From one perspective you can get with ellipse less imaging problems then you would have with rectangular horn (in the lower MF range of you upperbass horn). You would also would be able to locate your MF driver above the short side of elliptical mouth, prolonging the longer side of ellipse and making the mouth size to have as larger size. Sound good, isn’t it? However, in reality if you make larger surface of mouth then you need to make the length of the horn larger as well. So, let compare the round 36” horn which would be approximately 36” long (I do not want to circulate it now but I did it in past).  Your 400Hz horn in time aligned position will be 18” behind the 36” horn’s mouth, which is manageable in case the upper edge of the upperbass and the lover edge of MF are on the same plane. Now pretend that we made the elliptical mouth with cut off for 15Hz-20Hz lower and our elliptical is let say 36” by 50”. It looks like nothing changed and we found a “free” 20Hz but the horn of the same opening profile would be approximately 10”-15” longer. This makes the very same MF driver to sit 30” behind the upperbass horn’s mouth of the same height. This is a LOT of distance and you will have in this configuration a LOT of MF will bounce from the back of the upperbass horn. So, I feel that for upperbass horn the 32”-38” is a right size/height and it server a good support for MF sections. The ellipse midbass would be more interesting as would allow shaping the horn accordingly. The ellipse MF is more controversial as the MF horns are small anyhow. I see a benefit for ellipse upperbass if it sits above the MF but then what would be in such case below the MF? The direct radiator bass channel? Possible but I feel it is too valuable location to give it up to bass section, not to mention that you what to position your bass section where it needs to be but not where your MF channel happened to be. Rgs, Romy "I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-01-2009 Post does not mapped to Knowledge Tree Paul S San Diego, California, USA Posts 2,658 Joined on 10-12-2006 Post #: 108 Post ID: 11254 Reply to: 11253 Stupid Question From a Horn Loser fiogf49gjkf0d OK, I never managed to come up with a horn that did not sound like a horn, and maybe I'm a little bitter about this.  But as I read along here, I also wonder if I am missing something, and this raises what seems to me to be a critical question about horn development.  The question is, how come nobody ever talks about a way or ways to modify the horn itself (including its profile) during the development of the horn/driver/speaker installation? I mean, does anyone really expect to straight away come up with a "horn profile" via math (or voodoo) and then just turn or cast it, bolt on the driver and, voila? That certainly never worked for me.  And furthermore, it never worked for anyone else of my acquaintance, either. I do not say I know jack about horns, but if I have never heard a "horn-free" horn, may I presume that the odds of coming up with a good one are not good? And it seems only to get worse at lower frequencies, where the greater the contribution of the horn, the greater the "contribution" of the horn. Anyway, it just seems like it would be realistic to plan on and allow allow for modification of about every parameter of the horn during its development, if only to avoid getting stuck with a big, expensive loser, and no way to turn it around. Best regards, Paul S

08-01-2009 Post does not mapped to Knowledge Tree Dominik Poland Posts 48 Joined on 09-14-2008 Post #: 109 Post ID: 11255 Reply to: 11254 Reply from beginner fiogf49gjkf0d I mean, does anyone really expect to straight away come up with a "horn profile" via math (or voodoo) and then just turn or cast it, bolt on the driver and, voila? If we talking about upper-bass horn I think yes, via match. I readed somewhere in Jassie thrad that he change his upper-bass horn profile(from calculator) to better. But then John Hasquin wrote that it is impossible to hear those changes in profile. Somewhere I readed about matching driver exit angle and horn throat angle on mf Lecleah horns . Dominik

07-08-2011 Post does not mapped to Knowledge Tree AllenB Posts 3 Joined on 07-06-2011 Post #: 110 Post ID: 16656 Reply to: 2421 Must it be about loading? fiogf49gjkf0d I use a direct radiator monopole for below 650Hz, this is OK and I have it working well. I think that I want to control directivity so that I can stop floor/ceiling comb filtering which gives me problems of +/-6dB and more. Now I am using extra monopoles to cancel the reflections but I don't like this. My woofer does not have a high efficiency/bandwidth product so I have not thought about horn loading it. I thought I would use a 1:1 compression ratio (it is a 15" driver) and a conical horn only for directivity, like a waveguide. I don't need to control reflections much below 200Hz so I don't think I care if it becomes a direct radiator below there. I would just design for the right polar match at the upper crossover. I would like to know why you think this is a bad idea?