Supersteff

Thank you also from me for starting this thread 🙂. I decided to boy the book as a gift to my self! I have been looking for horn-knowledge all over the internet since my very first search-entry on the AltaVista-search-engine back in the 90´s, and the first homepage I found was Thomas Dunker´s Hornspeaker-homepage!!! I spend lots of time studying that Homepage. I even met Thomas at a triode-festival in the early 2000´s, where I also heard Peter Bahnsen´s three way cornerhorns with 108 dB/w/m sensitivity. Amazing. And now 20 years later we have this nice book. I have spent some time reading the first 8 chapters of the book, the historical part, and must say that I did enjoy it very much. It has been kind of a pleasant start of the learning curve for me, not too steep, providing some overview! Also I found it very interesting and enlightening to get to know why and when who invented what. It provided me with perspective and also some respect and awe of the capabilities of these early scientists moving forward on unproved ground. These guys did NOT have computers! And PWK did not have much driver-material to choose from for his constructions in the 40´s! Those were pioneers. I have just finished page 422. I have picked up quite some knowledge here and there in the historical part of the book, and have started to think : What do I want to get out of this book? What is of particular practical interest for me? It seems to me that I need to be very aware of what context some statements are made in, i.e. is a statement referring to an exponential horn or a conical horn!? Most horns up till recent times are some kind of exponential/curved wall horns, or horns combining exponential loading with partly straight walls to improve directivity! I am mostly interested in everything relating to big full-range MEH´s, like the K402 MEH, and some sort of a horn-subwoofer for that (maybe being a tapped horn of some sort?). And of course I am interested in, what I can fit into my living-room! Looking for good and reasonable compromises. I´ll continue reading................. Steffen

Hi StabMe If you live in Europa, you could also take a look at the following amps from Andre Buscher in germany. https://www.buscher-endstufen.de/produkte/ That are single-ended mosfet amplifiers inspired/or a bit like Nelson Pass´s Aleph 0. They seem to be very simple to operate. Regards from Denmark Steffen

Hi Chris I don't know if that's a compliment or critique. I think it's important that everyone feels free to express their (informed) feelings on the designs presented here, but note that this is a "two-handed game", and I don't always know what you are actually thinking about the subject(s) at hand. It was certainly meant as a compliment! I do agree with you on the necessity of big size of a horn, you do what is needed by physics. Form follows function. Steffen

I have been thinking a bit about this comment of yours: I have chosen to delete some of which I hade written here before, to prevent any misunderstandings or controversy. I hope the remaining writings still make sense. Maybe you were referring to all those "small" synergy´s on diyaudio? As I see it, the big-synergy-horn-approach is the best technology to reduce the negative effects off the room on the sound. And in many ways I see your MEH-approach as going to the extremes/limits of the technology! You aim to fully utilize boundery-effekts and directivity down to under the Schroeder-frequency, and that makes perfect sense to me. But it seems that the size needed for that is not often accepted by most people! I think you have also stated before, that people don´t know what they miss!! But it is the only logical approach in my view. Any way, I try to view the various constructions in their context, take what ever I can learn from them and leave the rest. I´m not in this to safe money, but to avoid common compromises. I am still not finished with all my house-projects, one of them being clearing a basement-room to become my synergy-workshop! So for the moment I have to do as good old Albert Einstein: Stick to thought-experiments! 😉 I have been looking at the SH96 that you posted pictures of, and wondered what the difference in horizontal dispersion would be, if the woofers are mounted on the Horizontal horn-walls (like in the SH96, but without reflex-ports!). Would the artifacts of the off-axis-ports move from the horizontal to the vertical plane (ceiling and floor), and make for a more clean horizontal dispersion? I guess one way to find out would be, to build a 60x60 synergy (without reflex-ports) and measure horizontal and vertical coverage? That was todays question to the professor 🙂 Steffen

Well that was actually my worry too. It seems you have debunked that issue too 🙂 . Hmm, it won´t make me feel better to do unnecessary things! And it could even be counterproductive in regard to attenuating woofer-sideband effekts! I would imagine, that the volume of compressed air should be just right to support output up to the notch-frequency!? I think a lot of my confusions and imagined problems stem from years of reading about issues on off-axis-ports on DiyAudio. Maybe those concerns are relevant to midrange-off-axis-ports, but not to woofer-off-axis-ports! It is very instructional for me to discuss these tings here, and sort out what really matters! You have stated it before: It is not that difficult to build a MEH! Regards Steffen

Hi Chris. From your answer I can see, that you are familiar with the synergy-builds done by mark100/gnarly over on diyaudio. I do NOT want to place a woofer-port on axis in the middle of the horn wall! My thinking is, that by moving the woofers/off-axis-ports further away from the throat (due to a lover "crossover"-requirement, i.e. 225Hz or something), the off-axis-ports (on the same horn-wall) will move away from each other in vertical distance (if the woofers are mounted on the sides of the horn) when you keep them in the corners! I´m worried to have the off-axis-ports located over the surround of the woofers, as can be seen on several Danley Synergy-speakers. It might not be an issue in PA, but is it an issue in HiFi? Is it a source of distortion, that can be eliminated? Mark100 writes, that he made experiments with the location of the ports relative to the woofers, stating that it sounded best when the ports where located centrally over the dust-cab of the woofer!? So when the off-axis-ports move apart from each other, say 10-12" , as they move away from the throat (as you have mentioned in your other thread on the AXI2050 in a K402) it could make sense to replace one 15" woofer with two 12" woofers side by side!? A lot of words!!! I just try to be as precise as possible in stating my point. And again someone might just have to do a somewhat controlled and well planed experiment to sea weather there is an issue or not!? Best regards Steffen

Hi Chris Interesting to see some clear T/S-parameters-recommendations, thank you 🙂. With the AXI2050, it will be possible to move the off-axis ports a bit further away from the throat, making space for for example 4 times 10" or12" woofers in stead of 2 times 15" woofers, so that the woofer can be placed concentric (is that a right word for the dust-cab placed right over the woofer-port?) over the woofer-port. I´ve seen that done by Mark100 on Diyaudio / gnarly here on Klipsch Community who has placed his woofers in that maner with some god results. I think it gives a more balanced load to the woofer-cone!? Well the question here actually is: Is it always best to wire woofers in parallel or is it OK to wire 4 drivers in series/parallel. Some professional woofers can be had in 16 Ohm, so four of them could make 4 Ohm coupled in parallel. Well, work calls!!!! Steffen

Thank you Chris for your repeated explanation and patience! Very much appreciated. I will read my way through that OLSON article, a lot to digest. In a way its like starting from scratch. A lot of thinking has to be turned upside down to get right. But I like that your responses are based on science. I guess things get even clearer, when I get started to build a big MEH and make my own experiences and measurements. By the way, I have noticed that you have tested the new Celestion AXI2050 driver and recommend it with boost in the top-octave. Interesting to see what implications that can have for the placement of the off-axis-ports of the woofers, i.e. lowering the crossover-frequency. We will see....... Steffen

@ Chris I have read through your edited response, and the sentence: It still doesn´t make sense to me. Paying attention to what? Steffen

Hi again Chris Have you tried Acourate? https://www.audiovero.de/en/acourate.php I have read a lot of good things about that software, its world-famous in Germany! Mitch Barnett has written a book about it, using the fir-filters generated by Acourate in JRiver. I think there is more to read on the computer-audiophile forum. Following your recommendations, it seems to make no sense to use room-correction other then correcting for room-modes, if the system is capable to detect them!? Steffen PS: Im also earning my right to PM again!!!!

Hi Chris Thank you for answering 🙂 It seems you did not finish the sentence in your post? I´m not sure how to understand that sentence? Are you referring to 1/4 wave spacing of the Full-range MEH and a Sub-horn? Steffen

Hi Chris Maybe its the language-barrier!? But I have real trouble wrapping my head around what you are pointing at. But here are my guesses: -Sub-Schroeder-frequency-room-modes, standing waves? Peaks can be attenuated, corrected electronically/DSP? -And then there is the positioning of the speaker in the room? Speakers can be moved around, up/down, back/forward or put in corners? -And then there is room-treatment to avoid early reflections? That would be my main guess! Well I hope you will reveal the answer soon 🙂. Regards from Denmark Steffen

Hi Chris. "Glad to hear the extra length of my CD s not a problem." Hmm. It might not affect the right placement of the woofer-ports in regard to hornflare (geometry), but how about the upper usable frequency range of the woofers? I would have thougt that the 1/4 wavelenght cancelation notch frequency is a reflection dependent on the depth of the compressiondriver!? And that that again will affect the upper usable frequency range of the woofer, and introduce the need for an other crossower-frequency/crossower -layout!? Hope I did manege to explain it right? Steffen Steffen