John Warren Posted March 12, 2017 Share Posted March 12, 2017 On 3/2/2017 at 9:41 PM, jwc said: Another Video and updated FAQ soon. Nice job with the vids. Good to see your son(?) as shop helper/apprentice. Hope he shares the same passions for this stuff as his dad. Link to comment Share on other sites More sharing options...
jwc Posted March 14, 2017 Share Posted March 14, 2017 Thank you John. Yes that is my son. He seems to have some interest at 13. He helped me a good bit with my Cornscalas when he was 12 and always wants to listen to them when in the audio room. He didn't get to help me much with the minipunches but has helped a little on some bigger horns I'm building right now. He won't let up about me building some more "snails" which he watch me make many years ago. For some reason....his memory is stuck on those big corner horns. He remembers the Jubilee-like clone and still refers to them as the "spaceships" in the garage. I actually try and encourage novelty electronics like speaker building, soldering crossovers, and building computers. He has seen a lot of this for his age. Maybe the interest will continue. Age 16 and the "fumes" are around the corner. Perfume and car fumes. 2 Link to comment Share on other sites More sharing options...
jason str Posted March 14, 2017 Share Posted March 14, 2017 1 hour ago, jwc said: Thank you John. Yes that is my son. He seems to have some interest at 13. He helped me a good bit with my Cornscalas when he was 12 and always wants to listen to them when in the audio room. He didn't get to help me much with the minipunches but has helped a little on some bigger horns I'm building right now. He won't let up about me building some more "snails" which he watch me make many years ago. For some reason....his memory is stuck on those big corner horns. He remembers the Jubilee-like clone and still refers to them as the "spaceships" in the garage. I actually try and encourage novelty electronics like speaker building, soldering crossovers, and building computers. He has seen a lot of this for his age. Maybe the interest will continue. Age 16 and the "fumes" are around the corner. Perfume and car fumes. Same here, my son is 24 and interested in my projects but very lazy unless it has skateboarding involved. Link to comment Share on other sites More sharing options...
Schu Posted March 14, 2017 Share Posted March 14, 2017 so you're into wood... build him a half pipe! Link to comment Share on other sites More sharing options...
jason str Posted March 14, 2017 Share Posted March 14, 2017 11 minutes ago, Schu said: so you're into wood... build him a half pipe! Many local skate parks & small back yard. Link to comment Share on other sites More sharing options...
DrWho Posted March 16, 2017 Share Posted March 16, 2017 On 3/3/2017 at 6:18 AM, jwc said: I was asked a generalized horn question which is a good one....... Q.I have a 110hz round tractrix horn. It has 40 inches diameter at mouth, and is about 27,5 inches deep. It starts loading around 150hz. How come JWC mini punch being such a shallow horn load so low? A. Yes, your horn is designed full space. This requires a longer horn length and bigger mouth. Design a Bass horn 1/4 space with appropriate drivers to match, and easily see lower frequencies can be obtained if put in 1/4 space. Even easier with a larger throat. Look at the true physical mouth size of the Jubilee and Khorn. Not very big. Designed for 1/8 space. If they were full space and meant to go below 40Hz, they will have a super huge mouth and a rediculous horn length.....wouldn't even want in you house..... (If you want to stay married). jc The reason it digs low is because the compression ratio is low. When the compression ratio is 1:1, then there is no acoustic gain. The driver excursion for a given SPL is the same. If the horn flare is narrow, then there is DI gain, but the total power is the same. This 12" driver has what, an 81 sq in Sd, and that's firing into a 49 sq in throat? That's a 2.2 dB max increase in power for an infinitely long horn. When the horn is shorter than infinity, then there is less gain at low frequencies. The shorter the horn, the higher that low frequency corner gets. What all that amounts to is a short flare horn like this is not much different than a direct radiator configuration, especially at the lower frequencies. This can be seen in hornresp if you setup a maxspl plot with very limited cone excursion and high power handling. 2.2dB at the top half of the passband isn't nothing, but it's a lot less than the 5.6dB gain over the full bandwidth of the Jubilee. That's why the Jubilee is so much longer. It starts with a smaller throat and loads to a much lower frequency. This isn't to detract from the design, but to point out why a small "horn" has a lower than expected low frequency corner. It's basically the direct radiator response of the drivers you're using. 1 Link to comment Share on other sites More sharing options...
jwc Posted April 17, 2017 Share Posted April 17, 2017 I've decided not to make the third video on you-tube....as I felt I really didn't have much to add other than making the back cover with a gasket and installing the woofers. So, this is a hybrid design as intended. The horn is shorter and it is ported in the back as an option. The throat was slightly bigger than the throat I used on a previous design of mine for 2 12" woofers and slighly bigger than say a Jubilee design. I actually made a bigger throat for 12" woofers on a folded horn design that I never posted here. If you look close at Bill Fitzmaurice "Jack" designs....the idea is "about" the same. The horn is very punchy and not boomy. Sounds good and if different woofers were chosen, it will play out further. Although, I can't say with any confidence with polars out to 1000Hz. Don't know. I had other projects on my plate....and didn't test that with other woofers. The bass bin has a foot print similar to a Klipsch Belle bass bin. I did not make this to compete with a Belle or anything....but since the idea was to make a bass bin in a small package...there had to be some compromise intended. I have made a comparison of the Belle Bass Bin and this minipunch in the exact same measuring spot with the exact same equipment. This will give tou an idea of the performance in room about 1/4 space. The performance was better where I played music from them which was also 1/4 space. But I didn't feel like moving the Belle in that spot to make the comparison. I got tired of moving things around. I never measured in a corner. Plans for DIY are on the Fastlane Audio site or a CNC quick cut version if Dave is back into doing this. Previous info about the build is here....https://community.klipsch.com/index.php?/topic/147849-jc-minipunch-bass-horn-plans/ Link to comment Share on other sites More sharing options...
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