Guest " " Posted October 8, 2011 Share Posted October 8, 2011 the reason that this hasn't been pursued by Klipsch or others that I'm aware of because of the market or that it's easier to add a sub to handle those specific frequencies? right...unlike 50 years ago...today we have high excurion subwoofers that have a small foot print and can be pushed by amps rated in hundreds of watts ....unlike 50 years ago when a fiveto 35 watt amp was common place and an accordian surround woofer was as high excursion as you are going to get. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 8, 2011 Author Share Posted October 8, 2011 Pete, Well let me tell you about that SHOP of Tools....! The Powermatic saw was purchased with the specific intent to be able to handle full sheets of plywood easily by ONE person. I sold my Delta Unisaw last year to purchase this one and am having second thoughts...........[:@] Not really....! I have never actually 'Set Up" the new saw, so guess what I have been spending most of the day on...? Silly me thought it would take thirty minutes or so....WRONG......!!!!!!!!!!!!!!! One thing about a sliding/horizontal panel saw is it has LOTS of adjustments, and I mean a LOT.....! Anywazzzzzz, after several hours, MANY Budweisers and beating the shit out of several squares, I can now make five cuts in either direction, either rip or cross cut and can come away with something accurate. In the past, I have never needed this type of accuracy before but I am now comfortable that the cuts will be as true as they can be. The saw has proven to be a challenge but I am confident that it is RIGHT....! Remember, with the slider it has to be accurate on either side of the blade, slider table to the left, rip fence to the right. In doing the many cuts for the cabinets, "Close Enough" will not Cut It.....No Pun intended...~! Tomorrow should be the wood butchering day and now that it is set up I feel that I can get everything cut in a couple of hours. Something tells me that this build is going to take longer than anticipated, but that is perfectly OK. I am pretty sure that the Drone idea is not quite fifty years old, as Roy may have some objections to aging him THAT much.....[H] Quote Link to comment Share on other sites More sharing options...
Pete H Posted October 9, 2011 Share Posted October 9, 2011 Can't wait to see the pictures and I'm sure the panel saw is going to save you a ton of time on the cutting. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 10, 2011 Author Share Posted October 10, 2011 We at least started cutting the Plywood yesterday. Of course, like everything else you plan, things change. Started cutting got three sheets cut and then company showed up unexpected.[N] I will update further this week as I should get the rest cut. Then I have to clean out a hole in the shop to start the assembly. Reason for the new building, I have completely run out of room.....! More to come, W. C. Quote Link to comment Share on other sites More sharing options...
jwc Posted October 13, 2011 Share Posted October 13, 2011 Looking forward to more pictures. BTW....I have a pair of K31's for borrow if you want to compare the performance of the Kappalites or even GPA 12" drivers. jc Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 17, 2011 Author Share Posted October 17, 2011 Sorry for the delay in posting...have been busy ...anyway, I have the saw jammed in a back room waiting for the new building and I had to move it as it was almost impossible to work the 5' x 5' sheets of Baltic where it was. Moved it, had to re-level and realign everything...ask me whay? If you notice some of the brown skidmarks un the next picture you will know when you mova a large saw, EVERYTHING goes out of adjustment. Any everything is cut and assembly will start tomorrow with cutting the Motor Boards Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 17, 2011 Author Share Posted October 17, 2011 Here are two Jub-Like cabinets...unaassembled......I am fortunate that I have a very experienced blade sharpening service close and I spent a couple of hours there today having my blade redone. He could tell bylooking at the 12" blade what the problem was...the guy is a Genious. When I moved the saw, something got out of alighment and caused it to start to burn the wood. The final culprit was the horizontal sliding table moved a 16th of an inch and caused it to bind. After realignment, it cuts like butter. We will be cutting the slots for the motor boards tomorrow and FINALLY start the assembly...SO glad all of the cutting is done.....~ Thank ypu for your patience....! Jc, I really appreciate the offer but I am looking for the Kappas in a couple of days. The assembly is probably going to take me a couple of weeks as I want to photograph every step of the assembly and you know how much time that takes. Anyway. I am looking forward to breaking out the Kreg Jig and start some Gluing and Screwing....! Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 23, 2011 Author Share Posted October 23, 2011 Sorry as I have not posted in a few days, been having some back issues.....![:@] Anyway, probably the hardest part of the build is cutting the ramps. I am using a Dewalt compound miter saw and I had to make a jig to cut the shallow 18 degree angle for the outboard ramp pieces. There were a total of 24 of these for the two cabinets and they are very time consuming. Having a band saw and miter gauge would have made this a lot easier, but I don't have one....... Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 23, 2011 Author Share Posted October 23, 2011 They fit the layout very well as the angles are 9 degrees for the center ends and the outtboard pieces are 18 degrees or 72 degrees depending on the side of the blade. Once I made the jig, it was easy to flop them for the reverse cut. Hope that made sense.....! Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 23, 2011 Author Share Posted October 23, 2011 All the ramp pieces are cut for both cabinets. Will cut the slots for the motorboard tomorrow and FINALLY, I can start the assembly..... The building construction has been taking just about all of my free time, but it will be worth it in the long run. I will be glad to have a shop that I can finally work in without having to move something out of the way. The Panel Saw needs room to breathe.....! Quote Link to comment Share on other sites More sharing options...
jwc Posted October 23, 2011 Share Posted October 23, 2011 Wow. It is finally happening Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted October 23, 2011 Share Posted October 23, 2011 Lookin' good! For the ramps, I originally tried using my crummy table saw to cut the angles. Then I got smart and found a radial arm saw on Craigslist (for next to nothing). Then things went more smoothly. It is easier for me to blame the tools rather then confess that I am inept. Let me get my bearings, it looks like the ramps you are using for the actives and the drone all have the same geometry (hence the same rapid initial flare rate). Is that the case? Are the throat sizes the same for all drivers (active and passive)? Interesting build and I am paying close attention. I may need to steal your good ideas when I breakdown and do "Jubilee build number two". -Tom Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 24, 2011 Share Posted October 24, 2011 Found a picture from an old post to illustrate the ramp extension concept. I can't help but to think if the ramps are not extended around the first turn, you are going to get a lot of cancellation due to the phase difference between the drone and active driver. Other than that, looks good and tight . Quote Link to comment Share on other sites More sharing options...
jwc Posted October 24, 2011 Share Posted October 24, 2011 SF. He shouldn't need those extensions as the initial ramps will expand to reach a total internal height of 37.5 inches before the first horn turn to go to the back. Also note...3 slots instead of two as he has another one there for the drone. I remember that drawing you posted....that was one's attempt to make a two driver jubilee expand at 38Hz at the ramps instead of the "fast 92Hz". The drone version won't have the "~92Hz fast expansion" before the first turn as this drone version will have 3 expanding chambers vs the two in the standard jubilee. With 3, the expansion is slower. jc Quote Link to comment Share on other sites More sharing options...
Edgar Posted October 24, 2011 Share Posted October 24, 2011 Those were my drawings, showing how a near-perfect 38Hz tractrix contour could be embedded in a stock-sized Jubilee cabinet. Greg Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 24, 2011 Share Posted October 24, 2011 JC Sounds good.....hopefully, no dip near the drones tune point.....some additional info....basiclly the furthur apart the drone is from the active...the less cancelation of frequencies you have. Extending the ramps will increase the apparent distance between the drone and active. Right now the distance is the distance down one active ramp and back up the drone ramp. I'm just wondering if the horn environment with aggrevate or minimize this effect. Also wondering if the size of the mouth on the passive should be different from the actives? Here's a copy paste from a site . -------------------quote----------- With the good, you gets some bad—passive radiators are not perfect. As mentioned before, passive radiators can reproduce tones up to 180 degrees out of phase of the woofer. Depending on the frequency generated and the positioning of the passive to that of the active woofer, the frequency response could have small amounts of cancellation. So long as the overall phase response does not contain any sudden changes or discontinuities, the human ear/brain should not detect this. However, when the phase response changes rapidly over a small range, it can be noticeable, as some people are more sensitive to this than others. Another inherent problem is the fairly sharp roll off of the PR. The frequencies below the passive radiator's tuning will roll off very rapidly. In addition, the air in the speaker box no longer acts like a spring to control and restore the motion of the PR and especially the woofer below the resonance of the PR. Much like a woofer in a vented enclosure, power handling of the woofer can be limited below the tuning frequency. This, in effect, could damage both the active woofer and the passive radiator. Quote Link to comment Share on other sites More sharing options...
jwc Posted October 24, 2011 Share Posted October 24, 2011 Phase and cancellation was a fear I had when I contemplated such a build. I feel that with my skill set and knowledge.....I don't know how to prevent it. I'm clueless on the phase. However, interesting is Roy's articcle about porting a horn in which he states cancellation wasn't a concern if the passive if reproducing frequencies that the actives weren't. That was on a different style horn than this but what I would want to try is to port the cabinet "low" and to tinker with the porting to "pick up" the response that drops off under 100Hz. Thing is....not sure how far out the passive will play....then you have to consider the cancellation thing again. jc Quote Link to comment Share on other sites More sharing options...
juniper8 Posted October 28, 2011 Share Posted October 28, 2011 Great build thread!!!! So much fun to see these builds, keep the pictures coming[8-|]!!!! Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 28, 2011 Share Posted October 28, 2011 However, interesting is Roy's articcle about porting a horn in which he states cancellation wasn't a concern if the passive if reproducing frequencies that the actives weren't. That was on a different style horn than this but what I would want to try is to port the cabinet "low" and to tinker with the porting to "pick up" the response that drops off under 100Hz. Thing is....not sure how far out the passive will play....then you have to consider the cancellation thing again. I think you prety much hit the engineering consideration. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 28, 2011 Share Posted October 28, 2011 However, interesting is Roy's articcle about porting a horn in which he states cancellation wasn't a concern if the passive if reproducing frequencies that the actives weren't. That was on a different style horn than this but what I would want to try is to port the cabinet "low" and to tinker with the porting to "pick up" the response that drops off under 100Hz. Thing is....not sure how far out the passive will play....then you have to consider the cancellation thing again. I think you prety much hit the engineering consideration. Quote Link to comment Share on other sites More sharing options...
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