djk Posted October 28, 2011 Share Posted October 28, 2011 "not sure how far out the passive will play" It will be limited to about a half-octave, tops. With two 12s in a Jub style horn I would start out with about 400 grams mass on the PR, and then go from there. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted October 29, 2011 Author Share Posted October 29, 2011 djk, This will be my "Stupid" question for the day..............What formula did you use to come up with 400 grams? Almost 15 ounces seems a bit heavy, but admittedly, I have no clue in this area. We have the K-12 passives and the weight can be added to those easily, but I am afraid that that much weight may cause damage to the cone rim pretty quickly. Maybe they are stronger than I think, who knows. The TC Sounds VMP 12 that you suggested has a max mass of 390 grams, am I missing something? Also it looks like it will require a full 12 inch cutout rather than a slot, unless we build a riser to accomodate it. They sure are proud of that Passive...... I look forward to your expertise in this area and appreciate your valuable input as we venture into uncharted territory. I hope this build will be a valuable attempt at researching this (Roy's) idea. We are afforded all the time that is necessary as I am certainly in no hurry and truly want to get this right. Sorry for the slowness of this build so far as I am dealing with a new building being constructed and of all things, I have to attend a wedding in SC today. The gods must be trying to tell them something, as the forcast is wind and rain and it is supposed to be an "Outdoor" wedding.........should be interesting, to say the least.....[] W. C. Quote Link to comment Share on other sites More sharing options...
djk Posted October 29, 2011 Share Posted October 29, 2011 "What formula did you use to come up with 400 grams? " It's an educated guess. I can model ordinary vented systems with a PR, but not a horn. BAsed on the back volume and assuming that it should be runed about a half-octave below the cut-off frequency of the horn, I would start with 400 grams and work from there. FYI, the 12" PR on the EV Interface A had 400 grams on it. "We have the K-12 passives and the weight can be added to those easily, but I am afraid that that much weight may cause damage to the cone rim pretty quickly. " The spider is what holds things up. "The TC Sounds VMP 12 that you suggested has a max mass of 390 grams, am I missing something? " Yes, that they have an idea of what is needed. "Also it looks like it will require a full 12 inch cutout rather than a slot, unless we build a riser to accomodate it. " I would probably just mount it in the correct sized cut-out, no reduced size throat, no ramps, etc. "They sure are proud of that Passive......" It looks well designed. "We are afforded all the time that is necessary as I am certainly in no hurry and truly want to get this right." Sometimes you just have to make some sawdust, measure, and try again. RCA Fan (Bill Woods) sometimes makes a dozen itterations of a new design, and that is with computer modeling and close to 40 years as a commercial designer. There is a chance that the idea will be a total bust. Someone will just have to try it and see, ******************************************************************************************************* Have a MSM1900 with the quad K55s measured, unhook one drive, measure, unhook two drivers, measure. This should give you and idea as to what effect the PR might have on the midrange response (but at 1/10 the frequency in the Jub). Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 djk, I appreciate your input immensly and please believe me, this is a tiotal learning experience for me. Anyway, time for some updates............. I have found that running full size templates on my plotter makes the layout process much easier and leaves the guess work out of any angle cuts. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 One of the nice things about this project was it gave me an excuse to buy more STUFF..........I have always wanted a nice set of bar clamps as all of the crap I have accumulated over the years is a mixed matched mess. Most of the clamps i had are C clamps that were better suited to welding rather than wood work and you never had enough of the same size. I caught these Bessey K Bar on sale and you get what you pay for. These are the finest clamps that I have ever used and they are just pure quality....! Below we are gluing the ramps to the motor board, when they set, I can flip it, use the template and screw. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Inserts were actually installed before the ramps were glued. The template also helped in laying out the T nuts to keep them from falling under a ramp. Just ask me how I know this................[] Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 I used a Jig saw to cut the slots....should ahve used a Router...Oh well, next time.....Screwed, glued and all 24 T nuts installed. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Gluing up the first set of side pieces Part E on the plans...Glue and Screw...Glue and Screw...Glue and Screw. The nice things with the clamps is they allow you to be able to turn the part over and screw long before the glue dries. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Clamping.................... Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Parts labeling is extremely important to me as it keeps me from using the wrong piece. Yes, I have done that also. Some of the pieces in this speaker are very close to the same size and for me it is easy to confuse them. Also with the many angles also being very close from part to part, it is just something that i have to do. Some of the angles are only 2 degrees different and I can not twll by just looking at them which is which. The drawings and templates have been a lifesaver for me and i don't know how some of the others that have built these did it without them, I know that JWC did his drawings by hand and i can truly appreciate the use of Cad and how it speeds the process up. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Pocket screws....these are freehand but I purchased a Kreg Jig and it made installing the bracing a breeze. I truly thought that the Kreg Jig was more of a toy than anything and I was even reluctant to try it. I tried to install a couple of the braces without it and it became a clamping nitemare so i was forced to try it out. After running the first screw in it was never look back or try a freehand pocket again. The Jig made aligning the parts easy and the screws hols as tight as anything i have tried. I am totally impressed with it and after about 150 holes the bit is still as sharp as ever. My fear was that the bit would dull very quickly and the cost was going to be in bits at 12.00 each. Sometimes it is nice to be wrong and learn a new trick. i would reccomend the Kreg Jig for any type of woodworking project as it does everything as advertised. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Another shot of the pyrimid of the Dog House......... Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Dry fit of the Dog House............today will be assembly of the rest of the panels for this cabinet. Time for suggestions........would any of you guys install the speakers at this stage when they are very easy to get to? I can certainly wrap them in plastic to keep any dust out. It appears that the Drone is going to be a "BEAR" to get to after everything is assembled, even though I know that I will have to get back to it to make adjustments and possibly even replacement with the "djk" drones. I am open for any and all suggestions.... Quote Link to comment Share on other sites More sharing options...
Coytee Posted November 5, 2011 Share Posted November 5, 2011 very nice. I always enjoy seeing the results of you guys who have skills! If I was making one next to you, it would probably look more like a toaster by now. [] Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 A couple of shots installing the brackets/spacers Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Another shot of the final brackets that are the ones that you will see from the front on the finished cabinet. Again, the Kreg Jig is an absolute life saver for this type of installation...... Quote Link to comment Share on other sites More sharing options...
tomlang Posted November 5, 2011 Share Posted November 5, 2011 1. Excellent job! 2. I will have to order a Kreg today. 3. Will you finish this one and test and/or modify before starting the second one? Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Coytee, I don't have any wood working skills at all, just tennacity (sp)......![] This is by far one of the most fun and frustrating things i have attempted as I am learning something on every step I do. It is one step forward, two sideways and always one backward undoing something that I thought was right in the first place. The sequence of assembly is critical and i hope that these pictures and narrative can help someone out in the future. It is NO fun to have to remove and redo something that has been glued and screwed. I should have probably waited until after the building was finished before I started this project but my impatience got the best of me. It would have been after the first of the year before I could ahve started and that was just unacceptable to my Brain. Hopefully we will start setting steel today if the wonderful crew even shows up. They probabl;y all went to mexico for the weekend...who knows and my Spanish SUCKS..........! W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Tom, Get the Kreg Master Jig set....best bang for the buck. You will never use the vacuum attachment but it is cute.....[H] I highly reccomend the Bessey Bar clamps also, they are pricey but it is the best clamp I have ever used and they have many other uses. Yes, I decided to build the one first even though all parts are cut for two. I was going to build two side by side but after I started the assembly the light bulb went off and I figured if it was a bust I could at least go back with a regular Jube. i have the standard motor boards cut also so it will not be a huge loss. One of the benifits of screwing rather than nailing is the dis-assembly is not quite as difficult as the gluing can be reversed pretty easily. W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 5, 2011 Author Share Posted November 5, 2011 Coytee, Hell take some time off, drive up to Charlotte and help me drink some beer.....! We can make TWO toasters or TOAST something with adult beverages. I don't need much of an excuse to stop work and drink.....I have officially joined the ranks of the retired as of last Monday![6] Quote Link to comment Share on other sites More sharing options...
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