jwc Posted November 7, 2011 Share Posted November 7, 2011 Questions for the Experts How smoothe does the signal path through the flair need to be? Does the bracing need to be rounded over or would it be a good idea? Would the end of the board at the second turn need to be rounded over or would it make a bit of difference? Same thing with the backside of the braces at the mouth, would rounding over the end facing the signal make any difference? I'm thinking of eliminating any turbelence caused by the bracing in the signal path kind of like wing vortices. Now is the time to do this before glueing of the parts. May sound silly but i am thinking in Fluid Dynamics or Air flow...seems like anything to eliminate any turbelence would be an improvement. W. C. The current jube production doesn't modify the braces to optimize flow. This build looks great. So did you tear off the last set of braces? Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Yesterday and todasy's Progress: After much thought and as long as i had not installed them yet, I desided to go ahead and round over the braces. Please NO safety lectures as I am building a router table and that is another project that is not finished. My timing really sucks. I have a brand new Powermatic Router Lift sitting in the box awaiting me to route a top for it to fit into. Any a very quick pass with a 3/8" round over bit gives a very smoothe edhe. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 After rounding............... Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Installing them on the RIGHT part this time (Part Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Man...Did I ever let some blood out yesterday.....! I needed some shims so I broke some scrap plywood pieces....(Note to self....NEVER break Plywood and put the very sharp end in a blind place) went to remove them while they had a bit of pressure on them and guess what...they are like little razors....! Guess It is giving it up for a great cause.......ended up with a quarter inch puncture in my little finger. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Part B with the braces glued and screwed......FINALLY Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Dry fitting panel C notice that I rounded the end of this panel also...May not do a thing but I feel better about it.............[] Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 They look so much better in the right place. Again...THANKS to everyone that noticed this and also a great amount of pleasure was derived from the ones that even tried to justify what I was doing. You guys are great and I really appreciate all of the interest in this build. Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted November 7, 2011 Share Posted November 7, 2011 WC, things look good! One thing I did on my build, that others did not do, is to put a couple of struts after the 90 deg turn (between the two parallel sections that are about 2.xx inches apart. I thought this would give some more solidity to the cabinet. At the very least it made me rest easier. At this point you can probably wedge them in and screw on one side. Whether it makes a difference or not ... who knows. good luck, -tom Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Dry fitting the final Panels G, H, I. I am using a letter system to identify all of the parts that corresponds to an AutoCad drawing that I have done. I will make that available along with a build sheet (Instructions) after some checking of this cabinet is done. The instructions are in a Word document and will list all of the places that mistakes can be made, just ask me how I know that................. Along with the drawings are several sheets of templates that can be printed on 8-1/2" x 11 (for the braces) and a templet set for the motor board that can be printed in three 11" x 17" (Tabloid) sheets. If you have a plotter or access to one you can print the whole thing. The size and placement of the ramps is critical as there is not much room to play with three 12 - 3/8" speakers in a 37 inch cabinet. I am saving these pictures in Picasa and will make the Album available also after this one is built and tested. I went ahead and installed the 12" passive as I know what a Bear it is going to be to get to after this thing is closed in, even with access doors top and bottom. Part A (the Face) will be removed so that the Parts M (Splitter) can be installed. This can be done anytime. The joint between G and H is just held together with duct tape and appears to be a bit out of alignment. I have checked the fit of all of the braces and joints and they all seem to have been cut correctly...Go Figure. There are a lot of angles in these cabinets and some of them are just a couple of degrees apart so it is very easy to get the pieces turned around. Labeling is a must before you glue anything...again ask me how I know these things....[] Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted November 7, 2011 Share Posted November 7, 2011 Goodness gracious, your build is going so much faster than what the rest of us went through. Keep up the good work! Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Tom, Are you taslking between panels B and E? I feel pretty confident about these 90 degree pieces as using the Kreg Jig makes for a pretty strong joint. I'm using Pro-Bond glue also (they use it across the street from me to build concrete forms) and it will actually rip the plywood layers before the joint gives up. Some of the strongest glue I have ever used. W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Tom, I think one of the reasons that it seems to be going so fast is that it took me the better part of three years to do the research and having a very detailed set of plans, with templates, really helps. It is because all of you guys before me, that have built these, did such a good job with your builds. I have just taken everything and compiled it into one set of working drawings. With Autocad, when it tells you 63 degrees you can count on it. Also having the Sliding Table Saw really speeded up the cutting process. I am probably able to devote more time in a strectch, than most of you guys could have done. I must say that building the new building has been a total distraction, as it takes your full concentration to do this assembly. That is one of the main reasons that I got the struts in the wrong place on Saturday...in a damn hurry and not paying attention. W. C. Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted November 7, 2011 Share Posted November 7, 2011 Tom, Are you taslking between panels B and E? I feel pretty confident about these 90 degree pieces as using the Kreg Jig makes for a pretty strong joint. I'm using Pro-Bond glue also (they use it across the street from me to build concrete forms) and it will actually rip the plywood layers before the joint gives up. Some of the strongest glue I have ever used. W. C. Yes, I was referring to the space between "B" and "E". Yes, the joint probably is pretty strong, but I don't apologize for overkill. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Where I am truly going to need help is when it comes to testing these. Installing the Passive/Drone is so far out of my expertise it isn't funny, but I love challenges. One advantage that I do have, is I have a very good set of ears and I definately know what it sounds like to be live, as I have spent some time on the road. In another life, I was a rigger/roadie for a year and a few months with a very popular gorup, many years ago. Also part of my career has been working Auditoriums, Coliseums and Convention Centers. W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 Tom, I can easily get back to that area and add additional bracing. I have increased the number of braces anyway for the three that are shown. I am using three each of those on each side. To add more at this point is not an issue at all. I am like you, overkill is OK as long as it does not impede the signal path. W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 It is time to really start some serious thoughts on the Drones. There was some earlier conversations in this thread about "tuning the Drone". My thoughts are that it needs to be tuned below the AR's. Does anyone have any charts or any information to start this off with. The present slot is 4-3/4" x 9-1/4" and can be varied to suit. The passives have an excursion limit of 1" in either direction, which is the limit of the cone movement. It may be time to invest into djk's suggestion of the TC Sounds VMP 12. I would like to explore the paremeters of the existing passives before we make a change. As to extending the ramps, it will be impossible to do anything after the first turn, as it will totally interfere with the flair of the two AR's. Whatever we do it will mix after the first turn, hence the tuning below the AR's. I have NO idea what Roy had in mind for the Jube Passives, but what I have installed is the klipsch K-12 Passive with an extension ring to allow full movement of the cone. I can easily add weight, as I am just looking for a starting point. This is where the techno $hit will get the best of me but I am willing to try any and everything that anyone suggest. While I understand that all of this is purely subjective and an experiment, I would like to have a substantial starting point, that everyone can possibly agree upon. Is that even possible?....[8-|] Let the fun and flames begin....................[6] W. C. Quote Link to comment Share on other sites More sharing options...
Panacea Engineering Posted November 7, 2011 Author Share Posted November 7, 2011 It may be better for anyone that has serious suggestions on the passive, to offer them in a PM or email as I do not want to start any kind of "Mine is better than yours" type of responses in this thread. As I am the ultimate one that is going to be trying the various suggestions, it may be best to do it "In the Blind" for the present. While I certainly will give credit where it is due, I just do not want to start any arguments, as it relates to this build. Hopefully that makes some semblence of sense. I have already had some incredible suggestions and I have a couple of sources that I can "Bounce" ideas off of. I just don't want to build this speaker ten times to accomodate everyone's suggestions or to ruffel anyone's feathers if their suggestion is not used. I have already seen this happen in several builds and the building/testing process. Please feel free to post any and all suggestions but do not be discouraged, if for some reason, they are not used. I want a lively and intelligent discussion, I just do not want this to degrade into any kind of argument. W. C. Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted November 8, 2011 Share Posted November 8, 2011 WC: A couple of points that I should have mentioned earlier. 1. Now is probably a good time to gather up some software for doing the speaker measurements. You will certainly need this when you tune the drone. The package I use, and it is free and avaliable over at DIYaudio, is "HolmImpulse". This will do basic freq response measures and you can also use it to do the impedance measures (this is critical for tuning the drone as well as checking for air leaks etc). You will also need a micropone (a Behringer ECM is fine and only costs about $50) and possibly an outboard DAC ( many inexpensive choices available - check the DIYaudio threads). The microphone will probably also need a biasing voltage (phantom power) and can be supplied by an expensive mixer (again Behringer has a new unit for about $50 and there are other alternatives). Mike Bentz also has a DIY system listed on his web site. My recommendation for the Holminpulse is beacause it seems to work with the largest number of microphone, DACs, operating systems. Otherwise, make sure the software will work with your combination of hardware, OS etc. 2. When you mount the drivers, the factory build uses a pair of 1/4 inch gaskets (giving 1/2 inch set back from the motorboard). This seems like more than enough clearance, but I did not want to find out the hard way. Quote Link to comment Share on other sites More sharing options...
jwc Posted November 8, 2011 Share Posted November 8, 2011 Don't worry about flames. My opinion is to leave the slot opening for the drone the same size of your actives. Don't worry about change any ramps/flares. Leave all the above as a standard....then tinker with tuning the drone. My guess is to tune the drone somewhere 30Hz to 50Hz. djk would be of good value to tell you what mass to stick on there. I have never tuned a drone. yes...at some point gonna have to get some measuring equip. Quote Link to comment Share on other sites More sharing options...
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