Sorry for the late reply guys and wow! Lot of action and looks like I missed it. I was busy last weekend and couldnt reply.
if you feel that this conversation is hijacking your thread please feel free to ask mods to move this to a separate thread.
My last post on this in this thread so as not to derail it.
Please take the discussion elsewhere guys and let us enjoy the pics.
Let this thread be Captain's build thread. Being a senior member he is, I am sure he won't mind little offtopic related discussion. Though most suggestion are very helpful; do not shall I say nit pick the build which is 'already done'.
Thank you for your concern folks. However, since the purpose of the thread is to add to the knowledge base of the forum and would be (hopefully) useful to members taking up build threads in future, any OT is welcome as long as the discussion remains constructive and civil.
Smooth does not equate to optimal adhesion. A little rough is better, IMO, as long as the surfaces align and they are adequately clamped after gluing up. And, with MDF [which I assume you're using] with what I've seen, cuts using a power saw are more than adequately smooth. I wish I had a picture to upload here to show how smooth but I didn't take any the last time during a build. As far as I know [with what was told to me by the guy who builds them for me] the sharpness of the saw is everything so if their cut surfaces are not smooth it's time for them to change the blade. Also, using a circular saw, the guy who builds them for me ALWAYS tells me that the size will be +- 2mm from what I've given.
Ill have to disagree with you on the point highlighted above. When I said smooth finish, I didnt mean mirror finish which can be achieved only by sanding and buffing. My post was based on what I saw. For all I know, since he is having a leverage of 1mm which he is shaving off, he may be skimping on the blade. BTW, yesterday while we were finishing I broached the subject with him.
Im quoting him here:
"Yes, jigsaw and circular saws can be used to cut exactly to the given dimensions but there are practical problems. Though theoretically MDF is a homogeneous material, in practice youll find that some portions have slightly more density. When the jigsaw transits from less dense to the denser portion or vice versa, the blade would quiver (minutely) while moving up and down which would result in minute waver in the cut which has to be invariably shaven plain. In case of circular saw, it is useful only for making big external cuts; it is not possible to cut minute internal cuts. Some expensive German machines are available where one need to just put in the dimensions and the machine would take care of the rest but they are very expensive. Just the blade costs Rs. 50000/- Even sharpening the blade for reuse costs Rs. 2000/- for which, it has to be sent to Bangalore and would take three to four days including transportation time. So it is more practical to sacrifice an mm of MDF. Incidentally, CNC would result in much more wastage of material as the bit used for cutting is thick.
You can remove the screws once the glue is dry.
I had discussed exactly the same much early during the build.
His reply was:
Though MDF is a much denser than wood, it doesn't have interlinking layers. If there are no screws and two panels are just glued on, if sufficient force is exerted, the panels get separated with the layer right adjacent to the glue layer giving away. Even liquid nails are no match to the good old self-tapping screws.
He had explained how someone brought him an imported JBL subwoofer whose liquid nails had gavin away and how he had to make a new box of the given specs to fix it.
MDF basically splits or chips when you nail into it with no holding power as it has a layered internal structure.
The nails can be gently tapped by a punch so they recess in the mdf slightly. I hope this will solve the problem.
Yes, Ive seen the splitting of MDF due to driving of nails during the build when the baffles was temporarily fixed for routing the edges for levelling. However, I cant agree that it doesnt have
any holding power; Id say it is because it has inadequate holding power.
According to Santhosh, the popping is not just because of the lesser holding power but because of constant flexing of the panels due to in and out movement of woofer cone. The resultant mechanical stress and strain is what results in the nails popping out. However, in the present case (of surround speakers), since the panel dimensions and speaker volume are quite small compared to the size of the woofer cone, the nail popping is a nonissue.
I've got furniture at home which is made of MDF using this method and it's been 5+ years now - not one bulge anywhere. For additional strength at the edges, the carpenter also drilled pilot/guide holes and at intervals inserted regular wood screws along the edges. The screw heads were counter sunk and a mixture of MDF sawdust and diluted Fevicol used to fill the holes.
Thats exactly how we are making my speakers.
Sire, can I make a suggestion, instead of these connectors, use Binding post that can be screwed through the box wall or a Speakon connector. These types of connectors (again binding post in a plastic base) might affect the sealed system.
Since these are going to be wall mounted and thus the space available at the rear would be limited, we reckoned that it would be best to use bare wire. Hence those cups supplied by Danny are used which have sealing gasket and hence there would be no air leaks. Im thinking of using the binding posts on the mains and the Centre but Santhosh has ruled out the usual Red/Black plastic lined ones as the flimsy few micron thick stoppers would give away after tightening/loosening a few times. Give me some time and Ill post the pics for understanding the issue better.
What's your plan for the finishing? Veneering or painting?
what are you planning for the finish?
Im vacillating between Veneer and some special paint. Im going to the factory sometime to check out the special paint in the evening and will update.
and let's get back to the build, folks.....
