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Old 22nd August 2009, 01:52 PM   #11
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Well It has been nearly four years, but I decided it was time for an update I pretty much did nothing at all on my speaker project from The last post, Nov 2005 until probably about 6 months ago.

I thought that I needed to veneer the back bafle before I glued it on due to the tightness of the tweeter compartment and the feeling I could not connect the speaker terminals after the box was glued together, My veneer after being rolled up for nearly 4 years was rather curly when I cut it. I tried to flatten it but failed, finally tried a different approach (spraying with 90% water 10% glycerine and clamping for a few days) and it flattened out nicely. However I decided to try mounting the terminals with the backs clamped in place and found I could do it with no problem. The thing that prompted me to do this was the worry the baffles would warp after veneering if they weren't already attached to the box.

Anyway aside from all that I had never been happy with the dirver cutouts, or the fit for the rear baffle. I decided to attack the chamfers on the driver cutouts with a tungsten carbide tip on the dremel, and now have much nicer flares on the inside of my front baffles. After a lot of sanding (only one box so far) I got the rear of the box so that when the baffle was sitting on it there was virtually no differences (few thou at most), I was happy enough with it and this afternoon glued the rear baffle onto the one box that has been completed.

Tonight I also soldered on the connectors for the internal wiring for one box (just the two cables for the woofers, I'd already done the tweeter cables for both boxes.

I've attached a few photos of recent activity, showing the old flares and the new ones, and also my makeshift sanding block

Also the shot showing the original flare, if you look on the left you will see another mod I made that wasn't on the original plan. I put some extra blocks in, in the tweeter compartment which are on the sides and glued to the font baffle.

Tony.
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Old 19th September 2009, 04:04 AM   #12
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OK Well I have made some progress since the last post. I have done a LOT of sanding since then. Glued the rear baffles on. More sanding, Filling, more sanding, and today I have decided to take the plunge and try putting the first peice of veneer on.

I'm doing it on the bottom of one of the cabinets. I originally wasn't even going to bother veneering the bottoms, but decided that A) it would mean that it was properly sealed on the bottom, and B) it was a good place for my first attempt, as if I completely screw it up then at least it isn't visible

The first problem was that the front baffles were around 1mm to short (as mentioned earlier in the thread, I tried building up with filler but it hasn't worked particularly well, and I'm going to be chamfering the front baffles any way so decided to just go ahead anyway and forget about the front bit Chances are this is more likely to be an unmittigated disater than a complete success

I noticed last weekend when sanding, that the sides of my cabinets have small dips in the middles of the pannels.. I'd really like to have them dead flat, but I just don't know if I can do that much sanding , and after my dodgy filling I don't think filler is an option, but I'll probably regret it if I don't so I suspect there is more sanding to go before I takle the veneering of the main parts of the cabinet.

Anyway here are some more photos of the progress.

The 1st shows that a speaker box is an attractive drawing surface for a 21 month old the second is the back of the box after a LOT of sanding almost perfectly flat and ready for gluing the baffle on. Said 21 month old can be seen in the background playing with the dirt in the potplant... Third shows dodgy attempt at filling the area where the baffle is uneven. fourth more filling (I screwed the second baffle after a nightmare of a time getting the first one lined up. Thanks To AndrewT for reminding me of the value of screwing and gluing. and finally the fifth one shows my efforts today. No glue seepage which is good in one respect as their won't be contamination of the other veneer if there is no seepage when I get to it, but bad in another as I'm not sure if I have used enough glue! I guess time will tell!

Tony.
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Old 19th September 2009, 11:24 AM   #13
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Well that went better than it could have

Veneer seems to have stuck solid. No bubbles it even seems to have stuck down at the ends where it rolls over a little (I find it it is very hard getting a completely flat sanded surface, always seems to round off at the edges somewhat).

I went to do the second box and discovered to my horror that the top of it had a really deep (I assume sanding) gouge in it so I once again got out the filler and filled it up. Though I took a different approach this time. Rather than using the spatular and over filling and sanding down hoping it would be flat, I ran the straight edge over it and it pretty much took away all the filler it didn't need and left what it did.. heres hoping anyway. So the second box is now going to have to wait till next weekend, as this filler takes 48hours to properly cure.

Pic attached of the result.. Will trim once the glue has had 24 hours to cure.

I used Bostic MDF glue slightly thinned with a little filtered water and applied with a small foam paint roller. I then placed the piece of veneer on the surface, smoothed it out with my hands, and then rolled with a wooden rolling pin. finally put the caul on and clamped for about two hours. I'll try trimming it with my veneer trimming bit and router... hope that goes ok!!

fist pic is the other piece of MDF for the bottom of the second cabinet, not 100% flat, but very malleable after treating with 90% water and 10% glycerine, and flattening for a couple of weeks. The second is the first box with veneer attached, showing clearly the rounding on the ends Oh well at leat it won't be a problem at the front once I chamfer the baffle also note the first is probably a better indication of colour. Was taken in full sun, the second was in the shade after a lot of smoke from a bush fire came along.

Tony.
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Old 20th September 2009, 03:38 AM   #14
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Default slowly making progress :)

Well I decided to get out the router and use the veneer trimming bit today (note I have never done any of this before so it is a learning experience) It worked very nicely along the grain, but I was a bit concerned with the result at first when trimming accross the grain... ended up looking very splintery and rough, but a quick go with some 220grit glass paper and a sanding block cleaned it up very nicely and all was well.

One very important thing I discovered was not to have the speed on the router set too fast! I have a variable speed router and it seems that speed setting two is about right. One was too slow and above three starts to burn the edge of the veneer (as can be seen in the attached photo).

Since I had the router out I decided to do a test with my chamfering bit (it is a huge one, 1/2" drive gives a 22mm chamfer (that is in 22mm and down 22mm not the distance along the chamfer). I got it for Christmas 4 years ago and till now has never been used. Again some important aspects. It worked best on about speed setting three. Additionally the direction of travel of the router is critical, it must be moving so that the leading edge of the bit is not biting in (this is quite possibly why I had the problem accross the grain with the veneer so will try this on the next bottom piece), if so it gets a very jerky and uneven cut. effectively cutting with the trailing edge is required.. Using a piece of scrap to work out which way works is mandatory! again attached is a pic of the piece of scrap which I sanded lightly with 220 grit glass paper after finishing the cut. I think the result when applied to the baffle will be quite acceptable

The veneer split somewhat on the font when I trimmed it, but this did not suprise me in the slightest (as previously mentioned this edge had been built up with filler and still wasn't flat). As the chamfer will be 22mm back, almost all of the problem area will be cut away anyway so I'm not concerned.

Tony.
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Old 20th September 2009, 04:52 AM   #15
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I hope it's not too late, but a little more breathing room for the backwave on the midwoofs would be helpful- the roundovers are good but you're still blocking a lot of the basket windows, from what I can see.

Nice work overall
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Old 20th September 2009, 06:17 AM   #16
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Hi Badman, It may not be as bad as it looks in that shot, I had a hard time getting a decent shot of the woofer, and the camera tends to flatten the perspective quite a bit making things look worse... This one didn't make the cut quality wise, but probably is the best for showing how much (or little) breathing space there actually is.

It wouldn't be too late to take out more material, but it would be quite a lot harder now that the backs have been glued on, and it wouldn't actually be possible to inspect the results with the woofer inserted Getting the dermel (or whatever) in through the front speaker cutout would probably be a bit awkward too.

I'm pretty pleased how it is coming along now, though I just had a bit of a nerve racking moment gluing on the rear baffle veneer. I smoothed it all down with my hands, went very nicely, realised I'd forgotten the rolling pin, raced in to get it, and when I got back the veneer had curled up on both long sides rather severly, probably should have wiped it down with the damp cloth I used for cleaning the surface but, somewhat panicked when it wouldn't stay down and just quickly shoved the caul on and clamped it... hopefully that wasn't a mistake! Oh well live and learn! I'll find out when I take the clamps off I guess... Might be able to iron it if there are any problems.

Tony.
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Old 20th September 2009, 06:42 AM   #17
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Tony, That looks way to tight. It looks as if the clearance on the bottom of the woofer is near to zero. Is it?

Terry
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Old 20th September 2009, 09:25 AM   #18
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Hi Terry, ummm yeah it probably is... This was something I was concerned about originally even with my prototype but these drivers have strange flanges that I hadn't encountered before and I really wasn't sure how to deal with them. The only way I could see that I could get a seal on them was to use the flange on the inner edge right next to the basket.

I've attached a bunch of photos here which show the woofer (note it really is an MW144 it is mis-labled!) The drivers did not come with gaskets (from memory Terry Paget (Aus distributer told me he uses silicon, I'd have to go back through the emails it was a long time ago!).

SO probably I should have a thick narrow gasket just in the channel where the screws are, and my cutout should only be that wide (it did worry me that only the very thin rim of the basket would be in contact with the baffle if I did this)... That was what I thought originally, but I'm pretty sure TP told me to use the inner surface for the seal, could be wrong though, I'll have to find the emails...

If that is the case All is not lost, I can draw another circle as an absolute limit where to cut to and probably just dremel out to that. Some 6mm thick neoprene carefully cut would probably suffice for a gasget.

Thanks,

Tony.
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Old 20th September 2009, 01:19 PM   #19
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OK well it seems that the veneering of the back of the box this afternoon was successful. I guess once I trim the veneer I will have a better idea.

I've attached some photos of this afternoons effort, sans the one where the veneer curled right up which I didn't take because I was too busy panicking that the glue would dry as it was a warm afternoon.

The first problem I had to deal with was that I had some splits in the ends of the veneer, these were dealt with by placing some 3M magic tape on the non glue side, being carefull to make sure the split was as tightly together as possible before applying the tape.

I cleaned down the MDF with a damp sponge cloth, and also both sides of the veneer, being careful to fully ring out the sponge cloth so as to not get any surface too damp.

Then I mixed the glue with a little filtered water and applied with the paint roller. Smoothed down the veneer with my hands and it flattened out nicely. forgot the rolling pin as mentioned in a previous post, and discovered to my horror that the veneer had curled up by the time I got back, and wouldn't stay down by itself... in hindsight, I think at that point I should have sponged down the non glue side and it probably would have flattened back out again, but I instead ran the rolling pin over it (to no effect) and then wacked the caul on and clamped it for approx 1.5 hours.

I would have left it a bit longer but for the thunder storm that was coming up, and decided it was time to bring it inside! The result appears to be a completely flat, no bubbles surface which seems properly stuck down..

another barage of photos below

1st shows taping of splits. 2nd the setup before proceeding (sans rolling pin). 3rd surface of box after applying the glue. 4th clamping. 5th the end result. Note that for the back surface I didn't worry about matching the grain (note it is running the opposite direction to the bottom pannel) the veneer for the sides and top were cut from one continuous piece so will wrap around so to speak. I figured it was less important for the back..,

Tony.
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Last edited by wintermute; 20th September 2009 at 01:22 PM.
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Old 20th September 2009, 02:05 PM   #20
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Looks Great, keep the pictures comin!

Josh
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