Zaph SR71 Floorstanders finally finished

[Silver1omo]

Re: Zaph SR71 Floorstanders finally finished

There is no glue line in the roundover close up. So he cut the L shapes.

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Beautiful work

I have built 2 pieces of furniture using translam, the hand plane is your best friend and then a random orbit sander.


The amount of elbow grease will depend on the accuracy of the cuts and how you glue up. The coffee table/chest took forever (my first woodworking project), the "rack" was a lot easier.
The table/chest was done on 2011 and no de-lamination so far...

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Thanks for all the kind words about the speakers. I am really happy with the way they turned out. To answer a few of the questions:

1. Yes, I actually cut the BB ply into 'L' shapes. I cut a panel to the right size and then drew a 45 degree line on each side at one corner and drew a parallel line 3/4" on each side of each line, on each side of the board. I then cut each leg the "short" line. Then I finished each cut with a jig saw. I then cut the next L shape. When I was done, the left over piece was almost perfectly sized for one side panel. Here's the basic layout on a 5' x 5' board.



The strips you see at the bottom were for the previous project. I did a pair of Bargain Minis for my desk at the office. Similar concept for those except the grain ran horizontal from one side, around the baffle to the other side and then the top was birch veneer. It was a test bed for the Ebony finish and it didn't turn out as well. I want to post a build thread for those at some point as well.

2. I used a random orbit sander with 50 grit to smooth the face. It took some time, but not as much as I expected. It probably took an hour or so and 3 disks of 50 grit to do each speaker. It was more time consuming to mark, biscuit cut and join all the L shapes.

3. Very few issues with voids in the plywood. The trick is to use good quality, furniture grade, true Baltic birch with 13 core plies. Real BB ply is just as straight, more dense, and more dimensionally stable than MDF. The bigger issue was very fine "gaps" at the glue joints. The birch veneer wouldn't cut completely smooth so when you glued the piece veneer to veneer you would get little recesses at the joint that needed to be filled. I used a good, smooth filler before my final sand and it took care of it.

4. I cut the Ls with each leg being 3/4" wide which, when assembled, provided a 3/4" thick baffle and top. I probably would have gone thicker for the baffle but I would have had to buy another sheet of Baltic birch. At $75 for a 5' x 5' sheet I didn't want to do that. It was still cheaper than MDF with a hardwood veneer, but a bit more work.

5. Yes, the extra circle on the baffle is for a future .5 woofer if I ever decide to try it.

One item of note if you do something like this. If you want to get a really dark stain on the "end grain" don't sand any smoother than 120 grit. My first sample board was sanded to 220 grit and I couldn't get the stain to take. I used a Sherwin Williams BAC wiping stain that they pumped with extra pigment and it still wouldn't take. On one sample I let it dry completely without wiping and the first finish coat of tung oil took it right off. The trick is to sand only to 120 grit, do about 3 coats of the BAC stain, letting each coat dry completely. The last application of stain gets rubbed in, wiped off, and then left to dry for 24 hours. You then apply the first coat of Tung oil (or polyurethane if you prefer) very lightly and let it dry. The next coats can then be applied normally.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

At first I thought that they were 'L' cut as well. Appears to be a mitre when zoomed in on the last photo of the first post. Although, when I look at the previous two photos I'm less certain. I used a similar translaminated construction approach on my ongoing build (cjd's Ansonica). My baffle is approximately 1.5" thick in the middle, with the outside layers getting thicker to facilitate facet cuts and constrained by the walls. Which brings me to the question about levelling. I had a few different surfaces to level, with only the top on a regular box plane. I used a hands plane to true up my surfaces and some sanding and scraping before funishing. Sure I had to resharpen the plane a couple times, but sure beat a sanding block.

Winsnrswin, any problems with stability of the slab or layers delaminating? I had some splitting once I glued the boxes up when the weather changed.

Not at this point. It's been a pretty long project. I started the project back in November and the pieces sat unfinished (in a conditioned house) through the winter and spring. We're getting into the 90s here in Kansas now so I'll let you know for sure in a few months. Baltic birch is used a LOT in custom furniture and cabinetry so I really don't expect to see any problems.

I used a hand plane just a little bit on a couple of spots, but for the most part the biscuits helped to line everything up really well. Lots of random orbit sanding though.

[Thezeek]

Re: Zaph SR71 Floorstanders finally finished

Nice.

[knowledgebass]

Re: Zaph SR71 Floorstanders finally finished

Not at this point. It's been a pretty long project. I started the project back in November and the pieces sat unfinished (in a conditioned house) through the winter and spring. We're getting into the 90s here in Kansas now so I'll let you know for sure in a few months. Baltic birch is used a LOT in custom furniture and cabinetry so I really don't expect to see any problems.

I used a hand plane just a little bit on a couple of spots, but for the most part the biscuits helped to line everything up really well. Lots of random orbit sanding though.

Ha, I started in September! So does that mean I'm winning? I started seeing movement in my baffle as soon as the seasons changed. Width wise. It is dimensionally stable on two axis, but the thickness behaves more like wood (which normally isn't a problem until you stack a bunch of it together to make a panel).

The L panel is crazy. I've not seen anyone tackle it this way. In the one photo it looks like a mitre (maybe it's a shadow or pencil line), but I did notice the round over looked so clean, I just assumed you got a better joint than me!

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

The way you did that top corner and roundover is very slick! I need to keep that in mind for future projects. Looks like some table saw trickery getting the blade close to the 90deg part without going through.

Amazing job with fitment, sanding (and more sanding) and finishing.

Looks like the finger will heal up with not too much permanent damage, chalk it up to luck and learn from it. :-) This looks like a safe solution to holding small pieces on a router table. Remember seeing a video on the shield. http://www.mobilesolutions-usa.com/s...ger_Saver.html or http://www.mobilesolutions-usa.com/s...er_Shield.html

Thanks for the link. Looks like a very useful tool. Also much cheaper than the emergency room copay

[doctormorbius]

Re: Zaph SR71 Floorstanders finally finished

Winsnrswin, that's a great looking pair of towers. Excellent work on the Baltic Birch.

I have a couple of quick questions about the cabinet dimensions. Other than the height, are all of the internal dimensions the same as what is recommended on Zaph's site? Also, how tall did you make these?

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Thanks for the compliment.

The internal dimensions are ALMOST identical to Zaph's design. I made a slight adjustment for the fact that the crossover is not mounted in the enclosure. It's probably not enough to make a difference in the performance of the speaker, but I'm funny that way. Considering the fact that I wanted to be able to convert to a 2.5 way in the future I wanted the volumes that the woofers see to be as identical as possible. Since the volume taken up by the tweeter and the volume taken up by the crossover are very similar (estimated on the crossover, of course) I decided to take the crossover out of the upper enclosure and make that enclosure a touch smaller to compensate. I then made the lower enclosure the same gross volume as the top and installed the crossover in it. That made the net volume that each woofer would see as close to identical as possible.

The fact is that the change is probably so small that you wouldn't even notice the difference when measuring but, like I said, I'm funny that way.


The actual height of the tower in 39". With tiptoes that puts the center of the tweeter at about 36". That was a compromise dimension for me. It's probably a touch above ear height for my sofa setup if I use them with the home theater, but it's a touch lower than ear height for my desk chair if I use them in the office. I tend to move speakers around a bit so I had to think about different listening heights. However, either one is close enough that I haven't been able to tell a difference between right on axis and slightly above or below.

Oh, and I forgot to mention that the left over volume at the bottom of the speaker is filled with fine grout sand for stability.

[doctormorbius]

Re: Zaph SR71 Floorstanders finally finished

Thanks for the reply. 36" to the center of the tweeter would be perfect for me for the same reasons. In the living room it would be a tad high, but in my office it would be a skosh low.

They really do look great. I hope to build a pair of these as floor standers myself some day.

[6thplanet]

Re: Zaph SR71 Floorstanders finally finished

Nice touch on the cabs! The finish is right on the money for those enclosures and speaker selection, great job! Also, glad you still have all your digits!

[mzisserson]

Re: Zaph SR71 Floorstanders finally finished

WoW!