Zaph SR71 Floorstanders finally finished

[winsnrswin]

Just finished my second full range speaker project ever. My first project was a pair of Zaph Bargain Mini's using the ND20 tweeter. I was VERY happy with the result so I decided to try something a little bigger this time. After much research I decided to go with a pair of SR71s. I really wanted a pair of floor standing speakers so that's the direction I chose to go. I'll apologize for some of the photograph gaps. I had a hard time remembering to take pictures at every phase.

I started with a 5' x 5' sheet of 3/4" Baltic birch ply and cut it on the table saw into 'L' shapes to form the top and the baffle. The idea was to create a straight grain effect to run over the top and down the front of the speaker. I also cut panels of BB for the sides of the speakers.






After cutting all the 'L' pieces (22 to be exact) I biscuit joined them together to make the two baffles.





I then evened out the face and top with 50 grit and used a router and circle jig to cut the tweeter and woofer openings.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished



Along the way I decided to treat these speakers as a bit of a test bed. It may or may not turn out to make any sense, but I thought it might be fun at some point to try to convert these to a 2.5 way speaker so I built the cabinets to allow for a second midrange. I've found the best way to learn things is by doing so why not.

Here are the primary finish pieces after the cutouts for the second driver.



Now for preliminary assembly:



Notice I did provide a separate enclosure for each woofer to allow the speakers to be built as 2 way now, but be modified in the future. My plan was to put the crossover in the lower enclosure so I modified the volume of each enclosure to account for that. since one enclosure housed the tweeter and the other the crossover, they ended up pretty close to the same volume.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Here's where I had a little lapse in photography so I'll have to rely on descriptions.

So the next step was to provide a fill for the 2nd woofer cutout that would look finished and intentional now, but be removable in the future. I cut round pieces of 1/4" Baltic birch to size, cut it to the right thickness to work as an "inlay". To make sure I didn't have any issues with the thinner pieces resonating I glued a round piece of 3/4" mdf to the back and then solidly hot glued them into the 2nd woofer opening from the back side.

The next step was to round over the edges of the top and baffle. The plan was to use a 3/4" round over bit on the top front edge first, then round over the sides of the baffle and top with a 1 1/4" thumbnail bit.

Unfortunately, before I could do that I was forced to take a 4 week break for a rather hard learned lesson about shop safety. The middle finger on my left hand also got the 1 1/4" thumbnail bit. Warning: Don't enlarge the second picture below if you get queasy at all.



If the mods think the second picture is inappropriate please remove it or let me know and I will. However, I wanted to post it as a reminder to people about what our shop tools can do. I am VERY methodical about shop safety. My father taught me and he was a stickler for safety. I've taken middle school wood shop, high school wood shop, and we had a full wood shop in college for building models. I've taken the tests and been safety certified at every level.

However, this one time I got careless. I hadn't been in the shop in several weeks and I was excited to be out there and wanted to get a lot done. I wanted to take a look at the profile of the new thumbnail bit to see if I wanted to use it so I installed it in my router table and grabbed a piece of scrap wood to check the height. I entered the bit at the wrong angle and it shot the piece of wood across the garage. I had a pretty good hold of it though and it dragged my finger into the bit in the process. It was one split second of carelessness. All that being said I was darned lucky. From the right angle you could actually see the end of the bone, but I didn't damage it. If I had it would have been a much bigger deal.

Ok, sorry for the lecture, back to the project. I didn't want to work with shop tools with a rather loose bandage around my hand, so I had to wait about 4 weeks until I was down to a tight fitting set of band aids. The next step was to round over the edges as described.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Next was sanding the whole thing to 120 grit and cutting the back panels with port openings.



I went ahead and cut openings for both, but only installed an outer flange in the lower port just to make the opening look finished.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

So, now it was ready for stain. One of my favorite pair of speakers are the Yamaha NS1000s with the ebony cabinets. My father bought a pair new in 1978 and he has handed them down to me. I love the way they sound but I also love the color and finish of the cabinets. So, I decided to pay homage to the NS1000s and go with an ebony stain and a satin oil finish.



So, next I moved inside for assembly.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Installed drivers, added damping material as per Zaph's instructions, installed crossovers seal tape for the back panel.



Also, a quick update pick on the finger:



If I remember correctly this picture was about 9 weeks after the incident. It's been about 4 months at this point and the end of the finger is still numb. I'm guessing it always will be. Guess I shredded the ends of quite a few nerves.

[winsnrswin]

Re: Zaph SR71 Floorstanders finally finished

Last but not least, pics of the finished project:



As for the sound, I am simply floored by them. I couldn't be happier. Very detailed and very smooth. Great bass extension, especially for a small 2 way. My original plan was to replace a pair of 685s as the front left and right for the home theater and then build a center to go with them, but I like them so well I may just have to keep them in my office for a while for 2 channel listening. I am working on a sub to go with them, based on the Vifa 10" reed cone subwoofer driver that PE had on closeout for a while.

I'm definitely sold on the DIY route now.

[jakeparsons]

Re: Zaph SR71 Floorstanders finally finished

Those look great! I am sorry about the finger! I am SHOCKED I haven't had a similar accident in 14 years of woodworking... No pun intended, but I am keeping my fingers crossed ;)

[Melby Audio]

Re: Zaph SR71 Floorstanders finally finished

Wow, those cabinets look amazing. I finish alot of my cabints in ebony too. What is the purpose of the circle below the woofer? Just for looks or room to upgrade?

[joeybutts]

Re: Zaph SR71 Floorstanders finally finished

Wow, those cabinets look amazing. I finish alot of my cabints in ebony too. What is the purpose of the circle below the woofer? Just for looks or room to upgrade?

"Along the way I decided to treat these speakers as a bit of a test bed. It may or may not turn out to make any sense, but I thought it might be fun at some point to try to convert these to a 2.5 way speaker so I built the cabinets to allow for a second midrange."

[Paul Carmody]

Re: Zaph SR71 Floorstanders finally finished

The trick you did on the baffle is really, really cool. I literally cannot stop staring at the pictures. So let me get this right: you cut the l-shape strips on a table saw? How did you do the 90 degree angle (without slicing the whole way through)? Also, how wide were the strips? And how long did you have to sand them to a flat baffle?

[Mike220]

Re: Zaph SR71 Floorstanders finally finished

I think he just put 45 degree angles on them and biscuits to hold them together. Its a great idea. Plus it saves the cost of veneer for baffle and top! I am interested in how much sanding is required and if he had alot of voids to fill. Its like a time consuming but economical zebrawood!

[johnastockman]

Re: Zaph SR71 Floorstanders finally finished

Absolutely beautiful work! The laminated pieces for the front and top is a sensational idea and I love how it turned out. Very creative and the finish turned out great too. And some think my retail audio/stereo store experiences are gross homogenizations and I have an invalid "bias" for DIY designs. Your experiences with the SQ of those speakers is just like so many of my friends and family, and that's why they have a DIY design in their home...and so do I. Great write-up and good pics; thanks for speaking about safety and showing those pics. It could maybe save a newcomer's fingers.


John A.

[WesL]

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

[knowledgebass]

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.