SDA 1C dovetailed walnut project

TennMan

Here is what I used and they worked well. I like the Torx drive or Allen drive screws better than Phillips head screws. You don't have to constantly press in to get the driver to solidly connect to the screw:

#8-32 Hurricane Nuts 50 Pcs.

I removed 1/3 of the radius from the flange of the hurricane nut before installing to prevent it from hanging over the edge of the holes in the cabinet.

Alloy Steel Socket Cap Screw,

• Black Oxide Finish,
• Button Head, Internal Hex Drive,
• 1" Length, Fully Threaded,
• #8-32 UNC Threads,
• Imported (Pack of 100)

westmassguy

TennMan wrote: »

I removed 1/3 of the radius from the flange of the hurricane nut before installing to prevent it from hanging over the edge of the holes in the cabinet.

That's overkill Ronnie. There's plenty of clearance. The Hurricane Nuts don't interfere with the Driver or PRs.

TennMan

westmassguy wrote: »

That's overkill Ronnie. There's plenty of clearance. The Hurricane Nuts don't interfere with the Driver or PRs.

I would agree that it is not needed but I think it makes a better looking job not to have the flange overlapping the holes. If you have a bench vice you can snap off the side of the flange easily, Then hit it a lick with a file to smooth the edge and your ready to install.

crispybrown

westmassguy wrote: »

Great resource. The four, Flat, Phillips Head screws on the RDOs are M4 X1/4" or 6.35 MM. I think it will be easier to find 8-32 Flat Head Phillips for the outer mounting screws, rather than the other way around.

It should be easy to find both, but I don't think 8-32 flat head Phillips will sit right in the plastic of the tweeters.

nspindel

Also be very careful not to over tighten the tweeters or you'll crack the plastic!

westmassguy

Thought I'd update on the tweeter machine screws. I was able to locate some M6 X 6mm, flat head, black oxide cap screws that match the 1" I used on the four outside mounts:

Much cleaner look than the Phillips head mixed with the flat, cap screws.

drumminman

crispybrown wrote: »

It should be easy to find both, but I don't think 8-32 flat head Phillips will sit right in the plastic of the tweeters.

They won't. What you want is 8-32 oval head machine screws, like these: http://www.go2marine.com/product/43973F/18-8-ss-phillips-oval-head-machine-screw-8-32.html?WT.srch=1&WT.mc_id=gb1&utm_source=googlebase&utm_medium=productfeed&utm_campaign=googleshopping&gclid=CMeDobuw7LsCFWJo7Aodng0AiQ

It's what Polk used.

TennMan

I think the head of the screw is a cosmetic preference. The cutout for the tweeter in the baffle is going to align it properly regardless of the shape of the head of the screw. All I have installed are a really close fit.

crispybrown

OK, it has been much longer than I anticipated, partly because I took so long to complete the tung oil finish, and partly just time taken to get around to posting pictures, but...

Firstly, I found Larry had no more tweeter or binding post rings available, so I decided to make my own. I cut the binding post rings using a bench grinder, drill press, hole saw used previously for a bathroom project and a lot of patience. I cut the tweeter 'rings' in a similar way using a couple of different size hole saws to make the odd shape.

I then did a lot of reading up on weld nuts, brazing, acetylene etc before deciding rivet nuts looked like a better idea. In theory to fit a rivet nut into sheet metal you simply drill a hole, insert it and use a tool much like a rivet gun to squish it slightly. In practice I found the tool is expensive and the hole has to be very precise to get the rivet to both fit, then sufficiently tighten. After some failed attempts I decided to solder the rivet nuts into the slightly too large holes I drilled. This worked incredibly well and easily, and the solder seems more than strong enough for the application. A coat of black paint hid any grinding and solder ugliness!

The custom tweeter rings provided for the possibility of using M4 philips head screws to mount the tweeters, matching those holding the plastic front plates to the magnets. I'm quite pleased with the look of these, even though they don't really "match" the screws holding the bass/mid drivers in:

I lost count of how many coats of tung oil, sanding with fine sandpaper and 0000 steel wool it took, but finally I was bored enough to convince myself the finish was sufficient and buff it with a wool pad:

Fortunately the drawn out schedule did give me time to fit gimpod's boards and Cardas litz chassis wire (thanks to nspindel for lending me the solder pot necessary to make use of this wire practical!)

Finally upon reassembly and basic testing, I listen to a few familiar tracks I noticed some unwanted vibrations. This iOS app https://itunes.apple.com/us/app/signal-generator/id409241018?mt=8&at=10lGyj&ign-mpt=uo%3D8 proved useful in eliminating them. As I slowly swept from 1hz to 20kHz and back I found and fixed:
- Chassis wires between the binding post cup and board vibrating against each other.
- Chassis wires to the tweeters vibrating against the chassis.
- Thin flexible copper wire between the connection spades and mid/bass driver coils vibrating against *the cone itself* (gently pulling them away was the fix)

I highly recommend anyone who hasn't already done so use a similar app or an actual physical audio signal generator to find and eliminate nasty buzzing both in the speakers and in the room itself - the overall effect on sound was significant, and your chances of finding them all by playing music is slim.

It's been way too long to objectively say whether the 1Cs sound 'better' and during the project my amplifier has been re-capped anyway, but I'm happy with the sound and the new look gained wife acceptance factor (at least to the degree possible with speakers of this size!)

westmassguy

Those came out beautiful. I too run sweep test tones after assembly. Very revealing in some cases. Enjoy them!

Moose68Bash

Extraordinary work -- looks and craftsmanship!

Well done!

Enjoy those beautiful speakers -- listening and looking!

nspindel

That's about as nice as a pair of 1C's can get!!! Very proud to have owned these bad boys at one point, and glad I picked the right guy to pass them on to. Outstanding work.

Oldfatdogs

Very nice,love the walnut.

Dan

Toolfan66

Very Nice!!! Great job on the rings as well..

That's how it's done, dream it, see it, and make it happen!!!

chandler9a

I have been waiting for someone to do this for a long time, great job. Really nice to see what it looks like!

I would like to do this to one of my pairs of SDA's some day

pumpkinman

What else can be said.
Stunning

boston1450

Those are beautiful. Great workmanship

zane77

A very unique one off pair, great job!

DarqueKnight

Congrats. Great work on the rings.

headrott

You did very well on those rings and you SDA wood. They look great and I am sure sound phenominl. Enjoy the improved audio quality and music.

amb426amb1

Great read....love the workmanship you put into those speakers. Now sit back and enjoy!

BlueBirdMusic

crispybrown,
Just ran into this older thread. Kudos to your work and research. I love the big dovetail joints. How are they sounding to you.

ken brydson

BlueBirdMusic wrote: »

crispybrown,
Just ran into this older thread. Kudos to your work and research. I love the big dovetail joints. How are they sounding to you.

He hasn't been on here since November 2014...

BlueBirdMusic

Thanks Ken,

I thought I may "wake" him. I owe you a "thank you" to from when you cleared my sign on problems a year or two or three years ago. Thanks!
Harry Jones
Marietta GA

Nightfall

You must be thinking of Kenneth Swauger

crispybrown

BlueBirdMusic wrote: »

Thanks Ken,

I thought I may "wake" him. I owe you a "thank you" to from when you cleared my sign on problems a year or two or three years ago. Thanks!
Harry Jones
Marietta GA

Indeed you did wake me thanks to email alerts!

Glad you like the look. The only issue I have had with them since has been one of the side panels coming loose. That I blame on my commitment issues... I glued the sides on with caulk rather than strong adhesive in case for any reason I had to get them off again. To fix this I will probably have to use some more serious glue on the side of the cabinet and in the dovetails. I am paranoid about vibration issues after I glue them in a nonreversible way though.

Sound wise I am happy and have not tweaked them further. I was tempted to add a tweeter resistor to tone down the treble slightly but so far not tempted enough to do it. The crazy treble was one of the things I loved about the speakers when I first heard them - it sounds great in my opinion at sensible volumes at the minor expense of hearing damage at non-sensible volumes. :-)

Anyway, the last couple of years have been spent rebuilding bicycles and a very old bathroom sink, so the SDAs have 'only' been listened to.

nspindel

You thought my treble was crazy?