Documenting: My SDA-1c upgrades from start to finish

pitdogg2

Gardenstater wrote: »

I guess I need my memory refreshed here.....what is the reason for wanting to replace the inductors?

Less resistance, tighter tolerances and better bass as @audioluvr stated.
More pluses than minus's.

The hand wound inductors by Polk were OK but the perfect lay inductors by Jantzen and Solen are much better.
Jantzen also makes a near zero resistance C-Coil Toroidal Core inductor that VR3 used.

Gardenstater

Understood on replacing the sub bass inductor (16mH) with a lower DCR one; going from 18awg to 17awg. Just not clear on why the need to replace the other 5 inductors as well. Will that be worth breaking the budget over?

Also, in looking at the schematic I'm not understanding where the 1.1mH, 13awg inductor is going to go because there is nothing close on the schematic I'm looking at.

westmassguy

plastic_avatar wrote: »

VR3 helped me out with info on inductors:
Comes out to about $225, before shipping.

I'm at $940 in, which is under where I wanted to be (minus pizza and gas). I don't know if I can justify another $300.
$1300, with internal wiring and a Dreadnought still to go (if I go all out)... that's getting into 'Is it worth it for a pair of 1c?' territory.
I'm finally starting to put some stuff on FB and ebay to pad the pocketbook. We shall see.

---

Giving the Monitor 12 a big workout this past week.
If I listen to a baseline of 72 to 75db (peaks to 81), the Yamaha P2250 I picked up a few weeks ago (thinking ahead to the 1c) is fantastic! I got it for a steal. It's just a wall of pressure that feels like I'm at a show, without bursting my eardrums for an hour of listening.
The Hu are particularly enjoyable on CD, and I'll be able to make concrete comparisons when the 1c are up and running.

There is no 1.1 mH inductor on the 1C. I beleive it should be the 2.5 mH, stock # 000-1119. You have stock # 000-0119 listed.

Gardenstater

OK so you're talking about maybe another $41 to replace the other 5 inductors with perfect lay 4N inductors that might even give a size reduction. I think you should do it.

Another inductor value might be off a tad unless it was intentional. That 1.25mH one is 22awg on the schematic and you have 20awg.

Hansvelton

Gardenstater wrote: »

Understood on replacing the sub bass inductor (16mH) with a lower DCR one; going from 18awg to 17awg. Just not clear on why the need to replace the other 5 inductors as well. Will that be worth breaking the budget over?

Also, in looking at the schematic I'm not understanding where the 1.1mH, 13awg inductor is going to go because there is nothing close on the schematic I'm looking at.

I mean, even the "Sub bass" inductor is only going to make a very small change true. The other ones, really no "Need" to replace them.

DarqueKnight

plastic_avatar wrote: »

$1300, with internal wiring and a Dreadnought still to go (if I go all out)... that's getting into 'Is it worth it for a pair of 1c?' territory.

It was worth it for my three pairs of SDA CRS+s, which are much smaller than the SDA 1C. I was not planning to go "all out" with my CRS+s...but one thing lead to another...and the more resolution and musical detail I got...the more I wanted.

My condolences to your wallet.

Discussion of the crossover parts (including inductors) and SDA inductor upgrades for my first pair of SDA CRS+s:

https://forum.polkaudio.com/discussion/111976/crs-1989-version-pcb-xover-and-sda-inductor-upgrade

Discussion of internal wiring replacement and 1000 VA Dreadnought for my first pair of SDA CRS+s:

https://forum.polkaudio.com/discussion/157041/cardas-internal-wire-upgrade-for-the-sda-crs-1989-version

DarqueKnight

Hansvelton wrote: »

I mean, even the "Sub bass" inductor is only going to make a very small change true.

Changing the "sub bass" SDA inductor in all of my SDAs made a big difference. I even went through two iterations of low DCR SDA inductors. The stock SDA inductors were first replaced with Northcreek inductors. The Northcreek inductors were replaced with Solen perfect lay inductors.

Hansvelton wrote: »

The other ones, really no "Need" to replace them.

I agree that there is no "need". However, Jantzen's perfect lay inductors provided some very nice sonic improvements in all of my SDAs.

SDA CRS+ custom crossover board with Jantzen perfect lay inductors.

plastic_avatar

I wanted to have all the pieces in order before I started assembly.

- The guys convinced me to upgrade coils and do the Dreadnaught, but I have to wait til at least the end of the year to do those. Those just have to wait.

- I may replace wiring next year. It depends on how the 1c sound with the other mods.

- Everything else is here!

And sure, I spent about 30 hours printing prototype/draft plates for xschop's Wuhan tweeter mod (plus at least 16 hours in front of the computer the past few weeks), but I think it was worth it!

The top plates for each side look like this:



I can make the pattern look like different things. I like how this looks when the light hits ut from different angles.

And the bottom plates on each side?

Well, they look like this, because I have respect for all the work @xschop did. He inspired me to make my own version, and it's only right that I give proper attribution:



And this is how I'll mount them in each cab (they'll be coated with resin to make them look finished before then... these are raw from the printer):

xschop

Unnecessary, but nice homage. I'm flattered.
Glad you got the magnet screws sorted out. And you added the throat bevel too.
Is that ABS plastic or like black delrin material? I really like that starburst pattern...

Wuhans ride or die, baby.😂

I was in shop today machining a large chunk of ABS... Finicky material.

BlueBirdMusic

@plastic_avatar

That was a very nice and kind gesture for xschop!!

plastic_avatar

xschop wrote: »

I was in shop today machining a large chunk of ABS... Finicky material.

I have a spool of bright blue ABS, but haven't tried it. These are printed in PLA+. Really happy with the strength from the infill pattern I used.

I can't get my second (used) printer to work right, either. It's got the modified extruder for the ABS (and others)...

I swear, if we move out of the country and I have to leave my stereo behind... I'm going to be pissed.

[all options for the future are open]


Ferrofluid and sealing questions

Ferrofluid

I looked around and there don't seem to be definitive notes/results for anyone experimenting with ferrofluid in the 2000. I understand it would affect the movement of the tweeter (I imagine 2 ways: through dampening of vibrations caused by the throat around the coil (and subsequent affect on the fabric of the dome) *and* by acting like a shock absorber and slowing (but helping control) the movement of the coil in the void of the throat).

I would think your dome doping mod achieves similar effects. Just on the end of the transmission of vibration in the mechanism, rather than at the start. Make sense?

I wondered if ferrofluid vs doping vs none vs both would yield interesting results used in tandem/cooperation between the 2 tweeters on each side of the 1c... If a coil dampening might be better for the upper tweet and a dome doping might be better for the lower tweet, for instance. I have no baseine for comparison, though. Just going hog wild on my thinking

{i}Sealing{/i]

I'll put a little piece of tape between the tab and the magnet housing, as per your examples, when I put it all together.

Has anyone experimented with a thin glue sealant between the dome plate and the tweeter plate?

I'm thinking there are 2 planes for air leakage in the version I'm doing: between the dome plate and the magnet housing *and* between the dome housing and the tweeter plate. Plus opportunities for vibration reduction. I know, overthinking... but I wondered if a thin coating of a flexible glue/sealant on both sides of the dome plate would be a positive?

---

@BlueBirdMusic

He's one of a healthy handful of people here that listen to my whacked-out beginner's ideas and missteps with a ton of patience. And since all the modding I'm doing on the tweeter started with him, it's only fair it be represented on my finished pair, right?



Plus, as someone who had a plagiarist steal my writings in college... attribution is a thing for me [laughs sadly].

pitdogg2

Has anyone experimented with a thin glue sealant between the dome plate and the tweeter plate?

More air is coming through the voice coil dust caps than you're trying to stop through the tweeter plate.

xschop

I don't think it would hurt to add a thin layer between your bezel and plastic dome housing. Just remember voice coil has to center up with pole piece after being tightened down.

Polk added a thin Teflon gasket between diaphragm and top plate on the RDOs. I believe for anti-resonance.

plastic_avatar

pitdogg2 wrote: »

More air is coming through the voice coil dust caps than you're trying to stop through the tweeter plate.

I was curious about that.

If ferrofluid is used in the magnet throat, would the air behind the dome be a pocket? Especially if doped?

skipshot12

Looking forward to the the end result & listening evaluation….

plastic_avatar

@skipshot12
Eventually!
- I have to print off a couple more tweeter plates. I messed up the finish trying to coat them =(
- My side project helping a friend prototype a board game has consumed almost all my free time the past 8 weeks, so I'm WAAAAAAAY behind.

(Sitting in front of my Monitor 12, looking at the empty faces of my 1C as I type this...)

skipshot12

I hear that. It's always something.

Just received 8 194's in the mail today and can't wait to start the upgrades.
Was gonna leave them stock for a while and just enjoy the speakers.
But I just can't wait to start messin' with them.

plastic_avatar

So now I gotta play catch-up!

You'll be done with more before I get going!

skipshot12

How the heck do you's add what gear you have at the bottom of your posts?

audioluvr

Click on your avatar, click on "Edit Profile" go down to Signature settings

skipshot12

Cool
Tanks

plastic_avatar

It's 100% not intuitive.

plastic_avatar

Assembly Part 1

Well, my game project is out of the build phase, so back to the 1C!

Tonight it was time to complete assembly of the Wuhans.

So, for anyone who cares, after absorbing info from xschop and others, I had to:

- order the replacement domes on ebay (Ali Baba has them, too)
- order the right size screws with help from all my forum friends
- replicate, model, and print replacement tweeter plates based on xschop's designs (it took... 14 iterations to get right), the thin gaskets between tweeter and magnet/pole piece, and made my own needlessly complicated felt replacement (using wools from VR3 and xschop)
- glue the magnets
- cut out the plastic around the screw holes on the tweeters so they fit correctly
- glue everything to keep tight
- and now they're buttoned up and ready to go into the cabinets!

And I can't find my bottle of Viramin A to dope the domes! I gotta get more =[ Then the debate on whether to dope all dones... or just the lower tweeters (leaving the top ones un-coated.

Overkill? Probably... but that's my thing

xschop

Nicely done. Maybe try the Vit A oil after initial listening, then report back after subsequent applications.

The backing shims should also help with anti-resonance. Would be an interesting experiment to hear if any different between plastic or paper style.
Just be cognizant of the possibility that the Wuhans coil underhang/plunge depths may be shorter than the SL2000's and the shims may be unnecessary as they were intended for the Sl2000's cavity design. Hope that helps.

If your pink fish-eye apparati work out, then those wuhans will be right on par with a set of 194's.

plastic_avatar

Good point on the coil depth. I should've examined that more closely... I'll do that on the spare.

I tried to gauge if the .43mm backer height would affect it compared to naked... but couldn't tell that it was off enough to matter (I am just flying this plane as a difficult student, as you know). I listened to the first test assembly w/o it. I thought there was a difference at first listening to the final assembly. Thought I heard some distortion. But trying other songs and tracks, they blended nicely with the 198 on the right (still using the 12's as a mule). Running in the wrong box, the biggest difference is the 198 is a bit louder on the high end. But, again, different tweeter, different crossover, just making sure (to my ear) that they work

I'll hold off and coat per your suggestion.

I couldn't have done this without you!

Now, to the phase plugs!

(I could've coated the plates or made them on a friend's resin printer (for that smooth look), but I kind of like the pattern when the light hits the face on these. And it's a personal reminder of what I had to do to get the things where I wanted them.)

xschop

Good deal. I don't think 15-20 thousandths will make much difference.

Your 1C's will be on another level once plugged. You might want to test a drop of Loctite 271 on your final plastic choice as it is methacrylate and likes to chemically melt some plastics.

plastic_avatar

I've been wondering about which glue to use on the printed plugs in the 12's.

I might even hold off for now, and just put yours in the 1C asap, so I don't waste any mire time getting them up and running!

I'm really excited to see if my fine motor tremors can hold off enough for me to do the plugs w/o making a mess. I might have to get one of the kids to help. I spilled superglue twice making the Cubes this month... had to enlist some steadier hands on the game project this past labor day.

F1nut

I could of had the RD0194.

plastic_avatar

And next year, when my budget for fun stuff resets, I might buy them. And coils for the crossovers and an 800 coil version of the Dread.

But for this year, I was able to do things like braces, plugs, and better-than-Daytons-in-my-12's crossover parts.

Annnnd I learned even more about 3D printing and modeling, plus tweeter construction stuff I never had a firm grasp on.

Time and effort well spent

I'm looking forward to some in-depth listening and comparisons between the 1C, 12, RTi10, and my homebuklt 2-ways I'm getting new cabinets for this winter.

I also hope someone can take the extra 2000 I'm Wuhan'ing to test against other tweeters for real. I don't have the equipment for that kind of test.

plastic_avatar

Today I worked on the midwoofers.

Since I'm a little too shaky for curve cuts and fine details, I did what I could to make everything in straight lines.

It's not 100% basket coverage on the exterior, but I think it's more than enough to get the benefit of the inner foam and outer added mass.

I have all the measurements for each foam and aluminized rubber piece. I'll finish cutting the missing pieces tomorrow/Tuesday. Then I can assembly line the installation on the remaining 7 drivers.

I gotta glue the magnets, too.

Plugs will be last.

After that? Either modding or printing the rear assembly for the SDA cable replacement