SDA SRS 2 need CPR and ICU life support

F1nut

My old clamps were just too large for my workbench and kept poking me in the ribs where they hung off. So i had to pick up some smaller new ones. I only got two because the splits in the wood only came in about three inches in from the side. I kept a good watch for any leveraged movement towards the center caused from clamping the ends, and was happy to see that the splits didn't lengthen from that counterforce. I had a plan for it if it had occurred.

Very good, sir.

If i stay with the original format, mostly fabric sides with the strips of walnut... any suggestions on stain color for wood? Original walnut, something warmer, or black stain?

I take it you'll be using a wiping stain, so whatever brown tone suits you. I wouldn't do black, but that's just me. If you know anyone that has spray equipment, I'd recommend a dye mixed with the lacquer. That will result in a very even color tone with excellent transparency.

F1nut

my strips looked slightly different too but I assumed because it was veneer rather than solid wood.

It's not the solid verses veneer. It's that every tree is individual with things like different growth rates, different soils, etc. influencing the end result.

There's something about aged wood that seems just as refined

I can make a brand new piece of walnut look exactly like a 100 year old piece.

I know that mdf would be the better choice longterm if warranted but is it also because of the acoustics, or is it just the warping/cracking issues?

The warping/cracking issues.

PolkieMan

Welcome! Good work your doing there!
Wish I could find a beat up set to do a complete redo.
Did you say what you paid for them?
I stained my SDA 1C top caps with Minwax red mahogany.

proffitt

No, I've initially not said what I paid for them. But my hesitation was more for all of your benefit, than mine. Of course I'm thinking about hearing them for the first time in a few weeks/months after I finish mauling them with the machete! While you guys are listening to yours tonight.

$50.

PolkieMan

Well I am not going a say you got a good deal that is obvious.

SDA 1C top caps with Minwax red mahogany.

TNHNDYMAN

^ Nice look Polkieman. How did you avoid getting stain on the side fabric panels?

PolkieMan

I took great care :redface:.
Used glad cling wrap pushed in a bit with a plastic spatula.:redface:
I used real fine steel wool to rub in the stain, removed the excess with a old rag
and then with real fine steel wool again used Johnsons paste wax
removed the excess with a old rag and polished with a microfibre cloth
it now has a smooth deep gloss.:cheesygrin:

TNHNDYMAN wrote: »

^ Nice look Polkieman. How did you avoid getting stain on the side fabric panels?

nikonik

PolkieMan wrote: »

Well I am not going a say you got a good deal that is obvious.

SDA 1C top caps with Minwax red mahogany.

Looks sweeet! Red has always been my favorite color for polk speakers.

bigaltx24

Great to see you rescuing these Proffitt, you'll get plenty of good karma for your efforts, and also wind up with a nice set of speakers.

westmassguy

proffitt wrote: »

My old clamps were just too large for my workbench and kept poking me in the ribs where they hung off. So i had to pick up some smaller new ones. I only got two because the splits in the wood only came in about three inches in from the side. I kept a good watch for any leveraged movement towards the center caused from clamping the ends, and was happy to see that the splits didn't lengthen from that counterforce. I had a plan for it if it had occurred.

Even Polk thought to try to start with really nice Walnut before he got wise to MDF. I'm just getting started and i like the way the walnut looks, and way better than oak too, so I'm glad to know for sure that the side strips are certainly walnut. They'll stain similarly if that's what i decide to do with the color.

If i stay with the original format, mostly fabric sides with the strips of walnut... any suggestions on stain color for wood? Original walnut, something warmer, or black stain?

proffitt, welcome, and best of luck on your new project.
For the solid tops and bottoms, be sure to stain and finish ALL sides the same. Even the parts that won't be seen. This will help to prevent future warping or cupping.
For stain, my personal favorite for vintage walnut is Minwax English Chestnut. It's a VERY warm, medium brown, pigmented wiping stain. Since it's pigmented, be sure to wipe off any excess stain thoroughly between coats.
If any fill is required, I use a product called Wunderfil. It's available in many different shades including walnut.
For finish, many here choose some form of oil, but I prefer something more durable, and I personally loathe any type of gloss finish on wood.
Until recently, I had been using Deft Spray Satin Finish for my restorations. It's actually less Satin, and more Matte when fully dry. Only problem is it takes forever to dry.
I now use a specialty product from Krylon, # 1311 Matte Spray Finish. Extremely easy to work with, very fast dry time, and a finish that is truely Matte. Once it's fully dry, you can lightly buff it with some fine natural burlap to remove any minor imperfections or overspray.

Toolfan66

I would love to have this project!!!

proffitt

So far the project is really fun. And anticipating the outcome certainly weighs in heavy.

I'm thinking about starting a new thread for the electrical/electronics upgrades and keeping this thread strictly for the "furniture". Does that meet with proper forum etiquette? From my reading I'm thinking the electronics parts is going to get very confusing and I'm going to have lots of questions.

I think I've decided not to go with balck stain. I ate at a restaurant last night that had a translucent black stained wood table exactly like what i was envisioning. It looked really neat, contemporary, but i realized that the black wood, black fabric would have zero contrast, and i think i would be disappointed. So I'm going with the red mohogany or something dark with a red glow to it. Keep it more original looking. Agreed, no high gloss. i have some rub on satin poly that i did another piece with that has a nice finish to it. Probably stick with that.

F1nut... is that for Formula 1? Big race today at the new track in Austin. Exciting!!! l love racing when the cars turn BOTH right AND left!

westmassguy

proffitt wrote: »

So far the project is really fun. And anticipating the outcome certainly weighs in heavy.

I'm thinking about starting a new thread for the electrical/electronics upgrades and keeping this thread strictly for the "furniture". Does that meet with proper forum etiquette? From my reading I'm thinking the electronics parts is going to get very confusing and I'm going to have lots of questions.

I think I've decided not to go with balck stain. I ate at a restaurant last night that had a translucent black stained wood table exactly like what i was envisioning. It looked really neat, contemporary, but i realized that the black wood, black fabric would have zero contrast, and i think i would be disappointed. So I'm going with the red mohogany or something dark with a red glow to it. Keep it more original looking. Agreed, no high gloss. i have some rub on satin poly that i did another piece with that has a nice finish to it. Probably stick with that.

F1nut... is that for Formula 1? Big race today at the new track in Austin. Exciting!!! l love racing when the cars turn BOTH right AND left!

You've got the underside of the caps to experiment with different stains. The rub-on poly is good, but you'll need to apply several coats to offer any protection. If your prepwork/finish sanding is done properly, you'll just need a fine Scotchbrite pad in between coats.

proffitt

Shurkey, thanks. Wow, after reading that, I can go back and read everything you guys have written up to this point and actually know a little about what you are talking about. Just a little.

OK, sounds like i want to do a few things.
1) upgrade the SDA SRS 2 set to RDO-198 tweeters. Got it.
2) Upgrade electrocal components, order this list:

Lows:
2 Dayton DMPC 100uF
2 Dayton DMPC 90uF
4 Dayton DMPC 33uF

Highs:
6 Mills resistors 2.7 ohm
2 Mills 4 ohm
2 Sonicaps 5.8uF
2 12uF

And from all the work that InspiredSports did, when he was talking about the fine tuning of the resistor value and finally settled on 2.7, he was talking about line item #1 under the "Highs" directly above, the 6 mills resistors?

3) and I need to remove the polyswitch and jumper the connectors where it was removed?

4) and I need to find a interconnect cable. Mine is blade/blade. Do I just need to find/make the blade/blade? Or switch to some other connector type?

Is all this right? What am i missing?

The top caps have gone to a friends to plane down a hair to get to raw wood. They were real bad. I've stripped someone's incredibly poor varnish job on the side strips and bottoms and I'm down to bare wood. Going to go sand for a while now.

F1nut

Sanding is highly overrated. Just sand lightly with 150 grit serrated and be done. Before appling any finish, and in between coats use a tack cloth.

F1nut... is that for Formula 1? Big race today at the new track in Austin. Exciting!!! l love racing when the cars turn BOTH right AND left!

Yes sir!

F1nut

I now use a specialty product from Krylon, # 1311 Matte Spray Finish.

That's not really meant for furniture. Check out the spray can clear coats from Behlen or Masters.

westmassguy

F1nut wrote: »

Sanding is highly overrated. Just sand lightly with 150 grit serrated and be done. Before appling any finish, and in between coats use a tack cloth.

With all due respect F1nut, couldn't disagree more. As with everything else, the final finish is only as good as the prep work. Even the best planers leave ripples. 180, 220, 320 then final polish with supper-fine sanding sponge. Your staining and final finish will be showroom. There's no substitute for proper prep work.

proffitt

Shurkey, thanks. Wow, after reading that, I can go back and read everything you guys have written up to this point and actually know a little about what you are talking about. Just a little.

OK, sounds like i want to do a few things.
1) upgrade the SDA SRS 2 set to RDO-198 tweeters. Got it.
2) Upgrade electrocal components, order this list:

Lows:
2 Dayton DMPC 100uF
2 Dayton DMPC 90uF
4 Dayton DMPC 33uF

Highs:
6 Mills resistors 2.7 ohm
2 Mills 4 ohm
2 Sonicaps 5.8uF
2 12uF

And from all the work that InspiredSports did, when he was talking about the fine tuning of the resistor value and finally settled on 2.7, he was talking about line item #1 under the "Highs" directly above, the 6 mills resistors?

3) and I need to remove the polyswitch and jumper the connectors where it was removed?

4) and I need to find a interconnect cable. Mine is blade/blade. Do I just need to find/make the blade/blade? Or switch to some other connector type?

Is all this right? What am i missing?

The top caps have gone to a friends to plane down a hair to get to raw wood. They were real bad. I've stripped someone's incredibly poor varnish job on the side strips and bottoms and I'm down to bare wood. Going to go sand for a while now.

westmassguy

F1nut wrote: »

That's not really meant for furniture. Check out the spray can clear coats from Behlen or Masters.

For high wear applications, no it's not, but we're not talking about high wear, unless he's planing on using them as step stools

F1nut

westmassguy wrote: »

With all due respect F1nut, couldn't disagree more. As with everything else, the final finish is only as good as the prep work. Even the best planers leave ripples. 180, 220, 320 then final polish with supper-fine sanding sponge. Your staining and final finish will be showroom. There's no substitute for proper prep work.

All that prep work stuff is a common misconception. I never sand any piece of wood/furniture in my shop past 150 grit, there's no point as the clear coat finish will almost always require rubbing out.

BTW, if you have ripples from a planer start with 80 or 100 grit to level things out quickly, then work up to 150 and stop.

Since you're talking about pigmented wiping stains, sanding wood to 320 or higher will actually inhibit the absorption of the stain. You can see this for yourself by taking a board of say oak and sand half of it to 150 and the other half to the supper-fine sanding sponge thing you do. After hitting it with a tack cloth, apply the stain and wipe off. The 150 half will retain more color because you haven't closed off as many pores as the supper-fine sanding sponge half. Now, apply a clear coat, let cure and rub out. You will not be able to tell from the look/feel of the clear coat finish (other than the color difference) which half was originally sanded to what grit.

Schurkey

proffitt wrote: »

Shurkey, thanks. Wow, after reading that, I can go back and read everything you guys have written up to this point and actually know a little about what you are talking about. Just a little.

OK, sounds like i want to do a few things.
1) upgrade the SDA SRS 2 set to RDO-198 tweeters. Got it.
2) Upgrade electrocal components, order this list:

Lows:
2 Dayton DMPC 100uF
2 Dayton DMPC 90uF
4 Dayton DMPC 33uF

100 + 90 = 190uF. OEM is 185uF. Within 5%, completely acceptable.
33uF is similarly within 5% of the stock 34uF. Same as what I used.

I chose ERSE 91uF X 2 for each speaker, 4 total. Provides 182uf, and a nice symmetrical split in capacitance value. The ERSE caps are 3% tolerance instead of 5%, another bonus. Increases the shipping cost, though. You might consider getting the SDA inductors from ERSE if you choose to include that mod. Seems to me I ordered 10 mH, 16-gauge. Then unwind five turns to drop to 9.6mH. I can find the part number if you care.

proffitt wrote: »

Highs:
6 Mills resistors 2.7 ohm
2 Mills 4 ohm
2 Sonicaps 5.8uF
2 12uF

And from all the work that InspiredSports did, when he was talking about the fine tuning of the resistor value and finally settled on 2.7, he was talking about line item #1 under the "Highs" directly above, the 6 mills resistors?

3) and I need to remove the polyswitch and jumper the connectors where it was removed?

4) and I need to find a interconnect cable. Mine is blade/blade. Do I just need to find/make the blade/blade? Or switch to some other connector type?

Is all this right? What am i missing?

inspiredsports went to a 1.5--2.0 ohm resistor at the input of the HF board. I would have dropped to a 1.5 ohm resistor in that same location if I'd been bright enough to think of it. Later, he went back to a 2.7 ohm resistor there, for reasons I don't understand. You can ELIMINATE the 4.0 ohm resistors, and replace them with another two 2.7s, total of eight, not six.

Considering how inexpensive they are, I suggest ordering an array of extra resistor pairs, from 1.5 ohm up to 2.5, and the eight 2.7s. My 1Bs have 2.0 ohm resistors there, and the treble isn't prominent enough for me--and you'll have MORE mid/bass than I do due to larger cabinet and larger passive radiator.

Yes, eliminate the polyswitch and the tiny silver-mica bypass caps. The lead wire of the input resistor will be long enough to bypass the polyswitch with.

If I didn't have the OEM SDA cable, I'd add two regular binding posts to each speaker, four total, and then use ordinary speaker wire rather than try to find the original-style cable ends.

Since the high-frequency board is totally separate from the low-frequency board, you could install separate binding posts plus jumpers, just like the later SRS-2s that are based on the 1C electronics. I don't think this is a particularly attractive mod; I certainly have no plans to bi-amp the speakers. Just mentioning that it's possible and not difficult.

westmassguy

F1nut wrote: »

All that prep work stuff is a common misconception. I never sand any piece of wood/furniture in my shop past 150 grit, there's no point as the clear coat finish will almost always require rubbing out.

BTW, if you have ripples from a planer start with 80 or 100 grit to level things out quickly, then work up to 150 and stop.

Since you're talking about pigmented wiping stains, sanding wood to 320 or higher will actually inhibit the absorption of the stain. You can see this for yourself by taking a board of say oak and sand half of it to 150 and the other half to the supper-fine sanding sponge thing you do. After hitting it with a tack cloth, apply the stain and wipe off. The 150 half will retain more color because you haven't closed off as many pores as the supper-fine sanding sponge half. Now, apply a clear coat, let cure and rub out. You will not be able to tell from the look/feel of the clear coat finish (other than the color difference) which half was originally sanded to what grit.

I guess we went to different schools. I would never dream of refinishing a customers cabinet that way. I START with 150 grit to cut through the old finsh. I certainly would never finish with it. The reason the wood sanded with 150 grit takes up more stain is very simple, the wood fibers are sticking up, and small scratches from the rough paper hold more of the stain. It would be like painting a terry cloth towel vs painting a smooth linen sheet. The towel has more nubs, nooks and crannys to hold the paint, where-as the linen sheet is smooth and the paint glides right on.
The beauty of pigmented stains, when applied to properly prepared wood, is that you can control the shade. Yes, the hard portions of the wood will not absorb as well as the softer portion, thats when a 2nd or 3rd coat may be applied, depending on how dark you want it. As far as Oak and other open grained woods are concerned, I always use a grain filler, for an even color.
We'll have to agree to disagree

F1nut

I guess we went to different schools.

We sure did.

I never sand to cut through an old finish, that's a ton of work that is completely unnecessary. Hand stripping wins the day.

I never use pigmented wiping stains on my customers furniture. I use only dyes as they provide a more uniform color, have infinite shades/tones, apply easier, dry faster, can be mixed and sprayed with the clear coat in one step (many advantages to that), but most importantly are transparent.

westmassguy

F1nut wrote: »

We sure did.

I never sand to cut through an old finish, that's a ton of work that is completely unnecessary. Hand stripping wins the day.

I never use pigmented wiping stains on my customers furniture. I use only dyes as they provide a more uniform color, have infinite shades/tones, apply easier, dry faster, can be mixed and sprayed with the clear coat in one step (many advantages to that), but most importantly are transparent.

Dye stains have their place as do pigmented stains, and hand stripping with chemical solvents is too unpredictable for my taste.

Different strokes for different folks.

proffitt

Schurkey... so this is what i need here?:

Lows:
2 Dayton DMPC 100uF
2 Dayton DMPC 90uF
4 Dayton DMPC 33uF

Highs:
8 Mills resistors 2.7 ohm
xxxxxxxx
2 Sonicaps 5.8uF
2 12uF

I want to make the order tomorrow morning. And you'll be able to tell me where they go?

And I'll jumper the leads from the poly switch.
and I'll replace the 4 old tweeters with 4 new 198s.

Now still wondering what to do about the interconnect cable.

everybody here is so helpful. Thanks, I can use it!

nikonik

You just missed a cable on eBay. Buy now for 32 and it was a blade/blade!

F1nut

westmassguy wrote: »

Different strokes for different folks.

Indeed.

Dye stains have their place as do pigmented stains,

I can't really think of when a pigmented wiping stain would have any advantage unless one isn't set up for or have the skill set to use dyes.

and hand stripping with chemical solvents is too unpredictable for my taste.

Ok, that comment baffles me. Unpredictable how?

westmassguy

F1nut wrote: »

Ok, that comment baffles me. Unpredictable how?

Chemical strippers and solvents can bleach and or discolor the wood, leave blotches. The original stain may be lifted on one area, and still remain in other areas.
That's what I meant by unpredictable.

proffitt

nikonik wrote: »

You just missed a cable on eBay. Buy now for 32 and it was a blade/blade!

Dang. Good to know they are out there though. Thanks.

Schurkey

Additional suggestions in bold.

proffitt wrote: »

Schurkey... so this is what i need here?:

Lows:
2 Dayton DMPC 100uF
2 Dayton DMPC 90uF
4 Dayton DMPC 33uF

Highs:
8 Mills resistors 2.7 ohm
2 Mills resistors 1.5 ohm
2 Mills resistors ~1.75 ohm if available
2 Mills resistors 2.0 ohm
2 Mills resistors 2.5 ohm
2 Sonicaps 5.8uF
2 12uF

Binding posts as needed/desired. I'd install two per speaker in a heartbeat rather than hunt down an OEM blade/blade cable, if I didn't already own one.

Self-adhesive damping material (dynamat or equivalent; I used Partsexpress damping sheets but I don't remember how many--2 or 3. Four would be PLENTY.

I used rope caulk, available at any hardware store, to seal the drivers to the cabinets; folks are now tending to use gaskets cut from thin insulation/packing foam--Armacell brand???


Quality solder, hot glue for securing caps after installation

I want to make the order tomorrow morning. And you'll be able to tell me where they go?

Install all caps and all resistors so the leads solder to the same hole in the circuit board as the one you're replacing. Do one board at a time so you have one to compare to. If the leads aren't long enough, a short bit of insulated wire will extend the leads.

And I'll jumper the leads from the poly switch.
and I'll replace the 4 old tweeters with 4 new 198s.

Now still wondering what to do about the interconnect cable.

everybody here is so helpful. Thanks, I can use it!