Polk SDA-SRS 1.2tl Refurb

[Tronman 51]

Here is the schematic for the crossover if you were interested:

 

/yetanotherforum/uploadfiles/20150814145513373.pdf 

 

If you would like I can give you the schematic for the left and the right so just let me know. 

[zumbini 6,147]

 

 

Here is the schematic for the crossover if you were interested: /yetanotherforum/uploadfiles/20150814145513373.pdf 

Thanks Tronman. I'm sure that'll come in handy down the road.

 

 

 

 

If you would like I can give you the schematic for the left and the right so just let me know.

That would be great. THANKS! 

 

[DSkip 28]

Dom, please don't replace the surrounds and just work on new drivers as you can get around to them. In the meantime, perhaps some clear nail-polish can do the trick? I'd rather see a cheap route like that than changing the entire surrounds with a product dissimilar to the original surrounds. The summed difference with all those drivers might drastically change the intended operation of the speaker.

 

Regardless, the main thing is to keep a sealed enclosure and those holes definitely defeat that design philosophy. The nail polish may be the route you are forced to take with the passives anyways, given their scarcity as noted by Dan.

 

PS - $60 is not the Polkie price, its the list price. The Polkie price is lower than that. Keep in mind also that those guys stepping up to the plate to help you replace those drivers are not doing it for show. They'd all like to see those speakers back up to their pedigree and want to help however they can.

[zumbini 6,147]

As I noted earlier, I plan to begin by sealing the rips, tears and pinholes with rubber inner tube adhesive.

If that doesn't work I see no downside to replacing the surrounds with a similar butyl rubber product.

I don't see how that could be worse than leaving them unsealed.

 

Unless I win the lotto a complete restoration/upgrade is just not in my budget.

[kve777 6,888]

Use the 'Right Stuff" or urethane. Tire tube cement isn't going to cut it. 

[Tronman 51]

zumbini,

 

    You are correct "I don't see how that could be worse than leaving them unsealed" you want these sealed up as tight as you can!!  Since you are going to be working on these it would be a good idea to seal the woofers up with ARMACELL - it's in the pipe section of Home Depot.  It's actually a type of pipe insulation tape that works great to make sure you get a air tight seal on the woofer, tweeters and the connector on the back for the speaker wire.

Here are the other two schematics for you - these can be really fun to work on.  I know you have already done the speaker cloth but here is a link I found that really helped me out and anyone else thinking of redoing the cloth:

http://www.humanspeakers.com/cgi-bin/page.pl?page=howto/grill-cloth.txt   it's on the Humanspeakers website if the link does not work.  

 

Here are the right and left schematics for you  

 

/yetanotherforum/uploadfiles/20150814200213711.pdf

/yetanotherforum/uploadfiles/20150814200243440.pdf 

 

Here is the speaker cloth I used, this is the more expensive but it is beautiful and one order should do both speakers. For these I would spend the couple of extra bucks.

http://www.parts-express.com

 

Mellotone Premium Black Speaker Grill Cloth Yard 64" Wide 

 

Here is the other stuff I use that works good just not as nice. 

http://www.parts-express.com/

Parts Express Speaker Grill Cloth Black Yard 70" Wide

 

[zumbini 6,147]

Use the 'Right Stuff" or urethane. Tire tube cement isn't going to cut it.

This is vulcanizing rubber adhesive Kevin. I got the idea from a guy on the Polk forum.

Apply a thin bead to both edges of a rip with a toothpick then mate them edge to edge.

The adhesive remains flexible when cured and the joint will stand up to internal pressure.

 

[DSkip 28]

Sorry man. I read through the thread but must have missed that. I think you've got a good plan.

 

Keep us posted. Also, if you are going to clean the drivers, they ususally recommend windex.

[Daddyjt 9,612]

Living in a big country with a small population (at least in my part) just doesnt offer deals like this often.

I envy the deals you guys get and the choices of equipment in your back yards.

 

Those are great deal Dom, your son is going to love 'em.

 

My wife was just saying the other day how we needed more big ass speakers around

the house.....I'm trying to oblige her.  

 

I am in the same boat as you, Perry.  It kills me to see how many deals pop up on the coasts down here.  Most of my good acquisitions involve a 400+ mile round trip.

 

On the plus side, it does save me a lot of money (and space)...

[zumbini 6,147]

Didn't see you mention it but you do have the interconnect cable for those guys??

 

Yes, I have BOTH ICs, the stock cable that came with SDA speakers, and the A1-I for non-common ground amps.

 

We are currently driving the 1.2tl's in SDA mode with an M-1.5t (common ground),

I'd like to try bi-amping them but not until the surrounds have been repaired/replaced.

[zumbini 6,147]

I was going to start repairing the surrounds today but my tube of rubber glue is dated 1996.

I decided not to take a chance with it and changed gears to cleaning the mid woofer cones.

 

In some of my original photos you may have noticed what looks like water spotting on the cones.

 

 

I suspect the original owner may have sprayed cat repellant on them as a preventative measure.

A Polk site member suggested wiping them down with a soft cloth soaked with Windex.

 

It took a couple of wet/dry cycles but most of the "water spots" are gone now and the cones are uniformly tacky. 

 

BEFORE                                                                                                                AFTER 

 

[CT-Seven 764]

Looking good! Love them POLKS

[Tronman 51]

Zumbini,

 

"Yes, I have BOTH ICs, the stock cable that came with SDA speakers, and the A1-I for non-common ground amps. 

That is great!!  Especially the A1-I as those don't come around very often 

 

I was just thinking when I picked up my first pair of SDA SRS 1.2tl's and I was auditioning them at the guys house I did not notice that 3 of the tweeters were blown until I got back to my house.  The point being have you verified that all 8 are working correctly??  You can use a paper towel tube or just cup each one individually as it is difficult to hear each one by itself when all 4 are on at the same time.

If one is going to blow it is normally the top one as this one gets the greatest frequencies and therefore the most power.  The other 3 are crossed over differently and a little lower if you look at the schematic.

The other thing I have noticed is that over the years the wire to voice coil will actually break from the years of the slight vibration, I have noticed that the couple I have taken apart the voice coil shows no damage but right at the point the wire goes into to the tweeter it will break.  Now this is on the SL-2000 as these are clear and you can actually see the wire on the SL-3000 you can't since they are basically black.

 Here is a picture of the new RDO198 that replaces the SL3000.  These can be differentiated from the RDO194 by the Large terminal you see in the picture which is the NEGATIVE Terminal.  The RDO194 terminals are both the same size (Small).

 

 

 

[Tronman 51]

Keep us updated on how your surround repair is going, on mine I sacrificed one of the woofers and used the surround out of it to repair a couple of the other ones that weren't to bad.  I used rubber cement as I could put it on both pieces of surround let it get tacky then stick them together.

The couple I did came out really good but man can that get tedious when you have to get behind the supports on the basket so all I can do is wish you luck as I've been there and done that   Good Luck 

[Tronman 51]

Just a quick note on the bi-amping.  Most people who have tried this really didn't notice any improvement from all the polk forum info I have read.

 

But with that being said I am running mine bi-amped only because I have a Sunfire Cinema Grand Signature 400 Seven with the Current Output Terminals vs the Voltage Output Terminals going to the tweeters for that tube sound but have fun and try different configurations that is the only reason mine are set up that way.

[zumbini 6,147]

...have you verified that all 8 are working correctly??...If one is going to blow it is normally the top one as this one gets the greatest frequencies and therefore the most power.  The other 3 are crossed over differently and a little lower if you look at the schematic

Yep. That was the 1st thing I did after powering up. They seem to be A-OK.

 

 

...You can use a paper towel tube....as it is difficult to hear each one by itself when all 4 are on at the same time...

That's a great idea. I'll keep that in mind for the next time. 

 

 

...The other thing I have noticed is that over the years the wire to voice coil will actually break from the years of the slight vibration, I have noticed that the couple I have taken apart the voice coil shows no damage but right at the point the wire goes into to the tweeter it will break.

Another great tip Tronman. THANKS!

[CT-Seven 764]

Great tips!!

[zumbini 6,147]

Keep us updated on how your surround repair is going, on mine I sacrificed one of the woofers and used the surround out of it to repair a couple of the other ones that weren't to bad.  I used rubber cement as I could put it on both pieces of surround let it get tacky then stick them together. The couple I did came out really good but man can that get tedious when you have to get behind the supports on the basket so all I can do is wish you luck as I've been there and done that   Good Luck 

 

I repaired one of the mid woofers with the most damage last night using RTV gasket maker.

I prepped the area with sandpaper and applied RTV sparingly using a miniature paint brush.

Took a while to figure out the best technique so the result isn't very pretty, but it IS air tight.

Only time will tell how durable the repair will be....

 

BEFORE

 

AFTER

[DSkip 28]

Awesome. Pretty or not, the end result is just good sound. I have a pair of 3.1tl's that someone one the Polk forum gave to me for free. They already have the upgraded RD0198 tweeters, but every single woofer and one of the radiators have pushed in dust caps. It ain't the prettiest, but the sound is great. Luckily they were all in functional order and no rips/tears in the surrounds.

 

I tried a few techniques to pull them out, but they didn't work. I just accepted it and enjoyed them as is. The 1.2tl and SRS 2 are the two versions I haven't heard, but of all the rest I have, the 3.1tl was the first to impress me in stock form. I plan to eventually upgrade the 3.1s because they transform to a completely different speaker, but like you, the funds to do it are not exactly in excess for me right now.

[Daddyjt 9,612]

Dom,

 

I haven't really examined any of the components of mine yet, so just wondering if the baskets are of a design that would allow you to work from the inside of the surround?

 

In all honesty, your repair looks good!

[zumbini 6,147]

Dom,
I haven't really examined any of the components of mine yet, so just wondering if the baskets are of a design that would allow you to work from the inside of the surround?

 

The pillars of the stamped mid woofer basket are rather wide making rear access difficult.

So I decided to leave the mid woofers installed and do all the repairs from the front.

 

 

[kve777 6,888]

I'm glad you went with the RTV. It remains very flexible for a long time. In car engines it seals good where expansion and contraction rates are high due to dissimilar metals. Like intake manifold to engine block. If you get failures, it will most likely be the rubber next to the repair. If you want to thin the RTV, Toluene or Xylene will work, paint it on to the surrounds completely to "rejuvenate" them.

[zumbini 6,147]

I'm glad you went with the RTV. It remains very flexible for a long time. In car engines it seals good where expansion and contraction rates are high due to dissimilar metals. Like intake manifold to engine block. If you get failures, it will most likely be the rubber next to the repair. If you want to thin the RTV, Toluene or Xylene will work, paint it on to the surrounds completely to "rejuvenate" them.

 

Thanks Kev. I was just googling for an RTV thinner. I believe I have a can of toluene in the garage from my days in printing.

[zumbini 6,147]

A few days ago I figured out how to remove the side panels. (They are attached with 8 friction fit body panel pins.)

 

 

Yesterday I stripped one of the panels down. and figured out how to remove the wood accent pieces.

(Lots of tiny finish nails with the heads buried; stuck to the grill cloth adhesive via incidental contact.)

I'll be recovering these panels with the same material I used on the speaker grills.  

 

 

 

 

[zumbini 6,147]

....I have a pair of 3.1tl's....every single woofer and one of the radiators have pushed in dust caps....I tried a few techniques to pull them out, but they didn't work....

 

The dust caps on the 1.2tl's are pretty thin so I was able to pull the dented one out with no problem.

Start with Scotch or painter's blue tape and escalate to something more agressive like duct tape if needed.

Cut the tape so one end is narrower than a flat(ish) spot at the lowest point of the dent.

Use your finger, a pencil eraser or burnishing tool to get the tape to adhere, and pull easy.

 

On dust caps that are non-porous I have used a straw attached to a portable vacuum cleaner.

I've also used a blob of the adhesive they use to attach credit cards to a letter when mailed.

If all else fails I poke a tiny hole in the dust cap and use a dental pick to pull it out.