SDA SRS 1.2TL - long time Polk fan

wwresto

Hello Polk fanatics! Pretty sure I was logged onto this site some years back as wildwhl, but couldn't recall so new login now. I've had MANY Polk products in my audiophile life and always wanted a set of the SRS since I first experienced them around 1986 in a proper demo. My dream speakers since I was a kid I suppose. Up popped today on local CL a set - they're rough - and I have my work cutout for me. Truth is they're not matched - one is a 1.2 (the right) and the other a 1.2TL (the left). Price was very right so I couldn't pass them up!

However, I do have plans to end up with a matched set with upgrades to my liking. Over the last couple of weeks I've turned off the motorcycle side of my brain and recharged the music side - SDA2's kicked it off and a pair of Monitor 5JR's (Always loved those little buggers!)

A few years back I went on a binge and collected a whole boatload of Vintage Polks. At one point I had SDA2, Monitor 5jr, 7, 10, 12, RTA12 and a whole bunch of other crap in my shop. Not the best listening environment, but nobody complained.

No idea why I thought I should get rid of all of it. I ended up with LSi15's as my mains in the house with matching center channel. They were all paired with a Velodyne DD10 sub, and four in-ceiling Noble Fidelity L-65s in the ceiling handling rear/side surround duties. A Yamaha RX3800 drives it all. For some other brain **** reasoning of mine I sold the LSi15's (had an offer I couldn't refuse) and now a pair of Monitor Audio Silver 5i sit in that spot.

In the past I've owned a whole slew of other equipment - Polk, Klipsch, Sunfire, Dynaudio Gemini (DIY speakers - miss those suckers a ton) and more.

I guess if its in your blood, it is in your blood!

Will post progress of the resurrection/rebuild as it goes along. Need several drivers and will probably rework the xo's to my liking. Adcom GFA 555 sitting here for power - front end to be assembled over time. Couple different preamps hanging around. Just going to gel and let it all evolve - and ef the WAF!

WW

Nightfall

What the heck are those 10 foot tall speakers with 14 mid woofs? :eek:

wwresto

Nightfall wrote: »

What the heck are those 10 foot tall speakers with 14 mid woofs? :eek:

Ahhh...the midbass towers of the line arrays I attempted. Had a 4 ft tall ribbon section for each one. Never quite finished them. Lot of work, bi-amped and actively crossed. Outstanding power-handling and imaging. Another of those projects I got to 8/10's with and switched gears. Last I knew they lived in a 40x60 shop (the midbass towers) running full range with a big old Altec Horn or similar strapped to the top - belting out some serious decibels over the grinders/welders/hammers working below them...

F1nut

Welcome back. You've got your work cut out....hope you go 10/10 on these.

drumminman

Welcome back! Looking forward to your rebuild on the 1.2's. Post pics too - love some good audio DIY.

monepolk

Welcome back I look forward to following your progress on these.

wwresto

Basic analysis done today. Only 3 usable tweeters. All the mw6511 seem alright (will need to clean and test further). Going to need four mw6503.

Interestingly it appears that while the one cabinet is not marked TL (and clearly doesn't match the other - stain/wood color slightly different) the driver compliments AND the crossovers are from the 1.2TL makeup. Crossovers need work for sure.

Not sure how nuts I'm going to go - but life is about dreams - and this is one I intend to live. Think step one will be calling (Helen?) and ordering up some drivers. Going to spend some dime on xo's too...

WW

boston1450

Welcome back & hope your having fun with those Polks & those towers sure do attract peoples eye. Lol

F1nut

wwresto wrote: »

Interestingly it appears that while the one cabinet is not marked TL (and clearly doesn't match the other - stain/wood color slightly different) the driver compliments AND the crossovers are from the 1.2TL makeup. Crossovers need work for sure.

Wouldn't it be nice to know how they became a pair?

PolkieMan

Yea that's what I was thinking too how would you end up with two oddballs years apart?
I'm sure that you will have two matched 1.2TLS when you are through with them.
Did you know about the SDA Handbook?
Download that, lots of good information, your going to need.

F1nut wrote: »

Wouldn't it be nice to know how they became a pair?

chandler9a

this will be an interesting, and worth while project for sure.

Maybe I should know this already but are the cabinets for those two models the same? I mean bracing and all? I thought there was some discussion about converting a pair of 1.2 to 1.2TLs and how some thought it may not work out.

Hopefully they can be paired nicely, such a great speaker to own.

F1nut

this will be an interesting, and worth while project for sure.

Maybe I should know this already but are the cabinets for those two models the same? I mean bracing and all?

I'm pretty sure the cabinets are the same.

I thought there was some discussion about converting a pair of 1.2 to 1.2TLs and how some thought it may not work out.

Polk offered an upgrade kit to convert the 1.2 to the 1.2TL, so it's very doable.

wwresto

F1nut wrote: »

I'm pretty sure the cabinets are the same.



Polk offered an upgrade kit to convert the 1.2 to the 1.2TL, so it's very doable.

Truth is I'm now not convinced they were not both 1.2TL's from day one. While the cabinets appear different colors, I suspect one is just sunfaded more/differently than the other. The units aren't marked the same on the label, and in the SDA handbook (awesome resource BTW) there is mention of the labeling inconsistency that followed the Polk Audio line through those years. I have noticed that on several models I've owned in the past.

I won't be selling them. I won't be in any rush, either, to complete them. Two kids, a wife (for now!) and a dog keep me pretty busy - not to mention the cnc hobby work and motorcycles and that darn crap part of the equation - earning a living! Today I hope to fully disassemble both cabinets, further analyze the balance of the drivers, and put together a plan. Will likely chase drivers first so I have them on hand. One MW has a shifted magnet but I'm actually inclined to replace all drivers, and hold onto the still functional originals as spares.

If I'm not too distracted with shop tidying duties today, I'll snap a few starting point pics. Yes - these are indeed a PROJECT and the great thing is that I don't have any other projects right now (lies, all lies)!

drumminman

Whoa, very slick! Did you build that frame?

What motor are you planning on? This deserves a separate thread.

wwresto

drumminman wrote: »

Whoa, very slick! Did you build that frame?

What motor are you planning on? This deserves a separate thread.

That's an RC31 (aka NT650 or Hawk GT) frame, with Durbahn monocoque bodywork. I dig the little underpowered Hawk. This one has been punched to 700cc by JD Hord and will end up around 290 lbs wet (about 100 lbs lighter than stock, with an approximate 50% increase in HP ~67hp).

Couple pics of some of the craziness here - lower triple for the Durbahn build, my current Gray street hawk, the white one is another custom in progress for my buddy (almost done - maybe two weeks if I don't detour on the SDA project too much!)...

wwresto

Lasareath wrote: »

Yes! Very Cool! Are you putting a Gas Motor or All Electric?

Like these: http://www.brammo.com/home/

Brammo is a very cool little company (the Ariel Atom importing kicked them off to a decent start if I recall). I'm not quite ready to own an electric bike - but they're getting close to a legitimate offering in my book.

Now, back to speakers

WW

Toolfan66

Ok, here's the deal, forget about what the labels say, you cannot count on those with vintage SDA's.

The 1.2tl cabinets have an added brace on the back wall just above the passive radiator.

The passive radiators in the 1.2tl's have an added weight on the very back, so if you wanted to do a quick check that would tell you a lot

If the tweeters are all original, then that would be the dead give away, as the SL2000 tweeter looks compleatly different then the SL3000 tweeter..

Would love to see pictures of these speakers. Pull the passives and take some pictures of the back side of them and the interior of the cabinet, and post them..

I had the set of 1.2's and have done a full TL conversion. The one lucky part for me was I found a set of 15" passives from a set of 1.2tl's. that's not the deal breaker in tl'ing a set of 1.2's..

wwresto

Both cabinets have the same PR with silver weight (see photo). Both cabinets have the brace from baffle to back of speaker just above the PR/below the XO. Crossovers are labeled BE-2001C and BE-2000C. I believe these are both TL's.

Now, how do those side grill pieces come off the cabinet? Monday I'm going to get seriously into this project.

WW

PolkieMan

Crossovers are labeled BE-2001C and BE-2000C so they are different.
Here is what I would do.
Download the SDA Handbook.
Verify the MW drivers and wiring match the 1.2tls
Verify the tweeters wiring also, of course is 1.2tls specs.
Buy the Gimpod boards with Sonic Caps and Mills
Get the proper inductors for 1.2tls, get VR3 to help you on the inductors.
Buy Rdo-198 tweeters and modify the rear speaker wire input pots for new SDA interconnect.

wwresto

PolkieMan wrote: »

Crossovers are labeled BE-2001C and BE-2000C so they are different.
Here is what I would do.
Download the SDA Handbook.
Verify the MW drivers and wiring match the 1.2tls
Verify the tweeters wiring also, of course is 1.2tls specs.
Buy the Gimpod boards with Sonic Caps and Mills
Get the proper inductors for 1.2tls, get VR3 to help you on the inductors.
Buy Rdo-198 tweeters and modify the rear speaker wire input pots for new SDA interconnect.

Thanks for that bit of input.

I've already downloaded the manual, and verified the wiring and drivers are all the same per cabinet. Only difference is the label on the back and designation on the crossovers. The SDA manual I have does not list the BE-2001C so that is a touch confusing (this is the crossover that came out of the cabinet labeled as 1.2TL).

Each speaker contains 4 ea SL3000 MW6503 and MW6511.

Regardless, they WILL BE my own version of an upgraded 1.2TL when all is done

WW

(seeking out VR3 contact info now)

halo71

Welcome back!

PolkieMan

Look on page 12 at Table 2.6.
They are different because of the newer tweeters for the TL.
See Appendix 3 25 and 26

How much do you have in them right now?

F1nut

The SDA manual I have does not list the BE-2001C so that is a touch confusing (this is the crossover that came out of the cabinet labeled as 1.2TL).

I have to believe that was a typo.

What are the serial numbers of the two speakers?

wwresto

PolkieMan wrote: »

Look on page 12 at Table 2.6.
They are different because of the newer tweeters for the TL.
See Appendix 3 25 and 26

How much do you have in them right now?

Again, both speakers have identical drivers throughout (8xSL3000, 8xMW6503, 8xMW6511) - with date ranges stamped on them all within 6 months - mid to late 1989. I know there is one SL2000 in one of the pictures, but that is from my stash of SDA spares from long ago. The left/right grills of both speakers are dated from 11/89 to 1/23/90. The crossover labeled BE2000-C has date of 2/8/89, the BE-2001C is dated 10/30/89. I've measured the value of (some of) the xo components and they match. The xo wiring/board is identical. The only component difference of note thus far is the polyswitches with one using 3x of smaller value and the other using a single switch of larger value. Both PR's have the same part number and are matches.

The serial numbers are 6174 (labeled SRS 1.2) and 6770 (labeled SRS 1.2TL) I've completely disassembled them at this point. All wiring is identical (though one speaker uses white wiring with colored rings for identity, and the other has solid colored wiring).

Tweeters
3 SL3000's Good enough to reuse (but I won't)
2 SL3000's marginal
3 SL3000's goners

MW6511
7 MW6511 in good/great condition
1 MW6511 in usable condition - cone has a soft area

MW6503
4 MW6503 in good/great condition
1 MW6503 in usable condition
2 MW6503 with bad surrounds
1 MW6503 with shifted magnet

Passive Radiators
2 MW150 in 9/10 condition - totally going to reuse those

All hardwood and cabinets in good condition. Will refinish the hardwood carefully, and recover the side grilles. Will likely make new front grilles (Did not come with these).

A nice, simple restoration will follow soon. Mods planned of course....need to get a bottle of wine uncorked tonight and start the dream

WW

(in regards to budget - an acquaintance bought these locally this weekend and called me because he was over his head. He paid ~$100 IIRC. We traded for some simple machining time. Technically I'm at 0$)

F1nut

They are definitely a pair put together. The top and bottom end caps in your pic are walnut while the one in the middle is oak.

wwresto

F1nut wrote: »

They are definitely a pair put together. The top and bottom end caps in your pic are walnut while the one in the middle is oak.

Could be correct. I should be better able to identify hardwoods given my youth of cabinetry, but these are just dirty end caps that need refinishing right now. I believe 3 are walnut and one is oak, but I could be wrong. The lightest colored one is clearly faded...

I've an idea of what the replacement MW's go for - how about the RD tweeters?

WW

F1nut

I think the MW's are $60.00 each. I know the tweeters are $48.00 each, but you have to tell them you are a Club Polk member to get the discounted price.

nooshinjohn

I would get all the needed MW's from Ebay rather than the Chinese replacements, but that's just me.

wwresto

nooshinjohn wrote: »

I would get all the needed MW's from Ebay rather than the Chinese replacements, but that's just me.

When you note Chinese replacements - are you referring to those that Polk sells now - or something else? Where were the drivers mfg in the 80's (I know many speaker companies started using Chi mfg plants to their specs as far back as the late 70's, just curious to who/where the original SDA SRS drivers were made).

WW

F1nut

When you note Chinese replacements - are you referring to those that Polk sells now -

He is. The current replacements are the same spec wise. Their appearance is slightly different with the dust cap being slightly larger, no exposed leads and the rubber surround does not have the cut outs around the screw holes. You should trim the rubber a bit before mounting.

nooshinjohn

wwresto wrote: »

When you note Chinese replacements - are you referring to those that Polk sells now - or something else? Where were the drivers mfg in the 80's (I know many speaker companies started using Chi mfg plants to their specs as far back as the late 70's, just curious to who/where the original SDA SRS drivers were made).

WW

The reasons cited by F1 are the reasons I would opt for originals. You noted that you would just get replacements for all of them, but at roughly 500 bucks per cabinet, you would be looking at a huge chunk of money spent just on drivers. You can get 4 or 5 originals, all of the RDO-198s, and still have the money left over for the crossover upgrades with that kind of coin.

There have been a few that say the originals perform better than the replacements as well, but with zero experience with them, I will leave that to others to haggle about.