A Real SL 2000 Hack. Replace stock (burnt voice coils) with "silk diaphragm dome ".

stogie

Directly from Polk.

westmassguy

OldmanSRS wrote: »

Where does one buy the RDO-194's. I've been MIA from here for a couple of years and many brain cells ago.

Thanks,
Greg

Tech/Product Support

9AM-5:30PM EST Mon-Fri

1-800-377-POLK (7655) Option 1
Be sure to tell them you're a Club Polk Member. They're $48.00 each plus tax, with free shipping.

OldmanSRS

That's what I'm looking for. Thanks guys.

aprazer402

Not trying to de-rail this. Simple question. After I purchase either the 194 or 198 replacements from Polk, can I use the box they came in (assuming a box) to store the existing tweeters to store or ship if I resell them? Thanks in advance.

Schurkey

Yup. I've got a functional SL2000 sitting cozy inside an RD0-198 box.

aprazer402

Good to know. Thanks.

voltz

I shipped two sl-2000 to Kevin using my RDO boxes.

VSAT88

Well the real Silk domes came in from China. They were in a box with no packing materials whatsoever. Just two Silk diaphragms floating around in a box so I thought that for sure they were toast. Upon close examination they were in perfect order so I tore the first drivers back apart ripping out those plastic, mylar or whatever material they were diaphragms out. I never liked the sound and I do not think anyone here would either. Take it from me if you decide to try this buy the ones that westmassguy bought they are much much better ! I followed almost to the letter the operation that westmassguy posted. Much success followed. They sound a whole lot better than SL 2000z that is for sure. I can actually sit here and listen to the speakers for extended periods. Would I do it again ? Well sure I would and probably will. If nothing else happened it convinced me 100% to buy brand new RDO-194z from Polk. I love silk domes, I always have and it seems I still do. I did notice that on my rebuild I had a voice coil scraping. I could not understand why. I centered the voice coil before I glued it and none of the other three I did scraped..I found that I put the magnet in differently. I had it upside down from the way I took it off. I really do not see how that should have made any difference but when I turned it around I had not a problem. One thing that I noticed was the red paint or mark on one side the voice coil of the new diaphragm where the lead comes out. I used that as positive each time with all four I did and it seems to be OK. I have not changed phase so I am still not 100% that I have positive to positive and negative to negative so I will probably swap the leads on both speakers one day to see how she sounds that way however right or wrong they really do sound great, especially for $10.00..well $20.00 for me because I got trigger happy and bought a crap pair the first time...So Super thanks to westmassguy for the link to the real deal and the wright up as well !

westmassguy

Glad they worked out for you.

pitdogg2

Wonder how well they would work on the SL 1000 tweeter? At least they have a metal face plate which may be more forgiving of the heat

westmassguy

pitdogg2 wrote: »

Wonder how well they would work on the SL 1000 tweeter? At least they have a metal face plate which may be more forgiving of the heat

The SL1000 is essentially the same tweeter as the SL2000. Same resonance peak at 12-13KHz. Should be a good candidate. You'll have to insulate the coil wires though.
The SL2000 has a plastic bezel, so no insulation was needed.

VSAT88

BTW, does anyone recommend that I change the crossover network now that I am running these Silk domes like in the TL MOD a 5.8 uF Cap (I think??). keep in mind that I will buy RDO-194 Tweeters in a while...Thanks.

westmassguy

RDO-198s have a slightly different frequency response than the 194s. The "TL" Mod compensates for this with the 5.8uf Cap across a resistor forming a contour network.
If you're going with 194s, stay with the same value caps that are in there.

zumbini

Will the VC's you linked to fit in the SL3000? Are they electronically similar? Four of the SL3000's in my son's new (to us) 1.2tl's have fried voice coils and we can't afford to buy Polk replacements right now.

Schurkey

VSAT88 wrote: »

BTW, does anyone recommend that I change the crossover network now that I am running these Silk domes like in the TL MOD a 5.8 uF Cap (I think??). keep in mind that I will buy RDO-194 Tweeters in a while...Thanks.

Who knows? I haven't seen any evidence of testing these voice coils for installed impedance, frequency response, etc. Even if the kits come with a spec sheet, the manufacturer wouldn't know what tweeter body they'd be installed into.

NOBODY KNOWS what the crossover mods should be to get the most out of these voice coil kits.

westmassguy

I'd be happy to send one of mine to anyone that has the equipment to measure it properly. My ears tell me it's a pretty good match.

VSAT88

Besides the $ figure one reason I wanted to try this is the "purist" factor. These are SL 2000 tweeters. They are the original driver that Polk put in this speaker. Yes the voice coil and dome are different, fact remains that the actual assembly are the same. I really would like it if someone with proper test equipment and knowledge would test these for "installed impedance, frequency response, etc." That would be a little icing on the cake. I agree with you westmassguy, they do seem to be a pretty good match. Once again, a $10.00 and a few hours tops lets you be the judge

VSAT88

zumbini wrote: »

Will the VC's you linked to fit in the SL3000? Are they electronically similar? Four of the SL3000's in my son's new (to us) 1.2tl's have fried voice coils and we can't afford to buy Polk replacements right now.

zumbini, I have no experience whatsoever with the SL 3000 or the 1.2tl speakers however I will tell you how I went about figuring on the first hack. OK, the tweeters are fried so taking them apart will not hurt them. I took one apart watching pretty closely how it came apart and how things were oriented. Then a vernier caliper was used to measure the voice diameter as well as the voice coil gap to the center (best I could anyway) I then kept those measurements. I did not worry whatsoever about voice coil depth. I measured one of my good working SL 2000 tweeters for DC resistance with a volt ohm meter and kept that measurement. Then I went looking for a diaphragm with as close a measurement as I could find to those figures. I put them in when they arrived but I was not happy with the sound however this proved it would work. I watched the thread and westmassguy found a set of diaphragms that were real silk and installed them in his Sl 2000 driver frames. I had to try that as he said his were much improved and mine sounded like some some cheap wallyworld tweeters. I can not believe how much better they sound than the stock SL 2000z now that the hack is complete. Don't get me wrong, I am going with RDO 194z from Polk for these SDA 2b speakers and these will pull duty in my shop RT8T speakers but those have Dayton 6 1/2 replacement mid woofers anyway.

VSAT88

westmassguy wrote: »

Glad they worked out for you.

Thanks, as I said above these will pull duty in my shop speakers (RTA 8T) after I order RDO 194s for these SDA 2b's. What I wanted to ask was how did you determine polarity when you installed your diaphragms ? I used the red mark underneath the dome on the voice coil as positive on both of mine..

westmassguy

VSAT88 wrote: »

westmassguy wrote: »

Glad they worked out for you.

Thanks, as I said above these will pull duty in my shop speakers (RTA 8T) after I order RDO 194s for these SDA 2b's. What I wanted to ask was how did you determine polarity when you installed your diaphragms ? I used the red mark underneath the dome on the voice coil as positive on both of mine..

Mine were NOT color coded. After they were completed, I took a pair of alligator clip jumpers, and a AAA Battery, BRIEFLY Touched the terminals to determine which direction the voice coil moved.

zumbini

Thanks for your insights. I am a retired plant/project/process engineer with a life-long love of audio gear and music, and a penchant for fixing things. The 1.2tl's were given to me by a friend and I knew they needed work. I am very happy with my Legacy Audio satellites and subs so I passed them on to my 19 y/o son who inherited my love of audio gear and music. I hope to have them fully restored by the time he graduates from college. (Zack is a talented drummer and a rising sophmore at MIT.)

pitdogg2

Not too many Legacy speakers I've walked away from in dislike.....Once in a while Bill invites us down to see new goodies knowing darn well I cannot afford them but will treat me like I've bought millions from him. Outstanding guy.

To be honest I'd have a hard time deciding which will be my forever speaker should i ever when the lotto

zumbini

Bill Duddleston is a great guy, and a heck of an engineer. I visited his original shop in Springfield in the mid 80's and spent several days listening to his toys and working up a design for my sub/sat system. When the speakers were ready he drove them up to Chicago and spent the afternoon tweaking them with me.

15 years later my youngest brother bought a pair of custom Rosewood Focus SE's from him with built-in 350W bass amps and a one of a kind Sherbourn processor. He got the same treatment.

About 5 years ago I called Bill to ask about upgrading my satellites. After a week of discussions and emails we agreed on a plan and I shipped him the speakers. He replaced the original drivers with Whisper ribbon tweeters and Audax mids and installed new bi-ampable crossovers. He also spec'd out new 12" drivers for the subs and sent me a pair at close to his cost.

I'm probably set for life now but I'll continue to praise and recommend his products.

VSAT88

westmassguy wrote: »

VSAT88 wrote: »

westmassguy wrote: »

Glad they worked out for you.

Thanks, as I said above these will pull duty in my shop speakers (RTA 8T) after I order RDO 194s for these SDA 2b's. What I wanted to ask was how did you determine polarity when you installed your diaphragms ? I used the red mark underneath the dome on the voice coil as positive on both of mine..

Mine were NOT color coded. After they were completed, I took a pair of alligator clip jumpers, and a AAA Battery, BRIEFLY Touched the terminals to determine which direction the voice coil moved.

These are images of how I received mine. A red (looks like a Sharpie type mark) on one side next to the blue glue. I guess that's glue of some kind anyway.....



This is the second image of the red mark...



This is an image of the other side of the voice coil...No red mark. Only the blue glue stuff..



Finished Tweeters, No not pretty but sound pretty damn good for a $10.00 bill !



I did as you did. I took a 1.5 V AAA battery and used it to check for sure the polarity was correct. I found that the side with the red mark was indeed the positive side. I used a small piece of tissue paper on top of the silk dome so I could see the movement as when I tried without it I could not tell the direction of movement.

pitdogg2

Guys every sl2000 I have seen has had the + - imprinted onto the plastic bezel right next to where you attach the leads.....under the gasket

westmassguy

pitdogg2 wrote: »

Guys every sl2000 I have seen has had the + - imprinted onto the plastic bezel right next to where you attach the leads.....under the gasket

True, but we changed the dome, coil, and coil wires. Mine were not marked, so I had no way to determine + or-

pitdogg2

my bad what was I thinking....

VSAT88

pitdogg2 wrote: »

my bad what was I thinking....

You were probably thinking for just a quick moment like I do almost all the time !

Schurkey

zumbini wrote: »

Will the VC's you linked to fit in the SL3000?

Even if they "fit", are you going to replace the ferrofluid, or leave them "dry"? I'm not sure what seals-in the ferrofluid, or what viscosity to buy.

First Guess: Ferrofluid will make the job MUCH more complicated.

westmassguy

Ferrofluid doesn't normally need to be "sealed", it's held in the gap by the magnetic field created by the magnet. You're correct however, Ferrofluid comes in a wide range of viscosity and magnetization. Finding the right one would be a problem. I've never disassembled an SL3000, however the SL2000s and SL2500s I have do not contain Ferrofluid.