I'm Upgrading my Caps & Resistors for my 1.2TL's

[tom t]

a little busy there??? boy ,it sounds like you have your work cut out for you. at least you can say you have the biggest pair of polk speakers known to man.

[Lasareath]

Here's a quote from Jeff @ SoniCraft.com

"BTW, you really should not glue the bodies of the resistors together.
You really do not want anything touching the bodies of the resistors so that you have air all the way around."

So, I tried to remove some glue with an exacto knife.

Bad idea.

I stabbed the 2.7ohm resistor and there's little wires coming out of the wound.

Also, by pulling off the hot glue the writing on the side of the resistors has come off. The outer most layer of black coating has come off of the resistors.

I called Jeff and he said if the windings are not visible then you should not have any problems.

He said the 2.7 resistor should be replaced. He Offered to send me a free replacement.

I said thanks and decided to leave the rest alone. Untill the next day when I had some time and I tried again on the other crossover. On the second crossover I moved the 15ohm resistor too far and the end cracked off!!!!

The lead is still connected and I hooked both back up and they have been playing all weekend and they sound fine.

But this is driving me NUTS!!!!!!!

I called Sonic Craft and ordered 10 more Mills Resistors MRA-12's, all 10 with 2nd day shipping was $55.00

I'm gonna rip out all of them and clean up all the glue and redo them all.

This is a warning to all out there that will be doing their crossovers in the future!

Try to keep room all around the resistors, they should not be touching anything.

Only the leads should be supporting them.

Do NOT bend the leads without using a needle nose pilers. you can crack the end of the resistors. Clamp down the needle nose on the lead and then bend the lead.

Do NOT use hot glue on any of your resistors!!!

They need breathing room!

Sal

[hearingimpared]

What idiot told you to hot glue your resistors???:o

[ben62670]

a little busy there??? boy ,it sounds like you have your work cut out for you. at least you can say you have the biggest pair of polk speakers known to man.

http://www.polkaudio.com/forums/show...t=53273&page=6
POST 167 :D

[Lasareath]

What idiot told you to hot glue your resistors???:o

It's nobody's fault but my own, I had my finger on the trigger!

[analog97]

You guys have me pumped to try the 1.2TL x-over upgrade. I have a set with original x-overs and, although they sound awesome, they seem a tad bass shy. So, I routinely use a Paradigm Reference Servo 15 with them. Does it make sense that bass-shy 1.2 TL's may have a x-over weakness? Also, it looks as if you just de-solder the caps and put in the new caps, but size differences force using a lot of the hot glue. Is this basically it? You gents are to be commended for your hard work!! Yeah, I know these speakers are worth it.

[hearingimpared]

You guys have me pumped to try the 1.2TL x-over upgrade. I have a set with original x-overs and, although they sound awesome, they seem a tad bass shy. So, I routinely use a Paradigm Reference Servo 15 with them. Does it make sense that bass-shy 1.2 TL's may have a x-over weakness? Also, it looks as if you just de-solder the caps and put in the new caps, but size differences force using a lot of the hot glue. Is this basically it? You gents are to be commended for your hard work!! Yeah, I know these speakers are worth it.

The hot glue is mainly for vibration control. . .think about how much energy there is within those monster boxes.

I can tell you this that the Sonic Cap & Mills resistor upgrades have greatly improved my bass response. While they were burning in, I moved my 1.2tls from 13" out from the wall to 8" and now it sounds like a have a subwoofer in the configuration.

[tom t]

sal, just bite the bullet and buy the infinity rs1b's on e-bay now. belive me, you will never look back!!!!!!!. if yor lucky they will go for around $3,500. just kidding, i know you love your 1.2's

[heiney9]

You guys have me pumped to try the 1.2TL x-over upgrade. I have a set with original x-overs and, although they sound awesome, they seem a tad bass shy. So, I routinely use a Paradigm Reference Servo 15 with them. Does it make sense that bass-shy 1.2 TL's may have a x-over weakness? Also, it looks as if you just de-solder the caps and put in the new caps, but size differences force using a lot of the hot glue. Is this basically it? You gents are to be commended for your hard work!! Yeah, I know these speakers are worth it.

It's a no brainer if you think you are up to the task. Remember to take your time and do one x-over at a time. Mock every piece up ahead of time draw stick diagrams if you have to and approach it with some degree to logic and you will be fine. This refreshing after ample break-in will transform your speakers.

Next up the RD0198-1 silk dome replacement tweeters will really knock your socks off. :D

[tom t]

ben , i see the pictures of the speakers you made,real nice and interesting. now just make 10 more sets and all the polkies on this site will line up to buy them. it can be your new career!!!!!

[analog97]

Yes, i think I'm up to it. In the last year my DIY sklills have accomplished the building of 7 projects, all from Jim Hagerman's Hagtech line. So, I can follow directions, de-solder and replace resistors and capacitors. I am assuming the 1.2 TL PCB is labelled and you simply replace the resistors and caps with the new replacements? Is that basically it? Thanks again for the big shoulders of others in this forum to stand on. It really helps!!!

[heiney9]

Yes, i think I'm up to it. In the last year my DIY sklills have accomplished the building of 7 projects, all from Jim Hagerman's Hagtech line. So, I can follow directions, de-solder and replace resistors and capacitors. I am assuming the 1.2 TL PCB is labelled and you simply replace the resistors and caps with the new replacements? Is that basically it? Thanks again for the big shoulders of others in this forum to stand on. It really helps!!!

Search this site for others posts on pointers and tips and feel free to Call Ken at Polk Customer Service. Polk is 2nd to none for helping folks out and Ken Swauger is the man :)

[ben62670]

ben , i see the pictures of the speakers you made,real nice and interesting. now just make 10 more sets and all the polkies on this site will line up to buy them. it can be your new career!!!!!

I would share design planning if someone wanted to build some. I can't imagine shipping something like this! I could build the XO's, and wiring harnesses too.

[hearingimpared]

Next up the RD0198-1 silk dome replacement tweeters will really knock your socks off. :D

Yep it will knock your socks off however, I did my silk dome RD0198s first then the crossovers. I think if you replace your tweeters before doing the crossovers it will pop your fear cherry about doing the crossovers.

I'd be glad to help you out with both upgrades. I also placed Dynamat on the basket spokes of all the midwoofers and passive radiators.

[F1nut]

Does it make sense that bass-shy 1.2 TL's may have a x-over weakness?

I've never considered big SDA's to be bass shy. Maybe you just aren't use to nice tight real bass or your room has issues or your power isn't up to the task.

[heiney9]

I've never considered big SDA's to be bass shy. Maybe you just aren't use to nice tight real bass or your room has issues or your power isn't up to the task.

+1; I have smaller 1C's and the bass is simply stunning.

[Jockos]

On my 11t's I used quite abit of glue to mount a capacitor on top of 2 resistors. Will this alter the sound? or is the breathing space just for cooling?

Thanks
Jockos

[hearingimpared]

On my 11t's I used quite abit of glue to mount a capacitor on top of 2 resistors. Will this alter the sound? or is the breathing space just for cooling?

Thanks
Jockos

Cooling:)

[ben62670]

If you are lacking Bass It is usually due to 3 things.
1 Air leaks around drivers
2 under powered
3 bad driver/drivers

[hearingimpared]

If you are lacking Bass It is usually due to 3 things.
1 Air leaks around drivers
2 under powered
3 bad driver/drivers

4. Bad overall placement
5. Toed in

[analog97]

Lasareath,

Your post was extremely helpful re: crossover re-do. Thank you for the time you have put in!! Couple questions:

1. You chose to use a Mundorf Silver/Oil cap in each x-over. Is this a CRITICAL location for sound reproduction? Was that your thinking?
2. The Sonicap 13.5 microfarad cap is custom. They will do this at Sonic Craft?
3. How did you arrive at the replacement values for the resistors and caps? Were they all clearly labeled on the "old" components or do you have a circuit diagram?

Thanks in advance. Your help is as gigantic as your Polk 1.2TL's....

[heiney9]

If you are lacking Bass It is usually due to 3 things.
1 Air leaks around drivers
2 under powered
3 bad driver/drivers

It could also be a x-over issue in conjuction with the above. My 5b's had much better bass when the x-overs were refreshed.

[hearingimpared]

Lasareath,

Your post was extremely helpful re: crossover re-do. Thank you for the time you have put in!! Couple questions:

1. You chose to use a Mundorf Silver/Oil cap in each x-over. Is this a CRITICAL location for sound reproduction? Was that your thinking?
2. The Sonicap 13.5 microfarad cap is custom. They will do this at Sonic Craft?
3. How did you arrive at the replacement values for the resistors and caps? Were they all clearly labeled on the "old" components or do you have a circuit diagram?

Thanks in advance. Your help is as gigantic as your Polk 1.2TL's....

I can help with these.

1. The reason for the Mundorf was that they didn't have the proper tolerance of capcitor in Sonic Cap so he went with the Mundorf.

2. Yes, call and tell Elliot what you need or want and he can do most anything.

3. Off the schematic. They were pretty clearly labeled on the bodies of the components but I wouldn't count on it in every case.

[analog97]

Thanks to "Hearing Loss" for your reply!! Is the schematic available somewhere? TIA.

[heiney9]

Thanks to "Hearing Loss" for your reply!! Is the schematic available somewhere? TIA.

You are in luck in that the SDA schematics have been posted in the past couple of days (Vintage speaker forum). I always warn people to have the schematic in front of you and then double check the actual parts on the PCB. Polk used to change things on the fly, so as many have discovered there might be some slightly different value parts or an added or deleted part here and there.

Check, double check, and then re-check again before disassembly.

Good luck

H9

[analog97]

Thanks, H9. Found the schematic from Darquenight. Also looked carefully at the posted pictures of the 1.2TL x-over pcb. I see a lot of holes without solder pads, so am assuming there is some point-point wiring on the underside of the pcb? Thanks again.

[F1nut]

No point to point wiring, just some unused holes.

Do you plan on retaining the silver mica bypass caps?

[analog97]

F1,

I just noticed (thanks to you) that the schematic posted for the 1.2TL's includes 2 silver 750pf caps you described. Those 2 caps were not included in the re-build description parts list posted by Lasareath. So, I am wondering what is the thinking here? What is the expert consensus on the replacement of those 2 silver caps?

[hearingimpared]

I didn't and neither did Sal replace the silver mica caps. They are no longer necessary with the Sonic Caps.

[george daniel]

F1,

I just noticed (thanks to you) that the schematic posted for the 1.2TL's includes 2 silver 750pf caps you described. Those 2 caps were not included in the re-build description parts list posted by Lasareath. So, I am wondering what is the thinking here? What is the expert consensus on the replacement of those 2 silver caps?

IIRC,,some eliminate (use a jumper instead of the SM) and others myself,have used a .1Uf sonicap in place of the SM,,,have fun, and good luck.