Polk SDA 1C refresh

[Navy_Goat]

Now that I have my 2BTL SDAs sounding amazing and they are once again front and center in the living room it is time to get to work on my 1Cs. I did the 2BTLs in phases to get some idea for how the sound was changing throughout the process. I feel no need to do the same thing for the second set. I just want to skip to the end. So here is the plan:

4.4 and 12 uF caps - Sonic Craft
20 uF caps - Clarity PX
Mills resistors - Sonic Craft
Replace seals if needed - Already have Armacell on hand
H-Nuts - PE
Machine Screws - McMaster Carr
RD0194 - Midwest Speaker Repair

This time I will order some new boards. I wanted to see how difficult using OEM boards would be. Been there done that now. Everyone advises getting new boards and no surprise, they are all right. The new boards add a modest expense with the boards and required connectors and hardware. At this point I have ordered new boards for both sets of speakers. I will eventually retrofit them intot he 2Bs also.

After experiencing the improvement in bass response in the smaller 2Bs I have decided to upgrade the main inductor in the signal path for low end sound. It seemed to be unnecessary before I experienced the massive improvement in my 2BTLs, but now I am wondering how much better the low end can get. I would appreciate any input you all might have on this point?

Questions and comments are always welcome....

Cheers,
Caleb

 

[Navy_Goat]

Progress so far:

Hardware on order from Mouser.

Dynamat on order (Ebay). I may look at the feasibility to use a laser engraver to cut the dynamat into precise sizes for each leg of the basket? I get bored when out to sea so I may try to work this out next time we go out.

Sonic Barrier + H-Nuts on order from PE.

RD0194 on order from Midwest Speaker Repair.

8-32 screws on order from McMaster Carr.

I am on the fence about a few values for some of the components. Research is ongoing. I will update when a decision is made.

 

[Navy_Goat]

Just got them back together. Completed the following:

New RD0194 HF drivers
Dynamat 6.5 driver and PR baskets
New Crossover boards
New Caps and resistors
New connectors on the board side
Sonic Barrier behind woofers

I did not install the H-Nuts, I may get to that later. The gaskets were fine so I did not replace them.

I am also waiting on a pair of instructors to replace the large inductor on the LF side for both speakers. A pair for my 2Bs will also be inbound shortly.

I also didn't take any pictures...... Maybe next time.

I ended up going with all the OEM values. I was on the fence about dropping the resistance on the HF side to make up for the extra mid range that these tend to have. I still may go that route after things have settled?

Playing Jesse Cook Blue Guitar Sessions now as they begin the process of settling the new components in. Sound is already much improved. I look forward to hearing where they end up. If they follow the same pattern my 2Bs did I will be pretty happy by the time they are fully burned in.

I now have these in the front of my living room with my other SDAs in the back of the room hooked up to my NAD 7175.

 

[7whales7]

Just got them back together. Completed the following:

New RD0194 HF drivers
Dynamat 6.5 driver and PR baskets
New Crossover boards
New Caps and resistors
New connectors on the board side
Sonic Barrier behind woofers

I did not install the H-Nuts, I may get to that later. The gaskets were fine so I did not replace them.

I am also waiting on a pair of instructors to replace the large inductor on the LF side for both speakers. A pair for my 2Bs will also be inbound shortly.

I also didn't take any pictures...... Maybe next time.

I ended up going with all the OEM values. I was on the fence about dropping the resistance on the HF side to make up for the extra mid range that these tend to have. I still may go that route after things have settled?

Playing Jesse Cook Blue Guitar Sessions now as they begin the process of settling the new components in. Sound is already much improved. I look forward to hearing where they end up. If they follow the same pattern my 2Bs did I will be pretty happy by the time they are fully burned in.

I now have these in the front of my living room with my other SDAs in the back of the room hooked up to my NAD 7175.

Is the NAD 7175 your main amp powering your SDA's?

 

[Navy_Goat]

The NAD is in a second system but is powering my SDA-2BTLs. Right now they should be a 6 ohm load, but that will be lowered to 4 or so when I replace the LF inductor (in the mail to me now). Main system is powered by a Parasound HCA 1500a.

 

[Stan man]

Hello,
just a tip.
You'd generate a lot more interest and feedback, if you'd just ad some pics of your project.

 

[Navy_Goat]

I'm sure you are right. I should have taken some pictures while I was working.

 

[Navy_Goat]

I picked up a set of SDA SRS 2.3tl speakers two weeks ago. I plan to leave them alone for at least a few months. We will be moving and anyway they sound really good. I have now experienced the different between all 4 tweeters common to the SDA line and the SL3000 is definitely superior to the SL2000. I will eventually replace the SL3000 with RD0198, but that can wait until I do the crossovers. I will glue the magnets sooner rather than later. At that point I may install H Nuts and new gaskets if needed.

I will have to start a new thread and include some pictures as suggested when I start the new project.