Polk SDA 1C's What to upgrade.

Irrenhaus

Hi all

I know this has been ask many times, sorry. So I have these for a few months now and really like how they sound and best guess after upgrades they will sound better. I was thinking of getting a new DAC but I rather try to do the upgrades now that I am on vacation and there is no work travel and get the DAC once they are SDA's are burn-in.

Here what I was thinking:

1. Crossovers will use SoniCaps and Mills Resistors. Boards well may use the stock ones, build my own or get the ones from Gimpod. Still undecided.
2. Tweeters RDO-194-1
3. Dynamat all that is required and JB Weld the magnets

What else can I do?

Do I upgrade the interconnect cable? I have the original pin/blade.

Sorry if I am not correct on what I am asking. I am a rookie to the SDA's

One cool part of this upgrade is that my daughter(15) is offering to help and learn.

Cheers

F1nut

Get in on the Dreadnought group buy.

Get on the waiting list for Larry's rings.

Spike those speakers.

deronb1

That is cool your daughter is interested. From what you listed and F1s input, not much else to do. You might consider ideal placement, room treatments and other accrutraments that can help.

george daniel

replace/upgrade the stock binding posts.

westmassguy

Forget the JB Weld, get a few tubes of Loctite Power Grab Clear Acrylic. You can do the magnet assemblies and reseal the cabinet internally with it.
Blackhole5 behind the woofers.
Replace the Pin/Blade with SpeakON connectors and you favorite flavor of good speaker wire.
New Binding Posts.
Replace the Sub-bass drive inductor with an Erse SuperQ Laminated Steel Inductor for improved deep bass.
Larry's Rings or Hurricane Nuts

Mike Reeter

Rebuild your 1C's in steps as you can afford the upgrades, you will be rewarded with each step along the way.

dpowell

I did items 1 and 2 on a pair of 1C's I had and the results were amazing. I would have done the others but I sold them when I bought the 2.3TL's I'm using now. I'd upgrade the tweeters first and get comfortable with what you're hearing. Then you will truly understand the benefit of the XO upgrade when you do that......or just do it all at once and enjoy audio nirvana.

Moose68Bash

dpowell wrote: »

I did items 1 and 2 on a pair of 1C's I had and the results were amazing. I would have done the others but I sold them when I bought the 2.3TL's I'm using now. I'd upgrade the tweeters first and get comfortable with what you're hearing. Then you will truly understand the benefit of the XO upgrade when you do that......or just do it all at once and enjoy audio nirvana.

My 1Cs were done all at once, and I second dpowell's description of my pleasure in the result.

I joined the recent A-V transformer group buy to upgrade my Dreadnought from a Toroid of Maryland transformer to the A-V 1000VA transformer. This, I hope, will be the last time I do anything to the 1Cs.

The SRS 1.2s are another matter! I still need to TL them. :~)

dhlogic

I've looked at the SDA Handbook read the upgrade section with recommendations by Polk engineers and knowledgeable members of the community here and I have a question.

westmassguy brings up replacing the large SDA circuit inductor with one with lower DCR. My question is, how low is too low? Another thread gave the DCR of the stock coils and I remember the large 16mH coil being something like 2.55R. Well I can buy 16mH coils in larger gauges giving me 1.27R, 0.97R, and 0.59R options. If I'm not concerned with price and they still fit in the cabinet hehe, is there anything else to consider that would preclude one from going to the lowest DCR available? Thanks!

Schurkey

dhlogic wrote: »

If I'm not concerned with price and they still fit in the cabinet hehe, is there anything else to consider that would preclude one from going to the lowest DCR available?

As the DCR drops, so does the speaker impedance. You'll pull more current from the amplifier; make sure your amp will tolerate that.

Make sure the coil won't saturate. My 1Bs got a 16-gauge coil only because my supplier is perpetually back-ordered on the 14-gauge units. The 16-gauge coil handles ~500 watts before saturation, and that's good enough for me.

westmassguy

The 16 gauge Erse SuperQ can handle even the big SDAs. Remember, that inductor is only connected to the dimensional woofers, and only handles frequencies below 150 Hz

westmassguy

dhlogic wrote: »

I've looked at the SDA Handbook read the upgrade section with recommendations by Polk engineers and knowledgeable members of the community here and I have a question.

westmassguy brings up replacing the large SDA circuit inductor with one with lower DCR. My question is, how low is too low? Another thread gave the DCR of the stock coils and I remember the large 16mH coil being something like 2.55R. Well I can buy 16mH coils in larger gauges giving me 1.27R, 0.97R, and 0.59R options. If I'm not concerned with price and they still fit in the cabinet hehe, is there anything else to consider that would preclude one from going to the lowest DCR available? Thanks!

The original is around 2.5-2.6 ohms if memory serves. It keeps the overall impedance high enough so most quality amplifiers can handle the load. When you drop from 2.5 to .5 ohms, the later SDAs will no longer be 6 ohm nominal, they'll be 4 ohm. Earlier 3rd generation SDAs like my 2As, that were 4 ohm to begin with, drop to 3.5 approximately, and drop below 3 ohms at certain frequencies.

dhlogic

And if I go with an air coil inductor, the issue of saturation completely goes away doesn't it?

westmassguy I knew the lower DCR would lower the nominal impedance of the speakers from the various anecdotes I've read, but I don't fully understand it. I am unable to articulate why droping the inductors resistance from 2.5 to .5 ohms would lower the speakers impedance from 6 to 4 ohms.

Is there a thread that explains this a little more or is it just a case of needing to learn more electronic theory to understand and calculate it?

westmassguy

It's actually explained sort of by MP himself in that section of the handbook. Inductors have a measurable DC Resistance, but AC Resistance (Impedance) changes due to many factors including Reactance. Volumes have been written about coils. Try these for starters:
http://en.wikipedia.org/wiki/Inductor
http://www.audioholics.com/loudspeaker-design/the-loudspeaker-crossover/the-loudspeaker-crossover-the-brains-of-your-system-part-ii-page-2

Don't blame me if your eyes start to glaze over

Schurkey

dhlogic wrote: »

And if I go with an air coil inductor, the issue of saturation completely goes away doesn't it?

Yes, but you won't have the very low DCR that makes this worthwhile.

dhlogic

westmassguy thanks for the links. I'll do some reading.

Schurkey yep after doing some comparisons of coils with similar gauge wire, the ferric coil will have a DCR several times lower than the air core. The benefits of an air coil are not really applicable to me as I will never saturate a coil like the Erse anyways. Plus the cost difference is quite extreme.

http://www.northcreekmusic.com/NorthCreekCoilPrices.PDF They could make a 10AWG air coil with similar DCR of the Erse, for 20x the price.

I've been reading old posts about this for quite sometime and finally came across the one were F1nut shares a message from Matt Polk about why they chose the inductor they did and why you might want to upgrade them.

http://www.polkaudio.com/forums/showthread.php?66983-Erse-Inductors

F1nut

dhlogic, I would suggest you do the other mods, tweeters, crossovers, Dynamat, spikes, rings, etc. before you mess around with the 16mH inductor as after those mods you are likely to find no further increase in bass response is desired.

Irrenhaus

Hi all

Thanks for the advice. One more question, How much Dynamat will I need?

Cheers

westmassguy

A "Wedge Pack" will be plenty. This is the cheapest place I've found: http://www.ebay.com/itm/230606838862?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Irrenhaus

Hi all,

So I have been home for some time after getting hurt due to a fire. More on that one separate post maybe.

So I have been taking on some projects that were on the back burner due to a lot of work and now I do have the time off and funds are available. Not the best way to get the time off, but it is what it is.

So I have order all the components to restore the crossovers. Already have the Gimpod's boards. Dynamat is here and will for sure get spikes and hurricane nuts.

Now I contacted Polk to get the RDO 194 and here is the reply. Not sure but I guess I am better calling.

"Regretfully, there are no longer parts or replacements available for this product. This may simply be because or age, technological advancements, or business decisions."

And this was my request:

I am looking for the replacement RDO-194-1 tweeters for the Polk SDA 1C.

Serial #
R SDA 1 7932
L SDA 1 7931

Wow on the original post I said my daughter (15) will help with the upgrades. Now she is 20 but I am sure she will still be interested to help out but how fast time goes by......

Cheers

F1nut

Try RD0194 or just buy them here.

https://www.midwestspeakerrepair.com/shop/home-audio/tweeters/polk-audio-1-tweeters/polk-audio-sl2000-1-inch-dome-tweeter/

Irrenhaus

F1nut wrote: »

Try RD0194 or just buy them here.

https://www.midwestspeakerrepair.com/shop/home-audio/tweeters/polk-audio-1-tweeters/polk-audio-sl2000-1-inch-dome-tweeter/

Hi F1 thanks for the info.

Now one question is RDO (letter O) or RD0 (zero number) that may be my mistake.

Thanks

verb

OMG sorry to hear you got hurt! Hope you're on the road to recovery. Another omen for me here. I need to get my 1C upgrade going again. Now where's that thread?

F1nut

Irrenhaus wrote: »

F1nut wrote: »

Try RD0194 or just buy them here.

https://www.midwestspeakerrepair.com/shop/home-audio/tweeters/polk-audio-1-tweeters/polk-audio-sl2000-1-inch-dome-tweeter/

Hi F1 thanks for the info.

Now one question is RDO (letter O) or RD0 (zero number) that may be my mistake.

Thanks

It's a zero.

pitdogg2

Unfortunately I was told when i ordered my RD-0198's once all the 194/198's were gone there'd be no more ordered by Polk....
Damn shame

F1nut

I'm sure it's because someone at Polk thinks as long as they support the original SDA's it will affect the sales of the new ones. Of course, they couldn't be more wrong.

My understanding is that Midwest is planning to have the tweeters made, so all hope is not lost.

Schurkey

F1nut wrote: »

I'm sure it's because someone at Polk thinks as long as they support the original SDA's it will affect the sales of the new ones. Of course, they couldn't be more wrong.

My understanding is that Midwest is planning to have the tweeters made, so all hope is not lost.

I'm betting Polk has figured out that the Chinese supplier can't maintain proper quality control, and they'd rather dump the RD0-series replacements than deal with the defects.

I'm not holding my breath on Midwest finding a better supplier. I bet they go right back to the same supplier that Polk dumped. But what do I know?

F1nut

Nope, that's not it.

Toolfan66

pitdogg2 wrote: »

Unfortunately I was told when i ordered my RD-0198's once all the 194/198's were gone there'd be no more ordered by Polk....
Damn shame

F1nut wrote: »

I'm sure it's because someone at Polk thinks as long as they support the original SDA's it will affect the sales of the new ones. Of course, they couldn't be more wrong.

My understanding is that Midwest is planning to have the tweeters made, so all hope is not lost.

Shame, they couldn't be more wrong in my house, hope the quality is the same it was years ago or better with Midwest, guess I should have ordered a few extra a few years ago..

Irrenhaus

Okay order has been done for the RD0-194.
Will be here in a few days.

Gerres26

I guess I better hold onto my couple spare 198's that have broken tabs and repair them for a rainy day