I Got a free set of Polk SDA-1C's

DangerDad

I was these speakers tucked away in the corners of my uncles house and drooled over them every time I was there. He gave them to me because he knows that I would truly appreciate them. I got them home not knowing anything more than they were older Polks and if nothing else they would make good shop speakers! Having done some homework on them I found out they are they are pretty desirable speakers. So I hooked them up to see if I had any blown drivers and wow... They sound great for something from the late 80's! I was wondering what difference the tweeter upgrades make and how much are they. What other best bang for the buck upgrades are there that would make these speakers sound even better for more years to come?

You can see how big they are next to my TriTrix mtm TL's!


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ken brydson

Welcome to Club Polk. Check your wallet at the door

Nice speaks, enjoy the ride...

MrBuhl

If you use the search function, you will find many many threads and upgrades. 1c's are fine speakers but IMO amazing speakers with upgrades.

On the low end (cheap side)
Spike them
Dynamat the drivers
Remount drivers with hurricane nuts
Replace any bad gaskets with armacell
Locktite the magnets on your woofers
Locktite the cabinets for a good seal/reinforcement
Move the batting back where it belongs and staple (wouldn't do that till you decide crossovers)
Use a more transparent grill cloth

On the Medium side
Add Blackhole 5 or NoRez behind the woofers
Change binding posts to higher quality versions
Upgrade SDA cable to better quality with SpeakOn connectors

On the high end
Upgrade the SL2000's to RDO-194's
Upgrade the crossovers
Build or buy a dreadnaught

There are a myriad of threads here to describe all of the above, but I think that gives you a general lay of the land. Good luck, enjoy, you just got one heck of a giveaway!

Moose68Bash

DangerDad,

Welcome to Club Polk, and hearty congratulations on a wonderful "find" and gift from a very good uncle.

I bought a pair of 1Cs new in 1989 and have done just about all the modification to them that are done by the guys on this Forum.

You can read about it in the following discussion, if you are interested:

http://forum.polkaudio.com/discussion/147471/now-i-have-the-mods-completed-on-my-1cs#latest

I hope you have the SDA interconnect cable that came stock with the speakers. If not, you should immediately either fabricate one or purchase one. You will not get the best out of your vintage gems without the SDA effect, and you don't get it without the interconnect. If you want to take this to the next level, you can build a Dreadnought to insert in the SDA circuit to further improve the effect.

In my opinion, the first modification you should make is to install the RD0-194-1 tweeters that can be purchased from Polk. They are discounted for Club Polk members when you identify yourself.

Many of the mods on these speakers can be done by anybody who is reasonable capable with simple tools -- in which category I place myself. You should definitely protect your drivers from magnet shift by applying JB Weld or a similar product to the magnets on the drivers, and you can improve the sound quality by applying Dynamat Xtreme to the metal baskets on the drivers and passive radiator. Black Hole 5 or a similar product applied to the inside of the cabinets will also reduce resonance and improve sound quality. Several discussion on the Forum deal with these topics.

If you have the wherewithal to install spikes on the speakers, this mod will improve your bass noticeably.

If you are handy with a soldering iron and electronics "repair," there is a lot you can do by upgrading your crossovers with a Gimpod circuit board, modern capacitors, resistors, inductors and wiring. Vr3Mods can also do this work for you with outstanding results. Trey -- dba Vr3 Mods -- has done four sets of crossovers for me. His work is superb, and he is reasonably "priced" and will work with you to fit your budget.

Again, welcome to Club Polk. The guys on this Forum have virtually infinite wisdom and experience about vintage Polks and are very generous with their know how.

Oh, by the way, the rabbit hole awaits thee, my friend!

DangerDad

Thanks MrBuhl! I will be doing all the low cost upgrades for sure! Im very good at soldering and was hoping to upgrade the crossovers but i'm not sure what to order and where to put them...any pictures would help a lot!

DangerDad

Yes I have the SDA interconnect cable that came stock with the speakers. Is it true that they play the outer drivers out of phase? Seems to go against everything I've learned...

MrBuhl

DangerDad wrote: »

Thanks MrBuhl! I will be doing all the low cost upgrades for sure! Im very good at soldering and was hoping to upgrade the crossovers but i'm not sure what to order and where to put them...any pictures would help a lot!

If you're handy with an iron - there are lots of more senior members who can help you out here - plus some great threads describing the options - I had another member Westmassguy do mine because I'm not so talented! The Crossovers will make a big difference, as long as they are opened up for the other upgrades, I'd do those at the same time.

F1nut

SDA's don't like being close to things like side walls, which is exactly what you have with those other speakers, so get rid of them if you want to experience what SDA has to offer. Next, add spikes and not the cheap steel ones.

Nightfall

Am I blind? I don't see an amp, receiver, nothing?

DangerDad

Space is hard to come by in my house...I will only have one of these towers in this room. But for a side by side comparison this will have to do...I will be pulling the SDA's apart here soon to give them some TLC but as of right now they are growing on me in a big way! I kinda feel like I should offer to pay for them...

DangerDad

Its under the center channel...Its just a Pioneer VSX-520 for now, but I will be upgrading that and putting it out in the shop.

cnh

Welcome the the Polk "vanilla" forums; what about "chocolate" you say? Ask Polk! lol

Be careful with that Pioneer, it can F-up your speakers if you push it at all and it will do it instantaneously! A 520 can't put out much power to begin with and only to 8 ohm speakers that are relatively efficient. I have some of the Andrew Jones bookies and the center on a 7XX series in my basement and I have to crank that up, carefully?

You REALLY need some quality amplification for those. Stick around, lots of suggestions. And yes, the walls are a B.! SDAs do not like rooms that don't have at least 14' of continuous uninterrupted wall space on one side.

FREE is GOOD!

Enjoy!

DangerDad

My amp spec's say its guaranteed for 6-16 ohm's but at 6 ohms they might only put out 100wpc. I only run this in a 2.1 so hopefully I can get by for now. but if you think im going to F-up these vintage towers I will keep it on the low...not that I have a choice with a wife and two little girls in the house!

DangerDad

Thanks! I'm stoked that I finally have a nice set of vintage audio! All my friends can suck-it you can't have these! So what amp would be better for a good 2.1 system? these are 6ohm 50-500 watts but I don't need really any more that 300w I don't think...!?

Nightfall

You'd have to get a receiver with preouts or a pre/pro in order to use a real amp. One of the Pioneer SC's is about the cheapest viable route that has decent power. Upper echelon of Yamaha Aventage have decent (but not a lot) power too, my RX-A1020 was bench tested at 155 x 2.

If you really want to get into mid-fi, the Parasound Halo Integrated looks quite nice.

DangerDad

Mid-fi...haha! Im just getting into this home audio thing and I don't want to hurt these speakers!...Im looking for a solid setup not crazy exotic but worthy of my speakers.

Nightfall

If you're not cranking it loud you aren't going to hurt them with your current receiver. Especially with an old polyswitch that probably trips before it should.

I played my speakers, which are 4 ohm and less in cases, on a Yamaha RX-V667 and never popped a fuse, and that AVR was gutless.

F1nut

My amp spec's say its guaranteed for 6-16 ohm's but at 6 ohms they might only put out 100wpc. I only run this in a 2.1

You've got to get your terminology correct. It's not an amp, it's an AVR. I see it lists for $229.00, weighs 20lbs. and is rated at 80 watts, one channel driven. So, maybe 50 wpc, 2 channels driven. Don't crank it with the SDA's.

DangerDad

I can learn....been doing it the hard way all my life!

comfortablycurt

A free set of SDA 1Cs? Nice! That's a hell of a score.

As others have pointed out, you're going to want to be careful with the volume knob on your receiver. Receivers in that type of price range are typically designed to drive smaller speakers that are less power hungry and tend to run at 8 ohms. It'll be fine driving them at low to moderate volumes though. Just make sure you monitor the receiver to make sure it isn't getting too hot.

F1nut

DangerDad wrote: »

I can learn....been doing it the hard way all my life!

Good response, I like you.

westmassguy

Welcome to CP, and the Rabbit Hole. Would you Uncle consider adopting a 58 year old Nephew?

drumminman

Congrats on your free speaks DD. You'll be amazed at the sound quality improvement after doing the mods described above.

[Deleted User]

welcome and nice speakers. U Lucky!

leftwinger57

Welcome to CP. Getting speakers gifted always better than paying for them. 1Cs look a bit more beefy for lack of a better word than my 2Bs with the double tweeters and double drivers. Dave could compare them to me. About the mods, since your way ahead of the game getting them for free then yes mods are in order and they do work. Stay focused, some say do it piecemeal and I have to disagree. I only wanted to take them apart the minimal amount of times so if you plan on doing mods, have all your parts, tools and time ready to go. Ask along the way many here will help and be glad to do so. Very nice gift, and believe me not all of us have that optimal room for every speaker and their best positioning. As told before SDAs like real power between 100/200 wpc of stand alone amplifier NOT avr ratings.

erniejade

If you do get an amp, please make sure its a common ground amp.

DangerDad

Can anybody shoot me a link or website to shop for a good amp for these? What should I look for other than a common ground amp and watts?

Nightfall

You need an AVR with preouts or a preamp to use a stand alone amp.

DangerDad

My current amp has a Preouts for surround back or front height speakers...Im guessing this isn't what I need right?

Nightfall

You don't have an amp, you have an AVR. You are correct, that isn't what you need.

DangerDad

Nightfall...Would you run these SDA's off your RX-A1020 AVR?