Polk Audio SDA CRS+ Mods...

F1nut

Vr3MxStyler2k3 wrote: »

I actually asked a member about that and he said it was not a necessary upgrade.

You didn't ask me. Having done the crossover upgrades and using the RDO194-1's, then doing the TL upgrade I can say without any doubt that the TL upgrade puts them into another league.

Wouldnt we get a better signal just soldering them directly to the board??

What Tony said.

VR3

I will look into the 4.1tl mod

evhudsons

Wow, I am getting great info here! I bought my crs+ new in the Navy around 1989, and they have survived everything I've gone through, my pride and joy. The other day one fell off the speaker stand, and both magnets separated. I put them back thinking it was OK, but as you know they are not. Is it possible to send them somewhere to be fixed? I got two 6503's on eBay to get them working in an emergency, and in doing so found this forum and learned of the tweeter upgrade to the rdo194's
My wife hated my speakers due to the look, veneer coming loose, aged and faded screen, but I will never cave in. They have outlasted girlfriends, dogs, another wife, and plenty of drunk friends. After my RDO194 upgrade, the wife was blown away, and I mean it was a complete 180! She and her dad have owned multi-thousand dollar speakers, and she said mine now sound better than any she's had or heard.
So the reason I am posting here, is it is my first post ever, and I was looking to upgrade the look of my speakers as the veneer and screen cover need it. It isn't awful, but I want to make it really nice, it's been over 20 years. I found the screen material on partsexpress, but want to figure out if it is easier to re-veneer, or go with the just wood, and maybe a stain.

two questions I have though even though the thread is wrong,

I had a mw6511 and a mw6510 driver in one speaker. How important was that as opposed to having to replacement mw6503's? Obviously they are different and for a reason. My other speaker is still stock for the drivers. The tweeter upgrade was mind boggling to say the least, waaaayyyyy more than I ever anticipated, so I don't know if it is worth hunting down stock drivers or stick with two questionable replacements that weren't there to begin with.

And on the same note, if the upgrade to the rdo194's was so massive for me, is it still worth it to go to the trouble of soldering the crossovers and upgrading to the rdo198's? I think it was called the tl upgrade.

and....I also just want to say everyone, now I know I'm not alone in the world personally owning and enjoying my sda crs experience. I didn't know anyone even still had these. I can still put on an old jazz record and just close my eyes and hear the band playing throughout the whole stage. For any newbies, call polk now, get the replacement tweeters, you don't need to do anything other than use a screwdriver, and your speakers will explode with life it already had but didn't know. Now I'm pulling out everything to listen to again like I've never heard it before!

I do have the interconnect cord, not the original stands, but I have a massive subwoofer powered by it's own big receiver, and gets the signal from the subwoofer out from my main avr, so bass from the sda crs is no issue at all.

thanks, and any ideas on the veneer vs wood stain would be vastly appreciated!

VR3

Glad you are digging them.

If you want to bring them back up to speed..

I recommend doing the crossovers, dynamat, new seals, no-rez on the interior.

Now putting a new veneer on it is up to you definitely worth it if you plan to keep them for that much longer!

evhudsons

I plan on keeping them until I can't hear anymore.

so,...what is dynamat, how/where new seals, and what is no-rez?

Someone posted a link to a real wood veneer, I might do that if I can put it over the old veneer. I think I'll glue for now the little pieces on the corners coming loose, and then polishing the present veneer, and see how it looks after I replace the grill cloth.

F1nut

You should never apply new veneer over old.

Oldfatdogs

Here is a link from another member that did his monitor 10s. http://www.polkaudio.com/forums/showthread.php?t=61901&highlight=veneering+monitor To give you a idea.

evhudsons

Great link!
I'll hold off major changes until I am better skilled and have more time for the veneer. I really don't want to screw it up. I have an older crap speaker that I will test first to even see if I want to go that route. Is the veneer just vinyl? I always thought it was wood and used lemon oil over the years to shine them up, but in looking up veneer see there are two types. If it is wood, I'll stick to the lemon oil, but if it is vinyl, should I just polish and wax it?

nspindel

Glad you're still so enthralled with your CRS+'s, evhudsons. Sounds like you bought yours right around the same time I bought mine. My CRS+'s were a birthday present to myself, on October 3, 1989. I had them up until around 2004, when I purchased a pair of SDA-2B's close to home and sold the CRS+'s. A several years later I upgraded again from 2B's to 1C's, which is what I'm using right now. I also know that I'll be downsizing homes in a few years, so I've gone full circle and purchased another pair of CRS+'s that will eventually replace the 1C's in a few years.

You'll find that you are in good company here. There are many of us who have been using SDA's for over 20 years, like yourself. There are others on here who have found their way to SDA's more recently, after discovering their reputation on this forum.

Either way, you'll be quite surprised when you start reading about all the tweaks and mods people have discovered and applied to these speakers. Just about every modification is well documented in these threads, with photographs and step by step instructions.

The easiest modification, by far, is swapping the old SL-2000 tweeter for a new RDO-194. As you've already seen, replacing the tweeter with the newer silk-domes is such a great change because it eliminates the annoying frequency spike that the older plastic-domed tweeters suffered from.

There are a lot more adjustments to make, all of which I plan on doing to my new CRS+'s. Let me itemize these for you, so you can research each of these changes on the forum:

1) New wood veneer - As you've already seen, you can use a heat gun to remove the stock vinyl and replace with wood veneer of your choice. There are numerous threads where people have done this work with great success.

2) Crossover rebuild - The stock crossovers are now over 20 years old, generally past the recommended lifespan of the electronic components used in the circuitry. Newer, higher quality components can be used to replace the original electronics, which will greatly improve depth, detail, soundstage, and overall tonality of the speakers. The four main aspects of rebuilding the crossover are replacing the capacitors, removing the bypass capacitors, replacing the resistors, and removing the polyswitch.

3) Crossover board replacement - One of our members, gimpod, has designed replacement circuit boards for the stock crossovers. So instead of simply replacing certain electronics on the original board, you would use a completely new board, replace the electronics as described in 2), but also move any remaining electronics from the old board to Tony's and mount the board in the cabinet. You'll find that a lot of the newer components are considerably larger than the original electronics, and mounting them on the stock circuit boards can be difficult. Tony's new boards are designed from scratch to handle the larger modern components, and are quite nice to work with.

4) Inductor replacement - One of the more debated topics on the forums is whether or not to replace the large coils that your CRS+ crossovers are mounted on. There is a statement from Matthew Polk confirming that the original coils have a relatively high DC resistance that was used to compensate for current limitations in the amps that were common when these speakers were designed. Modern amplifiers shouldn't have the same current limitations, and using a lower DCR inductor in place of the stock one has been found to increase bass depth and slam. I have personally done this mod and am quite happy with it.

4) The "TL" mod. The addition of a 5.8uf capacitor in the crossover circuit would allow you to use the RD0198 tweeter instead of the RD0194 tweeter. Most around here agree that the 198 is a better tweeter, and if your crossover is condusive to the upgrade (yours is) then it is worthwhile.

5) Dynamat - Commonly used for sound dampening in automotive applications, you can use Dynamat (Dynamat Extreme is recommended) to eliminate resonance in the driver and passive radiator baskets, which has been found to provide better bass focus and all around sonic improvements.

6) Rings - Larry (TOOLFORLIFEFAN) has access to some amazing machinery and has created metal rings that you can mount from the inside of the cabinets, and allow you to attach the drivers and the passive radiator much more securely than you can simply by using the stock method of wood screws into to the cabinet. The more secure fit of the rings has been found to tighten up bass and improve sound stage.

7) New seals - The drivers, tweeters, and passive radiator have a thin layer of foam that sits between them and the cabinet, intended to compress into an airtight seal. Many have replaced these with various products, the best of which (or even the overall necessity to do the mod in the first place) is still a somewhat debated topic. Two items already being used and debated are Armaflex and Mortite. I intend to test both of these myself.

8) JB Weld - as you've already discovered, the magnets can shift, ruining the driver. People are using JBWeld on the drivers to ensure that this doesn't happen.

9) Speaker binding post replacement - Pretty self explanatory, often considered jewelry for your speakers, but many of us like it. Not suggesting you'll get huge sonic benefits from this mod, though.

10) A custom SDA cable - The pin/blade connector can be replaced with a single speaker binding post, and then you can use the speaker wire of your choice to replace the stock pin/blade SDA cable. You'll get a much improved SDA signal between the speakers, which will greatly improve soundstage and imaging. A very worthwhile mod.

11) New grill cloth - also self explanatory, and sounds like something you're already intending to do.

Welcome to the forums, always great seeing more people like yourself on here - long-time dedicated Polk/SDA enthusiasts who are just now discovering that the speakers you already love are capable of much, much more than you thought, even after owning them for over 20 years.

Stick around, do some research, gather the courage to do these mods, and take your listening to a whole new level!

F1nut

evhudsons wrote: »

Is the veneer just vinyl? I always thought it was wood and used lemon oil over the years to shine them up, but in looking up veneer see there are two types. If it is wood, I'll stick to the lemon oil, but if it is vinyl, should I just polish and wax it?

Some CRS+'s came with wood veneer, some came with vinyl laminate. Regardless, the use of lemon oil, polish or wax is not something that I recommend, especially not lemon oil. It is nothing more than mineral oil with lemon scent added. Not much different than wiping your speakers/furniture down with motor oil.

evhudsons

Thanks everyone! This is exactly what I have been looking for in advice. I will begin the exciting project of bringing my speakers back to life. I had not heard of the internet cable upgrade, and will try that before doing anything internal.
After that I think I will try the crossover mods, sometime in the summer when I am less busy. My wife thought I was crazy to care so much for the speakers. I would kindly but firmly scold her for using them as a shelf, leaving remotes etc on them, and she would always point out that they were old, good but outdated. Now after the tweeter upgrade, she is fully converted. She sat with me on the couch in the sweet spot in the dark and she finally understood my love for the speakers.

what do you recommend for cleaning the speakers? They don't have stains or anything, but they seem to be in need of a major clean/buff or something.

Thanks new friends!

nspindel

Specifically with respect to the veneer work, have a look at this thread of mine from a few months back, where I'm soliciting advice to re-veneer my CRS+'s. There are a few links to other threads, which you should check out:

http://www.polkaudio.com/forums/showthread.php?t=118499

nspindel

Sorry.... Internet cable???

audiocr381ve

nspindel wrote: »

Sorry.... Internet cable???

lol, yes now the speakers can stream internet radio!

evhudsons, cool story! After doing the most important of upgrades to my SDA 2B's, my wife still doesn't appreciate the sound. It seems I can't impress her with any gear. I do have a new system almost completed that I think will finally tip the scale.

Nspindel, if I don't end up selling the speakers I'm going to try the inductor replacement. The bass has much improved after all of the mods and burn in but I still use tone control to turn up the bass 3, even 4 notches on my receiver - even after playing with positioning for hours.

nspindel

audiocr381ve wrote: »

lol, yes now the speakers can stream internet radio!

evhudsons, cool story! After doing the most important of upgrades to my SDA 2B's, my wife still doesn't appreciate the sound. It seems I can't impress her with any gear. I do have a new system almost completed that I think will finally tip the scale.

Nspindel, if I don't end up selling the speakers I'm going to try the inductor replacement. The bass has much improved after all of the mods and burn in but I still use tone control to turn up the bass 3, even 4 notches on my receiver - even after playing with positioning for hours.

So let me get this straight. You keep the bass turned up 3 or 4 notches, but you're considering selling your speakers because your neighbor is complaining about the bass. But if you can't sell them, you're going to swap the inductors so that you have better bass.

Are you starting to understand why a lot of people find your posts to be bordering on the insane?

sda2mike

QUOTE from audiocr381ve

'I can't impress her with any gear'

his trroubles go much deeper than audio gear...sad case, really

nspindel

Actually, sorry. You're not considering selling your speakers. They're most definitely for sale, and you lowered your price three times in under 48 hours of listing them.

heiney9

nspindel wrote: »

So let me get this straight. You keep the bass turned up 3 or 4 notches, but you're considering selling your speakers because your neighbor is complaining about the bass. But if you can't sell them, you're going to swap the inductors so that you have better bass.

Are you starting to understand why a lot of people find your posts to be bordering on the insane?

What he said ^^^. Tone controls are evil. In this case your neighbor's incessant complaining about bass and all the time you neglect to tell us you have the bass control turned up? :rolleyes:. The speakers are corner loaded as well, no wonder it sounds so terrible.

You think Paradigm bookies and an Emotiva amp is going to tip the scale? You don't get any nookie if you can't impress the wifey with your manly stereo? :rolleyes: Grow Up!!

You are a real trip audiocr8ve, a real trip.

H9

nspindel

evhudsons, where do you live? If you're in southern california you could save yourself an awful lot of work by buying audiocr381ve's 2B's. They wouldn't be bookshelf speakers, but the mods are already done!

audiocr381ve

Or maybe you're just the most over-analytical **** on earth.

I should clarify, since the incident, I DO NOT boost the bass. Obviously. You guys are great at twisting things for your own amusement.

About the upgrade, I have a 4 wheel drive truck that I don't take off roading everyday, but it's good to know I have it when I need it.

audiocr381ve

Ahhh, nevermind again. I let my mouth get the best of me.

VR3

Keep this crap out of my thread.

Thanks and bye!

Can the mods delete everything stupid in this thread?

evhudsons

ha ha, truly hilarious! And internet cable, I had to reread. Obviously posting during chaotic work hours sometimes disconnects the brain from the fingers. I'm not sure how I could think interconnect cable, and come out with internet cable.

I'm in Key West actually, or I might be interested in getting my friend to buy them.

Question for bass as that came up, a bypass filter on my avr can be set at 60, 80 or 100. I am running the subwoofer line from my main avr to the rca inputs on another receiver amp (single rca out split to two rca's). Would it be best to change the pass filter on my avr and to 60, 80 or 100? I don't need the bass for the crs speakers as the separate woofer which is ridiculously huge with it's own full amp will get the entire neighborhood bringing in their lawn furniture when I play a thunderstorm track. They are two 12 inch 4ohm heavy woofers in an ported bandpass box as big as they get, and the amp is a full on pioneer which really does it's one job well, cranking the bass. I have to make sure it isn't cranked too loud, but it even would make bass heads happy listening to classical music. It used to be in my 1974 vw camper van. I used it as a seat, and my car subwoofer. In Tallahassee at a local hangout lake (Lake Bradford), I would play the thunderstorm CD to make everyone thing a storm was coming in, and then my friends and our girlfriends would have the whole lake to ourselves. So it would be better for me to have less bass in the CRS I would think.

nspindel

I suppose for HT uses, where there's a separate subwoofer track in 7.1, a sub is kind of mandatory. My SDA's are in a 2-channel system. No sub at all. SDA's have more than enough beautiful bass on their own. I've had people on this forum listen to my setup and were looking around the room to see where I was hiding the subwoofer. Alas, there wasn't one to be found.

But that's me, ymmv.

heiney9

With my 1C's I've had people ask me all kinds of questions; 1) were did you hide the sub? 2) I don't see your center channel? How do you get such a solid, deep center image? 3) where do you hide your surround speakers? 4) what kind of dolby processor setting are you using to get such a full sound?

In all cases people are floored it's coming from (2) front firing speakers. The obvious next question is, where can I get those for myself? Only to be greeted with a sour face when I explain they have been OOP since the early 90's.

I then explain the modifications to the tweeters and x-overs and how important set-up is and then I explain how good my gear is to make them perform in the best possible way.

H9

nspindel

heiney9 wrote: »

With my 1C's I've had people ask me all kinds of questions; 1) were did you hide the sub? 2) I don't see your center channel? How do you get such a solid, deep center image? 3) where do you hide your surround speakers? 4) what kind of dolby processor setting are you using to get such a full sound?

In all cases people are floored it's coming from (2) front firing speakers. The obvious next question is, where can I get those for myself? Only to be greeted with a sour face when I explain they have been OOP since the early 90's.

I then explain the modifications to the tweeters and x-overs and how important set-up is and then I explain how good my gear is to make them perform in the best possible way.

H9

The man knoweth what he talketh of...

VR3

Alright!

One crossover is modded - these are actually going to a forum member - he is sending me his crossovers and I am sending these out.

12 hours turn around time baby! YEAH!!

VR3

Pics would help eh?

Oldfatdogs

You have been a busy man, nice work.Do you get any sleep?

gimpod

Vr3MxStyler2k3 wrote: »

Alright!

One crossover is modded - these are actually going to a forum member - he is sending me his crossovers and I am sending these out.

12 hours turn around time baby! YEAH!!

Please don't take this the wrong way but.

!! Danger Will Robinson Danger !!

I see 2 problems here.

1. You replaced C4 (750pf by-pass cap) with a jumper BIG NO NO, by doing so you've by-passed C3 (12mF cap). Get that jumper out of there and leave C4 blank.

2. You've run one end of the 40mF cap (2 20's pigged backed) through the middle of an air core inductor also not a good idea. I know it's in a shunt configuration but it could cause problems.

Hope you haven't shipped these yet. Just a friendly heads-up