4.1TL Modification for 1989 version SDA CRS+

F1nut

Sal, no I woudn't say the RD0194-1 has less detail. I can only say that in my CRS+'s that the vocals seemed to be somewhat recessed, yet they are definitely better than the SL2000. As the 1C's use a different crossover I can't say how they sound in them, but just about everyone that has made the change loves the way the new tweeters sound.

F1nut

The discounted Club Polk price is $48.00 each. Be sure to mention that you are a CP member and shipping is free. You can put your SL2000's up for sale to recoup some of the money.

Stew

F1 and DarqueKnight - Did you notice any overall change in the brightness of the CRS+'s with the RD0198-1 vs. the RD0194-1?

DarqueKnight

I didn't.

F1nut

Neither of the two are as bright as the SL2000. However, as stated before, I do prefer the overall sound of the RD0198-1.

Stew

This sounds tempting. Anyone thinking of trying the TL mod on 2B's or 1C's?

Stew

I found an old thread last night that compared the sound of the original SDA SRS to the 1.2TL. This thread indicated that the SRS had more mid bass punch and the 1.2TL had more low bass. Some liked one better, some liked the other. Has anyone noticed a change in the Mid Bass vs. Low Bass after upgrading the CRS+ to the TL version and if so, what are your impressions?

Zap Rowsdower

Stew,

I found that both mid bass and low bass improved after performing the 4.1TL mod.

Stew

Thanks to all for the info. I may have to try this when I have some time. Anyone have an estimate on the going rate for used RD0194-1's and SL2000's?

Stew

I'm still pondering the idea of an SDA 2B-TL. I noticed that the crs+ has an efficiency of 92 db vs. 89.7 for the 2B. My assumption is that less energy goes into the smaller volume of the CRS+, therefore the mids are more efficient. The tweeters should have the same efficiency though. If this is correct, the 2b should sound brighter than the CRS+. Has anyone compared the two and noticed this difference? If the 2B does sound brighter, I'm wondering if the RD0198-1 (with added capacitor) would be too much. Any thoughts?

DarqueKnight

I owned both the 2B and CRS+ a few years ago. I did not notice a difference in tweeter brightness between the two. The main difference I heard was more bass impact and extension with the 2B. From the upper midrange to the treble, I could not distinguish between the two.

F1nut

Also note that the CRS+ is rated at 89.5dB, not 92dB. Like DarqueKnight, I've never noticed a difference in the highs/mids between the two models, only the bass response.

dorokusai

Isn't the efficiency equally dependent on the power provided? Thus, a variable?

Stew

dorokusai wrote:

Isn't the efficiency equally dependent on the power provided? Thus, a variable?

Speaker efficiency or sensitivity is usually listed as db at one watt at one meter. Every time you double the power you add 3 db. SPL also falls off with distance but I'm not sure how much. I think I've seen estimates of 3 db/meter for a typical speaker but not sure on that one.

Stew

F1nut wrote:

Also note that the CRS+ is rated at 89.5dB, not 92dB.

Well, it sounded like a good theory:p Shoots the heck out of that one - but that's a good thing! Now I have no excuse except for the $100. I just spent $400 on a used NAD C370 so it may be a month or two before I get around to this. If no one beats me to it, though, I'll create the world's first pair of SDA 2B-TL's! Thanks to all for the idea and the info. I'll keep everyone posted.

Stew

I just ordered a pair of 5.8 uF Sonicap Gen I's. Their website only shows 5.6 and 6.2 uF but I read on another post that they will provide custom values. They checked their inventory and said no problem. No additional cost either.

I previously did the crossover upgrade with Solens for the lowpass (20 uF and 39 uF) and Sonicaps for the high pass (12 uF Gen I with 0.1 uF Gen II bypass). I'm planning to take F1's advice and remove the bypass unless someone convinces me otherwise in the meantime.

Now I just need some RD0198-1's.

P.S. Does anyone have a .pdf of the CRS+ crossover schematic that shows this mod? If so, I would appreciate it if you could email it to me. I have the same crossover schematic for the 2B but it doesn't show the 4.1TL mod. It's simple enough without it but it would be nice to have.

F1nut

Stew, PM me your email addy.

schwarcw

Good luck Stew! Good to see you posting! Let us know how your project turns out!

Stew

Thanks Carl! Looks like you've been having fun with some projects. I'm looking forward to this one.

Thanks for the schematic F1!

Stew

Ordered the RD0198-1's on Monday. Arrived Wednesday. Polk CS Rocks! Caps should be here today.

schwarcw

You'll like the Sonicaps! I've got wood for the Silver Oil Mundorf's. I'm looking for a project to use them.

nspindel

DarqueKnight wrote: »

Cabinet refinishing: $175.
Crossover capacitors and resistors: $208.
Three pairs of Cardas CCGR-S binding posts: $96.
RD0198-1 tweeters: $96.
Custom SDA interconnect cable: $107.
Grille cloth: $5.

Total modifications/upgrades: $687.
Increase in aural satisfaction: Priceless.

Hi DarqueNight, thank you for all the valuable information - I'm about to start the same upgrade to my 2B's. I was curious about your custom interconnect cable. I notice it's only a single conductor, whereas the original pin/blade is dual conductor. Are you still using the original cable for the second conductor?

Also wondering how much of an improvement you saw from this aspect of the upgrade. The cable plus the binding posts cost you about $140. Would you consider this aspect of your upgrade "worth it" (realizing of course that this is a tricky question to answer). So let me ask it another way - I'm using a stock Squeezebox as my source. Do you think I'd get better bang for the buck using that amount of money to make a custom interconnect, or to replace the stock power supply on the Squeezebox?

Thanks!

DarqueKnight

nspindel wrote: »

Hi DarqueNight, thank you for all the valuable information - I'm about to start the same upgrade to my 2B's. I was curious about your custom interconnect cable. I notice it's only a single conductor, whereas the original pin/blade is dual conductor. Are you still using the original cable for the second conductor?

The original pin/blade cable has both wires soldered to the pin. The blade is there to provide a stronger mechanical connection to the jack. With the blade/blade interconnect, both conductors carry a signal (unless it is used on an early version SDA 1C or SDA 2B, in which case only one pin carries a signal...confused?)

nspindel wrote: »

Also wondering how much of an improvement you saw from this aspect of the upgrade. The cable plus the binding posts cost you about $140. Would you consider this aspect of your upgrade "worth it" (realizing of course that this is a tricky question to answer). So let me ask it another way - I'm using a stock Squeezebox as my source. Do you think I'd get better bang for the buck using that amount of money to make a custom interconnect, or to replace the stock power supply on the Squeezebox?

I discussed the differences improved SDA inconnects made here.

I have replaced the binding posts on all of my SDA's and have never heard any sonic improvements from this upgrade. The better binding posts do provide a better mechanical connection and look a lot nicer.:)

I had never heard of a Squeezebox until you mentioned it. I had to look it up. Since I have no familiarity with this device I don't know if a power supply modification will have a desirable effect. Also, I don't know if you will realize any sonic benefit using a custon SDA interconnect with this source.

nspindel

Ah, I never realized the pin/blade was only a single conductor, I always thought it was two conductors.

Definitely have a look at the Squeezebox, if you've got a music library on the computer it is an AMAZING piece of gear. There's an audiophile version of it (***cough*** 6!!! ***cough*** times the price) called the Transporter. Check it out:

http://www.slimdevices.com

As for the power supply on it, they sell a great product with a $2 switching power supply. I haven't experimented with other psu's, but the slimdevices forums are full of people saying that a higher quality linear power supply has a dramatic improvement, so I've been considering this guy:

http://www.welbornelabs.com/squeeze.htm

Not all that different a price than the custom interconnect you built, therein the reason for my question.


Thanks for the great advice!

nspindel

Looking for some advice here - I have two cheapo soldering irons, neither of which works particularly well. I also have a Weller soldering gun, which works just great. Would the project I'm about to embark on be doable with a soldering gun as opposed to a point-tipped iron? Did a bunch of searches, and I'm seeing the Weller 60W soldering iron/station setups in the $100 range. I'm not planning on embarking down a major diy hobbyist route, so I'm not too keen on paying up so high for a soldering iron. Will my Weller gun be appropriate to use?

I've considered buying a good iron in the past, but I just don't have much use for it. The vast majority of the soldering that I've done in the past 15 years or so has been on the plumbing side, not electrical. Now I KNOW that my mapp gas blowtorch should be kept far away from my crossovers ;-)

DarqueKnight

I use either a 45W or 15W point tipped soldering iron, with a clip on heat sink between the component lead and the component, for board work. I have an 800W soldering gun that I have only used for soldering wire to Cardas binding posts, as the lower watt irons were inadequate for the job.

I would not use a gun for board level work because they are more difficult to handle in cramped quarters and, most importantly, the extra heat can burn the board, damage parts, and cause board traces to lift.

You should also use a good quality solder like Cardas Quad-Eutectic solder.

nspindel

Yep - I ordered the Cardis Quad solder along with the Sonicaps/Mills. Maybe I'll try replacing the tips on the cheapo irons I have and test them with some sacrificial parts from rat shack before I touch the real thing. If the gun will be too hot for the board, then blowtorch I use for the plumbing work is definitely out of the question ;-)

MillerLiteScott

I bought a soldering station from RS for like $20 something. It has a 20 watt and 40 watt setting. A spring like holder for the iron and a sponge to clean the tip off with. It works for me. They also have all the other accessories if you like to accessorize for your soldiering. I have yet to buy a lifetime supply expensive solder yet.

Scott

nspindel

Hmmm, think I'm going to stop off at the rat shack after work, there's one right on the way home. I can do $20...

schwarcw

The cheap pencil iron will work best. As Raife said it's close quarters in there and the Weller gun would be awkward to use. De soldering is the tough part. Good luck and take some pictures for us:D