SDA-2B Consensus on Modifying the Crossover's

Toolfan66

Maybe it's best you just leave them stock. Your tag name audiocr381ve (audiocreative) don't fit this thread..


Just saying...

On3s&Z3r0s

audiocr381ve wrote: »

The TL mod is what Gimpod listed for parts right?

If you want to keep the tweeters you've currently got, you'd buy everything in the parts list except the 5.8uF caps. If you want to do the TL mod, you buy the 5.8's and a new pair of tweeters from Polk customer service. 5.8uF is not a standard value, so you can go with 5.6uF (I actually used a pair of 6.0uF), or if you buy Sonicaps from soniccraft.com and talk to the right people (Jeff? Elliott?) they will make custom value 5.8uF caps for you.

As for the rest of it, you definitely shouldn't take it personally even if it gets personal.

heiney9

audiocr381ve wrote: »

The TL mod is what Gimpod listed for parts right?

Refreshing, modifying, tomatoes, tamotoes. Again, just because Polk approved it doesn't mean it sounds better to me. I'm not sitting on the fence here trying to see who liked and who didn't. I'm actually going to do it, and play it safe. Am I not making that clear? I'll trust your ears when my ears believe you...(attempt at being clever but it turned out being weird)

With your panache for taking it slow and letting *your* ears decide, why would you jump right to the TL mod? If your current concerns and methodology hold true you should just do a straight mod, listen and then make a 3rd board as well as getting another pair of tweeters and then do the TL mod. By then you'll have twice as much money in these than you could ever hope to get if you sold them, and then your ears will know for sure which of the 3 iterations you prefer.

H9

Joe08867

You are way over thinking this. It is an update of the original with higher quality parts.

The TL mod is an awesome sounding one. And worth the extra cost of new tweeters. I understand it may sound like snake oil but it isn't. It changes the speakers to more revealing more open and honest to the music being played through them.

If you want to save some coin, buying another set of crossovers to compare isn't the way to do it.

I do have a question. Where did you read all these mixed reviews. If you are talking about here the consensus would be easily 80-20 in favor of the update and mod probably closer to 90-10 in favor.

On3s&Z3r0s

Joe08867 wrote: »

I do have a question. Where did you read all these mixed reviews. If you are talking about here the consensus would be easily 80-20 in favor of the update and mod probably closer to 90-10 in favor.

I was wondering the same thing... I haven't ever seen it discussed anywhere besides CP. But by the same token I wonder how many have actually done the 2B TL mod as opposed to the CRS+ TL mod. It seems like more folks have done that one. I wonder how much "extrapolation" is going on from one model to the other.

heiney9

On3s&Z3r0s wrote: »

I was wondering the same thing... I haven't ever seen it discussed anywhere besides CP. But by the same token I wonder how many have actually done the 2B TL mod as opposed to the CRS+ TL mod. It seems like more folks have done that one. I wonder how much "extrapolation" is going on from one model to the other.

No extrapolation as the x-overs and drivers are identical in the late CRS + and late 2B's. Identical. I would also venture the 2B TL mod has been done more than the CRS + TL mod.

H9

P.s. People here sure know how to beat a dead horse..............to death

On3s&Z3r0s

heiney9 wrote: »

No extrapolation as the x-overs and drivers are identical in the late CRS + and late 2B's. Identical. I would also venture the 2B TL mod has been done more than the CRS + TL mod.

H9

P.s. People here sure know how to beat a dead horse..............to death

So the cabinet and PR don't make any difference to the bass presence of the speaker? C'mon.

You could be right about the numbers... it does seem the TL'd 2Bs show up for sale fairly often. Most of the in-depth reviews I've seen seem to have been from the CRS+ side, so that could be coloring my impression.

heiney9

On3s&Z3r0s wrote: »

So the cabinet and PR don't make any difference to the bass presence of the speaker? C'mon.

You were talking about extrapolating the x-over. I'm simply reiterating the x-over components and drivers are exactly the same in both speakers, the performance differs slightly obviously. That's what this thread is about, right? Modifying a crossover.

If you look at 2B's and later CRS+'s every part is identical, except the cabinets, but I thought that would be obvious after one look at both speakers.

H9

audiocr381ve

The gentlemen who sold me the speakers is a very intelligent man who designs and builds his own speakers. He's a ridiculously smart dude who has been around the block and couldn't have been more strenuous about communicating to me to keep the originals and build new ones in case the grass ins't greener on the other side. That coupled with me spending a lot of time and money upgrading parts in my DAC to no avail.

I don't want to sound like I'm over thinking this, because I'm absolutely not. Just playing it safe. What is the harm in keeping the old XO's? I also don't want to sound ungrateful for the help and support, because with out you guys I wouldn't think about touching the speakers. So again, thanks for the support.

To put it simply, and to beat my own dead horse, making new crossovers to keep the old ones seems to be about as easy as upgrading/refreshing/modifying the current board.

PS: I have the upgraded RDO-194's for those of you who might not have caught that.

On3s&Z3r0s

Ok, I guess I was unclear. We were talking about positive versus negative reviews. I was wondering how many people TL'd their CRS+ and said, "The TL mod sounds great!" referring to the application of the mod to the CRS+ and not having heard the mod on the 2B. Since the cabinet and PR always differ, any crossover upgrade will sound different between the two models (ignoring for the moment whether the TL mod, as opposed to just upgrading all stock caps and resistors, should sound different since it focuses on the high-end).

That was all I was saying. I know what the 2B TL sounds like and how stock 2B's sound different than modded ones, but I can't say the same for CRS+'s, and it goes both ways.

Also, not to pick nits, but the CRS+ and 2B's didn't all necessarily use the same drivers. Many of the CRS+'s used the MW6510 for their stereo mid and 2B's use the 6503.

dpowell

Once you upgrade the XO's, you won't want to go back. Plain and simple. Just give the new caps enough time to burn in.

heiney9

On3s&Z3r0s wrote: »

Also, not to pick nits, but the CRS+ and 2B's didn't all necessarily use the same drivers. Many of the CRS+'s used the MW6510 for their stereo mid and 2B's use the 6503.

JHC, I said late 2B's..........you don't need to school me on SDA's, I assure you! Anyway since this has become a mild pissing contest...I'm done here. It's a dead, mutilated, buried, beat down horse.

Good luck to everyone

H9

heiney9

dpowell wrote: »

Once you upgrade the XO's, you won't want to go back. Plain and simple. Just give the new caps enough time to burn in.

They already know everything, so save your breath. If they don't know everything the fine gentleman that sold him the SDA's does. Certainly those of us who have spent 20+ years, selling, listening, upgrading, talking to Polk engineers as well as Matt Polk himself (indepth about modern improvements) about SDA's don't know squat.

H9

On3s&Z3r0s

heiney9 wrote: »

They already know everything, so save your breath. If they don't know everything the fine gentleman that sold him the SDA's does. Certainly those of us who have spent 20+ years, selling, listening, upgrading, talking to Polk engineers as well as Matt Polk himself (indepth about modern improvements) about SDA's don't know squat.

H9

For chrissakes, it's Friday afternoon. Relax already. Your information would appear to disagree with Gimpod's (http://www.polkaudio.com/forums/showthread.php?t=118190). It sounds like the 2B's always used the 6503 and the later CRS+ used the 6510, contrary to your earlier assertion. The schematics back that up as well. That thread also suggests that Polk recommended the mod for use with the 6510 driver that the 2B's don't have.

I agree with you that a pissing match over what speakers had what drivers isn't really the point. The point is you seem to be suggesting that there aren't important differences between the models that would have a bearing on how they are affected by the TL mod. That just doesn't hold water.

It's a discussion worth having how the different models take to a given mod even if their stock crossovers are the same.

Toolfan66

The Crossovers in the CRS+ AND 2B's are the same, the tl mod is the same as well, I am on the path of tl'ing my CRS+ and a buddy I work with just got some 2B's and I am going to tl them as well..

On3s&Z3r0s

TOOLFORLIFEFAN wrote: »

The Crossovers in the CRS+ AND 2B's are the same, the tl mod is the same as well, I am on the path of tl'ing my CRS+ and a buddy I work with just got some 2B's and I am going to tl them as well..

I'd definitely be interested in hearing how they both turn out. And (seriously, not to make a big deal out of it, but just out of curiosity) which version of the CRS+ they are, since there were a few.

Have you done any previous to this, or are these your first ones using the 4.1 schematic?

TennMan

TOOLFORLIFEFAN wrote: »

The Crossovers in the CRS+ AND 2B's are the same, the tl mod is the same as well, I am on the path of tl'ing my CRS+ and a buddy I work with just got some 2B's and I am going to tl them as well..

Is the reason you TL them just so you can install the RDO-198 tweeter or is there some other reason as well? If it's just the tweeter is the 198 that much better than the 194? I'm just curious. I own 10Bs but hope to get some SDAs someday.

Face

audiocr381ve wrote: »

The gentlemen who sold me the speakers is a very intelligent man who designs and builds his own speakers. He's a ridiculously smart dude who has been around the block and couldn't have been more strenuous about communicating to me to keep the originals and build new ones in case the grass ins't greener on the other side. That coupled with me spending a lot of time and money upgrading parts in my DAC to no avail.

Recommending against replacing 20 year old electrolytic caps and replacing a tweeter with an improved design and lower distortion doesn't sound very intelligent to me.

Toolfan66

TennMan wrote: »

Is the reason you TL them just so you can install the RDO-198 tweeter or is there some other reason as well? If it's just the tweeter is the 198 that much better than the 194? I'm just curious. I own 10Bs but hope to get some SDAs someday.

Yes the 198's are better IMO, With that said I like the 194's as well, that is what I have in my 1C's.. I have 198's in my 1.2tl's and will have 198's in my CRS+'s

Toolfan66

On3s&Z3r0s wrote: »

I'd definitely be interested in hearing how they both turn out. And (seriously, not to make a big deal out of it, but just out of curiosity) which version of the CRS+ they are, since there were a few.

Have you done any previous to this, or are these your first ones using the 4.1 schematic?

They will turn out just fine, I did a 4.1tl mod on a set of 2B's about 2 months ago.. This mod is very well worth it...

My CRS+'s are from 1986 with a 2 piece crossover, but I found a set of 2B crossovers on eBay for $50 and will use them in these speakers for the 4.1tl upgrade. there is even a sticker on the crossovers that say 2B/CRS+, and yes I have the MW6511/MW6510 drivers to make this mod happen.. I just turned 1986 into 1989..

F1nut

The gentlemen who sold me the speakers is a very intelligent man who designs and builds his own speakers. He's a ridiculously smart dude who has been around the block and couldn't have been more strenuous about communicating to me to keep the originals and build new ones in case the grass ins't greener on the other side.

So smart that he didn't tell you that you can simply remove the new caps/resistors if you don't like the sound and put the old parts back in? Doesn't seem like a smart guy to me.

F1nut

On3s&Z3r0s wrote: »

For chrissakes, it's Friday afternoon. Relax already. Your information would appear to disagree with Gimpod's (http://www.polkaudio.com/forums/showthread.php?t=118190). It sounds like the 2B's always used the 6503 and the later CRS+ used the 6510, contrary to your earlier assertion. The schematics back that up as well. That thread also suggests that Polk recommended the mod for use with the 6510 driver that the 2B's don't have.

I agree with you that a pissing match over what speakers had what drivers isn't really the point. The point is you seem to be suggesting that there aren't important differences between the models that would have a bearing on how they are affected by the TL mod. That just doesn't hold water.

It's a discussion worth having how the different models take to a given mod even if their stock crossovers are the same.

The TL mod is for the tweeter circuit ONLY!

On3s&Z3r0s

Face wrote: »

Recommending against replacing 20 year old electrolytic caps and replacing a tweeter with an improved design and lower distortion doesn't sound very intelligent to me.

Yeah, but you have to grant that it's a question of marginal benefit. I've never seen a thread with such strong opinions on replacing the two paralleled 130uF electrolytics in the 2A's. Why not?

And I do understand (mentioned it in an earlier post) that the TL part of the crossover upgrade is separate from the overall crossover rebuild. I'm just trying to get a better handle on what most people mean when they make the sweeping statements about TL = greatness.

Face

The 2A's aren't as common.

I've rebuilt/modded more than a few vintage Polks. Some of the electrolytic caps I tested have drifted over 20%, that alone is good reason why they should be swapped out for film caps.

TL'd 2B's are my favorite SDA's, and I'm not the only one who feels this way.

FTGV

On3s&Z3r0s wrote: »

I've never seen a thread with such strong opinions on replacing the two paralleled 130uF electrolytics in the 2A's. Why not?

Maybe because they are IMO the least sonically critcal component as their purpose appears to be that of high filtering of the dimensional signal.

On3s&Z3r0s

All in all I totally agree that the mod is worth doing. The 2B's start out good, I'm sure better components on the crossover and 194's make them better, and TL mods (plus some other tweaks) are what it takes to make them as good as they can be. But I think the question about the big electrolytics in the 2A XO's and whether to swap out inductors, etc. points out that different mods are marginal and variable in their effect, and especially in the case of the inductors may make the speaker a different animal than Polk intended. It also makes sense wanting to keep a set of XO's stock or apply different mods to different XO's. DarqueKnight does as much with his several pairs of CRS+ when he tries out mods against each other. I'm sure everyone wishes they could have their own SDA tweak test lab.

jcandy

There are two fundamental reasons for wanting to keep the stock crossover in my opinion: (1) so that you'll have a 100% stock crossover for posterity, (2) so that you'll have a fully-intact reference crossover. If you have skill and measurement equipment, the potential improvements to the crossover (with the RD0-194) are much more extensive than simply upgrading caps. For example, the response irregularity in the 2kHz region might be improved by going to LR4. Depending on the reflectivity of your room, different values of the tweeter series resistance, for example, will be optimal.

FTGV

jcandy wrote: »

For example, the response irregularity in the 2kHz region might be improved by going to LR4.

If I owned a pair improving the axial response would be something I would want to pursue since having linear on axis response is arguably the most important trait in a good loudspeaker.

jcandy

FTGV wrote: »

If I owned a pair improving the axial response would be something I would want to pursue since having linear on axis response is arguably the most important trait in a good loudspeaker.

Its not even arguable, its a fact. I drove to LA earlier this week to listen to this lecture:

http://seanolive.blogspot.com/

He reported on extensive listening tests conducted at Harman International (on trained listeners and untrained listeners from different countries). On-axis (or, "first arrival" as he called it) FR was by far the single most important characteristic in overall ranking of the quality of a loudspeaker in BLIND testing. He also had some very bad things to say about "audio reviewers", who performed worse than audio retailers on listening tests. He showed extremely precise FR measurements of numerous high-end loudspeakers, including a certain $11,000 electrostatic loudspeaker that was a favorite in audio reviews but consistently rated terrible in blind listening (worse than a $600 Infinity floorstander). Of the speakers he showed, you could basically predict how well it would score in blind testing just by looking at the on-axis FR. I was surprised how little he discussed distortion, but it was mentioned that fatigue due to distortion takes hours to set it.

audiocr381ve

jcandy wrote: »

There are two fundamental reasons for wanting to keep the stock crossover in my opinion: (1) so that you'll have a 100% stock crossover for posterity, (2) so that you'll have a fully-intact reference crossover. If you have skill and measurement equipment, the potential improvements to the crossover (with the RD0-194) are much more extensive than simply upgrading caps. For example, the response irregularity in the 2kHz region might be improved by going to LR4. Depending on the reflectivity of your room, different values of the tweeter series resistance, for example, will be optimal.

To points 1 & 2, exactly. If I had such articulation I would have said it that way!