Question on SDA 1

quadzilla

I found a set of SDA 1's within driving distance, but the guy doesn't know if they're 1s, 1Bs, 1Cs, etc. He said they use a pin-blade cable though, so does that equal 1C? Or when did polk start using pin-blade? Because if I can't TL these, I don't want them, so before I drive 4 hours, I'd like to try to figure that out. Or does SDA 1 printed on the back just mean the original SDA 1?

nwohlford

For 1C, my understanding is that first check for vertical aligned tweeters (1 and 1A have the horizontal aligned tweeters) and then they should also have a couple inches of wood on the front above the grills. On 1Bs, the grill covers go all the way to the top.

michaeljhsda2

Request a photo of the speakers from him and/or ask him how many tweeters and MW's there are.

quadzilla

The tweeters are vertically aligned. And there's a about an inch or so of wood above and below the grilles.

I'm looking at couple of pictures of them now. But that doesn't tell me much since I don't know the SDA line that well. Thus, I submit the question to the hive mind of the forums.

michaeljhsda2

Sounds like 1C's. The 1B's only have 1 tweeter IIRC. Are the endcaps oak?

quadzilla

That's what I'm thinking. These are the pics that I have. He said he would provide serial #s after he gets back to his house.

quadzilla

From looking at these pics, I'm going to say yes. I also just called the guy and told him I'm driving down. It sounds like I at least need to go see them. Hopefully there are no blown drivers.

heiney9

You can't TL 1C's, well someone has theoretically tried, but they can't be TL'd per the factory spec (4.1TL) like the CRS + and 2B pin/blade can.

Still, they are 1C's and if they are in good shape and reasonable, jump on them. TL is nice but I wouldn't fret about it if you can't do it.

H9

michaeljhsda2

quadzilla wrote: »

From looking at these pics, I'm going to say yes. I also just called the guy and told him I'm driving down. It sounds like I at least need to go see them. Hopefully there are no blown drivers.

Great speakers IMO. Go for it!

heiney9

What's the asking price?

bluecomet

heiney9 is right, you can't tl the 1c's but you can swap the tweets to rdo 194's which is a good upgrade on an already excellent speaker.

Schurkey

michaeljhsda2 wrote: »

Sounds like 1C's. The 1B's only have 1 tweeter IIRC.

Same driver count as 1Cs, although different MW drivers. Double, vertical tweeters.

Studio 1Cs even have the same cabinet design as the 1B. Typically black instead of the 1B's brown.

You're thinking of the SDA SRS 3.1TL--single tweeter. (Or the newer SDA 2s)

michaeljhsda2

Yep. I'm thinking of the 2B's.

quadzilla

Welp, if I can't TL'em, then I guess I wasted a trip and the cash. I've heard the RDO 194s, and while good, they just don't really even come close to the 198s to my ear. And at least I've got my TL'ed CRS+s.

Toolfan66

FWIW, I love the 1C's and could care less about not TL'ing them. sometimes I feel the TL is a bit overrated, DON'T GET ME WRONG!! they are fantastic and I have mad love for them but I have yet to hear an SDA I don't like,the original SDA SRS's,2B's,CRS+'s,2.3's,and of course the 1C's are all FANTASTIC SPEAKERS,and I get bothered when I see someone that want's to get their ears on a set of SDA's and they pass on these models to wait for a set of TL's because of what they read on the forum about them,these models should not be over looked.

IMO mod the piss out of the 1C's put some tubes to them and ENJOY!!!

michaeljhsda2

^^^amen to that^^^

quadzilla

TOOLFORLIFEFAN wrote: »

FWIW, I love the 1C's and could care less about not TL'ing them. sometimes I feel the TL is a bit overrated, DON'T GET ME WRONG!! they are fantastic and I have mad love for them but I have yet to hear an SDA I don't like,the original SDA SRS's,2B's,CRS+'s,2.3's,and of course the 1C's are all FANTASTIC SPEAKERS,and I get bothered when I see someone that want's to get their ears on a set of SDA's and they pass on these models to wait for a set of TL's because of what they read on the forum about them,these models should not be over looked.

IMO mod the piss out of the 1C's put some tubes to them and ENJOY!!!

Except, like I said, I have a set of CRS+s that are TL'ed. I did listen to those for a few months with RDO 194s before the TL treatment. So I'm not just wanting to do this just because I read about the TL treatment on the forum. I've actually heard the complete transition from SL2000 to 194 to 198 and associated xover upgrades/mods.

Further, I'm going to say that I hooked these up, and frankly, compared to my TL'ed CRS+s, the high end is pretty nasty. It's forward, it's harsh, it's sibilant, and it's splashy. At the same time, they did let me confirm what I suspected as to why I wasn't happy with the CRS+s - I need more speaker to get the bottom end I want. The 1Cs beat the CRS+s hands down in the mid-bass and below, even with the old non-upgraded xovers. From the bottom of the mid-range up, the CRS+s take the win, probably because of the upgraded xover components and the 198s. But the CRS+s have no where near the slam and definition in the mid-bass downwards that the 1Cs have.

So I may go ahead and do the xovers, 194s, new end caps, etc, but these are pretty unlikely to go on the keeper list. Which sort of seems like it's a waste of time, since I buy speakers to listen to, not modify. In other words, the mods and upgrades are a means to an end (making the music sound more real), not the end itself. I know others seem to love the modifying part as much or more than the listening part, but I hate it to the point that at the end of a mod, it's more a feeling of "finally.... that's over" than it is "look what I did!"

Also, already have tubes on them. Tried sand too. I just don't like the stock tweeters at all. And to my ears, the 194 is only a slight upgrade (gets rid of the 13KHz knee). So I'll say it again: it's the 198 that's the real upgrade, and the only one really worth having/doing.

heiney9

Upgrade the x-overs, do the RD0's, larrys rings,spike them and then come back. You haven't even heard the 1C's modded yet and you're already down playing them.

Of cpourse the sl2000 is going to sound the way it did compared to the RD0's. Not even a contest or worth mentioning.

Get your mod on and spend some time with them and then come back and comment.

The TL mod while worthwhile, isn't the be all, end all of modding on SDA's. It's overrated and I agree with TFLF.

H9

H9

dpowell

heiney9 wrote: »

Upgrade the x-overs, do the RD0's, larrys rings,spike them and then come back. You haven't even heard the 1C's modded yet and you're already down playing them.

+1 What he said ^

Schurkey

Maybe I've missed a thread or twenty. Has anyone actually removed the 4.4uf cap in the 1C or SRS 2 pin/blade crossover, replaced it with a 5.8uf cap, and installed a pair of 198s?

This seems to work for the 1B and SRS 2 blade/blade; I'd expect it to work on the newer version as well.

But what do I know?

quadzilla

Schurkey wrote: »

Maybe I've missed a thread or twenty. Has anyone actually removed the 4.4uf cap in the 1C or SRS 2 pin/blade crossover, replaced it with a 5.8uf cap, and installed a pair of 198s?

This seems to work for the 1B and SRS 2 blade/blade; I'd expect it to work on the newer version as well.

But what do I know?

Hmmm... this I will have to look into. Thanks for a helpful post.

Looking at the schematics, the 1C is an SRS 2 are the same at the circuit level, the 1C just isn't bi-amp capable. Which goes also give me something else to look into, which would be modding the xover to add bi-amp capability. My pre has 2 sets of outputs, so running 2 sets of amps would be easy. If I grabbed a set of gimpod's boards, or just breadboarded my own with point-to-point wiring, adding bi-amp should be relatively easy.

I also noticed that my CRS+s boards are marked CRS/2B, which is also encouraging in that regard.

heiney9

quadzilla wrote: »

Hmmm... this I will have to look into. Thanks for a helpful post.

Looking at the schematics, the 1C is an SRS 2 are the same at the circuit level, the 1C just isn't bi-amp capable. Which goes also give me something else to look into, which would be modding the xover to add bi-amp capability. My pre has 2 sets of outputs, so running 2 sets of amps would be easy. If I grabbed a set of gimpod's boards, or just breadboarded my own with point-to-point wiring, adding bi-amp should be relatively easy.

I also noticed that my CRS+s boards are marked CRS/2B, which is also encouraging in that regard.

I believe TL'ing the 1C's has been tried and the final outcome was that they couldn't be. Poke around on the board because it has been discussed pretty comprehensively, I think.

The Pin/Blade CRS+ uses the same x-over as the Pin/Blade 2B, that's why the x-over boards are marked that way.

H9

Schurkey

heiney9 wrote: »

I believe TL'ing the 1C's has been tried and the final outcome was that they couldn't be. Poke around on the board because it has been discussed pretty comprehensively, I think.

That's why I asked if I'd missed some threads.

I don't EVER recall anyone actually trying the 198s/5.8uf cap mod on the 1C. Seems like "everyone" knows it "can't be done", but "nobody" has actually worked the crossover mathematics OR given it empirical testing to PROVE it can't be done with good sonic results. I do understand that there's considerable difference in the HF crossover circuitry between the 1B and 1C; but is it just coincidence that they both have a 4.4uf cap? It seems to me that the 4.4uf cap is a tuning aid for the SL2000; and the 5.8 is the equivalent tuning aid for the 198.

If I've failed to find the appropriate posts, fine, I screwed up.

But what I think has happened is that no-one has tried it; and we're all hearing the same UNPROVEN theory from each other--gossip going around the circle.

For myself, I'm neither an electrical engineer, mathematician, or 1C owner; I'm in no position to prove anything one way or another. I'd just like to be able to read about real results based on mathematical modeling or cut-and-try, instead of just reading that it won't work for unspecified reasons.

quadzilla

So far, I haven't found anything other that an SRS 2 thread where it worked. Since the circuits are identical with the exception of bi-amping, I don't see why the SRS 2 would be TL capable and the 1C wouldn't.

quadzilla

So this thead greatly informs this debate.

Replacing the 4.4 cap with a 5.8 and using the RDO198 was suggested by Matthew Polk as a modifcation to the SRS 2. For the rest, identical xover circuits, etc.

Schurkey

quadzilla wrote: »

So far, I haven't found anything other that an SRS 2 thread where it worked. Since the circuits are identical with the exception of bi-amping, I don't see why the SRS 2 would be TL capable and the 1C wouldn't.

quadzilla wrote: »

So this thead greatly informs this debate.

Replacing the 4.4 cap with a 5.8 and using the RDO198 was suggested by Matthew Polk as a modifcation to the SRS 2. For the rest, identical xover circuits, etc.

But the SRS 2 came in two versions, and the MP-suggested modification applies to the earlier blade/blade version--which is essentially the same circuit as the 1B.

The later SRS 2 pin/blade, and the 1C have nearly identical crossovers; but not the same as the earlier SRS 2 blade/blade, and the 1B.



From the other thread:

ben62670 wrote: »

It's an easy mod. All you have to do is parallel a 5.8uf cap with a 2.7 ohm resister where the poly switch is located.

inspiredsports wrote: »

Ben, a bunch of us had detailed discussions about this (spanning several weeks of thought and good debate) when I TL'd my SDA SRS 2's and I think we concluded adding a 5.8 there was the wrong location in the circuit...

I tend to agree that Ben's approach is incorrect.

inspiredsports wrote: »

The 1C circuit is entirely different than the 1B, 2B, CRS and SRS 2 circuits that can take the mod in that there is no 4.4 already in play in the right location to be replaced. The 5.8 in the 4.4 spot to allow for the substitution of the RDO198-1 was suggested by Matthew Polk. Placing it anywhere else would be speculative.

There IS a 4.4uf cap in the 1C HF crossover, the question is whether it's placed in the circuit in a way that substituting a 5.8 will properly adapt the crossover to the 198. My heart says it will work, but every idiot has an opinion; and I can't back up mine with research. So, again: Is having a 4.4 in the 1B AND the 1C crossover a coincidence?

inspiredsports wrote: »

I'd love to solve the mystery of TL'ing a 1C, but I honestly don't see how it can be done.

I'm grateful that inspiredsports pioneered the "TL-mod" for the blade/blade SRS 2s. Some folks told him early in the process that it "couldn't be done", and he didn't listen to them. If he says that "TL-ing" the 1C can't be done...it certainly seems like that's the Final Answer. I swear, that 4.4uf cap in the 1C crossover is just TAUNTING me. If I had a pair of 1Cs or SRS pin/blades to play with, I'd change caps and tweeters and see what happens...but I don't, and I don't ever expect to. (Might be dragging home some 2.3s in the near future, though!)

Toolfan66

I have some 5.8's coming, and I also have 4 198's in my goodie box!! Should I try it??? I just might!!!

cincycat13

TOOLFORLIFEFAN wrote: »

I have some 5.8's coming, and I also have 4 198's in my goodie box!! Should I try it??? I just might!!!

Lol Larry. I really considered putting the 2.3 tl tweeter array on my 2.3 when I rebuilt with gimpod boards. A couple of inductors was all I really needed different considering I was changing all caps resistors and tweets anyway... But my impression from other as I took it was I would create a dead spot so I played safe. Have fun if you try.

To the op. If you can listen to the larger sda before you spend too much as it sounds like you like the sda sound and the more mid with the 1c. I had some 2b that I was going to tl but I got the 2.3 cheap and when I did a stock a/b test the 2bs got traded for some 15tl either way. Have fun

gimpod

quadzilla wrote: »

So far, I haven't found anything other that an SRS 2 thread where it worked. Since the circuits are identical with the exception of bi-amping, I don't see why the SRS 2 would be TL capable and the 1C wouldn't.

Because there talking about the 1986 (Blade/Blade) SDA SRS 2 and SDA 1B. The SDA 1C crossover IS completely different.

quadzilla wrote: »

So this thead greatly informs this debate.

Replacing the 4.4 cap with a 5.8 and using the RDO198 was suggested by Matthew Polk as a modifcation to the SRS 2. For the rest, identical xover circuits, etc.

Not really, I suggest you go back and re-read it. As far as MP's suggestion go's here it is and remember he's talking about the SDA 1B not the SDA 1C, pay close attention to the part's in bold which is just the case in regards to the SDA 1C crossover. Besides that 4.4uF cap is in the circuit for the bottom tweeter, there is a whole lot more to consider than just swapping a cap, I've looked into doing this and have come to the conclusion that you'd have to redesign the entire crossover not just the HF section. Don't believe me just look at the differences between the 1.2 and 1.2TL crossovers.

########## Matt Polk's words #######################################

"Yes, that modification should work. The 5.8 uf cap, also known as a "By-pass cap", should only be added across the resistor that is in series with the input signal and not the one that is in series with the small inductor.

The inductance of the tweeter voice-coil causes the impedance to rise at high frequencies contributing to a gentle roll-off. The by-pass cap modification allowed us to compensate for that roll-off without disturbing the carefully tuned relationship between the tweeter and the drivers in the crossover region."

Regards, Ken, Polk Audio

################################################## ##############

TOOLFORLIFEFAN wrote: »

I have some 5.8's coming, and I also have 4 198's in my goodie box!! Should I try it??? I just might!!!

Don't do it.

Toolfan66

Don't worry I won't do it my 1C's are fine just the way they are..

quadzilla

OK, I see that the 86 version is considerably different. That sucks royally. Now I'm back to I don't like the RDO-194, so there seems to be little point in me messing with these further. I might feel differently if I'd never heard the 198s, but I have, and there's no going back. Especially since I would be looking at another 600-800 to get a speaker that would merely sound OK, as opposed to one I really like.

I might also see if I can get ahold of Tracy. He's got some heavily modded 1Cs, so before I make a final decision, it'd be worth it if I could get an ear on his. It's always possible that the 194s would work in the 1Cs. They didn't do it for me in my M10s or CRS+s, and that's what I'm going on until I hear something that changes my mind.