View Full Version : A little love for the 2B TL's
Last year I managed to get to get my hands on a pair of SDA 2B's. Shortly after receiving them, I performed the TL mod, which entails a small modification to the crossover which allows you to upgrade from theSL2000/RD0-194 tweeter to the SL3000/RD0-198.
While performing the upgrade, I replaced all caps with Dayton and the single resistor to a Mills. The difference was more than subtle. Highs were much smoother and overall tonality improved.
For the last few months I've been working on a custom speakers, my own driver selection and custom crossover. I'm starting to wrap things up, so it's time to break them down and finish the cabinets. In the meantime, I needed to hook another pair of speakers up in that rig, but in terms of sound quality, I wanted something comparable to what I built. Plus I wanted something that's easier to lug around than SRS 2's.
While designing speakers, I've been playing with different caps from Duelund, Claritycap, and Obbligato. Of course the ones I preferred the most were also the most expensive, but fortunately I came across the Claritycap ESA. They may not be as transparent, have the spatial information, or tone of a Duelund CAST, but they aren't too far behind either. For the price, they're an absolute bargain. They're pretty neutral or even a little on the warm side with great tone and good spatial information(imaging/soundstage). In fact, I prefer them to the copper Duelund VSF.
I also decided to use a Duelund resistors, unlike Mills they don't add any coloration, and because there was only one per crossover, otherwise it would have blown my budget.
While upgrading the crossovers, I also applied dynamat the baskets and replaced the midwoofer gaskets with Mortite. I also removed all unnecessary jumpers from the HF section. Instead of 3, there's only one jumper in the HF circuit, after the contour circuit(2.7ohm/5.8) to the tweeter connector. I compensated by raising the 2.7ohm resistor to a 3.0ohm. I also applied DeoxIt to all terminals and connectors.
What came next? As some would say, "Such good sound". The speaker was greatly improved top to bottom. Highs are sweet with excellent detail and no harshness. Tonality is greatly improved, cymbals now sound like cymbals, even as far down as male vocals are improved. And low end is now even more impressive due to the Mortite.
http://face.cleanandquiet.com/store/SDA%202B%20TL%20Crossover.jpg
george daniel
08-17-2009, 11:18 AM
Nice work sir,,hopefully I can get my ears on a pair (such as yours)of 2B's one day.Nice,, indeed.
Conradicles
08-17-2009, 11:57 AM
Good job Face...nice work. Hope to do mine one day as well.
comfortablycurt
08-17-2009, 02:17 PM
Very nice! Eventually I'd like to sell my 2A's and pick up a pair of 2B's so I can perform the TL mods.
MillerLiteScott
08-17-2009, 06:51 PM
Mike could you elaborate some more on the elimination to the HF jumpers that are not needed. I have the TL mod with Sonicaps and Mills, dynamat and mortite. Do you recommend any other mods or cap/resister mods that won't force me to sell my first born.
F1nut
08-17-2009, 07:12 PM
Purdy! :D
Mike could you elaborate some more on the elimination to the HF jumpers that are not needed. I have the TL mod with Sonicaps and Mills, dynamat and mortite. Do you recommend any other mods or cap/resister mods that won't force me to sell my first born.
It's been a while since the first time I did this.
IIRC, from the + input, there's one jumper and then the polyswitch(which was replaced by a jumper first time around). There's another jumper after the contour circuit, but the inductor's leads aren't long enough to bypass it.
In the picture below, the + is the positive input, on the same trace is the 12uf's lead instead of a jumper. Due to the size of the 12uf ESA, I also used a different location on the board for it's other lead. Up top you see the solder joints for the 5.8uf/3ohm, then the tweeter output. The circled area is all the crap that I removed.
http://face.cleanandquiet.com/store/SDA%202B%20TL%20Crossover%20Back.jpg
What's wrong with using ESA's? IMO, you'll have to spend A LOT more for something noticeably better.
hearingimpared
08-17-2009, 07:40 PM
Looks great Mike.
schwarcw
08-18-2009, 12:04 AM
Nice work Mike! I don't see the resistors??:confused:
It's the thin cardboard tube.
jerryj12
08-18-2009, 12:57 AM
It's the thin cardboard tube.
Wow. I only wish I knew how to do that. Great job.:D
schwarcw
08-18-2009, 11:33 PM
It's the thin cardboard tube.
Very cool! I've never seen this resistor before! Nice job on the build.
MillerLiteScott
08-19-2009, 06:57 PM
Thanks Mike. That may be a bit over my head right now.
polrbehr
10-05-2009, 04:22 PM
Nice work sir,,hopefully I can get my ears on a pair (such as yours)of 2B's one day.Nice,, indeed.
I've been saying the same thing for awhile.
Now, it's a reality. Only had them for a few days now, but I am extremely happy with them. They really are nice sounding speakers, for those that don't know.
Maybe a review would be in order? ;)
NJPOLKER
10-05-2009, 05:42 PM
Reviews are always in order but not that easy to do properly.
inspiredsports
05-08-2011, 03:42 PM
Sharing the love for 2B's, I found this thread researching ClarityCaps.
I TL'd my 2B's in late '08 using all Gen I Sonicaps and 12W Mills resistors, and am contemplating replacing just the 5.8uf (5.6 only in ClarityCap ESA) and 12uf Sonicaps with ClarityCap ESA's. I'll leave the Sonicaps in the low pass alone for now.
Is there anything else I need to consider besides simply desoldering the 5.8 and 12 and soldering the ESA's back in their place?
audiocr381ve
05-08-2011, 03:58 PM
Sharing the love for 2B's, I found this thread researching ClarityCaps.
I TL'd my 2B's in late '08 using all Gen I Sonicaps and 12W Mills resistors, and am contemplating replacing just the 5.8uf (5.6 only in ClarityCap ESA) and 12uf Sonicaps with ClarityCap ESA's. I'll leave the Sonicaps in the low pass alone for now.
Is there anything else I need to consider besides simply desoldering the 5.8 and 12 and soldering the ESA's back in their place?
What made you decide to do this?
Are the Clarity caps cheaper? I've heard nothing but good things about the Clarity caps and if they're cheaper, God bless em' :)
Sharing the love for 2B's, I found this thread researching ClarityCaps.
I TL'd my 2B's in late '08 using all Gen I Sonicaps and 12W Mills resistors, and am contemplating replacing just the 5.8uf (5.6 only in ClarityCap ESA) and 12uf Sonicaps with ClarityCap ESA's. I'll leave the Sonicaps in the low pass alone for now.
Is there anything else I need to consider besides simply desoldering the 5.8 and 12 and soldering the ESA's back in their place?
No, you should be fine. I would also recommend the Duelund resistor while you're in there, it'll add more transparency.
inspiredsports
05-08-2011, 07:41 PM
No, you should be fine. I would also recommend the Duelund resistor while you're in there, it'll add more transparency.
Thanks!
That's the 2.7 ohm 10 Watt Silver/Graphite?
inspiredsports
05-08-2011, 07:53 PM
What made you decide to do this?
Are the Clarity caps cheaper? I've heard nothing but good things about the Clarity caps and if they're cheaper, God bless em' :)
It's a hobby and it keeps me busy. Besides, I've gone completely over the edge, and I guess 2 short answers might be, "because I can", and "just to be different." :biggrin:
I'm a point now where I have 3 favorite quads for my amp that have distinctinct sonic characteristics, and even single tubes in my preamp that make a difference in both phono and line stages.
I believe the ClarityCaps will prove to be even a bit more revealing than the Sonicaps.
I think another way to say this too is the 3 components in the high pass that we are talking about here cost $40 per crossover (15% less when on sale) from Soniccraft, and at least twice as much using ClarityCaps and the Deuland Resistor.
SonicCaps get you 98% of the way there for a really, really good price. I'm now going to start playing in that 2% arena that can cost from 200% to 2,000% more to eke out the last percentage points of my own unique, personal preference of what is "best".
I used a 3.0 ohm since I also eliminated the poly, but either would work.
inspiredsports
05-08-2011, 08:00 PM
I used a 3.0 ohm since I also eliminated the poly, but either would work.
And bypassed the 3.0 ohm with the 5.6 cap?
If so, does that change anything since you are no longer bypassing a 2.7?
It pads down the tweeter a little more to compensate for removing the polyswitch as pictured above.
inspiredsports
05-08-2011, 09:22 PM
It pads down the tweeter a little more to compensate for removing the polyswitch as pictured above.
No, I get that part about what it does and why you went to 3.
In my specific case, I installed a separate .5 ohm resistor to compensate for the stock .5 ohm RDE050A Polk polyswitch that was removed. Separately, there is a 2.7 ohm 12W Mills resistor bypassed with the custom valued 5.8uf Sonicap.
My concern is that adding the resistance of the replaced polyswitch PLUS the 2.7 and bypassing the sum total would yield a different sonic result. Am I wrong in thinking ONLY 2.7 ohms of resistance should be bypassed and the resistance of the polyswitch should NOT?
Either lose the .5ohm and use a 3ohm in parallel or keep the .5ohm and use a 2.7ohm in parallel. I'd rather just use a single resistor, less parts in the signal path.
inspiredsports
05-08-2011, 09:31 PM
I must be being thick here, and don't understand how the circuitry actually works, but it seems the 5.8uf bypass cap would behave differently (sound different) bypassing 3 ohms versus 2.7 ohms.
Are you saying it does not matter?
dorokusai
05-08-2011, 09:33 PM
Mike - Do you have any spare 27uf or 20uf caps.....8 to 6 of them? Maybe some 4.5 to 5uf caps....maybe 4? All 250v. A shot in the dark but figured I'd ask.
inspiredsports
05-08-2011, 09:53 PM
I'm a visual learner. . . here goes . . .
I must be being thick here, and don't understand how the circuitry actually works, but it seems the 5.8uf bypass cap would behave differently (sound different) bypassing 3 ohms versus 2.7 ohms.
Are you saying it does not matter?
http://www.diyaudioandvideo.com/Calculator/Contour/Help.aspx
http://www.diyaudioandvideo.com/Calculator/Contour/
Mike - Do you have any spare 27uf or 20uf caps.....8 to 6 of them? Maybe some 4.5 to 5uf caps....maybe 4? All 250v. A shot in the dark but figured I'd ask.
6-8 of that value, doubtful. Shoot me an email through the forum and tell me what you're looking to do and what grade caps you're looking for, I have a few bins of various values/brands.
I'm a visual learner. . . here goes . . .The second one is correct.
dorokusai
05-08-2011, 10:05 PM
Sent.
inspiredsports
05-08-2011, 10:12 PM
http://www.diyaudioandvideo.com/Calculator/Contour/Help.aspx
http://www.diyaudioandvideo.com/Calculator/Contour/
6-8 of that value, doubtful. Shoot me an email through the forum and tell me what you're looking to do and what grade caps you're looking for, I have a few bins of various values/brands.
The second one is correct.
I knew the second was correct, but if you bypassed 3 ohms, to my way of thinking you essentially did what the left side of my image shows as resistance is additive. Maybe I should have shown the .5 ohm polyswitch as a simple resistor, but I don't think the poly is any different from a simple resistor until it trips.
Joe08867
05-09-2011, 10:27 AM
The second one is the one you want to use. The first one is bypassing the resistor and poly so it negates there existence.
inspiredsports
05-09-2011, 01:27 PM
I knew I was in trouble when I didn't edit the polyswitch out of my image in post 29 above.
I understand where the bypass should go, and that is how mine is done.
What I'm not clear on is that some remove the polyswitch and "make up" for the resistance of the polyswitch that has been removed from the circuit by using a larger resistor. They then place the 5.8uf bypass cap "over" this higher value resistor.
What I'm trying to learn is if the 5.8 over a larger value resistor in any way affects the sound quality at the tweeter when compared to bypassing a 2.7 ohm as Matt Polk originally prescribed. I'm inclined to stick with figure 2 in my image which is the way mine is currently done.
I have 4 cases shown in the image below and want to know if the impact of the 5.8uf bypass cap is the same in all 4 cases (for some reason when you click the thumbnail,the image shows as a black rectangle and you have to click on the black to get it to load)
No, it shouldn't affect sound quality. A larger bypass resistor will only pad the tweeter down a little more, to compensate for the removal of the poly switch. I found a 3.0ohm Duelund(as wired in the illustration on page 1) in the HF circuit very balanced. Results may vary if Mills or another brand is used instead.
inspiredsports
05-09-2011, 02:40 PM
Got it, Thanks!
So based on that, I see it would be best to eliminate the extra resistor (and extra solder joints) and go with a 3.2 ohm in my case (if I can find that value) or use a 3.0 as you did if 3.2 is unavailable.
I'm on it!
inspiredsports
05-09-2011, 03:43 PM
Post #37 promobank6 reported as spam for removal
audiocr381ve
11-07-2011, 04:50 PM
It's been a while since the first time I did this.
IIRC, from the + input, there's one jumper and then the polyswitch(which was replaced by a jumper first time around). There's another jumper after the contour circuit, but the inductor's leads aren't long enough to bypass it.
In the picture below, the + is the positive input, on the same trace is the 12uf's lead instead of a jumper. Due to the size of the 12uf ESA, I also used a different location on the board for it's other lead. Up top you see the solder joints for the 5.8uf/3ohm, then the tweeter output. The circled area is all the crap that I removed.
http://face.cleanandquiet.com/store/SDA%202B%20TL%20Crossover%20Back.jpg
What's wrong with using ESA's? IMO, you'll have to spend A LOT more for something noticeably better.
Face, I just ordered new parts for my CRS+'s and want to do the same thing you did with the Dueland resistor for the TL mod, except using Mundorf 3.3 ohm 10 Watt resistors.
You mentioned moving your 12uf cap lead. I won't have to do that in my crossovers so my question is if NOT having to move my 12uf cap lead will interfere with this mod. All I'm doing is adding the resistor to the 5.8uf cap position and removing the jumper at the "+" terminal where the poly used to be correct?
audiocr381ve
11-07-2011, 04:54 PM
Face, I just ordered new parts for my CRS+'s and want to do the same thing you did with the Dueland resistor for the TL mod, except using Mundorf 3.3 ohm 10 Watt resistors.
You mentioned moving your 12uf cap lead. I won't have to do that in my crossovers so my question is if NOT having to move my 12uf cap lead will interfere with this mod. All I'm doing is adding the resistor to the 5.8uf cap position and removing the jumper at the "+" terminal where the poly used to be correct?
Sheesh, I hope that made sense.
Toolfan66
11-07-2011, 05:19 PM
Just make it easy and get a set of boards from gimpod? It's so much easier then working with the small board.
Worth every penny and thats why I have two sets in my goodie box..
Face, I just ordered new parts for my CRS+'s and want to do the same thing you did with the Dueland resistor for the TL mod, except using Mundorf 3.3 ohm 10 Watt resistors.
You mentioned moving your 12uf cap lead. I won't have to do that in my crossovers so my question is if NOT having to move my 12uf cap lead will interfere with this mod. All I'm doing is adding the resistor to the 5.8uf cap position and removing the jumper at the "+" terminal where the poly used to be correct?Why are you using a 3.3uf? Are they on the bright side?
audiocr381ve
11-07-2011, 07:07 PM
Why are you using a 3.3uf? Are they on the bright side?
It was the closest to a 3 ohm Mundorf I could find on the Madisound website. I thought it wouldn't be a big deal but it looks like it would pad down the tweeter to much.
I ordered 3 ohm Mills resistors for my 2B's that I'll use for this project instead.
Does my approach to this sound okay? Parallel the 3 ohm (Mills now lol) to the 5.8uf cap and then remove the jumper at the "+" input?
audiocr381ve
11-09-2011, 02:32 AM
Any thoughts Face?
Removal of the jumper would depend on where you place the leg of the capacitor/resistor.
audiocr381ve
11-09-2011, 08:50 PM
Removal of the jumper would depend on where you place the leg of the capacitor/resistor.
Since we're talking about the same xover's, which cap/resistor are you talking about?
I'm sorry, if you wouldn't mind entertaining me, I'll ask the same question differently. If I placed the 5.8uf and 3.0 ohm resistor in the exact place you had them, (Holes "H" and top of "C5"), then what more do I have to do to? My goal is to eliminate the jumper at "S1" and use the higher value resister (3 ohm) to pad down the tweeter exactly as you did as opposed to adding a resistor to pad down the tweeter at "S1".
I'll move what I need to move to get it right, I just need some guidance. Thanks.
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