A little love for the 2B TL's

Face

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.

george daniel

Nice work sir,,hopefully I can get my ears on a pair (such as yours)of 2B's one day.Nice,, indeed.

Conradicles

Good job Face...nice work. Hope to do mine one day as well.

comfortablycurt

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

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

Purdy!

Face

MillerLiteScott wrote: »

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.



What's wrong with using ESA's? IMO, you'll have to spend A LOT more for something noticeably better.

hearingimpared

Looks great Mike.

Face

Thanks guys!

schwarcw

Nice work Mike! I don't see the resistors??

Face

It's the thin cardboard tube.

jerryj12

Face wrote: »

It's the thin cardboard tube.

Wow. I only wish I knew how to do that. Great job.:D

schwarcw

Face wrote: »

It's the thin cardboard tube.

Very cool! I've never seen this resistor before! Nice job on the build.

MillerLiteScott

Thanks Mike. That may be a bit over my head right now.

polrbehr

george daniel wrote: »

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

Reviews are always in order but not that easy to do properly.

inspiredsports

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

inspiredsports wrote: »

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'

Face

inspiredsports wrote: »

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

Face wrote: »

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

audiocr381ve wrote: »

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".

Face

I used a 3.0 ohm since I also eliminated the poly, but either would work.

inspiredsports

Face wrote: »

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?

Face

It pads down the tweeter a little more to compensate for removing the polyswitch as pictured above.

inspiredsports

Face wrote: »

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?

Face

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

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

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

I'm a visual learner. . . here goes . . .

Face

inspiredsports wrote: »

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/

dorokusai wrote: »

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.

inspiredsports wrote: »

I'm a visual learner. . . here goes . . .

The second one is correct.

dorokusai

Sent.